United States
Environmental Protection
Agency
Pollution Prevention
and Toxics
(7406)
EPA744R-94-005
February 1998
Cleaner Technologies
Substitutes Assessment
Industry: Screen Printing
DRAFT Use Cluster: Screen Reclamation
Developed in Cooperation with the Screen
Printing Association International and the
University of Tennessee Center for Clean
Products and Clean Technologies
-------
(2/12/98)
Cleaner Technologies Substitutes
Assessment
Executive Summary
Industry: Screen Printing
Use Cluster: Screen Reclamation
United States Environmental Protection Agency
Office of Pollution Prevention and Toxics
Design for the Environment Program
Developed in Cooperation with the Screen Printing Association
International and the University of Tennessee Center for Clean
Products and Clean Technologies
DRAFT
February 1998
-------
Disclaimer
Cleaner Technologies Substitutes Assessment: Screen Printing Screen Reclamation is
in draft form, should not be quoted or cited, and has not been subjected to required EPA policy
or technical reviews. The final version of this document is expected to be released in late-1994.
Information on cost and product usage in this document was provided by individual product
vendors and has not been independently corroborated by EPA. The use of specific trade names
or the identification of specific products or processes in this document are not intended to
represent an endorsement by the EPA or the U.S. government. Discussion of environmental
statutes is intended for information purposes only; this is not an official guidance document
and should not be relied on by companies in the printing industry to determine applicable
regulatory requirements.
DRAFT—September 1994 iii
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Acknowledgements
A special thanks is extended to the Screen Printing Association International (SPAI),
particularly Marci Kinter and Dan Marx, for their extensive efforts in the Design for the
Environment Screen Printing Project. We thank the members of the SPAI Environmental
Committee for their helpful comments and prior review of sections of this document.
This document was also developed in cooperation with the University of Tennessee
Center for Clean Products and Clean Technologies; much gratitude to Lori Kincaid and Dean
Menke for their active participation and useful advice.
We appreciate the participation of the following screen printing manufacturers in
various aspects of the project, including the performance demonstration. These manufacturers
can be contacted through the information given below. A particular thanks is extended to our
performance demonstration co-chair, Neil Holding, from Autotype Americas.
Amerchem
165 W. Mittel Drive
Wood Dale, IL 60191
Contact: J.P. Godinez
(708) 616-8600
Autotype Americas
2050 Hammond Drive
Schaumberg, IL 60173-3810
Contact: Neil Holding
(708) 303-5900
Ciot International Services
48 Marlin Drive
Whippany, NJ 07981-1279
Contact: George Ciottone
(201) 503-1922
Franmar Chemical Associates
P.O. Box 483
Normal, IL 61761
Contact: Frank Sliney
(309) 452-7526
Hydro Engineering, Inc.
865 West 2600 South
Salt Lake City, UT 84119
Contact: Bob Roberts
(801) 247-8424
Image Technology, Inc.
1170 North Armando St.
Anaheim, CA 92806
Contact: Harry Emtiaz
(714) 632-5292
KIWO
P.O. Box 1009
Seabrook, TX 77586
Contact: Clark King
1-800-KIWO-USA
Nichols and Associates, Inc.
111575 Rupp Drive
Burnsville, MN 55337
Contact: Oliver Nichols
(612) 895-1766
Ruemelin Manufacturing
3860 N. Palmer St.
Milwaukee, WI 53212
Contact: Charlie Ruemelin
(414) 962-6500
DRAFT—September 1994
IV
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The performance demonstration was successful due to the voluntary participation and
cooperation of the following screen printing facilities. We appreciate your valuable efforts.
Action Graphics, Louisville, KY
Artcraft, Portland, OR
Burlington Graphic Systems, Union Grove, WI
Coburn Corporation, Lakewood, NJ
Fastamps and Fasigns, Randolph, MA
Gangi Studios, N. Hollywood, CA
Gillespie Decals Inc., Wilsonville, OR
Identification Products, Bridgeport, CT
Ivey-Seright International, Inc., Seattle, WA
Karagraphic, Kent, WA
Leading Edge Graphics, Minnetonka, MN
M&M Displays Inc., Philadelphia, PA
Masterscreen Products Inc., Portland, OR
Mobius, Inc., Eugene, OR
Modagraphics, Rolling Meadows, IL
Morrison & Burke, Inc., Santa Ana, CA
Nameplate & Panel Technology, Carol Stream, IL
Paramount Screen Printing, Milwaukee, WI
Philadelphia Decal, Philadelphia, PA
Phillips Plastics Co., Fredonia, WI
Quantum Graphics, Redmond, WA
Royal Label, Boston, MA
Screen Process Specialists, Plymouth, WI
Much gratitude is extended to the following members of the U.S. Environmental
Protection Agency DfE Staff and DfE Printing Project Risk Management-2 (RM-2) Workgroup
who worked on this document.
DfE Staff:
Stephanie Bergman
Beverly Boyd
Kathryn Pirrotta Caballero
Jed Meline
RM-2 Workgroup:
Robert Boethling
Richard Clements
James Darr
Susan Dillman
Sondra Hollister
Pat Kennedy
Susan Krueger
Fred Metz
Economics, Exposure and Technology Division, OPPT
Economics, Exposure and Technology Division, OPPT
Economics, Exposure and Technology Division, OPPT
Economics, Exposure and Technology Division, OPPT
Exposure Assessment Branch, Economics, Exposure and
Technology Division, OPPT
Environmental Effects Branch, Health & Environmental
Review Division, OPPT
Risk Analysis Branch, Chemical Screening & Risk
Assessment Division, OPPT
Technical Programs Branch, Chemical Management
Division, OPPT
Exposure Assessment Branch, Economics, Exposure and
Technology Division, OPPT
Exposure Assessment Branch, Economics, Exposure and
Technology Division, OPPT
Regulatory Impacts Branch, Economics, Exposure and
Technology Division, OPPT
Industrial Chemistry Branch, Economics, Exposure and
Technology Division, OPPT
DRAFT—September 1994
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Paul Quillen Chemical Engineering Branch, Economics, Exposure and
Technology Division, OPPT
Paul Randall Office of Research & Development, Cincinnati, Ohio
Heidi Siegelbaum New Chemicals Branch, Chemical Control Division, OPPT
This document was prepared under EPA Contract 68-D2-0064, Work Assignment 2-23,
by ICF Incorporated of Fairfax, VA, under the direction of James Dickson. The EPA Work
Assignment Manager was Stephanie Bergman.
The basis of the Performance Demonstration was a report prepared by Abt Associates,
specifically Cheryl Keenan and Andrew Stoeckle, of Cambridge, MA for the EPA Office of
Research & Development.
For More Information
For more information on the DfE Printing Project or other DfE industry projects, contact
Pollution Prevention Information Clearinghouse (PPIC)
U.S. Environmental Protection Agency
401 M Street, SW (PM-211A)
Washington, DC 20460
Telephone: 202/260-1023
Facsimile: 202/260-0178
or
The Design for the Environment Program
U.S. Environmental Protection Agency
Office of Pollution Prevention and Toxics
401 M Street, SW (7406)
Washington, DC 20460
Telephone: 202/260-1678
DRAFT—September 1994 vi
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Executive Summary
The Design for the Environment (DfE) Program in EPA's Office of Pollution Prevention
and Toxics (OPPT) is a voluntary, cooperative program that works in partnership with industry
to develop and distribute pollution prevention and environmental and human health risk
information on alternative products, processes, and technologies. The DfE Program develops
technical information as well as information products such as case studies, video-conferences,
training videos, and software to help industries and the public make cleaner choices in their
business practices. All of the technical information developed by industry and the DfE Program
is assembled in a document called a Cleaner Technologies Substitutes Assessment (CTSA).
The CTSA forms the basis for subsequent information products and serves as a repository for
all of the technical information (environmental and human health, exposure and risk,
performance, and cost) that is developed in a DfE industry project. In the development of the
CTSA, the DfE Program harnesses the expertise for which OPPT is best known: comparative
and multi-media risk analysis, methods for evaluating alternatives for risk reduction, and
outreach to industry and the public on pollution prevention topics.
The DfE Program uses a new approach to compare the risk, performance and cost trade-
offs of alternatives in a decision focused evaluation. The approach evaluates a "use cluster,"
that is, a set of chemicals, processes and technologies that can substitute for one another in
performing a particular function. This method is different from traditional pollution
prevention approaches in that it does not focus strictly on waste minimization. Instead, the use
cluster approach explicitly arrays alternative chemicals, products and processes allowing
comparison of the risk management issues along with performance and cost in a systematic
way. During the process of identifying alternatives, attention is focused on finding newer,
cleaner substitutes as well as comparing traditional ones.
The DfE Program has been working with the screen printing industry to reduce risk and
prevent pollution in the use cluster of screen reclamation. Partners in this effort include the
Screen Printing Association International (SPAI) and the University of Tennessee's Center for
Clean Products and Clean Technologies. Through a process of collecting information on
currently existing screen reclamation alternatives and through a search for other promising
options, the DfE Program and the screen printing industry have compared alternative and
traditional screen reclamation products, technologies, and processes in terms of environmental
and human health exposure and risk, performance, and cost. The results of this comparative
assessment are contained in the Screen Reclamation Products Cleaner Technologies
Substitutes Assessment.
Specifically, the Cleaner Technologies Substitutes Assessment (CTSA) is an analytical tool
developed by the DfE Program for use by industry. The CTSA is intended to provide a flexible
format for systematically comparing the trade-off issues associated with a use cluster. In the
CTSA, traditional trade-off information such as cost and performance are brought together with
environmental trade-off information including comparisons of environmental releases, human
health and environmental exposures and risk, energy impacts, and resource conservation. The
goal of the CTSA is to offer a complete picture of the environmental and human health impacts,
cost and performance issues associated with traditional and alternative products, processes,
DRAFT-September 1994 ES-1
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
and technologies so that businesses can make more informed decisions that fit their particular
situation. Data contained in the CTSA will be used as the basis for information products
designed to reach individual printers and suppliers who may not have the resources to utilize
this information on their own.
Structure of the CTSA
The CTSA for Screen Printing Screen Reclamation focuses on the use cluster of screen
reclamation. Screen reclamation is a process (to clean a screen a printer must remove the ink,
the emulsion, and the haze from the screen) rather than a specific set of chemicals or
technologies. Therefore, the CTSA is structured to evaluate screen reclamation systems.
Systems typically include combinations of products designed to perform three functions:
remove ink, emulsion, and haze and are typically sold as a system (see figure ES-1). Within any
given screen reclamation system, the CTSA defines and evaluates the products used in the
system and the chemicals that make up the products that are used in that system. The DfE
Screen Printing Project has identified five individual methods and technologies through which
screen reclamation can be performed.
Profile of Screen Reclamation Use Cluster
To develop comparative information on screen reclamation products and technologies, an
array of different kinds of information about the industry is necessary. For example, in order
to develop exposure estimates, information about the work practices, the number of employees,
the chemicals used by employees, etc., is required. Chapter 1 in the CTSA provides
background information, including market information, on the screen printing industry, and
the screen reclamation process, in particular. It also describes some of the alternative cleaning
technologies that could be applicable to the screen printing industry.
The screen printing industry is characterized by small businesses employing an average
of 15 people or fewer. While screen printers can print on a variety of substrates, this effort
focuses on the approximately 20,000 facilities who print graphic arts materials, such as fine art
prints, billboard advertisements, point-of-purchase displays, posters, plastic banner wall
hangings, original equipment manufacturing, and electronic equipment.
The screen printing process involves stretching a porous mesh material over a frame to
form a screen. Part of the screen mesh is blocked by a stencil to define the image. A rubber-
type blade (squeegee) is swept across the surface of the screen, pressing ink through the
uncovered mesh to print the image defined by the stencil. After the screen has been used to
print numerous images, it needs to be cleaned for future use. Many screen printing facilities
reclaim their screens for reuse because the screen material is valuable and costly to replace.
While screen reclamation techniques may vary significantly from one screen printer to another,
two basic functions must be performed in order to restore a used screen to a condition where it
can be reused: removal of ink and removal of emulsion (stencil). A third step, removing any
remaining "ghost image" or haze, may also be required. (See Figure ES-1).
Screen Reclamation Methods
A variety of commercial products have been developed to perform each of these functions
and a complementary series of products (e.g., a particular brand of ink remover product,
emulsion remover product, and haze remover product) are often sold by manufacturers and
distributors as a package. For the purposes of this project, the trade-off issues associated with
DRAFT-September 1994 ES-2
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•o_
CD"
CD
Disposal of
Screen Mesh
(No Reclamation
Occurs)
i i i
2
Method 1
Ink Removal
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Emulsion
Removal/Water
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
Figure ES -1
Screen Printing Substitutes Tree
Screen Reclamation
Method 2
Ink Removal
See
Method 1
Emulsion
Removal/Water
Wash
See
Method 1
Haze Removal/
Water Wash
Product Groups
Include:
• GLYCOL ETHERS
• CAUSTICS
• DIBASIC ESTERS
• SOLVENTS
• SURFACTANTS
J
Method 3
Ink Removal
See
Method 1
Ink Degradant/|
Water Rinse
Product Groups
in Method 1 Ink
Removal
Screen
Degreaser
I
Product Groups
in Method 1 Ink
Removal
Emulsion
Removal/Water |
Wash
See
Method 1
Method 4
Water Only
See
Method 1
High Pressure |
Water Blast
(3000 psi)
Haze Removal/
High Pressure
Rinse
I
Product Groups
In Method 1
Emulsion Removal
Automatic
Screen Washer
(Enclosed System)
Technology available
for ink removal only
OR total removal (ink/
emulsion/haze removal).
See product groups in
Method 1.
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P
I
m
73
3
o
o
I
83
83
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83
83
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33
s?
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
a particular product system, consisting of an ink remover, emulsion remover and haze
remover, are frequently assessed. Screen printers use these product systems in a variety of
methods to reclaim screens.
DfE and SPAI identified five methods of undertaking screen reclamation; these are
exhibited in Figure ES-1. Method 1 illustrates how screen reclamation is performed with
products from the functional groups of ink removal and emulsion removal only. Under each
functional group, some of the categories of chemicals that might be found in these products are
listed. Some screen printers may use only products from these functional groups when
reclaiming screens. More common among screen printers is the additional use of a haze
remover in the screen reclamation process, as depicted in Method 2. Method 3 was developed
by technical staff at SPAI and is currently taught at SPAI in workshop classes; it is referred to
by the name "SPAI Workshop Process." It differs from Method 1 in that screen degreasers and
ink degradants are used in the screen reclamation process. It also differs from Method 2 in that
no haze remover is necessary. Method 4 employs both mechanical and chemical technologies to
reclaim a screen. The use of a high-pressure water blaster eliminates the need for an ink
remover in this method; however, emulsion and haze removers are still used. Method 5 involves
the use of an automatic screen washer, an enclosed system that can be used for ink removal
only, or as a complete system for screen cleaning.
Alternative Cleaning Processes
Because the Screen Reclamation CTSA is designed to be as comprehensive as possible, it
presents information on the fullest consideration of cleaning alternatives. Some of these
alternatives may be new or esoteric, others have been used in a cleaning function in other
industries and are discussed in the Screen Reclamation CTSA because they may have the
potential to be used in screen printing, perhaps with slight modifications. Some of these
technologies include blasting methods, stripping methods, and methods that involve pulse light
energy. Water-soluble stencils/emulsions also represent a product change that may affect other
aspects of the printing and reclamation process (e.g., inks used).
The descriptions of the technologies that are highlighted in the CTSA are not exhaustive,
but are intended to promote discussion of the use of potential alternative technologies in the
screen reclamation process. Currently, some of these technologies are used in high-tech
applications, and may not be economically feasible for the average screen printing
establishment. However, further research into these technologies, and their continued
development, may result in more cost-effective, easy-to-use applications in the screen printing
industry.
One alternative technology evaluated for its potential in screen reclamation was a
pressurized baking soda (sodium bicarbonate) spray. The pressurized baking soda spray, when
combined with water, could remove solvent and water-based ink from a screen; the spray was
ineffective in removing UV-curable ink. Emulsion could also be removed, with only a light haze
remaining on the screen. Issues such as potential damage to the screen mesh and cost-
effectiveness warrant further investigation, but equipment modifications could make the
technology feasible for use in screen reclamation.
Chemical Profiles
Another set of information that is required to complete the comparative analysis of
traditional and alternative screen reclamation products and technologies is chemical data. The
DRAFT-September 1994 ES4
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
screen printing industry identified seventy-two chemicals that are in use in screen reclamation.
These chemicals comprise the screen reclamation use cluster and range from hydrocarbon
solvents and glycol ethers, to surfactants, caustics and oxidizers. Specific information on each
chemical was developed to support the risk assessment of screen reclamation products. Each
chemical profile includes physical/chemical properties, industrial synthesis, aquatic toxicity,
environmental fate, and a hazard summary. The regulatory status of each chemical is also
provided as a ready reference, although the discussion of federal environmental regulations is
intended for information purposes only and should not be used as a guide for compliance.
Market profile information on each chemical, such as total U.S. production and total use in
screen reclamation, was also developed. Included in this section is a generic categorization of
some of the screen reclamation chemicals; this was developed in order to protect the
proprietary nature of the alternative screen reclamation products submitted by manufacturers.
Methodologies
Because the Screen Reclamation CTSA is the DfE Program's first CTSA and will serve as
a model for CTSA's developed for other DfE industry projects, it presents a full discussion of
the methodologies that are used to develop the comparative environmental and human health
risk information. The methodologies presented include: Environmental Releases and
Occupational Exposure Assessment, Population Exposure Assessment, Risk Assessment,
Performance Demonstration, Screen Reclamation Chemical Usage, and Cost Analysis. By
presenting this information in its entirety, the DfE Program hopes to make the evaluation
process completely visible so that others will be able to conduct some of these analyses
independently.
Most of the methodologies that are applied in this analysis are standard methodologies
that the Office of Pollution Prevention and Toxics' (OPPT) Existing Chemicals Program uses,
except for the Performance Demonstration, Chemical Usage, and the Cost Analysis
Methodologies that will be discussed in more detail later in this section. The human health
hazard information was drawn from both literature searches and from public databases such
as the Integrated Risk Information System (IRIS). Hazard information including
carcinogenicity, chronic health hazard and developmental toxicity was compiled when available.
Aquatic toxicity data were taken from literature when available but otherwise structure activity
relationships were used to estimate six types of aquatic toxicity. Release and exposure
estimates were based on values derived from product usage and work practices information
obtained from the Workplace Practices Questionnaire completed as part of the DfE project as
well as industry sources.
Performance Demonstration Methodology
To collect performance and cost information on alternative screen reclamation products,
EPA's Office of Research and Development and the DfE Program conducted a demonstration of
the performance of alternative screen reclamation products.
This type of analysis is not usually part of the work done by the Office of Pollution Prevention
and Toxics' Existing Chemicals Program. The performance demonstration methodology
summarizes how performance information was collected during both laboratory and
production run demonstrations with alternative screen reclamation products. The
methodology was developed jointly by EPA, screen printers, and product manufacturers and it
governs the demonstration of products in the laboratory and in the field.
DRAFT—September 1994 ES-5
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Performance data were collected for 11 alternative screen reclamation product systems
and one alternative technology. First, performance data were collected for the alternative
product systems in a laboratory setting at The Screen Printing Technical Foundation (SPTF).
Then, in thirty-day production runs at 23 volunteer facilities field performance information was
collected on alternative screen reclamation systems, including information on the time spent on
ink removal, volume of products used, and appearance of the screen following each step in the
reclamation process. It should be noted that the performance demonstrations are not rigorous
scientific investigations. Instead, a large portion of the performance information outlinesthe
printers' experiences with and opinions of these products as they were used in production runs
at their facilities. The DfE Program will be developing four performance demonstration case
studies for distribution to industry based on the more effective demonstrations.
Chemical Usage Methodology
Since there was no resource available providing specific screen reclamation chemical
volumes or cost information, the DfE Program worked with industry to develop techniques to
estimate both the chemical volume and basic cost information for the methods evaluated.
Chemical volume information is necessary to complete both the cumulative exposure estimates
and the basic cost comparisons.
The methodology for determining chemical usage summarizes the assumptions and
calculations used to estimate the annual national totals of chemicals used in screen
reclamation. The Use Cluster Analysis of the Printing Industry and The Workplace Practices
Questionnaire for Screen Printers developed as part of the DfE Printing Project, the Screen
Printing Association International 1990 Industry Profile Study and expert opinion estimates,
were used to develop an estimate of the chemical volumes. The information needed to develop
the estimates included the average screen size, the per screen volume of each type of
reclamation product, market shares, the number of screens cleaned yearly, and the number of
screen printing operations. The screen size, in conjunction with the amount of product used or
purchased and the number of screens cleaned, was used to determine the per screen product
usage. Typical formulations were then used to determine the chemical breakdown of the
reclamation products. Combining this information resulted in estimates of the volumes for
each of the chemicals involved in screen reclamation.
Cost Analysis Methodology
A cost methodology was developed to estimate the costs of baseline screen reclamation, as
well as the cost of six alternative chemical, technological and work practice substitutes. The
cost estimation methodology is intended to reflect standard industry practices and uses
representative data for the given screen reclamation substitutes. For each substitute method,
annual facility costs and per screen costs were estimated for individual facilities (those involved
in the performance demonstrations) whose operations were characteristic of the given
substitute method. For the hypothetical baseline facility, the total annual cost and per screen
cost were estimated for reclaiming six screens (2,127 in2 or 14.7 ft2) per day. In addition, each
facility's costs were normalized to allow cross-facility comparisons, particularly with the
baseline scenario. Normalized values adjust product usage, number of screens cleaned, and
number of rags laundered at demonstration facilities to reflect the screen size and number of
screens cleaned per day under the baseline scenario.
DRAFT—September 1994 ES-6
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Functional Groups in Screen Reclamation
The Screen Reclamation CTSA devotes two chapters to the subject of comparative risk.
Chapter 4, focuses on screen reclamation products, while Chapter 5 focuses on screen
reclamation systems. Chapter 4 presents cost and risk information by functional group (i.e.,
different ink removal product formulations) where the products evaluated might be simply
substituted for one another. The evaluations in Chapter 5 focus on systems of products
comparing both the formulations of the products within those systems and the changes in the
methods used to clean screens.
In Chapter 4, information on the characteristics associated with each of the ink remover,
emulsion remover and haze remover products is presented in a format that would allow
comparison of several types of products within each functional group. For example, 13
different formulations were evaluated for ink removers.
For each type of product (ink removers, emulsion removers and haze removers), several
pieces of information are provided: chemical properties (flash point, percent VOC, vapor
pressure), hazard summary (health effects description and aquatic hazard rankings), purchase
cost, occupational exposures and risk conclusions, environmental releases and population
exposure conclusions. A process safety hazard evaluation was not included but could be an
important consideration. For example, when substituting one product for another to avoid a
health concern, the new product might have fire hazard issues. A safety hazard evaluation
should be included in future CTSAs.
Information on total cost and product performance is not provided on product basis but
rather on a system basis. These products are typically sold as a system and more complete
cost and performance information is provided in Chapter 5 where systems of products are
evaluated.
One of the more important inputs required to conduct a comparative risk assessment is
product chemical formulation information. Since EPA is not developing specifications or
labeling standards for products, the DfE Screen Printing Project did not believe it was
necessary to give product names or to release proprietary formulation information to other
product manufacturers or to the public. To make the CTSA usable and flexible, the DfE
Program, in conjunction with the screen printing manufacturers and the Screen Printing
Association International devised a standard format that includes generic product formulations
and product names. The generic formulations and names allow the users of the CTSA to
compare chemical constituents in product systems in a range of volumes while protecting the
proprietary nature of the product formulations. Therefore, the chemical formulations for the
products in the functional groups are not all-inclusive and other formulations may be available
commercially.
Substitute Comparative Assessment of Screen Reclamation Systems
Chapter 5 in the CTSA compiles comparative risk, cost and performance data on
complete screen reclamation product systems. This comprehensive assessment details four
screen reclamation methods and the automatic screen washer and serves as the backbone of
the CTSA. Information is provided for each method and technology on occupational exposure
and risk, population exposure and risk, performance of traditional and alternative systems,
and the analysis of cost of traditional and alternative product systems when available. Table
ES-1 summarizes the cost and risk trade-offs for the methods evaluated.
DRAFT-September 1994 ES-7
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Method 1
Method 1 encompasses the use of only ink removal and emulsion removal products to
reclaim screens. The action of these two products can eliminate the use of a haze remover;
some screen printers are able to reclaim screens without the need for a haze remover.
Eliminating the haze remover achieves the highest priority in the pollution prevention
hierarchy, source reduction. Six systems were assessed that can be used with this method.
Many of these systems can also be used with a haze remover and are also included under
method 2.
Method 2
In a typical screen printing facility, ink remover, emulsion remover and haze remover are
all used in the process of screen reclamation. Method 2 incorporates the most common
practices in screen reclamation. For the purposes of determining occupational exposure to the
haze remover, it was assumed that screen reclaimers only used haze remover on 1-2 screens of
the estimated six screens reclaimed daily in the average small/medium screen printing facility.
Because Method 2 is the most representative of current screen reclamation practices, 14
systems are assessed that use this method including four traditional systems and ten
alternative systems.
Method 3
Method 3 was developed by technical staff at SPAI and is currently taught at SPAI in
workshop classes; it is referred to by the name "SPAI Workshop Process." It differs from
Method 1 in that screen degreasers and ink degradants are used in the screen reclamation
process. Method 3 also differs from Method 2 in that no haze remover is necessary. Technical
staff at SPAI developed this method specifically to avoid the use of haze removers, which can
damage the screen meshes well as contribute to human health and environmental risks. Only
one system was assessed using this method. Due to resource limitations, no performance
demonstration was completed for this method. However a cost assessment was completed and
issummarized table ES-1.
Method 4
Method 4 is currently in use in screen printing facilities as an alternative to traditional
screen reclamation. Method 4 utilizes the action of a high-pressure water blaster (3000 psi) so
that the need for ink removal chemicals is eliminated. Emulsion and haze remover chemicals
are still applied to the screen, and the water blaster also aids in removal of stencil and haze.
Because an ink remover is not used in screen reclamation in Method 4, source reduction, the
highest priority in the pollution prevention hierarchy, is achieved. Again, only one system was
evaluated using this method.
Automatic Screen Washer
Automatic screen washers are commercially available technologies that remove ink, or in
some cases, ink, emulsion and haze, by focusing appropriate reclamation products on a screen
DRAFT—September 1994 ES-8
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
mesh surface within a fully enclosed unit. The system can be selective, in that it can be used to
remove ink only, or to completely reclaim screens. These units employ facets of the washout
booth, pressurized sprayer/applicator, and filtration system to effectively remove ink. Because
these systems have a fully enclosed cleaning area, the amount of occupational exposure to the
chemical reclamation system in use can be minimized if used properly.
Due to the lack of manufacturer participation, the demonstration of the performance of
an automatic screen washer was not undertaken. However, a risk assessment was developed
for an automatic screen washing system used by a facility that participated in the performance
demonstration; this screen washer only removed ink. Experimental parameters used in the
occupational exposure and population exposure calculations were drawn from the data
available from this single site. The risk assessment could not be undertaken for the actual
solvents used in the screen washer as the composition of the ink remover was unknown.
Instead, two typical ink remover formulations were substituted to complete the assessment of
releases and risk. Also two cost estimates were developed to reflect different facility operations
and size. One estimate reflects a large enclosed system with automated movement of screens
through the cleaning process. The other estimate was conducted for a smaller piece of
equipment requiring manual loading and unloading of screens, as well as water rinsing of
residual ink remover.
Screen Disposal as a Method of Pollution Prevention
During the course of the assessment of various screen reclamation methods, it was
proposed that disposal of imaged screens, rather than reclamation might be a feasible alternative.
It was known that some screen printers with long production runs and extremely small screens,
such as those used to print on medicine bottles, simply cut the screen mesh out of the frame after
completion of the production run. By simply disposing of the screens, printers could eliminate the
high cost of reclamation chemicals and labor time associated with screen reclamation, as well as
reduce the risk associated with occupational and population exposure to these chemicals.
Conversely, printers would have to dispose of more screens, with the potential for some screens
to be designated as hazardous waste due to the chemicals applied to them during imaging and
printing. Due to the different types of source reduction involved in these two options, they are
difficult to directly compare in terms of pollution prevention. To determine whether screen
disposal was a cost-effective option, a cost estimate was developed to reflect the baseline facility's
operations and size. It was estimated that the total cost per year of disposing of the screens,
instead of reclaiming them, would be $74,141. The baseline cost of reclaiming screens for a year
was estimated at $9,399. Based on this analysis, it is clear that screen disposal is not a cost-
effective option for a majority of screen printing facilities. However, printers should not view this
cost estimate as a final analysis, because the operations of any one facility can be different from
the assumptions used in generating this analysis. It should be noted that screen disposal would be
more cost-effective under two circumstances that were not included in the baseline facility
estimates: where production runs approach the useful life of a screen and where the size of the
screen is relatively small.
DRAFT—September 1994 ES-9
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Summary of Risk Conclusions
The general conclusions for estimated risks from screen reclamation are outlined below. As
presented, the risk conclusions are for all of the methods, unless stated otherwise.
o Estimated worker dermal exposures to traditional and alternative screen reclamation
products can be high if proper protective clothing is not worn.
o All of the traditional products presented clear concerns for both inhalation exposures
and unprotected dermal exposures to workers.
o Only one of the alternative products (mu) presented a clear concern for inhalation
exposures to workers. In general, the alternative products are much less volatile than
the traditional products, and, therefore, have fewer releases to air.
o Health risks to the general population from ambient air and drinking water exposures
are estimated to be very low for all of the products evaluated due to low quantities of
releases from individual sites.
o The major health impact on the general population for screen reclamation products is
probably its release of volatile organic compounds that contribute to the formation of
photochemical smog in the ambient air. The traditional products, because of their
volatility, are likely to have a much greater impact than the alternative products on
ambient air quality.
o Use of an automatic screen washer for ink removal may significantly reduce air
emissions of certain volatile ink remover components, although the amount of
reduction depends on the specific components of the formulation. However, the
automatic screen washer is expensive and is probably unaffordable for most screen
printers.
Performance and Cost Summary
In Chapter 5, immediately following the risk assessment of each product system, is a
detailed performance summary. It includes a general summary of product performance, a
description of the product application method, results from the evaluation at the Screen Printing
Technical Foundations (SPTF), details of product performance reported separately for each
volunteer printing facility, and facility background information. For each product system, a table is
also included which provides certain summary statistics from the performance demonstrations at
the volunteer printing facilities and at SPTF (for three ink types). For a quick summary of the
results, the table providing summary statistics (Chapter 5) is very helpful.
DRAFT-September 1994 ES-10
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
In general, the alternative products performed similarly to traditional products but with
generally lower costs and generally more risk reduction than the traditional products. Three
systems/technologies consistently met the expectations of printers: Epsilon, Chi and Theta. Delta,
Mu and Phi also received mostly favorable reviews. Product Systems Alpha and Omicron AF, as
well as ink remover Beta, received mixed reviews, with performance documented as acceptable at
some facilities and unacceptable at others. Performance of Gamma, Omicron AE, and Zeta was
deemed unacceptable at the facilities that used these product systems. A performance assessment
of one traditional system, Traditional System 3, was also conducted; this evaluation was only
completed at SPTF. The performance of the products varied greatly with the different ink types;
the lacquer thinner removed the ink on screens printed with UV-curable and solvent-based inks,
but was completely incompatible with water-based ink. In the case of the screen printed with
solvent-based ink, the sodium hypochlorite (bleach) solution used as an emulsion remover caused
the screen mesh to rip.
Table ES-1 summarizes the cost and hazard issues by method and system for the alternative
systems. Summaries for the baseline method used in the cost estimates is given followed by the
four major methods of screen reclamation, automatic screen washer and simple disposal of the
screens without reclamation. Within the four primary screen reclamation methods the various
systems that can be used with those methods (e.g., alpha, chi, delta, etc.) are listed with the cost
and risk summaries. This table presents summaries only, for a more complete description of the
costs and exposure and hazard issues consult Chapter 5.
Overall Pollution Prevention Opportunities in Screen Reclamation
Pollution prevention, or source reduction, is the reduction of any hazardous substance,
pollutant, or contaminant entering any waste stream or otherwise released into the environment.
Pollution prevention can be accomplished through activities such as material substitution, process
improvements, changes in workplace practices and in-process recycling. The primary focus of
the CTSA through Chapter 5 is on material substitution, Chapter 6 lists ways to achieve pollution
prevention and risk reduction through improved workplace practices and equipment
modifications.
Pollution Prevention Through Improved Workplace Practices
In an effort to help industry think of pollution prevention options that might be available to
them and that do not require changing chemical products, the Screen Reclamation CTSA provides
information on improved workplace practices. The basic framework for pollution prevention
through improved workplace practices involves:
o raising employee awareness;
o materials management and inventory control;
o process improvement; and
o periodic, in-house audits.
DRAFT-September 1994 ES-11
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Table ES-1
Costs and Risk Trade-offs of Screen Reclamation Substitutes
System Evaluated
Baseline for Method 1 (Traditional System 4 - Haze
Remover)
Method 1: Chemical substitutes
for ink removal and emulsion
removal. No haze removal
required.
Chi (no haze
remover)
Beta
Baseline for All Other Methods (Traditional System 4)
Method 2: Chemical substitutes
for ink removal, emulsion
removal and haze removal.
Method 3: Chemical substitutes
for ink removal, degreasing and
emulsion removal. No haze
removal required.
Method 4: Technology substitute
of screen disposal in lieu of
reclamation.
Technology Substitute
Work Practice Substitute
Alpha
Chi
Delta
Epsilon
Gamma
Mu
Phi
Omicron-AE
Omicron-AF
Zeta
Omicron
Theta
Automatic Screen
Washer
Screen Disposal
Cost/Screen
$3.63
$1.95-2.83
$7.97
$6.27
$5.92-9.37
$3.25-3.89
$3.28-7.66
$3.08-5.29
$5.06-5.61
$4.79-9.33
$6.10-7.82
$5.49-10.85
$3.89-4.45
$5.39-8.99
$5.57
$4.53
$4.13-10.14
$49.43
Cost/Facility
$5,446
$2,918-4,245
$11,958
$9,399
$8,886-
14,062
$4,879-5,829
$4,917-
11,489
$4,624-7,930
$7,590-8,417
$7,185-
13,997
$9,233-
11,728
$8,240-
16,278
$5,836-6,675
$8,080-
13,479
$8,358
$6,797
6,198-15,213
$74,141
Risk Trade-offs
Clear concern for worker dermal
risks and worker inhalation risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
Clear concern for worker dermal
risks and worker inhalation risks
Moderate concern for worker
dermal risks and low concern for
inhalation risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
Marginal concerns for worker
dermal risks and very low
concerns for worker inhalation
risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
No risks associated with screen
reclamation products
Note: Costs presented are normalized costs. Ranges are presented when there was more than one facility using the method
and system in the performance demonstration.
DRAFT—September 1994
ES-12
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Raising employee awareness may be the best way to get employees to actively participate in
a pollution prevention program. Materials management and inventory control means
understanding how chemicals and materials. With this information opportunities for pollution
prevention can be identified. Process improvement through workplace practices requires re-
evaluating the day-to-day operations that make up the printing and screen reclamation processes
with the goal of waste minimization and pollution prevention. Finally, in-house audits can be used
to collect real-time data on the effectiveness of a pollution prevention program. These efforts can
give both operators and managers the incentive to strive for continuous improvement. Table ES-
2 lists some workplace practices that prevent pollution and describes the benefits associated with
them.
Pollution Prevention Through Equipment Modifications
In addition to workplace practices, several types of equipment can be used in screen
reclamation to prevent pollution. Such equipment includes sprayer/applicator systems, washout
booths, filtration systems, recirculation systems and distillation units. Illustrative examples of each
of these systems, as well as explanatory text, are outlined in Chapter 6 of the CTSA.
The use of sprayer/application systems to apply screen reclamation chemicals to the used
screen may reduce losses and potential exposures with more effective application. A washout
booth can also minimize exposures and waste by containing the reclamation process in a confined
area and collecting spent chemicals for proper reuse or disposal. Filtration systems can be used to
remove specific substances from the waste stream facilitating compliance and allowing the reuse
of some chemicals. Recirculation systems are generally required to reuse captured chemicals.
Typically, recirculation systems are used in conjunction with filtration systems, washout booths
and/or sprayer application systems. Distillation devices can provide an effective means of
recycling and reusing spent solvents.
Many of these systems can save money as well as facilitate compliance and prevent
pollution by reducing the amount of chemicals used in screen reclamation. Each printer would
need to examine his or her particular process to determine the applicability of any or all of the
above equipment modifications. In addition printers should consult applicable water and waste
disposal regulations to ensure compliance before making equipment changes.
Social Cost/Benefits of Alternative Screen Reclamation Processes
A summary of various macroeconomic considerations, including energy and natural
resource considerations and a social costs^eneflts analysis complete the Screen Reclamation
CTSA. These considerations allow printers to put into perspective their contributions to
environmental problems by discussing the aggregate impact issues.
DRAFT-September 1994 ES-13
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
Table ES-2: Workplace Practices and Their Benefits
Workplace Practices
Keep chemicals in safety cans or covered containers
between uses
Use plunger cans, squeeze bottles or specialized spraying
equipment to apply chemicals to the screen
Consider manual, spot-application of chemicals, where
applicable
Use a pump to transfer cleaning solutions from large
containers to the smaller containers used at the work station
Reduce the size of the towel or wipe used during clean-up
Reuse shop towels on the first pass with ink remover
Evaluate alternative chemical: water dilution ratios (increase
the amount of water)
Only apply chemicals where necessary
Avoid delays in cleaning and reclaiming the screen
Gravity-drain, wring, or centrifuge excess solvent from rags
Place catch basins around the screen during the screen
cleaning/reclamation process
Use appropriate personal protective equipment (gloves,
barrier cream, respirator, etc.)
Benefits
Reduces materials loss; increases worker safety; reduces
worker exposure
Reduces potential for accidental spills; reduces materials
use; reduces worker exposure
Reduces materials use; reduces worker exposure if aerosol
mists are avoided
Reduces potential for accidental spills; reduces worker
exposure
More efficient use of the towel; reduces solvent use;
reduces worker exposure
Reduces material (shop towel and ink remover) use; reduces
worker exposure
Reduces chemical usage with no loss of efficiency; reduced
worker exposure
Reduces chemical usage; reduces worker exposure
Simplify ink and emulsion removal; less potential for haze on
the screen
Recovers solvent for reuse
Captures chemical overspray for recovery and reuse
Reduces worker exposure
Energy and Natural Resource Considerations
When designing products or processes with the environment in mind, conservation of
energy and natural resources (e.g., materials) should also be a goal. The Screen Reclamation
CIS A identifies the areas where energy and materials are consumed as a result of the screen
reclamation process. For screen cleaning and reclamation chemicals, the DfE Screen Printing
Project elected to focus on energy and natural resource consumption during the use stage, when
printers are actually cleaning and reclaiming their screens. The data collected during the
performance demonstration did not allow for clearcut extrapolation because of the variety of
conditions present in screen printing shops. As a result, quantitative analysis was not possible.
Summarized below are some of the areas where energy and natural resources may be consumed
as a result of the screen reclamation process.
DRAFT—September 1994
ES-14
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
o During a water wash, the rate of energy use may be dependent on type of equipment
used to apply the water. High-pressure spray washes may require more energy than a
non-pressurized water wash.
o Also during a water wash, the use of hot or warm water washes are much more
energy intensive than those conducted at ambient water temperatures.
o Another source of resource consumption is disposable shop towels. In addition to the
consumption of resources, they also generate solid, potentially hazardous, waste and
increased disposal cost.
Social Costs/Benefits Analysis
There are a variety of issues that need to be considered when assessing the overall cost to
society that screen reclamation imposes. Many of the issues cannot be quantified but they ought
to be included in the decision-making process. The social cost/benefits section in the Screen
Reclamation CTSA offers a qualitative discussion of these issues.
The risk assessment conducted as a part of the CTSA analyzed the risk of both traditional
and alternative screen reclamation systems using four different methods. Automatic screen
washing and simple disposal of the used screens was also examined. A cost analysis was
performed to estimate the cost of each alternative screen reclamation method, technology, and
work practice evaluated in the CTSA. The social cost/benefits analysis compares in general
terms the costs and benefits (in terms of reduced human health risks) of switching to alternative
screen reclamation products, technologies, and work practices. In addition, this analysis looks
beyond just the costs (material, labor, etc.) and benefits (reduced worker health risks) to printing
operations of switching to alternative product systems and considers the potential for benefits to
society as a whole. Specifically, it considers the possibility that the use of screen reclamation
substitutes could result in reduced health risks to the general population, lower health insurance
and liability costs for the printing industry and society, and decreased adverse impacts to the
environment. Based on this analysis, the following conclusions were drawn.
o The population of workers exposed to screen reclamation products in the graphics
section of the screen printing industry is estimated to be as low as 20,000 or as high
as 60,000 depending on how many workers at each facility spend part of their time
reclaiming screens.
o The major benefit identified for switching from traditional screen reclamation methods
to alternative methods is a significant reduction in inhalation risks to workers.
o Among the chemical substitutes evaluated, labor was the largest portion of the
reclamation cost. For the technology and work practice substitutes, equipment and
materials constituted the largest portion of the reclamation cost. Alternative
products, however, did not necessarily have greater labor costs as compared to
DRAFT-September 1994 ES-15
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
traditional products. Rather the labor costs tended to depend on the mix of chemicals
and technologies (i.e., high pressure sprays) selected.
o The estimated cost associated with using the baseline traditional screen reclamation
system equaled $3.63/screen for method 1 and $6.27/screen for all other methods.
o Under the alternative systems, estimated costs range from $1.95/screen ($2,918 per
year) for Method 1 to $10.85/screen (Omicron-AE, Method 2).
o For all systems overall, alternative products are estimated to be less costly than
traditional systems depending on the technologies used (see table ES-1).
o The social benefit of switching to alternative screen reclamation products includes the
benefit to society of reduced risk from exposure to such hazardous wastes during
transport to landfills and in the event of migration of contaminants from the landfill
into groundwater. Printers may also receive benefits in the form of reduced
hazardous waste disposal costs since for most of the alternative product systems,
there might not be any hazardous waste. It should be noted that determination of
hazardous wastes was based on ignitability of chemical constituents; toxicity testing
could result in a different classification of the wastes as hazardous.
A more complete discussion of the social costs and benefits is included in Chapter 7 of the
CTSA.
Conclusion
The appendices include a glossary of terms used in the environmental fate summaries. Also
included is a sample questionnaire from the Workplace Practices Questionnaire and the basic
results of the survey. The evaluation sheets for both the observers and the participants in the
performance demonstration are also included. Finally, general methodology data and a
description of some of the models used are included in the appendices.
The draft of the Screen Reclamation Cleaner Technologies Substitutes Assessment is being
released for public review and comment for 90 days. After which, comments will be incorporated
and a final version of the Cleaner Technologies Substitutes Assessment will be released in the
spring of 1995.
DRAFT-September 1994 ES-16
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Chapter I
Profile of Screen Reclamation Use Cluster
Profile of Screen Printing
Overview of Screen Printing
Screen printing is probably the most versatile of the printing techniques, since it can place
relatively heavy deposits of ink onto practically any type of surface with few limitations on the size
and shape of the object being printed. The ability to print variable thicknesses of ink with a high
quantity of pigment allows for brilliant colors, back lighting effects, and durable products which
are able to withstand harsh outdoor weather conditions and laundering. Unlike many other
printing methods, substrates for screen printing can include all types of plastics, fabric, metals,
papers, as well as exotic substrates such as leather, masonite, glass, ceramics, wood, and
electronic circuit boards.1 While screen printing does compete with other printing techniques for
some products (especially for small paper substrate products), it has a specialized market niche
for many graphic art materials and textile printing applications. Comparatively low equipment
investment costs allow for low cost short production runs.
The screen printing process involves stretching a porous mesh material over a frame to form
a screen. Part of the screen mesh is blocked by a stencil to define the image. A rubber-type blade
(squeegee) is swept across the surface of the screen, pressing ink through the uncovered mesh to
print the image defined by the stencil. The substrate is then either manually placed onto drying
racks or placed onto a conveyor transport system for conveyance into a drying unit. The screen
and its stencil can be used repeatedly to print the same image multiple times.
The screen printing process differs in many ways from the other printing methods of
lithography, gravure, flexography, and letterpress. Because screen printing utilizes various
materials in a printing process that differs greatly from other printing methods, it presents
environmental challenges that are unique in the printing industry.
Products Printed
The majority of screen printers do not restrict their operations to printing on one substrate
or to the production of one end product. Textile products, however, are the most common
products in production. Surveys conducted by the Screen Printing Association International (SPAI)
show that approximately 54 percent of screen printers produce imprinted textile garments.2
Perhaps the most well known example is T-shirts. Textile printing also includes the markings and
patterns on towels, comforters, caps, visors, aprons, drapes, carpet, sheets, flags, and the basic
patterned material that is made into pants, dresses, and other clothing.
'Types of plastics used as substrates include acrylic, epoxies, vinyl, topcoated and nontopcoated polyester, and polycarbonate,
while fabric substrates can be either natural or synthetic. Metals used as substrates include aluminum, brass, copper, lacquer-
coated metals and steels. Paper substrates range from uncoated, coated and corrugated coated fiberboard to poster and
cardboard.
2Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 9.
DRAFT-September 1994 1-1
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Profile of Screen Printing Market Information on the Screen Printing Industry
Another major category of screen printed products includes graphic arts materials with
products as diverse as fine art prints, billboard advertisements, point-of-purchase displays (such
as those displayed in supermarkets), posters, plastic banner wallhangings, wallpaper, and decals.
Large banners, durable outdoor displays, and short poster runs are specialty products of many
commercial screen printing establishments.
Other applications include original equipment manufacturing (for example, the soft keypad
on cash registers at some fast food restaurants or the heating controls in a car), printing on
electronic equipment such as circuit boards, and product identification markings on products like
wine bottles, fire extinguishers, cosmetic compact covers, insulated beverage and food containers,
and aerosol spray cans.
Market Information on the Screen Printing Industry
Number of Screen Printing Facilities
The number of American screen printers and the quantity of their sales is difficult to
determine because parts of the screen printing industry are "captive in-plant screen departments"
within a separate manufacturing industry. For example, one step in toothpaste production is
screen printing product identification markings on the tube.
There are three major categories of screen printing facilities:
o Commercial Screen Printing Facilities (garments, signs, posters, decals, etc.)
o Industrial Screen Printing Facilities (panel fronts, circuits, glassware, original
equipment, etc.)
o In-Plant (Captive) Screen Printing Departments (markings and decals on products)
SPAI estimates that there are at least 40,000 plants in the U.S. with screen presses, consisting of
approximately 20,000 plants that focus on textile substrates (50 percent) and 20,000 graphics
printers.3 This number is derived from known addresses of screen printing shops. This estimate
includes in-plant operations and the majority of industrial screen printing operations.4
Quantity of Sales and Percent of Market
According to Bruno's Status of Printing 1989-90, screen printing accounted for less than
three percent of the total value of U.S. printing industry output in 1991. This figure excludes in-
plant "captured" printing. It has been estimated that the screen printing industry posted gross
sales of $ 13 billion in 1986.5 A statistical weighted average calculation performed from 1990 SPAI
3Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 9.
torrespondence between Kathryn Caballero, U.S. EPA, and Marcia Y. Kinter, Director of Government Affairs, SPAI, May 1994.
5Air and Waste Management Association, Air Pollution Engineering Manual, Buonicore, Anthony and Davis, Wayne T. (ed.),
(New York:Van Nostrand Reinhold, 1992), p. 288.
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
Survey Information estimated U.S. annual sales volume estimate of $21.9 billion in 1990.6
According to Bruno, the screen printing market is expected to show little or no growth between
1995 and 2025.7
Size of Screen Printers
The Screen Printing Industry is dominated by small businesses with the average screen print
shop having approximately 15 employees.8 From a 1992 Survey, Screen Printing Magazine
estimates the following size categories for screen printing facilities:9
o 1 to 20 employees (70.9 percent)
o 21 to 50 employees (14.0 percent)
o 51 to 100 employees (7.8 percent)
o More than 100 employees (7.4 percent)
The SPAI 1990 survey of U.S. screen printing companies showed that respondents had slightly
more than 20 employees and of the 20, approximately 14 were production workers, two were
managers/supervisors, two were sales personnel, and two were classified as "other".
Definition and Overview of Screen Reclamation
Definition of Screen Reclamation
For the purposes of the Design for the Environment Printing Project, screen reclamation will
be defined as the process that begins once excess ink has been carded off the screen and ends
when the screen is ready for reuse. Ink removal performed at press side was not evaluated as part
of this project.
Overview of Screen Reclamation
Purpose of Reclamation
Many screen printing facilities reclaim their screens for reuse because the screen material
is valuable and costly to replace. Screen fabric can be one of the more expensive supplies that a
screen printer uses and can have a large impact on cost of operations. For example, the most
commonly used fabric, polyester, costs $ 10 to $40 per square yard.10'11 A shop that wastes $ 100
6Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 10.
7Bruno's Status of Printing 1989-90, (1991), p. 17.
8Air and Waste Management Association, Air Pollution Engineering Manual, Buonicore, Anthony and Davis, Wayne T. (ed.),
(New York:Van Nostrand Reinhold, 1992), p. 397.
^uccilli, S., "The 1992 Industry Survey: Safety and Environmental Practices in the Screen-Printing Industry," Screen Printing
Magazine, (April 1992), p. 50.
'"Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 15.
"Frecska, T., Screen Printing Magazine, (1992), p. 120.
DRAFT—September 1994 I-3
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
to $200 per week, in fabric costs from ruining screens or failing to reclaim them, can increase its
annual production costs by as much as $5000 to $10,000.12 The average monthly expense for
fabric is $360.13 In addition, reclaiming screens has the advantage of saving labor time needed for
stretching mesh across the frame and adjusting it to the correct tension. Some printers believe that
using retensionable frames when stretching the mesh "work hardens" the fabric, improving the
printability and longevity of the screen. Other printers note that reusing screens for other jobs,
instead of storing them in an imaged screen inventory, saves both screen fabric costs and storage
space often needed for presses.
Screen Reclamation Frequency
While 90.3 percent of screen printers reclaim screens daily,14 not all screen printers attempt
to reclaim every screen. Some orders of a specific stencil may be reordered systematically (for
example, a stop sign or sale poster), in which case a screen printer may want to store the screen
and stencil until the customer returns and requests another run of the print. In other cases, the
screen may be very small (for example, a message printed on an plastic aspirin bottle). When
screens are small, the time and effort needed to reclaim the screen can be higher than the cost of
cutting out the fabric and replacing it.15
SPAI's 1990 Industry Profile Study reports that 68 percent of respondents reclaim between
1 and 10 screens per day and 17.3 percent reclaim between 11 and 20 screens per day.16 Many
operational factors determine the lifetime of a screen, including the roughness of substrate and ink,
number of impressions, the daily handling of the screen, and the types of products used to reclaim
the screen. The number of impressions printed affect the screen lifetime because repeated runs
of the squeegee over the fabric can weaken and warp the fibers of the mesh. A printer may mark
and date screens to keep track of the screen history, including number of impressions. Printers
discard the screen when it has been reclaimed a certain number of times or shows signs of
weakening.17
Screen Reclamation Process
Screen cleaning is the forgotten process in our industry. It generally takes place in
a dungeon-like area in the most remote corner of the shop. As a result, the forgotten
process has developed differently in every screen-printing business. Walk into ten
shops and you could easily find just as many different solvents and disposal
methods being used. - Steven Duccilli, Editor.18
12Frecska, T., Screen Printing Magazine, (1992), p. 120.
13Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 16.
"Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 23.
15Personal communication between Beverly Boyd, U.S. EPA, and Dutch Drehle, Screen Printing Association International, May
1993.
16Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991), p. 23.
"Personal communication between Beverly Boyd, U.S. EPA, and Dutch Drehle, Screen Printing Association International, May
1993.
18Duccilli, S., "In Search of Screen-Cleaning Standards," Screen Printing Magazine, (April 1993), p. 6.
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
While screen reclamation techniques may vary significantly from one screen printer to
another, two basic functions must be performed in order to restore a used screen to a condition
which it can be reused: removal of ink and removal of emulsion (stencil). A third step, removing
any remaining "ghost image" or haze, may be required depending upon the type of ink used,
effectiveness of ink removal and/or emulsion remover products, and the length of time that ink and
stencil have been on the screen.
A variety of commercial products have been developed to perform each of these functions and
a complementary series of products (i.e., a particular brand of ink remover product, emulsion
remover product, and haze remover product) are often sold by manufacturers and distributors as
a package. For the purposes of this project, the trade-off issues associated with a particular
screen reclamation system, consisting of an ink remover, emulsion remover and haze
remover, are typically assessed. Other products, such as screen degreaser and ink degradant,
sometimes play a role in the reclamation of screens. These are not assessed. Different equipment,
application techniques, and work practices play a role in the efficacy and quantity required of each
product. All of these affect the trade-offs associated with product systems.
Ink Removal
Ink categories include: traditional solvent-based inks (which includes enamels), ultraviolet
(UV)-curable inks, water-based inks and plastisols (for textile printing). Ink removal (also called
screen washing or screen cleaning) precedes stencil removal so that excess ink does not interfere
with removal of the stencil.
Ink is also removed at other times prior to screen reclamation (for example, when dust gets
into the ink and clogs the screen mesh, or at lunch break, to avoid ink drying on the screen). This
"process cleaning" usually occurs at press side. Screen cleaning performed as a part of screen
reclamation may be performed at press side, in a separate ink removal area of the shop, or in an
area where emulsion and haze are removed. This study will focus on ink removal performed as
a part of the screen reclamation process and not on process or press-side cleaning.
Emulsion (Stencil) Removal
Several types of emulsions or stencils, such as indirect or direct photo stencils, are used in
transferring an image to the screen.19 Most direct stencils are water-soluble and thus incompatible
with water-based inks. However, chemical curing of water-soluble stencils can improve their
resistance to water. A water-resistant stencil must accompany a solvent-based ink, and a solvent-
resistant stencil must accompany a water-based ink. Solvent and UV curable inks are typically
coupled with water-resistant emulsions. Thus, a commercial facility using 90 percent solvent-
based inks and 10 percent UV curable inks can use the same water resistant emulsion systems for
both inks. If, however, the screen printing facility wants to replace some of its solvent-based inks
with water-based inks, a new type of solvent resistant emulsion will have to be used to complement
the water-based inks. Using solvent-resistent emulsion with water-based inks will cause the
emulsion to erode quickly and pinholes will show up in the stencil.
Most emulsion removers are packaged in a water solution or as a powder to be dissolved in
water; the water acts as a carrier for the actual reclaiming chemical. The predominant chemical
in an emulsion remover is often sodium metaperiodate. Because periodate needs water as a carrier
19Direct photostencils are exposed in direct contact with the screen, after adhesion to the mesh. Conversely, indirect photo
stencils are exposed, developed and adhered to the mesh. Different chemicals are used for each type of stencil.
DRAFT—September 1994 I-5
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
to reach certain chemical groups in the emulsion, it is more difficult to reclaim a water-resistant
emulsion than one which is only solvent-resistant. Most commercially available emulsion remover
products are able to remove either water resistant or solvent resistant emulsions. High pressure
water spray can also facilitate emulsion removal and may lower the quantity of emulsion remover
required. Special care must be taken to ensure that the emulsion remover does not dry on the
screen, as the screen will become almost impossible to clean, even with repeated applications of
the remover.
Haze (Ghost Image) Removal
A haze or ghost image is sometimes visible after the emulsion has been removed. This
results from ink or stencil being caught in the knuckle (the area between the overlap of the screen
threads) or dried/stained into the threads of the screen. Staining of the mesh frequently occurs
when petroleum-based solvents are used in the ink removal process. The solvents dissolve the ink,
leaving behind traces of the pigment and resin in the screen. The residual pigment and resin bonds
to the screen after the solvent evaporates, leading to haze accumulation. Ghost images are
especially common when dark inks (blue, black, purple and green) are used, or if an excessively
long time period elapsed prior to ink removal from the screen. A ghost image is particularly likely
when using solvent-based ink systems, as opposed to other ink systems. If the ghost image is dark
or will interfere with later reimaging and printing, a haze remover product can be applied until the
image disappears or fades. The level of cleanliness required at the end of the process varies
depending on the kind of printing job that the screen will be used for after reclamation. Some
printers can use screens with light ghost haze, others cannot.
Haze removal can potentially damage the screen mesh, particularly caustic haze removers
that are traditionally used in the industry. The excessive use of these products, such as applying
the chemical and leaving it on the screen too long, can weaken the mesh.
Printer Environmental Concerns about Screen Reclamation
Concern on the part of screen printers and SPAI about screen cleaning and reclamation
stems from two sources; (1) the use of highly volatile organic solvents; (2) the common practice of
screen printers of allowing water from screen washing and reclaiming to go directly down the drain
without prior filtration. According to a 1992 survey by Screen Printing magazine, of the 250
companies that answered a question about the latter practice, 191 (76 percent) indicated they send
unfiltered waste down the drain.20 Depending on what is in the water (ink, ink remover chemicals,
emulsion, emulsion remover chemicals, and/or haze remover) this practice could contribute to
health and environmental problems since the water goes either directly to a wastewater treatment
facility, a body of water (streams, etc.) or a printer's septic tank.
Publicly Owned Treatment Works (POTWs), particularly in the Western states, have increased
awareness of the water discharge problem by tracing problem inputs into the sewer system back
to screen printers and levying fines on offenders. Three major categories of concern have been
raised by the POTWs:
o Heavy metals, which can be found in the residue of ink, can enter the sewer system
and contaminate sewage sludge
20Duccilli, S., "The 1992 Industry Survey: Safety and Environmental Practices in the Screen-Printing Industry," Screen Printing
Magazine, (April 1992), p. 53.
DRAFT—September 1994 I-6
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Identification of Screen Reclamation Functional Groups
o Heavy concentrations of certain chemicals can disrupt the pH balance at the treatment
plant and disrupt the bacterial systems essential to the sewage treatment process
o Combinations of mixtures with low flash points can cause flammability concerns in the
sewage system
Concern has also been expressed about screen printing facilities that discharge waste water
to septic tanks. In these cases, water containing ink cleaning solvents, ink residue, emulsion,
emulsion remover, haze remover products or other wastes could disrupt the bacterial balance in
septic tanks and/or contaminate local groundwater supplies.
Confusion has been exacerbated by "biodegradable", "drain safe", "solvent-free" claims on the
labels of many ink removal and emulsion removal products. Unfortunately, some printing facilities
that use so-called "biodegradable" products have mistaken these products for waste-disposal
panaceas. Simply because the product itself is drain permissible, does not mean that the product
combined with ink residue or emulsion residue from screen reclamation is also drain permissible.
Also, something which is currently drain permissible may contribute environmental problems and
may be subject to future regulation. Printers should always check with local, state and federal
water regulations prior to discharging a product marked "drain-safe" to water. An effort to
ascertain the environmental or health impact of the chemical may also be prudent.
While water concerns have inspired interest in this area, this Substitute Assessment
document presents an analysis of cross media effects (air, waste disposal, etc.) and will outline the
trade-off issues that are associated with different screen reclamation options, such as occupational
exposure concerns, total cost differences, performance effectiveness and toxicity of waste water.
Identification of Screen Reclamation Functional Groups
Figure 1-1 is a graphical model of the integration of all screen reclamation methods. It
separates the basic components of any screen reclamation process into five functional groups: ink
removal, screen degreasing, ink degrading, emulsion (stencil) removal and haze removal. A general
flow chart is depicted for the integration of these functional groups. However, this flow chart may
not be representative of all types of screen reclamation processes. Several steps that may be
included in the reclamation process are low-pressure and high-pressure water rinsing, which
typically involve different equipment. Preparation of the screen or disposal of waste from screen
reclamation are not included in this basic flow chart.
To concentrate on those functional groups most often associated with screen reclamation,
this CTSA focuses on the three functional groups of ink removal, emulsion removal and haze
removal. The parameters associated with the use of screen degreaser and ink degradant are not
discussed.
Identification of Screen Printing Substitute Trees for Screen Reclamation
Figure 1-2 depicts the five main methods (including the automatic screen washer) that are
used in screen reclamation. Because the actual process of screen reclamation can be performed
using any of these methods, these methods "substitute" for each other in screen reclamation. In
addition to the five methods, the substitute tree also suggests that the disposal of the screen mesh
without screen reclamation would be an option. This disposal option is considered in Chapter VI,
Overall Pollution Prevention Opportunities for Screen Reclamation.
DRAFT-September 1994 I-7
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Identification of Screen Reclamation Functional Groups
Figure I -1
Identification Of Screen Reclamation Functional Groups
This Exhibit is an Integration of Screen Reclamation Methods
Boxes denote
functional product
groups
Ink Removal
Screen
Degreaser
Ink
Degradant
Emulsion
(Stencil)
Removal
Haze
Removal/Water
Wash
Denotes step
without chemical
reclamation
products
High-Pressure^
Water Blaster
(3000 psi)
Screen is Reclaimed
Screen is Reclaimed
C47028-2
DRAFT—September 1994
I-8
-------
•o_
CD"
CD
Disposal of
Screen Mesh
(No Reclamation
Occurs)
Figure I - 2
Screen Printing Substitutes Tree
Screen Reclamation
Method 1
I
Method 2
Ink Removal
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Ink Removal
See
Method 1
Emulsion
Removal/Water |
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
Emulsion
Removal/Water
Wash
See
Method 1
Haze Removal/
Water Wash
Product Groups
Include:
• GLYCOL ETHERS
• CAUSTICS
• DIBASIC ESTERS
• SOLVENTS
• SURFACTANTS
J
Method 3
Ink Removal
See
Method 1
Ink Degradant/l
Water Rinse
Product Groups
in Method 1 Ink
Removal
Screen
Degreaser
I
Product Groups
in Method 1 Ink
Removal
Emulsion
Removal/Water I
Wash
^^M
See
Method 1
Method 4
Water Only
See
Method 1
High Pressure |
Water Blast
(3000 psi)
Haze Removal/
High Pressure
Rinse
I
Product Groups
In Method 1
Emulsion Removal
Automatic
Screen Washer
(Enclosed System)
Q_
CD
O
m
o
3
o
Technology available
for ink removal only
OR total removal (ink/
emulsion/haze removal).
See product groups in
Method 1.
o
5'
3
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o
3
m
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O
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m
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Identification of Screen Reclamation Functional Groups
Method 1 in Figure 1-2 illustrates that screen reclamation is performed with products from
the functional groups of ink removal and emulsion removal only. Under each functional group,
some of the categories of chemicals that might be found in these products are listed. Currently,
some screen printers only use products from these functional groups when reclaiming screens.
More common among screen printers is the additional use of a haze remover in the screen
reclamation process, as depicted in Method 2.
Method 3 was developed by technical staff at SPAI and is currently taught at SPAI in
workshop classes; it is referred to by the name "SPAI Workshop Process." It differs from Method
1 and Method 2 in that screen degreasers and ink degradants are used in the screen reclamation
process. It also differs from Method 2 in that no haze remover is deemed necessary. Technical
staff at SPAI developed this method to avoid the use of caustic haze removers, which can damage
the screen mesh.
Method 4 employs both mechanical and chemical technologies to reclaim a screen. No ink
remover is applied to the screen during Method 4; instead, removal of ink residue is accomplished
by the action of a high-pressure water. A small quantity of diluted emulsion remover is applied to
the screen prior to spraying with the high-pressure water blaster. Two different pressures are
typically used to remove the emulsion, and subsequently, the remaining ink. If a ghost or haze
image is apparent on the screen, a haze remover is sprayed on the screen and brushed from the
surface. The pressure spray is repeated and for heavy ghost images, the screen is turned over and
the action repeated on the reverse side.
Although the use of an automatic screen washer is not typically found at a screen printing
facility, it is a technology that can be used to reclaim screens. Automatic screen washers can be
used for ink removal only, or for ink removal, emulsion removal and haze removal. Some
automatic processing systems also rinse and dry screens. The screen is immersed in an enclosed
system, which then performs the desired screen reclamation function without the labor of the
screen reclamation employee.
DRAFT-September 1994 1-10
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Potential Screen Reclamation Substitute Technologies Blasting Technologies
Potential Screen Reclamation Technologies
Introduction
The methods presented in Exhibit 1-2 are traditional screen reclamation processes that use
chemicals combined with water washes to clean and reclaim the screen, including a relatively new
technology, the automated wash system. In order to fully examine alternatives in search of cleaner
technologies, it is useful to identify other process technologies not traditionally used in the printing
industry that may accomplish these same ink and the emulsion (stencil) removal functions.
Exhibit 1-3, Screen Printing Substitutes Tree, identifies technologies used in other industries to
remove a material from a substrate that could potentially be modified to reclaim screens, but are
not currently used for this purpose. Many of the suggested methods are established technologies
in paint stripping and parts cleaning applications. They include blasting methods, stripping
methods, and methods that involve pulse light energy. Water-soluble stencils/emulsions, also
presented below, represent a product change that will affect other aspects of the printing and
reclamation process (e.g., inks used). Except for the sodium bicarbonate blasting method, this
CTSA does not evaluate the performance or cost of these technologies in screen reclamation. The
intent of Figure 1-3 is to bring further thought into how screen reclamation could be performed.
The following are reviews of these technologies to evaluate potential feasibility and determine if
further research is warranted.
Blasting Technologies
Blasting methods, commonly known as media blasting, use the abrasive and/or fractioning
action of a propelled media to remove a coating. Dry media blasting uses air as the propellant for
solids of plastic, wheat starch, ice, or carbon dioxide (dry ice); wet media blasting utilizes water
as the propellant with sodium bicarbonate as the primary solid. To be effective the media must
be hard enough to remove the coating, but soft enough not to damage the underlying substrate.
Other factors affecting removal efficiency are application pressure, distance from surface, and angle
of application.
There are many aspects that affect the use of blasting technologies for screen reclamation.
The equipment required for a media blasting method is media dependent. Each method requires
a pressurized air/water source and a specifically designed nozzle for media delivery (plastic and
wheat starch units can be interchangeable). In addition, plastic media blasting will require media
separation and recycling prior to waste disposal. Wheat starch media blasting may require dust
control, but may not require media separation if the spent media and materials removed can be
discharged to the sewer. Also, wheat starch is highly moisture sensitive, thus requiring moisture
control within the process area. Carbon dioxide media blasting alleviates the potential disposal
problems of plastic and wheat starch media blasting; CO2 pellets, after impacting on the surface,
sublime rapidly to the gaseous state, thus leaving only the removed coating behind for disposal.
However, storage and pelletizing of CO2 requires relatively complex, energy intensive equipment.
Ice crystal blasting requires the maintenance of refrigeration, ice making, and ice handling
equipment.
Media blasting technologies have been successfully applied to large, industrial operations
such as building and bridge refinishing, and corrosion removal from process equipment.21
:1Armex Blast Media, (1993).
DRAFT-September 1994 1-11
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Figure 1-3
Screen Printing Substitutes Tree
Undemonstrated Technologies In Screen Reclamation
(The cost and performance of these technologies in screen reclamation is undetermined)
/
Blasting Methods
Dry Abrasives
• PLASTIC BEADS
• WHEAT STARCH
• CARBON DIOXIDE
• ICE CRYSTALS
Wet Abrasives
. SODIUM BICARBONATE
/
/
Pulse Light Energy
Laser Stripping
Flashlamp Stripping
\
\
Stripping Methods
Dry or Wet Mechanical
Sanding
Heat Gun to Burn Off Ink
Liquid Nitrogen (cryogenic)
Spray With Dry Blast Media
Use of
Water-Soluble
Stencils/Emulsion
To allow emulsion
removal with water only
8L
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8
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C47028-1-2
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Potential Screen Reclamation Substitute Technologies Pulse Light Energy Technologies
Starch media blasting units include small hand cabinets, and sodium bicarbonate units can be
either fixed or portable, both suggesting they can be used in small-scale applications.22
Other characteristics of the media blasting technologies may also lend themselves well to
screen reclamation if further research is directed toward development. Small-scale screen
reclamation applications may only require changes in operating pressure (reduced pressure),
media hardness, and equipment down-sizing. For example, adjustment of application pressure
and solids flow rate in the sodium bicarbonate system can control whether just oils and greases
are removed from a painted surface, or the paint is removed along with the oils and greases.23
Wheat starch has been used in industrial applications where surface etch must be avoided on
substrates of aluminum and magnesium, and carbon dioxide pellet blasting has been applied to
clean precise and delicate circuit boards.24
The small media size of wheat starch and sodium bicarbonate may adequately penetrate the
weave of the screen, removing both ink and stencil to a degree which could eliminate or reduce the
need for a haze removal step. Plastic media, as well as the other media blasting techniques, may
cause excessive wear and stretching of the screen mesh. This may result in a shortened screen life
and increased screen maintenance (e.g., adjustment of screen tension could be periodically
required). It has been documented that crystalline carbon dioxide damages woven fibers, thus
limiting its applications in the printing industry.25 Sodium bicarbonate may have similar damaging
effects on the materials of the screen mesh due to the chemical nature of the media which can
revert to caustic soda ash in the presence of water and heat.26 These limitations, however, should
not prevent further evaluation of many blasting technologies as a potential clean technology for the
screen reclamation process.
Pulse Light Energy Technologies
Pulse light energy technologies use an energy source to vaporize and fracture coatings off of
substrates. Laser and flashlamp methods are included in this technology. Laser stripping uses
high energy photons generated by a CO2 or neodymium (Nd) laser to vaporize the coating, leaving
an ash behind for disposal. Laser frequency selection can maximize coating removal while
minimizing substrate damage; layer-by-layer coating removal can be accomplished with proper
control.27 Initial tests and full-scale operations indicate heat damage of the substrate is a potential
problem with laser removal methods.28 Flashlamp methods use an intense pulse of light to
22U.S. EPA Economics and Technology Division, Office of Toxic Substances, Reducing Risk in Paint Stripping,
(Washington:GPO 12-13 February, 1991).
23Ibid.
24Ibid.
25Ibid.
26Ibid.
27"Light Stripping," Manufacturing Engineering, (September, 1992).
28Ibid.
DRAFT-September 1994 1-13
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Potential Screen Reclamation Substitute Technologies Stripping Technologies
vaporize the coating a microlayer at a time. Factors that contribute to the removal efficiency of the
flashlamp method include flash repetition rate, intensity, spectral content and flash duration.29
The equipment required for the laser and flashlamp methods are unique to the pulse light
energy technology. The energy (light) source may have a high capital cost, and energy requirements
may be substantial. These units may also be automated. Dust control and waste disposal
equipment may be combined in a single vacuum unit, with the volume of waste minimized due to
vaporization of the coating. The vapors, however, generated by these methods may require
personal protective equipment (respirators), as well as additional process area ventilation and
emissions control. Portable, full-scale CO2 laser units to remove paint from bridges (fitting on a
flat bed truck) can cost between $750,000 and $ 1,000,000.30
As with media blasting technologies, pulse light energy technologies have had successful
applications in large-scale operations such as bridge and airline fuselage refinishing. These
technologies, however, have not been applied to small-scale operations.31'32 Since many of the
operating parameters of laser and flashlamp units can be controlled, it may be possible to optimize
these methods to perform small-scale operations such as screen reclamation. The ability of these
methods to remove a single or microlayer of material from a substrate may make them useful in
a number of industries if they are cost effective. However, substrate heat sensitivity, vapor
generation, and high capital and operating costs may limit these processes from entering other
markets. A screen mesh, made of polymeric fibers, for example, may be permanently damaged in
the reclamation process from the heat generated by the pulse light energy technologies. Also, the
fumes generated from the vaporization of inks and stencils, when limited to a closed process area,
may cause health and safety hazards. Finally, the current costs of these technologies are
prohibitive to all but possibly the very largest screen printers. Pulse light energy technologies,
however, may be suitable for screen reclamation and therefore further study may be warranted.
Stripping Technologies
Stripping methods in Exhibit 1-3 include sanding, heat gun stripping, and cryogenic methods
to remove a coating from a substrate. Sanding methods also use the abrasive properties of a media
to remove the coating. The media, either on a sanding block (paper, cloth, etc.) or in a slurry, is
applied to the substrate and mechanically worked to remove the coating. Heat guns are intended
to either soften or burn the coating which is then scraped from the substrate. Cryogenic methods
cool a coating to cause it to contract, weaken and loosen from the substrate. This thermal
contraction is accomplished by the application of liquid nitrogen (-320°F at atmospheric pressure),
and the weakened coating is removed by media blasting methods or another mechanical
technique.33
29U.S. EPA Economics and Technology Division, Office of Toxic Substances, Reducing Risk in Paint Stripping,
(Washington:GPO 12-13 February, 1991).
^Correspondence between Dean Menke, UT Center for Clean Products, and Simon Engles, HDS Industries, July 1994.
31"Laser System Will Automate Paint Stripping," Laser Focus World, (June, 1991).
32
"Nd:YAG Lasers Strip Paint Effectively," Laser Focus World, (October, 1992).
33U.S. EPA Economics and Technology Division, Office of Toxic Substances, Reducing Risk in Paint Stripping,
(Washington:GPO 12-13 February, 1991).
DRAFT-September 1994 1-14
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Potential Screen Reclamation Substitute Technologies Stencils/Emulsions Chemistry
Stripping methods utilize diverse, technology-specific equipment. Sanding methods have the
potential to be automated, but are traditionally manual operations consisting solely of a sanding
block or slurry applied to the surface to be refinished. Heat guns typically utilize an electrical
power source to heat a metallic element held in contact with the coating. The heat softens or burns
the coating thus simplifying removal. After heating, the coating is promptly removed by a scraping
device or spatula. Cryogenics is the most energy intensive method of the stripping technologies.
Equipment includes units to liquify nitrogen, a chamber for substrate-liquid nitrogen contact, and
media blasting equipment.
Most stripping methods mentioned here appear to have a high potential to damage the
screen. Manual sanding methods could damage the screen in areas where there is no
stencil/emulsion and sanding media is in direct contact with the mesh. As with pulse light energy
technologies, the polymeric materials used for screen mesh may be permanently damaged if
subjected to temperature extremes; therefore, the heat gun method may not be feasible.
Cryogenics, with its extreme operating temperatures (cold) may also damage screen mesh.
However, the thermal resistance of most polymers to cold is greater than to heat, and the process
may warrant further research. However, current cryogenic technologies are probably too costly for
the average screen printer.
Stencils/Emulsions Chemistry
The substitute technologies presented above focussed on methods that could be used to
remove a stencil/emulsion that would traditionally be removed with chemical products. The use
of water-soluble stencils/emulsions, however, could eliminate the need for chemical removal
products as well as any of the above mentioned alternatives. Certain products of the indirect
stencil/emulsion process are water soluble and can be removed using only water to reclaim the
screen; other indirect stencil/emulsion products may use an enzyme or gelatin film decoater.
The image printed on a substrate in the screen printing process is defined by the stencil -
the area of the screen on which there is no emulsion blocking the flow of ink through the mesh to
the substrate. The stencil/emulsion is applied to the screen mesh using direct or indirect
processes. In direct processes (either capillary direct or direct emulsion), the printed image is
photographically developed after the emulsion is on the screen. This is accomplished by the
following procedure:
1. apply a water dispersion of polymer and sensitizers over the screen,
2. allow this to dry (this dried dispersion is still completely water soluble until exposed
to curing light),
3. block the desired image from the developing light,
4. expose the screen to light (usually UV), thus curing the dried dispersion (a reaction
between the sensitizers and polymer creating a cross-linked emulsion film), and
5. wash the uncured dried dispersion away with water.
During screen reclamation, emulsion remover is required for these products to break the cross
links and destroy the polymer network.
DRAFT-September 1994 1-15
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Potential Screen Reclamation Substitute Technologies Conclusions
Indirect processes, on the other hand, photographically develop the image of the emulsion
away from the screen and then apply the developed stencil/emulsion to the mesh. The procedure
to accomplish this is as follows:
1. expose the thin film emulsion to the desired image,
2. develop the image using a developing solution in a shallow tray,
3. wash away the uncured emulsion (image) with a aerator water nozzle,
4. adhere thin film emulsion to screen mesh and allow to dry, and
5. remove the supporting plastic film from the dried emulsion.
This stencil/emulsion can be removed during screen reclamation using an enzyme or gelatin film
decoater to soften the emulsion, which is then removed with a water spray. However, discussions
with printers and vendors of indirect emulsions indicated that a warm water wash alone can be
used to adequately remove the stencil/emulsion following ink removal. The water wash will take
approximately five minutes to sufficiently soften the emulsion (longer than a process using
chemicals), but this process time is chosen over chemical costs and disposal.34 Limitations of this
water-soluble stencil/emulsion lie in the inks used (no water-based inks, only oil- and rubber-based
can be used) and possibly the operating conditions (low humidity required).
Conclusions
Many of the substitute technologies presented in Exhibit 1-3 possess properties and
characteristics that may be applicable to the screen reclamation process performed by screen
printers. The technologies presented here are not exhaustive, and were solely intended to bring
further thought into the area of potential alternative technologies. Currently, these technologies
have high-tech applications, and therefore may not be economically feasible for the average printing
establishment. However, that is not to say that further research into these technologies, and their
continued development, could not result in more cost-effective, easy-to-use applications.
Issues that should be addressed when considering these alternative technologies in future
research include the following: effectiveness of ink, emulsion and haze removal; cost, both capital
and operating; potential of damaging screen; risk to human health and the environment from use
of the methods; waste generation and disposal; and energy and natural resource use. A multi-
media approach must be taken when researching the potential applications for these technologies.
For example, wheat starch and bicarbonate media blasting may be cleaned by washing with water
and disposing of the waste down the drain. This may simplify the cleaning process, but
consideration must be given to the local disposal and permitting requirements of wastewater
pretreatment and disposal; the inks and emulsion materials also washed down the drain could
impart an additional load on the wastewater treatment facility, and have the potential to be
hazardous. Also, as mentioned above, vapors generated from coating destruction by pulse light
energy technologies may require personnel protection equipment, ventilation and control.
^Correspondence between Dean Menke, UT Center for Clean Products, and Gary Coffey, Coffey Screen Printing, Knoxville,
TN and John Uhlman, Ulano, Brooklyn, NY.
DRAFT-September 1994 1-16
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Alternative Sodium Bicarbonate Screen Reclamation Technology Application Method
Alternative Sodium Bicarbonate Screen Reclamation Technology
General Summary of the Technology
The sodium bicarbonate screen reclamation technology consists of an enclosed spray cabinet
where pressurized sodium bicarbonate (baking soda) and water are sprayed onto the parts inside
the cabinet to clean them. Currently, this technology is used primarily for removing coatings, such
as paint, grease, or teflon from metal parts. As part of the DfE Performance Demonstration, the
sodium bicarbonate technology was tested to determine if it is potentially adaptable as an
alternative screen reclamation technology. A risk assessment was not conducted for the use of this
technology in screen reclamation. However, it is known that sodium bicarbonate (baking soda) is
a fairly innocuous chemical that is not a skin irritant and has a low toxicity; it is a common
ingredient in baked goods, toothpaste, detergents, air fresheners and deodorants.
Prior to this study, the sodium bicarbonate technology had never been tested for screen
reclamation applications. The cleaning procedure used during the test was a method developed
for cleaning metal parts, and adapted to screen reclamation. The screen was placed inside the
enclosure and held under the pressurized baking soda spray to remove the ink, emulsion and haze
from the screen simultaneously. The advantage of such a system for screen reclamation is that no
hazardous chemicals are used, and the need for ink remover, emulsion remover, and haze remover
is eliminated. In preliminary testing, the sodium bicarbonate technology showed potential for
effectively removing solvent- or water-based inks. Results on a screen with UV ink, however, were
poor. In all cases, further development and testing are needed before the technology could be used
in a screen printing facility.
Application Method
At this time, the sodium bicarbonate-based technology has not been developed specifically
for screen reclamation. It has been successful in replacing hazardous cleaning chemicals in other
applications such as in metal parts degreasing and paint and adhesives removal. To determine if
this technology could be adapted for screen reclamation, three screens were prepared for cleaning:
one with solvent-based ink, one with UV-curable ink, and a third screen with water-based ink. All
tests were conducted at the equipment manufacturer's facility. This particular manufacturer
developed the enclosed spray cabinet, and is a distributor of sodium bicarbonate. Because this
technology is still under development and is unproven for screen reclamation, no demonstrations
were conducted at printing facilities. An observer from the DfE Printing Project was present to
record information on the system's performance in cleaning the three test screens.
Tests were conducted in two different enclosures. Half of each screen was first cleaned in
an enclosure which delivered dry, pressurized baking soda to the screen. The second half of each
screen was cleaned in an enclosure which delivered both pressurized water and baking soda. The
same cleaning procedure was used for the two systems. After excess ink was carded off, the screen
was placed inside the enclosure with the flat side down. The door was locked and the operator
placed his hands through the gloves built into the box. By stepping on a foot pedal, the operator
started the flow of pressurized sodium bicarbonate from the fan nozzle mounted in the top of the
enclosure. The fan nozzle, designed by the enclosure manufacturer, spreads out the impact of the
sodium bicarbonate to reduce the stress on the screen. The nozzle used for testing dispersed the
sodium bicarbonate over an area approximately one inch wide by three inches long. On the wet
system, the same nozzle was used to deliver the sodium bicarbonate, and the water nozzle was
DRAFT-September 1994 1-17
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Alternative Sodium Bicarbonate Screen Reclamation Technology Alternative System Performance Results
mounted on the fan nozzle, so that the water and baking soda mixed together as they were
discharged. Holding the screen under the fan nozzle, the operator moved the screen from side to
side. The operator was able to see where the ink or emulsion remained on the screen by watching
through the primary viewing area. This window was purged with air to enhance visibility by
clearing the dust from the viewing area. When the first side was clean, the operator flipped the
screen over and repeated the cleaning procedure on the other side until all ink, emulsion, and haze
were removed.
During the test, the following parameters were used:
o Sodium Bicarbonate: 75 micron particle size
Delivered at 1 to 1.5 pounds/minute
Sodium bicarbonate delivered at 5 to 30 psi
Water delivered at 200 to 250 psi
o Screen: Polyester mesh mounted on wood frames
Dual-cure emulsion
13" x 23" outside diameter
o Inks: Solvent-based ink = Naz-Dar 9700 Series All Purpose Ink
9724 Black
UV-cured ink = Nor-Cote CD 1019 Opaque Black
Water-based ink = TW Graphics WB-5018 Black
o Ink application: Each type of ink was applied to one screen, carded off, and the
screen was allowed to dry for 18 hours before starting the
cleaning test.
Alternative System Performance Results
Dry Cleaning Process
During the demonstration, several different application methods were tested to optimize the
system performance. First, the screen with solvent-based ink was cleaned in a dry box; only
pressurized baking soda was delivered, without any water. At a pressure of 5 psi, some of the ink
and emulsion were removed, but very slowly. A heavy haze and some ink and emulsion residue
remained. To accelerate the removal, the pressure was increased to 10 psi. This pressure proved
to be too high and the screen developed pin holes and eventually ripped. The pressure was
reduced to 5 psi. To reduce the stress on the mesh, a flat plate was placed behind the screen.
Screen damage was reduced, but was not eliminated.
Similar results were obtained with the water-based ink screen. Significant ink and emulsion
residue remained on the screen after cleaning a 4 inch by 4 inch area for 5 minutes. Again, screen
wear and small holes were visible in some areas. After these disappointing results, dry testing was
discontinued in favor of the wet delivery system. The water serves to soften the sodium
bicarbonate, making it less abrasive than the dry delivery process. Because of the softening effect,
a higher pressure could be used with the wet delivery system without damaging the screen.
DRAFT-September 1994 1-18
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Alternative Sodium Bicarbonate Screen Reclamation Technology Alternative System Performance Results
After such poor performance was demonstrated using the dry cleaning process on the
solvent- and water-based ink screens, the decision was made to skip the dry process for the UV
ink screen, and start with the wet cleaning process. Additionally, the UV ink does not dry (unlike
the solvent- and water-based inks), and the manufacturer felt that the application of the dry sodium
bicarbonate would stick to the wet ink across the entire screen, instead of removing the ink. If the
sodium bicarbonate was covering the screen, the wet cleaning process test would not be valid.
Wet Cleaning Process
All three screens were tested using the wet process. Water was sprayed onto the screen at
200 to 250 psi, while the sodium bicarbonate was sprayed out of a fan nozzle at varying pressures.
On the screens where the dry process was used to clean half the screen, the wet process was used
for the other half. Performance clearly improved using the wet technology.
On the screen with UV ink, the sodium bicarbonate-based technology was completely
ineffective. After about 5 minutes of cleaning, there was almost no removal of the ink or the
emulsion. The operator increased the pressure to 20 psi to improve the system performance.
When there was no improvement at 20 psi, the pressure was increased to 30 psi. Even at the
higher pressure, there was no significant removal of the ink or the emulsion from the screen. The
operator put a glass plate behind the screen to concentrate the sodium bicarbonate and to support
the screen, but this did not help to remove the ink or emulsion. After approximately 10 minutes
of cleaning without any noticeable removal of ink, the test was stopped.
The solvent-based ink screen was cleaned first. At 5 psi, it took approximately 5 minutes
to remove the ink and emulsion from a 4 inch by 4 inch area of the screen. At this point the screen
was visually inspected. There was no visible damage to the screen, so the pressure was increased
to 10 psi. Another 4 inch by 4 inch area was cleaned, and at 10 psi, it took approximately 3
minutes. Some areas of the emulsion came off in stringy pieces. After cleaning the rest of the
screen, a light haze remained in the image area. Around the edges of the screen where the ink was
fairly thick, a heavy residue remained, but there was no ink or emulsion residue in the image area.
Total screen cleaning time for the half of the screen that was cleaned with the wet cleaning process
(a 10 inch by 10 inch area), took approximately 16 minutes.
Performance on the screen with water-based ink was similar to the screen with solvent-based
ink. On the water-based ink screen, all testing was conducted with the sodium bicarbonate
pressure at 10 psi. Initially, the ink started to come off fairly well, but very slowly. After a few
minutes, the ink began flaking off, instead of dissolving. The flaking made it significantly easier
to remove the ink. Again, the emulsion came off in stringy rolls. Ink residue remained around the
edges of the screen, but the image area was clean with a very slight haze. After closer inspection,
some very small spots of ink residue were apparent. In an effort to remove these spots, the
operator concentrated the spray on the small effected area. After one or two minutes, this
concentrated pressure ripped the screen. Total cleaning time for the portion of the screen that was
cleaned with wet cleaning (10 inches by 10 inches), was approximately 13 minutes.
Technology Potential
The cleaning procedures used during testing were the methods used for cleaning metal parts
and were not specifically developed for screen reclamation. With further testing and research, this
application method could be improved to clean the screens faster and with less possibility for
screen damage. For example, during the test, a piece of rigid material (safety glass) was held
DRAFT-September 1994 1-19
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I. PROFILE OF SCREEN RECLAMATION USE CLUSTER
Alternative Sodium Bicarbonate Screen Reclamation Technology Cost
behind the screen to reduce the pressure on the mesh. From the limited testing performed, this
support seemed to concentrate the cleaning media on the desired area while reducing the stress
on the screen. As another change that may improve performance, the operator suggested using hot
water. When cleaning the screens with solvent- and water-based ink, the emulsion came off in
stringy pieces that rolled off the screen. This reaction did not seem to increase or decrease the
removal efficiency, however, hot water may help dissolve the emulsion, potentially accelerating the
removal process. A third possible improvement in the application technique may be to add a small
platform inside the enclosure which would help the operator hold the screen closer to the spray
nozzle.
In addition to equipment modifications, several other variable changes that may be specific
to each facility should also be investigated. These factors include increasing or decreasing the
particle size of sodium bicarbonate, changing the pressure of the water or the sodium bicarbonate,
and changing the rate of delivery of the medium. With further research into improvements in the
sodium bicarbonate application, this technology could potentially reduce chemical use during
screen reclamation for printers using solvent-based or water-based inks.
Cost
Because the equipment used during testing was not developed specifically for screen
reclamation, it is difficult to estimate what the actual cost would be for a screen printing facility to
implement this technology. However, some rough estimates of equipment and chemical use are
available. The equipment used in the wet cleaning could range in cost from $32,000 to $52,000.
This estimate is subject to a wide range of actual operating conditions, including the type of
filtration and waste treatment that is necessary; the filtration and waste treatment needs will vary
depending on the ink and emulsion components on the screen. The blast media can cost between
$0.65 to $0.75 per pound, with the less expensive price available for large volume purchases.
Further research into the use of the sodium bicarbonate-based technology in screen reclamation
would give a better indication of the costs that could be expected for a typical screen printing
facility.
DRAFT-September 1994 I-20
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Chapter II
Screen Reclamation Chemicals
Introduction
Chapter 2, in which the characteristics of individual chemicals are detailed, is intended
for use as a reference section. The specific information concerning each chemical was
developed to support the risk assessment of screen reclamation products. Such information
includes physical/chemical properties, industrial synthesis, aquatic toxicity, environmental fate,
and a hazard summary. Tables II-4 through II-6 detail aquatic toxicity and hazard summary
data for the chemicals in the screen reclamation use cluster. The preface to these exhibits
explains the technical language and abbreviations used throughout the exhibits.
The regulatory status of a chemical was also provided as a ready reference; Table II-3 lists
those chemicals used in screen reclamation which trigger federal environmental regulations. In
addition, market profile information was developed to assess the overall production of the
chemical, and its use in screen reclamation. Originally, if it was determined that more than 5
percent of the U.S. production volume of a chemical was used in screen reclamation, an
analysis of the bulk chemical production, including occupational and population exposure
assessments, would be undertaken. However, due to the lack of information on the quantity of
specific chemicals used in screen reclamation, the latter analysis was not developed for any one
chemical. Instead, economists at EPA developed a methodology for estimating the quantity of
specific chemicals used in screen reclamation; this methodology is outlined in Chapter 3.
The chemicals that are discussed in this chapter comprise the screen reclamation use
cluster; Table II-1 lists all of the chemicals in the screen reclamation use cluster, as well as
their particular function in screen reclamation. Table II-1 also provides the page number on
which information about a specific chemical can be found. Table II-2 is a generic categorization
of some of the screen reclamation chemicals that was developed to protect the proprietary
nature of the alternative screen reclamation products submitted by manufacturers. In Chapters
4 and 5, specific chemicals in ink removers, emulsion removers and haze removers are
occasionally not identified by name, but by a generic category. For example, the product
category "propylene glycol series ethers" might refer to the presence of tripropylene glycol
methyl ether, propylene glycol methyl ether and methoxypropanol acetate. Although this
categorization was developed to protect proprietary formulations, the risk assessment
conducted for each type of screen reclamation product details the hazard and risk associated
with only those chemicals that occur in the actual product formulation.
DRAFT-September 1994 11-1
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II. SCREEN RECLAMATION CHEMICALS
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
Acetone
Alcohols, CR-Cin, ethoxylated
Alcohols, C19-C1d, ethoxylated
Benzyl alcohol
2-Butoxyethanol
Butyl Acetate
Butyrolactone
Cyclohexanol
Cyclohexanone
Diacetone alcohol
Dichloromethane
Diethyl adipate
Diethyl glutarate
Diethylene glycol
Diethylene glycol monobutyl
ether
Diethylene glycol butyl ether
acetate
Diisopropyl adipate
Dimethyl adipate
Dimethyl glutarate
Dimethyl succinate
Dipropylene glycol methyl ether
Dodecyl benzene sulfonic acid,
triethanol amine salt
CAS Number
67-64-1
71060-57-6
68439-50-9
100-51-6
111-76-2
123-86-4
96-48-0
108-93-0
108-94-1
123-42-2
75-09-2
141-28-6
818-38-2
111-46-6
112-34-5
124-17-4
6938-94-9
627-93-0
1119-40-0
106-65-0
34590-94-8
27323-41-7
Ink
Remover
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Emulsion
Remover
X
X
X
X
X
X
X
X
Haze
Remover
X
X
X
X
X
X
X
X
Possible
Substitutes
X
X
X
Page
Number
II-7
II-8
11-10
11-11
11-13
11-14
11-16
11-17
11-19
II-20
II-22
II-23
II-25
II-26
II-28
II-29
11-31
II-32
II-34
II-35
II-36
II-39
DRAFT—September 1994
II-2
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II. SCREEN RECLAMATION CHEMICALS
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
Ethyl acetate
Ethyl lactate
Ethyl oleate
Ethoxylated castor oil
Ethoxylated nonylphenol (np 4-
9.5)
Ethoxypropanol
Ethoxypropyl acetate
Furfuryl alcohol
Isobutyl isobutyrate
Isobutyl oleate
Isopropanol
d-Limonene
Methanol
Methoxypropanol acetate
Methyl ethyl ketone
Methyl lactate
Mineral spirits (straight run
naphtha)
Mineral spirits (light
hydrotreated)
N-methylpyrrolidone
2-Octadecanamine, N,N-
dimethyl-, N-oxide
Periodic acid
CAS Number
141-78-6
97-64-3
111-62-6
61791-12-6
9016-45-9
52125-53-8
54839-24-6
98-00-0
97-85-8
10024-47-2
67-63-0
5989-27-5
67-56-1
84540-57-8
78-93-3
547-64-8
64741-41-9
64742-47-8
872-50-4
71662-60-7
13444-71-8
Ink
Remover
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Emulsion
Remover
X
X
X
X
X
X
Haze
Remover
X
X
X
X
X
X
Possible
Substitutes
X
X
X
X
Page
Number
11-41
II-42
II-44
II-45
II-47
II-48
II-50
11-51
II-53
II-54
II-55
II-57
II-58
II-60
11-61
II-62
II-64
II-66
II-68
II-69
II-70
DRAFT—September 1994
II-3
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II. SCREEN RECLAMATION CHEMICALS
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
Phosphoric acid, mixed ester
w/ispropanol and ethoxylated
tridecanol
Potassium hydroxide
Propylene carbonate
Propylene glycol
Propylene glycol methyl ether
Propylene glycol methyl ether
acetate
Silica
Silica, fumed (amorphous,
crystalline-free)
Sodium bisulfate
Sodium hexametaphosphate
Sodium hydroxide
Sodium hypochlorite
Sodium lauryl sulfate
Sodium metasilicate
Sodium periodate
Sodium salt, dodecyl benzene
sulfonic acid
Solvent naphtha (petroleum),
light aliphatic
Solvent naphtha (petroleum),
light aromatic
Solvent naphtha (petroleum),
heavy aromatic
Tall oil, special
CAS Number
68186-42-5
1310-58-3
108-32-7
57-55-6
107-98-2
1320-67-8
108-65-6
7631-86-9
112945-52-5
10034-88-5
10124-56-8
1310-73-2
7681-52-9
151-21-3
6834-92-0
7790-28-5
25155-30-0
64742-89-8
64742-95-6
64742-94-5
68937-42-5
Ink
Remover
X
X
X
X
X
X
X
X
Emulsion
Remover
X
X
X
X
X
X
X
X
X
X
Haze
Remover
X
X
X
X
X
X
X
X
X
Possible
Substitutes
X
Page
Number
II-72
II-73
II-75
II-76
II-78
II-79
11-81
II-82
II-84
II-85
II-87
II-88
II-90
11-91
II-93
II-94
II-96
II-98
11-100
11-101
DRAFT—September 1994
II-4
-------
II. SCREEN RECLAMATION CHEMICALS
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
Terpineols
Tetrahydrofurfuryl alcohol
Toluene
1,1,1-Trichloroethane
1,2,4-trimethylbenzene
Tripropylene glycol methyl ether
Trisodium phosphate
Xylenes (dimethyl benzene)
CAS Number
8000-41-7
97-99-4
108-88-3
71-55-6
95-63-6
25498-49-1
7601-54-9
1330-20-7
Ink
Remover
X
X
X
X
X
X
X
Emulsion
Remover
X
X
Haze
Remover
X
X
X
Possible
Substitutes
Page
Number
11-103
11-104
11-106
11-107
11-109
11-110
11-112
11-114
DRAFT—September 1994
II-5
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II. SCREEN RECLAMATION CHEMICALS
Introduction
Categorization of Screen Reclamation Chemicals
In order to maintain confidentiality among the formulators and to simplify the evaluation
of the different screen reclamation systems, some of the constituent chemicals were categorized.
When a category is referred to (e.g., dibasic esters), that formulation includes one or more of
the chemicals in that category (e.g., diethyl adipate, diethyl glutarate, diisopropyl adipate, etc.)
Table 11-2.
Categorization of Screen Reclamation Chemicals for
Use in Alternative System Formulations
Category
Alkali/caustic
Alkyl benzyl sulfonates
Aromatic solvent naphtha
Derivatized plant oil
Dibasic esters
Diethylene glycol series ethers
Fatty alcohol ethers
Phosphate salt
Propylene glycol series ethers
Chemicals from Screen Reclamation Use Cluster in Category
Sodium hydroxide
Potassium hydroxide
Dodecyl benzene sulfonic acid, triethanol amine salt
Sodium salt, dodecyl benzene sulfonic acid
Solvent naphtha (petroleum), light aromatic
Solvent naphtha (petroleum), heavy aromatic
Tall oil, special
Ethoxylated castor oil
Diethyl adipate
Diethyl glutarate
Diisopropyl adipate
Dimethyl adipate
Dimethyl glutarate
Dimethyl succinate
Diethylene glycol butyl ether
Diethylene glycol butyl ether acetate
Alcohols, C8-C10, ethoxylated
Alcohols, C,,-CU, ethoxylated
Sodium hexametaphosphate
Trisodium phosphate
Dipropylene glycol methyl ether
Propylene glycol methyl ether
Tripropylene glycol methyl ether
Propylene glycol methyl ether acetate
Dipropylene glycol methyl ether acetate
Ethoxypropanol
Ethoxypropyl acetate
Methoxypropanol acetate
DRAFT—September 1994
II-6
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Acetone
Information on Individual Printing Chemicals
The following pages provide information on individual chemicals used in the screen
printing industry for screen reclamation.
Acetone
Chemical Properties and Information
Acetone [dimethyl ketone, 2-propanone]
CAS# 67-64-1
Molecular weight: 58.079
Melting Point: -95.4to-94°C(M)
Water Solubility: Miscible
Vapor Pressure: 185 mm Hg (20°C)
LogKow: -0.24 (M)
Henry's Law Constant: 3.97 x 10'5 atm-m3/mole (M)
Chemistry of Use: Solvent
C,HfiO
-"31 '6
Structure: CH,COCH.
3 3
Boiling Point: 56.2°C(M)
Density: 0.7908420 g/ml (M)
FlashPoint: -18°C(M)
Koc: 2 (E)
Above data are either measured (M) or estimated (E)
Acetone is the simplest and most important of the ketones. It is a colorless, flammable
liquid with a mildly pungent, somewhat aromatic odor. It shows typical reactions of aliphatic
saturated ketones. It undergoes many condensation reactions; condensation with amines yields
Schiff bases, and various esters condense readily with acetone in the presence of amine or
ammonia. It is stable to many of the usual oxidants. Acetone is highly flammable and has a
threshold limit value of 2400 mg/m3.
The two common methods of manufacturing acetone are 1) cumene hydroperoxide
cleavage and 2) the dehydrogenation of isopropyl alcohol. In the first process, benzene is
alkylated to cumene, which is oxidized to cumene hydroperoxide, which, in turn, is cleaved to
phenol and acetone. Acetone is a coproduct of this process, which is used to produce a large
fraction of phenol produced in the U.S.. In the second process, which is endothermic,
isopropanol is dehydrogenated catalytically, with a variety of possible catalysts, including
copper, silver, platinum, and palladium metal; sulfides of transition metals, as well as zinc
oxide-zirconium oxide, copper-chromium oxide, and copper-silicon dioxide combinations.
Market Profile
In 1992, total U.S. production was 230 million gallons. Imports were 9 million gallons
and exports were 27 million gallons. Total U.S. quantity estimated for use in screen
reclamation was 6.92 million gallons.
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
DRAFT-September 1994 II-7
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I. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Alcohols, Cs-Cio, Ethoxylated
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released on soil, acetone will volatilize into the air or leach into the ground where it will
probably biodegrade. Photolysis will be important on terrestrial surfaces and in surface waters
exposed to sunlight. If released to water, acetone may also be lost due to volatilization
(estimated half-life 20 hr from a model river) and biodegradation. Bioconcentration in aquatic
organisms and adsorption to sediment should not be important transport processes in water.
In the atmosphere, acetone will be lost by photolysis and reaction with photochemically
produced hydroxyl radicals. Half-life estimates from these combined processes average 22 days
and are shorter in summer and longer in winter. In air, acetone may also be washed out by
rain. Using a rapid and a moderate biodegradation rate for acetone in the STP fugacity model
results in 97 and 84 percent, respectively, predicted total removal from wastewater treatment
plants.
Health Hazard
See Table II-6 and accompanying summary
Alcohols, Cs-Cio, Ethoxylated
Chemical Properties and Information
Alcohols, C8-C10, ethoxylated [ethoxylated fatty alcohols]
CAS# 71060-57-6
Molecular weight: 150-220
Melting Point: <20°C(E)
Water Solubility: Dispersable (n=3 to 10) (E)
Vapor Pressure: <0.1 mm Hg (at20°C) (E)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Molecular formula varies
Structure: R (0-CH2-CH2)nOH, R = C8 to C10
Boiling Point: Decomposes (E)
Density: 1.02g/cm3(E)
FlashPoint: >100°C(E)
K • Not available
Above data are either measured (M) or estimated (E)
These chemicals will exhibit surfactant-like properties for n=3 to 10. When n> 10, they
will behave as mild surfactants. Melting point, boiling point, and flash point will increase as n
or R increases. They are soluble in alcohol and ether.
These chemicals are prepared by ethoxylation of alcohols with ethylene oxide.
DRAFT—September 1994
II-8
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I. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Alcohols, Cs-Cio, Ethoxylated
Market Profile
Production volumes for C8-C10 Ethoxylated Alcohols were not available. However, in
1992, total U.S. consumption of alcohol ethoxylates (including both C8-C10 and C12-C14) was 386
million pounds. In 1988, 29 million pounds of this chemical was exported. Data for imported
amounts was not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Alcohols, C8-C10, ethoxylated do not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, C8-C10 ethoxylated alcohols are expected to rapidly biodegrade. Two
factors influencing biodegradation are the number of ethylene oxide units in the hydrophilic
moiety and the structure of the hydrophobic moiety. Studies have shown that the linearity of
the hydrophobic moiety has a more pronounced effect on biodegradability than the hydrophobic
chain length, point of attachment of the polyglycol chain (i.e., whether alcohol moiety is primary
or secondary), or degree of ethoxylation. Biodegradation occurs by the p-oxidation of the alkyl
chain, scission of the hydrophobic and hydrophic moieties and step-wise removal of ethoxylate
groups, forming more hydrophobic metabolites. The C8-C10 ethoxylated alcohols will be highly
mobile in soil with the mobility increasing with increasing number of ethoxylate groups.
Volatilization from soil to the atmosphere is not expected to occur. Studies have shown that C8-
C10 ethoxylated alcohols undergo rapid biodegradation in river water; degradation is essentially
complete in about a week. Shorter chain ethoxylates may also partition to sediment and
particulate matter in the water column. Volatilization of C8-C10 ethoxylated alcohols to the
atmosphere is not expected to occur. If released to the atmosphere, C8-C10 ethoxylated alcohols
will be associated with aerosols and will be removed by wet and dry deposition. Using a rapid
biodegradation rate in the STP fugacity model results in 100 percent predicted total removal
from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-9
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Alcohols, Ci2-Ci4, ethoxylated
Alcohols, Ci2-Ci4, ethoxylated
Chemical Properties and Information
Alcohols, C12-C14, ethoxylated [ethoxylated fatty alcohols]
CAS# 68439-50-9
Molecular weight: >200
Melting Point: <50°C(E)
Water Solubility: Dispersable (n=3 to 10) (E)Vapor Pressure:
<0.01 mm Hg (E)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Molecular formula varies
Structure: R (0-CH2-CH2)nOH, R = C12 to C14
Boiling Point: Decomposes (E)
Density: 0.95g/cm3(E)
FlashPoint: >100°C(E)
K • Not available
Above data are either measured (M) or estimated (E)
These chemicals will exhibit surfactant-like properties for n=3 to 10. When n> 10, they
will behave as mild surfactants. Melting point, boiling point, and flash point will increase as n
or R increases. They are miscible in organic solvents.
These chemicals are prepared by ethoxylation of alcohols with ethylene oxide.
Market Profile
Production volumes for C12-C14 ethoxylated alcohols were not available. However, in
1992, total U.S. consumption of alcohol ethoxylates (including both C8-C10 and C12-C14) was 386
million pounds. In 1988, 29 million pounds of this chemical was exported. Data for imported
amounts was not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Alcohols, C12-C14, ethoxylated do not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, C12-C14 ethoxylated alcohols are expected to rapidly biodegrade. Two
factors influencing biodegradation are the number of ethylene oxide units in the hydrophilic
moiety and the structure of the hydrophobic moiety. Studies have shown that the linearity of
the hydrophobic moiety has a more pronounced effect on biodegradability than the hydrophobic
DRAFT—September 1994
11-10
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Alcohols, Ci2-Ci4, ethoxylated
chain length, point of attachment of the polyglycol chain (i.e., whether alcohol moiety is primary
or secondary), or degree of ethoxylation. Biodegradation occurs by the p-oxidation of the alkyl
chain, scission of the hydrophobic and hydrophic moieties and step-wise removal of ethoxylate
groups, forming more hydrophobic metabolites. The C12-C14 ethoxylated alcohols will be highly
mobile in soil with the mobility increasing with increasing number of ethoxylate groups.
Volatilization from soil to the atmosphere is not expected to occur. Studies have shown that
C12-C14 ethoxylated alcohols undergo rapid biodegradation in river water; degradation is
essentially complete in about a week. Shorter chain ethoxylates may also partition to sediment
and particulate matter in the water column. Volatilization of C12-C14 ethoxylated alcohols to the
atmosphere is not expected to occur. If released to the atmosphere, C12-C14 ethoxylated alcohols
will be associated with aerosols and will be removed by wet and dry deposition. Using a rapid
biodegradation rate in the STP fugacity model results in 100 percent predicted total removal
from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Benzyl Alcohol
Chemical Properties and Information
Benzyl alcohol [Benzenemethanol, Benzene carbinol, o
Hydroxy toluene]
CAS# 100-51-6
Molecular weight: 108.13
Melting Point: -15.19°C(M)
Water Solubility: 40 g/L (M)
Vapor Pressure: 0.048 mm Hg (at20°C) (E)
1mmHg(at58°C)(M)
LogKow: 1.10(M)
Henry's Law Constant: 2.1X10'7 atm-m3/mole (E)
Chemistry of Use: Solvent
C7H80
Structure:
Boiling Point: 204.7°C(M)
Density: 1.045 g/cm3(M)
FlashPoint: 101°C (closed cup) (M)
104°C (open cup) (M)
KOC:5-16(M)
Above data are either measured (M) or estimated (E)
This chemical has a faint aromatic odor and sharp burning taste. It is miscible with
alcohol, ether, chloroform, acetone.
Benzyl alcohol is produced by reaction of sodium or potassium carbonate with benzyl
chloride.
Market Profile
In 1988, total U.S. production was 4.8 million gallons; an additional 1.6 million gallons
was imported. Total U.S. production quantity for use in screen reclamation is unknown.
DRAFT—September 1994
11-11
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Benzyl Alcohol
Regulatory Status
Benzyl alcohol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, benzyl alcohol is expected to display high mobility. Volatilization from
moist soil to the atmosphere is not expected to be important, although it may slowly volatilize
from dry soils. Microbial degradation in soil may be rapid, especially in acclimated soils. If
released to water, benzyl alcohol is expected to undergo microbial degradation under aerobic
conditions. Biodegradation may be rapid under acclimated conditions. It is also expected to
slowly biodegrade under anaerobic conditions. Neither volatilization to the atmosphere,
chemical hydrolysis, direct photolytic degradation, chemical oxidation, bioconcentration in fish
and aquatic organisms, nor adsorption to sediment and suspended organic matter are expected
to be significant processes in environmental waters. If released to the atmosphere, benzyl
alcohol is expected to undergo a gas-phase reaction with photochemically produced hydroxyl
radicals; the estimated half life for this process is 16 hours. Its water solubility indicates that
benzyl alcohol may also undergo atmospheric removal by wet deposition processes; however,
its short atmospheric residence time suggests that wet deposition may be of limited importance.
Using a rapid biodegradation rate in the STP fugacity model results in 97 percent predicted
total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-12
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
2-Butoxyethanol
2-Butoxyethanol
Chemical Properties and Information
2-Butoxyethanol [Glycol ether EB; butyl Cellosolve; Dowanol
EB; Poly-Solv EB; glycol butyl ether, ethylene glycol
monobutyl ether]
CAS# 111-76-2
Molecular weight: 118.18
Melting Point: -75°C(M)
Water Solubility: Miscible (E)
Vapor Pressure: 3 mm Hg (25°C)(E)
Log Kow = 0.57 (E)
Henry's Law Constant: 2.1 x 10"8 atm-m3/mole (E)
Chemistry of Use: Solvent
C6H1402
Structure: CH3CH2CH2CH2OCH2CH2OH
Boiling Point: 171.2°C(M)
Density: 0.902 g/ml (M)
Flash Point: Open cup: 74°C (M)
Closed cup: 68°C(M)
Koc: 49 (E)
Above data are either measured (M) or estimated (E)
The physical state of 2-butoxyethanol is an oily, colorless liquid with mild rancid odor.
Glycol ethers are both ethers and alcohols. Their hydroxyl groups can be etherified, esterified,
chlorinated, or otherwise modified.
The reaction of ethylene oxide and alcohols gives a mixture of glycol monoethers and
monoethers of the lower polyethylene glycols.
Market Profile
In 1991, total U.S. production was 350 million gallons. In 1991, imports were 2.8
million gallons and in 1988, exports were 73.1 million gallons. Total U.S. production quantity
for use in screen reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary. The generic category of glycol ethers are also
listed as Hazardous Air Pollutants in the Clean Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
2-butoxyethanol is not expected to undergo hydrolysis or direct photolysis in the
environment. In water, volatilization, adsorption to sediments and suspended solids, and
bioconcentration in aquatic organisms are not expected to be important transport processes for
DRAFT—September 1994
11-13
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Butyrolactone
2-butoxyethanol. Aqueous screening test data indicate that biodegradation is likely to be the
most important removal mechanism of 2-butoxyethanol from aerobic soil and water. If released
to soil, 2-butoxyethanol is expected to display very high mobility. Volatilization from dry soil
surfaces will be important. In the atmosphere, 2-butoxyethanol is expected to exist almost
entirely in the gas-phase and reactions with photochemically produced hydroxyl radicals should
be fast (estimated half-life of 5.6 hrs). Using a rapid biodegradation rate for 2-butoxyethanol in
the STP fugacity model results in 97 percent predicted removal from wastewater treatment
plants; a moderate rate corresponds to 83 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
Butyl Acetate
Chemical Properties and Information
Butyl acetate [n-butyl acetate; butyl ethanoate]
CAS# 123-86-4
Molecular weight: 116
Melting Point: -77°C(M)
Water Solubility: 10g/l(E)
Vapor Pressure: 12.8 mm Hg (25°C)(M)
LogKow=1.82(M)
Henry's Law Constant: 2.81 x 10'4 atm-m3/mole (M)
Chemistry of Use: Solvent
C6H1202
Structure: CH,COOCH,CH,CH,CH
Boiling Point: 125-6°C(M)
Density: 0.883 g/ml (M)
FlashPoint: 29°C(M)
KOC:23(E)
Physical state: Liquid
Above data are either measured (M) or estimated (E)
Butyl acetate is a colorless, flammable liquid with a pleasant, fruity odor. It is miscible
with most organic solvents. The threshold limit value for air is 150 ppm. The vapors are
irritating to the eyes and respiratory tract. Synthetic esters are generally prepared by
reaction of an alcohol with an organic acid in the presence of a catalyst such as sulfuric acid or
p-toluene sulfonic acid. Butyl acetate thus may be prepared by the reaction of butanol and
acetic acid.
Market Profile
In 1992, total U.S. production was 250 million gallons. In 1991, imports were less than
100,000 million gallons. In 1992, exports were 127.5 million gallons. Total U.S. production
quantity for use in screen reclamation was estimated to be 1.92 million gallons.
DRAFT-September 1994 11-14
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Butyrolactone
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, butyl acetate is expected to rapidly biodegrade. Chemical hydrolysis is
not expected to occur in moist soils although it may occur in alkaline soils (pH greater than 8).
Butyl acetate is expected to display high mobility. Volatilization of butyl acetate to the
atmosphere from both dry and moist soil surfaces may be significant. If released to water,
butyl acetate is expected to biodegrade under aerobic conditions as 5-day theoretical BODs of
23-58 percent using a sewage seed, 21 percent in river water, and 40 percent in salt water have
been reported. Volatilization to the atmosphere is also expected to be important. The
hydrolysis half-lives of butyl acetate at pHs 7.0, 8.0, and 9.0 are about 3.1 years, 114 days and
11.4 days, respectively, at 20 °C indicating that hydrolysis will be important only in very
alkaline environmental waters. Adsorption to sediment and suspended organic matter and
bioconcentration in fish and aquatic organisms are not expected to be significant processes. If
released to air, butyl acetate will exist almost entirely in the gas-phase in the ambient
atmosphere. It may undergo atmospheric removal by the gas-phase reaction with
photochemically produced hydroxyl radicals with an estimated half-life of 2.5 days for this
process. Butyl acetate may also undergo atmospheric removal by wet deposition processes;
however, its short atmospheric residence time suggests that this process may be of limited
importance. Using a rapid biodegradation rate in the STP fugacity model results in 97 percent
predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-15
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Butyrolactone
Butyrolactone
Chemical Properties and Information
Butyrolactone [v-Butyrolactone; dihydro-2(3H)-furanone; 1,2-
butanolide; 1,4-butanolide; v-hydroxybutyric acid lactone; 3-
hydroxybutyric acid lactone; 4-hydroxybutanoic acid lactone]
CAS# 96-48-0
Molecular weight: 86
Melting Point: -44°C(M)
Water Solubility: miscible (M)
Vapor Pressure: 3.2 mm Hg (25° C)(M)
Log Kow = -0.640 (M)
Henry's Law Constant: 1.81 x 10"5 atm-m3/mole (E)
Chemistry of Use: Solvent
C4H602
Structure:
Boiling Point: 204°C(M)
Density: 1.125g/ml(M)
Flash Point: Open cup: 98°C (M)
KOC:53(E)
Physical state: Liquid
Above data are either measured (M) or estimated (E)
Butyrolactone undergoes characteristic y-lactone reactions including ring openings and
reactions wherein oxygen is replaced by another ring heteroatom. There is also a marked
reactivity of the alpha hydrogen atoms. Butyrolactone is soluble in methanol, ethanol, acetone,
ether and benzene.
Two routes are used for commercial production: the dehydrogenation of butanediol, and
hydrogenation of maleic anhydride to tetrahydrofuran and butyrolactone. In the former, the
exothermic dehydrogenation is carried out in a fixed bed at atmospheric pressure with
preheated butyrolactone over a copper-on-silica catalyst at 230 to 250°C. The yield of
butyrolactone, purified by distillation, is approximately 90 percent.
Market Profile
In 1990, total U.S. production was 67 million gallons. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Butyrolactone does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT-September 1994 11-16
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Cyclohexanol
Environmental Fate
In aqueous solutions butyrolactone is in dynamic equilibrium with its free acid and under
basic conditions the acid form may predominate. If released to soil, butyrolactone may
volatilize from both dry and moist soil to the atmosphere. It is expected to display moderate to
high mobility in soil. In basic soils, the free acid form may predominate which may alter both
the rate at which butyrolactone volatilizes from soil and the degree to which it adsorbs.
Biodegradation in acclimated aerobic soils is expected. If released to water, butyrolactone may
volatilize from water to the atmosphere. The estimated half-life for volatilization from a model
river is 1.5 days. Butyrolactone is not expected to bioconcentrate in fish and aquatic
organisms, nor is it expected to adsorb to sediment and suspended organic matter.
Biodegradation under aerobic conditions is expected. If released to the atmosphere,
butyrolactone is expected to undergo a gas-phase reaction with photochemically produced
hydroxyl radicals; the estimated half life for this process is 4.4 days. Butyrolactone may also
undergo atmospheric removal by both wet and dry deposition processes. Using a rapid
biodegradation rate for butyrolactone in the STP fugacity model results in 97 percent predicted
total removal from wastewater treatment plants. If a moderate biodegradation rate is used in
this model, 83 percent predicted total removal may be achieved.
Health Hazard
See Table II-6 and accompanying summary
Cyclohexanol
Chemical Properties and Information
CfiH,,0
12*-
Cyclohexanol [hexahydrophenol, hexalin]
CAS# 108-93-0 Structure:
Molecular weight: 100.16
Melting Point: 23-25°C(M)
Water Solubility: 36 g/l (at 20°C) (M)
Vapor Pressure: 0.8 torr (at 20°C) (M)
LogK . 1.23(M) Boiling Point: 161°C(M)
Henrys Law•Constant 1.02X10-
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Cyclohexanone
Market Profile
In 1992, total U.S. production for both cyclohexanol and cyclohexanone was 2.1 billion
gallons. Data for imported and exported amounts were not available. Total U.S. production
quantity for use in screen reclamation is unknown.
Regulatory Status
Cyclohexanol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, cyclohexanol will be expected to exhibit high to very high mobility in
soil. It will not hydrolyze in moist soil, but it may be subject to volatilization from near surface
soil. It may be subject to biodegradation in soil based upon results observed in laboratory
aqueous screening tests. If released to water, it will not be expected to adsorb to sediment or
suspended particulate matter or to bioconcentrate in aquatic organisms. It will not be expected
to hydrolyze or directly photolyze in water. It may be subject to biodegradation in natural
waters based upon results observed in laboratory biodegradation aqueous aerobic screening
tests using sewage and activated sludge inocula. It will be subject to volatilization from surface
waters with estimated half-lives of 23 hr for volatilization from a model river and 10.6 days for
volatilization from a model pond, respectively. If released to the atmosphere, it can be expected
to exist mainly in the vapor-phase in the ambient atmosphere based on its vapor pressure. The
estimated half-life for vapor-phase reaction with photochemically produced hydroxyl radicals is
22 hr at an atmospheric concentration of 5X104 hydroxyl radicals per cm3. Cyclohexanol will
not be expected to directly photolyze in the atmosphere. Using a rapid biodegradation rate for
cyclohexanol in the STP fugacity model, 97 percent removal can be predicted from wastewater
treatment plants. Using a moderate biodegradation rate for cyclohexanol in the STP fugacity
model, 84 percent removal can be predicted from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-18
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Cyclohexanone
Cyclohexanone
Chemical Properties and Information
Cyclohexanone [ketohexamethylene, pimelic ketone, cyclohexyl
ketone, Hytrol 0, Anone, Nadone]
CAS# 108-94-1
Molecular weight: 98
Melting Point: -47°C(M)
Water Solubility: 100g/l(E)
Vapor Pressure: 3.975 mm Hg (M) (20°C)
Log Kow = 0.81 (M)
Henry's Law Constant: 9 x 10"6 atm-m3/mole (M)
Chemistry of Use: Solvent
C6H100
Structure:
Boiling Point: 156.7°C(M)
Density: 0.9478 g/ml (M)
FlashPoint: Closed cup: 42°C(M)
Koc: 10(E)
Above data are either measured (M) or estimated (E)
Cyclohexanone is a colorless liquid with an odor suggestive of peppermint and acetone.
Cyclohexanone is miscible with methanol, ethanol, acetone, benzene, n-hexane, nitrobenzene,
dimethyl ether, naphtha, xylene, ethylene, glycol, isoamyl acetate, diethylamine, and most
organic solvents.
Cyclohexanone may be produced by the catalytic hydrogenation of phenol, by the catalytic
air oxidation of cyclohexanol, by the catalytic dehydrogenation of cyclohexanol, or by the
oxidation of cyclohexanol. The hydrogenation of phenol, which is best carried out in the liquid
phase, catalyzed by palladium on carbon, is the most efficient route.
Market Profile
In 1992, total U.S. production for both cyclohexanol and Cyclohexanone was 2.1 billion
gallons. Imports were 0.6 million gallons and exports were 48.5 million gallons. Total U.S.
production quantity of Cyclohexanone for use in screen reclamation was estimated to be
270,000 gallons.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT-September 1994 11-19
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Diacetone Alcohol
Environmental Fate
If released to the atmosphere, cyclohexanone will degrade by reaction with sunlight
produced hydroxyl radicals (half-life of about 1 day) and by direct photolysis (half-life of about
4.3 days). If released to water, cyclohexanone may degrade through biodegradation and
photolysis. Volatilization from environmental waters will not be rapid except from rapidly
moving, shallow streams. If released to soil, cyclohexanone will be susceptible to significant
leaching. Volatilization and photodegradation will occur on soil surfaces. Using a rapid and a
moderate biodegradation rate for cyclohexanone in the STP fugacity model results in about 97
and 83 percent, respectively, predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Diacetone Alcohol
Chemical Properties and Information
Diacetone alcohol [4-hydroxy-4-methyl-2-pentanone,
dimethylacetonylcarbinol, 2-methyl-2-pentanol-4-one; pyranton]
CAS# 123-42-2
Molecular weight: 116
Melting Point: -44°C(M)
Water Solubility: Miscible
Vapor Pressure: 0.97 mm Hg (M) (20°C)
Log Kow =-0.34 (E)
Henry's Law Constant: 1.4 x 10"9 atm-m3/mole (E)
Chemistry of Use: Solvent
C6H1202
Structure: (CH3)2C(OH)CH2COCH3
Boiling Point: 164°C(M)
Density: 0.9306 g/ml (M)
Flash Point: Open Cup: -66°C (M)
Koc: 21 (E)
Above data are either measured (M) or estimated (E)
Technical grade diacetone alcohol contains up to 15 percent acetone. Diacetone alcohol is
miscible with alcohol, ether, and other solvents. Its physical state is a colorless oily liquid with
a faint pleasant odor.
Diacetone alcohol may be produced from acetone in the presence of a base such as
barium hydroxide or calcium hydroxide. It can be isolated from the arctic bramble Rubus
articus, from green algae and from the sleepy grass sp. Stipa vaseyi.
Market Profile
In 1990, total U.S. production volume was 18 million gallons. In 1992, imports were 0.5
million gallons and exports were 1.8 million gallons. Total U.S. production quantity for use in
screen reclamation is unknown.
DRAFT—September 1994
II-20
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Pi acetone Alcohol
Regulatory Status
Diacetone alcohol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, diacetone alcohol will be expected to exhibit very high mobility.
Although no data were located regarding its biodegradation in soil, the compound may be
subject to biodegradation in soil based upon results observed in laboratory biodegradation
aqueous aerobic screening tests. It should not be subject to volatilization from moist
near-surface soil. However, it may volatilize from dry near-surface soil and other dry surfaces.
In water, it will not be expected to adsorb to sediment or suspended particulate matter or
bioconcentrate in aquatic organisms. Diacetone alcohol has been demonstrated to biodegrade
in aqueous aerobic screening tests. The compound may be subject to biodegradation in natural
waters. It should not be subject to volatilization from surface waters. Hydrolysis should not be
an important removal process. If released to the atmosphere, gas-phase diacetone alcohol will
react with photochemically produced hydroxyl radicals; the estimated half-life is 8 days (12-hr
daylight day). Diacetone alcohol may be susceptible to direct photolysis in the atmosphere
based upon its possible absorption of light at wavelengths greater than 290 nm. The
compound may be susceptible to removal from the atmosphere by washout because of its high
water solubility. Using a moderate biodegradation rate for diacetone alcohol in the STP fugacity
model, 83 percent total removal can be predicted from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-21
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Dichloromethane
Dichloromethane
Chemical Properties and Information
Dichloromethane [methylene chloride; methylene dichloride;
Freon 30; DCM]
CAS# 75-09-2
Molecular weight: 84.93
Melting Point: -97°C(M)
Water Solubility: 17g/l(M)
Vapor Pressure: 340 mm Hg (20°C) (M)
LogKow= 1.25(M)
Henry's Law Constant: 3.25 x 10'3 atm-m3/mole (M)
Chemistry of Use: Solvent
CH2CI2
Structure: CH2CI2
Boiling Point: 40-41°C(M)
Density: 1.33415g/ml (M)
FlashPoint: -96.8 °C(M)
Koc: 67 (M)
Physical state: Clear, colorless volatile liquid
Above data are either measured (M) or estimated (E)
Methylene chloride is nonflammable, and stable under normal laboratory storage
conditions. It is soluble in ether. Methylene chloride may form explosive mixtures with certain
materials.
Methylene chloride is produced industrially by (1) first reacting hydrogen chloride and
methanol in the vapor phase with the aid of a catalyst to give methyl chloride, and then
chlorinating, (the predominant method) or (2) directly reacting excess methane with chlorine at
high temperature (= 485-510°C), which produces multiple coproducts.
Market Profile
In 1991, total U.S. production was 240 million gallons. Imports were 5.6 million
gallonsss and exports were 79.0 million gallons. Total U.S. production quantity for use in
screen reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, dichloromethane is expected to display high mobility. It may rapidly
volatilize from both moist and dry soil to the atmosphere. Aerobic biodegradation may be
important for dichloromethane in acclimated soils. If released to water, volatilization to the
DRAFT—September 1994
II-22
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Pi ethyl Adipate
atmosphere is expected to be a rapid process. Neither bioconcentration in fish and aquatic
organisms nor adsorption to sediment and suspended organic matter are expected to be
significant. Dichloromethane has been found to slowly biodegrade under aerobic conditions. It
is also expected to slowly biodegrade under anaerobic conditions in sediment and groundwater.
If released to the atmosphere, dichloromethane is expected to persist for long periods of time.
The estimated half-life for the gas-phase reaction of dichloromethane with hydroxyl radicals is
approximately 88 days. Direct photolytic degradation is not expected to occur.
Dichloromethane may undergo atmospheric removal by wet deposition processes although any
removed by this processes is expected to rapidly re-volatilize to the atmosphere. Using a slow
biodegradation rate for dichloromethane in the STP fugacity model, 64 percent total removal
can be predicted from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Diethyl Adipate
Chemical Properties and Information
Diethyl adipate [Diethyl ester adipic acid]
CAS# 141-28-6
Molecular weight: 202.25
Melting Point: -19.8°C(M)
Water Solubility: 0.1g/L(E)
Vapor Pressure: 0.8 mm Hg (25°C)(E)
Log Kow = 2.37 (E)
Henry's Law Constant: 2.3 x 10"7 atm-m3/mole (E)
Chemistry of Use: Lubricant, Plasticizer
C10H1804
Structure: (C2H50)CO(CH2)4OC(OC2H5)
Boiling Point: 245°C(M)
Density: 1.002g/ml(M)
FlashPoint: 110°C(M)
Koc: 44 (E)
Physical state: Colorless liquid
Above data are either measured (M) or estimated (E)
Diethyl adipate is soluble in alcohol and ether. When heated to decomposition, it emits
acrid smoke and fumes. The production of adipic acid esters is second only to the production
of adipic acid polyamides. These esters are marketed as plasticizers.
Diethyl adipate is the esterification product of adipic acid and ethanol. Adipic acid is
produced by the oxidation with air and nitric acid, separately, of cyclohexane. Diethyl adipate,
along with other esters, is produced in the mother liquor during adipic acid manufacturing.
Diethyl adipate is produced along with other esters, and is subsequently separated and refined
by distillation.
Market Profile
In 1991, total U.S. production of adipate plasticizers was 35 million pounds. Data
specific to diethyl adipate was not available; nor were data for imported and exported amounts.
Total U.S. production quantity for use in screen reclamation is unknown.
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Pi ethyl Adipate
Regulatory Status
Diethyl adipate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, diethyl adipate is expected to display high mobility. Biodegradation in
aerobic soils may be rapid. Volatilization of diethyl adipate from both moist and dry soil to the
atmosphere is expected to be very slow. Chemical hydrolysis of the ester group is not expected
to be significant except for highly basic soils (pH greater thanS). If released to water, aerobic
biodegradation may be rapid. Diethyl adipate is not expected to bioconcentrate in fish and
aquatic organisms or adsorb to sediment and suspended organic matter. Volatilization of
diethyl adipate from water to the atmosphere will be very slow. Chemical hydrolysis may occur
in highly basic waters. If released to the atmosphere, diethyl adipate may undergo oxidation by
the gas-phase reaction with hydroxyl radicals with an estimated half-life of approximately 1.9
days. It may also undergo atmospheric removal by both wet and dry deposition processes;
however, its short atmospheric residence time suggests that wet deposition is of limited
importance. Using a rapid biodegradation rate for diethyl adipate in the STP fugacity model
results in 97 percent predicted total removal from wastewater treatment plants. If a moderate
biodegradation rate is used in this model, 85 percent predicted total removal may be achieved.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-24
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Pi ethyl Glutarate
Diethyl Glutarate
Chemical Properties and Information
Diethyl glutarate [Diethyl ester glutaric acid; diethyl
pentanedioic acid]
CAS# 818-38-2
Molecular weight: 188.2
Melting Point: -24.1°C(M)
Water Solubility: 8.8 g/L (at 20° C) (M)
Vapor Pressure: 0.1 mm Hg(25°C)(E)
LogKow=1.88(E)
Henry's Law Constant: 1.65 x 10"7 atm-m3/mole (E)
Chemistry of Use: Plasticizer
C9H1604
Structure: (C2H50)CO(CH2)3CO(OC2H5)
Boiling Point: 237°C(M)
Density: 1.022g/ml(M)
FlashPoint: 96°C(M)
KOC:20(E)
Physical state: Colorless liquid
Above data are either measured (M) or estimated (E)
Diethyl glutarate is incompatible with acids, bases, oxidizing agents, and reducing agents.
It is soluble in alcohol and ether. Diethyl glutarate can be isolated from the water extracts of
crude wool.
Diethyl glutarate is produced by the oxidation of cyclopentanol or cyclopentanone. The
resulting glutaric acid is then reacted with ethanol to give the product diethyl glutarate.
Esterification of glutaric acid followed by distillation gives adequate results.
Market Profile
In 1991, total U.S. production for glutarate plasticizers was 3 million pounds. This
category includes both diethyl glutarate and dimethyl glutarate, among others. Data specific to
Diethyl Glutarate were not available; nor were data for imported and exported amounts. Total
U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
Diethyl glutarate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, diethyl glutarate is expected to display very high mobility.
Biodegradation in acclimated aerobic soils may be rapid. Volatilization of diethyl glutarate from
moist soil to the atmosphere is expected to be very slow although volatilization from dry soil
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Pi ethyl Glutarate
may be significant. Chemical hydrolysis of the ester group is not expected to be significant
except for highly basic soils (pH greater thanS). If released to water, aerobic biodegradation
may be rapid especially in acclimated waters. Diethyl glutarate is not expected to appreciably
bioconcentrate in fish and aquatic organisms or adsorb to sediment and suspended organic
matter. Volatilization of diethyl glutarate from water to the atmosphere will likely be very slow.
Hydrolysis may occur in highly basic waters. If released to the atmosphere, diethyl glutarate
may undergo oxidation by the gas-phase reaction with hydroxyl radicals with an estimated half-
life of approximately 2.5 days. It may also undergo atmospheric removal by both wet and dry
deposition processes. Using a rapid biodegradation rate for diethyl glutarate in the STP
fugacity model results in 97 percent predicted total removal from wastewater treatment plants.
If a moderate biodegradation rate is used in this model, 84 percent predicted total removal may
be achieved.
Health Hazard
See Table II-6 and accompanying summary
Diethylene Glycol
Chemical Properties and Information
Diethylene glycol [2,2'-oxybisethanol, 2,2'-oxydiethanol,
diglycol, &,&'-dihydroxydiethyl ether, dihydroxyethyl ether,
ethylene diglycol, 3-oxa-1,5-pentanediol, DEC, Dicol, bis(2-
hydroxyethyl) ether, diglycol]
CAS# 111-46-6
Molecular weight: 106.12
Melting Point: -6.5°C(M)
Water Solubility: Miscible
Vapor Pressure: <0.0013 mm Hg at25°C (M)
LogKow:-1.47(E)
Henry's Law Constant: 2.03X10'9 atm-m3/mole (E)
Chemistry of Use: Solvent
C4H1003
Structure: HOCH,CH,OCH,CH,OH
Boiling Point: 245.8°C(M)
Density: 1.11 (M)
FlashPoint: 138°C(M)
Koc: 4(E)
Above data are either measured (M) or estimated (E)
Diethylene glycol is readily esterified with mono- and dicarboxylic acids to yield
plasticizers and resins. Diethylene glycol is similar in many respects to ethylene glycol but
contains an ether group. 1,4-Dioxane is prepared directly from diethylene glycol. It is miscible
with water and other polar solvents.
Diethylene glycol is a co-product when ethylene glycol is produced by ethylene oxide
hydrolysis. The acid-catalyzed hydrolysis reaction is conducted in a large excess of water at
moderate temperatures. This reaction yields approximately 9 to 10 percent diethylene glycol as
the primary by-product.
DRAFT-September 1994 II-26
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Pi ethyl en e Glycol
Market Profile
In 1991, total U.S. production was 369.2 million gallons. Imports in 1992 were about 99
million gallons; exports were about 25 million gallons. Total U.S. production quantity for use
in screen reclamation was estimated to be 122,000 gallons.
Regulatory Status
Diethylene glycol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, diethylene glycol is expected to biodegrade under aerobic conditions
and it may be rapid if acclimated organisms are present. It is expected to display high mobility,
although rapid biodegradation will decrease its potential to leach through soil. Volatilization of
diethylene glycol from both moist and dry soil to the atmosphere is not expected to be
important. If released to water, diethylene glycol is expected to biodegrade under aerobic
conditions and it may be rapid if acclimated organisms are present. Diethylene glycol is also
expected to slowly degrade under anaerobic conditions. Neither bioconcentration in fish and
aquatic organisms, adsorption to sediment and suspended organic matter, nor volatilization to
the atmosphere are expected to be important. If released to the atmosphere, diethylene glycol is
degraded rapidly by reaction with photochemically produced hydroxyl radicals (typical half-life
of 6.2 hours). Physical removal by wet deposition processes may also occur because of its
substantial water solubility; however, its short atmospheric residence time suggests that wet
deposition may be of limited importance. Using a rapid biodegradation rate in the STP fugacity
model results in 97 percent predicted total removal from wastewater treatment plants; a
moderate rate corresponds to 84 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-27
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Diethylene Glycol Monobutyl Ether
Diethylene Glycol Monobutyl Ether
Chemical Properties and Information
Diethylene glycol monobutyl ether [2-(2-butoxyethoxy)
ethanol; butyl ethyl Cellosolve; diethylene glycol butyl ether;
butyl Carbitol; Dowanol DB; Poly-Solv DB; butoxydiglycol,
butyl digol, butyl diicinol ]
CAS# 112-34-5
Molecular weight: 162.2
Melting Point: -68°C(M)
Water Solubility: Miscible (E)
Vapor Pressure: 0.02 mm Hg (E) (20° C)
Log Kow = 0.29 (E)
Henry's Law Constant: 1.5 x 10"9 atm-m3/mole (E)
Chemistry of Use: Solvent
C8H1803
Structure: C4H9OCH2CH2OCH2CH2OH
Boiling Point: 231° C(M)
Density: 0.954 g/ml (M)
FlashPoint: Open cup: 110°C(M)
Closed cup: 78°C(M)
Koc: 34 (E)
Above data are either measured (M) or estimated (E)
Glycol ethers are both ethers and alcohols. Their hydroxyl groups can be etherified,
esterified, chlorinated, or otherwise modified. Diethylene glycol monobutyl ether is miscible in
many organic solvents. It is a colorless liquid with a mild pleasant odor.
The reaction of ethylene oxide and alcohols gives a mixture of glycol monoethers and
monoethers of the lower polyethylene glycols.
Market Profile
In 1991, total U.S. production was 100 million gallons. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation was
estimated to be 420,000 gallons.
Regulatory Status
Diethylene glycol monobutyl ether does not trigger any federal environmental regulations.
However, the generic category of glycol ethers is listed as Hazardous Air Pollutants in the Clean
Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Diethylene Glycol Butyl Ether Acetate
Environmental Fate
Diethylene glycol monobutyl ether is not expected to undergo hydrolysis or direct
photolysis in the environment. Volatilization, adsorption and bioconcentration are not
important transport processes of diethylene glycol monobutyl ether in water. Aqueous
screening test data indicate that biodegradation may be an important removal mechanism of
diethylene glycol monobutyl ether from aerobic soil and water. If released to soil, diethylene
glycol monobutyl ether is expected to display very high mobility. Volatilization from dry soil
surfaces will be important. In the atmosphere, diethylene glycol monobutyl ether is expected to
exist almost entirely in the gas-phase and reactions with photochemically produced hydroxyl
radicals should be fast (estimated half-life of 3.5 hours). Physical removal of diethylene glycol
monobutyl ether from air by wet deposition may occur due to its high water solubility; however,
its short atmospheric residence time suggests that wet deposition is of limited importance.
Using a rapid biodegradation rate for diethylene glycol monobutyl ether in the STP fugacity
model results in 97 percent predicted removal from wastewater treatment plants; a moderate
rate corresponds to 83 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
Diethylene Glycol Butyl Ether Acetate
Chemical Properties and Information
Diethylene glycol butyl ether acetate [2-(2-butoxyethoxy)
ethanol acetate; butyl diethylene glycol acetate; diglycol
monobutyl ether acetate]
CAS# 124-17-4
Molecular weight: 204.26
Melting Point: -32.2°C(M)
Water Solubility: 65 g/l (M)
Vapor Pressure: <0.01 mm Hg (M) (20° C)
LogKow=1.3(E)
Henry's Law Constant: 9.9 x 10"8 atm-m3/mole (E)
Chemistry of Use: Solvent
C10H2004
Structure: C4H9(OC2H4)2OOCCH3
Boiling Point: 246.7°C(M)
Density: 0.9810 g/ml (M)
FlashPoint: Open cup: 115.6°C(M)
Koc: 15(E)
Above data are either measured (M) or estimated (E)
Diethylene glycol monobutyl ether acetate is soluble in ethanol, ether, acetone, and other
organic solvents. It is a liquid with a mild, not unpleasant odor. Its fire potential is moderate;
when exposed to heat or flame it emits degradation products, it can react with oxidizing
materials.
Diethylene glycol butyl ether acetate is manufactured by the esterification of diethylene
glycol monobutyl ether with acetic acid or acetic anhydride.
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Diethylene Glycol Butyl Ether Acetate
Market Profile
In 1991, total U.S. production of "other" E-series glycol ethers was 500,000 pounds. This
category includes diethylene glycol butyl ether acetate, as well as other minor E-series glycol
ethers. Data for imported and exported amounts were not available. Total U.S. production
quantity for use in screen reclamation is unknown.
Regulatory Status
Diethylene glycol butyl ether acetate does not trigger any federal environmental
regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Diethylene glycol butyl ether acetate is not expected to undergo hydrolysis or direct
photolysis in the environment. In water, volatilization, adsorption to sediments and suspended
solids, and bioconcentration in aquatic organisms are not expected to be important transport
processes for diethylene glycol butyl ether acetate. Biodegradation is likely to be the most
important removal mechanism of diethylene glycol butyl ether acetate from aerobic soil and
water based on a 4-week BOD of 100 percent of theoretical. If released to soil, diethylene glycol
butyl ether acetate is expected to display very high mobility. Volatilization from dry soil
surfaces will be important. In the atmosphere, diethylene glycol butyl ether acetate is expected
to exist almost entirely in the gas-phase and reactions with photochemically produced hydroxyl
radicals should be fast (estimated half-life of 3.8 hrs). Physical removal of diethylene glycol
butyl ether acetate from air by wet deposition may occur due to its high water solubility;
however, its short atmospheric residence time suggests that wet deposition is of limited
importance. Using a rapid biodegradation rate for diethylene glycol butyl ether acetate in the
STP fugacity model results in 97 percent predicted removal from wastewater treatment plants;
a moderate rate corresponds to 83 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-30
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Diisopropyl Adipate
Diisopropyl Adipate
Chemical Properties and Information
Diisopropyl adipate [Disopropyl adipate; 2,3-dimethylbutyl
adipate; adipic acid diisopropyl ester]
CAS# 6938-94-9
Molecular weight: 230.34
Melting Point: -1.1°C(M)
Water Solubility: 1 g/L (E)
Vapor Pressure: 0.02 mm Hg (25°C)(E)
LogKow = 3.2(E)
Henry's Law Constant: 1.3 x 10"6 atm-m3/mole (E)
Chemistry of Use: Lubricant, Plasticizer
C12H2204
Structure: -/-C3H702C(CH2)4C02-/-C3H7
Boiling Point: 257°C (at 760 mm Hg) (E)
Density: 0.9569 g/ml (M)
FlashPoint: 116°C(M)
Koc: 1311(E)
Physical state: Colorless, odorless liquid
Above data are either measured (M) or estimated (E)
Diisopropyl adipate is soluble in alcohol, ether, acetone and acetic acid. When heated to
decomposition, it emits acrid smoke and fumes. The largest consumption of adipic acid after
polyamides is the production of esters. These esters are marketed as plasticizers.
Diisopropyl adipate is the result of the esterification of adipic acid. Acid catalysts are
normally used, but the reaction will proceed at elevated temperatures if water is removed
during the reaction. Diisopropyl adipate, along with other esters, is produced in the mother
liquor during adipic acid manufacturing. Diisopropyl adipate is subsequently separated and
refined by distillation.
Market Profile
In 1991, total U.S. production of adipate plasticizers was 35 million pounds. This
category includes diisopropyl adipate, diethyl adipate, dimethyl adipate, and possibly others.
Data for imported and exported amounts were not available. Total U.S. production quantity for
use in screen reclamation is unknown.
Regulatory Status
Diisopropyl adipate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Dimethyl Adipate
Environmental Fate
If released to soil, diisopropyl adipate is expected to display low mobility. Biodegradation
in acclimated aerobic soils may be rapid. Volatilization of diisopropyl adipate from moist soil
to the atmosphere is expected to be very slow although volatilization from dry soil may occur.
Chemical hydrolysis of the ester group is not expected to be important except for highly basic
soils (pH greater than 8). If released to water, aerobic biodegradation may be rapid especially
in acclimated waters. Diisopropyl adipate is not expected to appreciably bioconcentrate in fish
and aquatic organisms although it may adsorb to sediment and suspended organic matter.
Volatilization of diisopropyl adipate from water to the atmosphere will likely be very slow.
Chemical hydrolysis may occur in highly basic waters. If released to the atmosphere,
diisopropyl adipate may undergo oxidation by the gas-phase reaction with hydroxyl radicals
with an estimated half-life of approximately 1 day. Using a rapid biodegradation rate for
diisopropyl adipate in the STP fugacity model results in 98 percent predicted total removal
from wastewater treatment plants. If a moderate biodegradation rate is used in this model, 88
percent predicted total removal may be achieved.
Health Hazard
See Table II-6 and accompanying summary
Dimethyl Adipate
Chemical Properties and Information
Dimethyl adipate [Dimethyl hexanedioate; methyl adipate;
dimethyl ester adipic acid]
CAS# 627-93-0
Molecular weight: 174.25
Melting Point: 8°C(M)
Water Solubility: 0.1 g/L(E)
Vapor Pressure: 0.06 mm Hg (25°C)(E)
LogKow=1.39(E)
Henry's Law Constant: 1.3 x 10"7 atm-m3/mole (E)
Chemistry of Use: Lubricant, Plasticizer
C8H1404
Structure: (CH30)CO(CH2)4CO(OCH3)
Boiling Point: 193.7°C (at 760 mm Hg)(E)
Density: 1.063 g/ml (M)
FlashPoint: 107°C(M)
Koc: 136(E)
Physical state: Colorless, odorless liquid
Above data are either measured (M) or estimated (E)
Dimethyl adipate is soluble in alcohol, ether and acetic acid. It is incompatible with
acids, bases, oxidizing agents and reducing agents. When heated to decomposition, it emits
acrid smoke and irritating fumes.
Dimethyl adipate is the result of the esterification of adipic acid. Adipic acid is produced
by the oxidation of cyclohexane first with air, then with nitric acid. The adipic acid is then
methylated to produce the dimethyl adipate.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dimethyl Adipate
Market Profile
In 1991, total U.S. production of adipate plasticizers was 35 million pounds. This
category includes diisopropyl adipate, diethyl adipate, dimethyl adipate, and possibly others.
Data for imported and exported amounts were not available. Total U.S. production quantity of
dimethyl adipate for use in screen reclamation was estimated to be 304,000 gallons.
Regulatory Status
Dimethyl adipate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, dimethyl adipate is expected to display moderate to high mobility.
Biodegradation in acclimated aerobic soils may be rapid. Volatilization of dimethyl adipate
from moist soil to the atmosphere is expected to be very slow although volatilization from dry
soil may be significant. Chemical hydrolysis of the ester group is not expected to be important
except in highly basic soils (pH greater thanS). If released to water, aerobic biodegradation
may be rapid especially in acclimated waters. Dimethyl adipate is not expected to appreciably
bioconcentrate in fish and aquatic organisms or adsorb to sediment and suspended organic
matter. Volatilization of dimethyl adipate from water to the atmosphere will be very slow.
Chemical hydrolysis may occur in highly basic waters. If released to the atmosphere, dimethyl
adipate may undergo oxidation by the gas-phase reaction with hydroxyl radicals with an
estimated half-life of approximately 3.3 days. It may also undergo atmospheric removal by wet
deposition processes because of its moderate water solubility. Using a rapid biodegradation
rate for dimethyl adipate in the STP fugacity model results in 97 percent predicted total
removal from wastewater treatment plants. If a moderate biodegradation rate is used in this
model, 85 percent predicted total removal may be achieved.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-33
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dimethyl Glutarate
Dimethyl Glutarate
Chemical Properties and Information
Dimethyl glutarate [glutaric acid, dimethyl ester; pentanedioic
acid, dimethyl ester]
CAS# 1119-40-0
Molecular weight: 160.17
Melting Point: -42.5°C(M)
Water Solubility: 1 g/L (E)
Vapor Pressure: 0.1 mm Hg (E)
Log Kow: 0.90 (E)
Henry's Law Constant: 9.1X10'8 atm-m3/mole (E)
Chemistry of Use: Solvent
C7H1204
Structure: CH302C(CH2)3C02CH:
Boiling Point: 214°C(M)
Density: 1.088 g/cm3(M)
FlashPoint: 100°C(E)
Koc: 6 (E)
Above data are either measured (M) or estimated (E)
This chemical has a faint, agreeable odor. It is soluble in alcohols and ether.
This chemical is synthesized by the reaction of methanol with glutaric acid.
Market Profile
In 1991, total U.S. production of glutarate plasticizers was 3.4 million pounds. This
category includes both dimethyl glutarate and diethyl glutarate, among others. Total U.S.
production quantity of dimethyl glutarate for use in screen reclamation was estimated to be
609,000 gallons.
Regulatory Status
Dimethyl glutarate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, dimethyl glutarate is expected to readily biodegrade especially if
acclimated organisms are present. In moist, highly alkaline soils, chemical hydrolysis may also
occur. It has a very low estimated adsorptivity to soil and therefore should be highly mobile in
soil. Volatilization from soil should not be important. If released to water, dimethyl glutarate is
expected to biodegrade. Since its estimated alkaline hydrolysis half-life is 60 days at pH 8,
chemical hydrolysis may contribute to its loss in alkaline waters (pH greater thanS).
Volatilization, bioconcentration in aquatic organisms, and adsorption to sediment and
DRAFT-September 1994 II-34
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dimethyl Succinate
suspended organic matter are not expected to be important. If released to the atmosphere,
dimethyl glutarate will degrade by reaction with photochemically-produced hydroxyl radicals
(estimated half-life of 9 days). Using a rapid biodegradation rate in the STP fugacity model
results in 97 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Dimethyl Succinate
Chemical Properties and Information
Dimethyl succinate [succinic acid, dimethyl ester; butanedioic
acid, dimethyl ester; methyl succinate]
CAS# 106-65-0
Molecular weight: 146.14
Melting Point: 19°C(M)
Water Solubility: 8.3 g/L (M)
Vapor Pressure: 0.1 mm Hg (E)
LogKow:0.19(M)
Henry's Law Constant: 5.8X10'6 atm-m3/mole (E)
Chemistry of Use: Solvent
C,H,A
Structure: CH302C(CH2)2C02CH:
Boiling Point: 196.4°C(M)
Density: 1.12g/cm3(M)
FlashPoint: 100°C(E)
Koc: 3 (E)
Above data are either measured (M) or estimated (E)
This is a colorless liquid. It is soluble in alcohols, acetone and ether. This chemical is
synthesized by the reaction of methanol with succinic acid.
Market Profile
Data for total U.S. production of this chemical is unknown. Total U.S. production
quantity for use in screen reclamation was estimated to be 304,000 gallons.
Regulatory Status
Dimethyl succinate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
DRAFT-September 1994 II-35
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Dipropylene Glycol Methyl Ether
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, dimethyl succinate is expected to biodegrade and this process may be
rapid if acclimated organisms are present. In moist, highly alkaline soils, chemical hydrolysis
may also occur. It is expected to be highly mobile in soil. Volatilization of dimethyl succinate
from both moist and dry surface soil to the atmosphere may contribute to its loss. If released
to water, dimethyl succinate it is expected to biodegrade. Neither bioconcentration in fish and
aquatic organisms nor adsorption to sediment and suspended organic matter are expected to
be important. Volatilization from water may contibute to its loss from bodies of water with a
strong current or wind; the estimated half-life in a model river is 8 days. The estimated
alkaline hydrolysis half-life at pH 8 is 85 days and therefore chemical hydrolysis may occur in
alkaline environmental media (pH greater than 8). If released to the atmosphere, dimethyl
succinate will degrade by reaction with photochemically-produced hydroxyl radicals (estimated
half-life of 37 days). Using a rapid biodegradation rate in the STP fugacity model results in 97
percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Dipropylene Glycol Methyl Ether
Chemical Properties and Information
Dipropylene glycol methyl ether [Glycol ether DPM; Dowanol
DPM]
CAS# 34590-94-8
Molecular weight: 148.2
Melting Point: -80°C(M)
Water Solubility: Miscible (E)
Vapor Pressure: 0.4 mm Hg (M) (25° C)
Log Kow =-0.35 (E)
Henry's Law Constant: 1.15 x 10"9 atm-m3/mole (E)
Chemistry of Use: Solvent
C7H1603
Structure: CH3CHOHCH2OCH2CH(OCH3)CH3
or
CH3CHCH2OCH2CHCH3
OH OCH3
Boiling Point: 188.3°C(M)
Density: 0.951 g/ml (M)
FlashPoint: 75°C(M)
Koc: 15(E)
Physical state: liquid
Above data are either measured (M) or estimated (E)
Glycol ethers are both ethers and alcohols. Their hydroxyl group can be etherified,
esterified, chlorinated, or otherwise modified. Dipropylene glycol methyl ether is miscible in
many organic solvents. It is a liquid with a mild, not unpleasant odor.
Glycol ethers are prepared by reacting propylene oxide with methanol.
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dipropylene Glycol Methyl Ether
Market Profile
In 1991, total U.S. production was 22 million pounds. Imports were less than 100,000
million gallons and exports were 0.6 million gallons. Total U.S. production quantity for use in
screen reclamation is unknown.
Regulatory Status
Dipropylene glycol methyl ether does not trigger any federal environmental regulations.
However, the generic category of glycol ethers is listed as Hazardous Air Pollutants in the Clean
Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
In water, dipropylene glycol methyl ether would not be expected to sorb to sediments or to
bioconcentrate in fish and aquatic organisms. The main degradation mechanism in water is
expected to be biodegradation. Unpublished data support this, with 34 percent and 72.9
percent of theoretical being observed in two screening tests (Strum test and OECD Screenin g
Test, respectively) and 93.7 percent of theoretical in a Zahn-Wellens test. Photolysis and
hydrolysis are probably not important removal processes for dipropylene glycol methyl ether in
water. Volatilization from water will not be important. In the atmosphere, dipropylene glycol
methyl ether will react with photochemically produced hydroxyl radicals (half-life of
approximately 3.4 hours). In soil, dipropylene glycol methyl ether will be highly mobile and
may leach to groundwater. In soil biodegradation will probably be the primary removal
mechanism; however, this process may require an acclimation period. Dipropylene glycol
methyl ether may volatilize from dry soil surfaces. Using a rapid biodegradation rate for
dipropylene glycol methyl ether in the STP fugacity model, 97 percent removal can be predicted
from wastewater treatment plants. Using a moderate biodegradation rate for dipropylene glycol
methyl ether in the STP fugacity model, 83 percent removal can be predicted from wastewater
treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-37
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dipropylene Glycol Methyl Ether Acetate
Dipropylene Glycol Methyl Ether Acetate
Chemical Properties and Information
Dipropylene glycol methyl ether acetate [Dowanol DPMA;
Acrosolv DPMA]
CAS# 88917-22-0
Molecular weight: 190
Melting Point: -90°C(M)
Water Solubility: Miscible (E)
Vapor Pressure: 0.02 mm Hg (E) (25° C)
Log Kow= 0.66 (E)
Henry's Law Constant: 7.5 x 10"8 atm-m3/mole (E)
Chemistry of Use: Solvent
C9H1804
Structure: CH,CHCH,OCH,CHCH
OCH3 OC=OCH3
Boiling Point: 200°C(E)
Density: 0.90 g/ml (E)
FlashPoint: 60°C(M)
Koc: 5 (E)
Physical state: liquid
Above data are either measured (M) or estimated (E)
Dipropylene glycol methyl ether acetate is a glycol derivative that is both an ether and an
ester. Dipropylene glycol methyl ether acetate is soluble in organic solvents.
Dipropylene glycol methyl ether acetate is produced by the esterification of dipropylene
glycol methyl ether.
Market Profile
In 1991, total U.S. production of "other" P-series glycol ethers was 1 million pounds.
This category includes dipropylene glycol methyl ether acetate, ethoxypropanol, ethoxypropyl
acetate, and propylene glycol methyl ether acetate, among possibly others. Data for imported
and exported amounts were not available. Total U.S. production quantity for use in screen
reclamation is unknown.
Regulatory Status
Dipropylene glycol methyl ether acetate does not trigger any federal environmental
regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Dipropylene glycol methyl ether acetate is not expected to undergo hydrolysis or direct
photolysis in the environment. In water, volatilization, adsorption to sediments and suspended
solids, and bioconcentration in aquatic organisms are not expected to be important transport
processes for dipropylene glycol methyl ether acetate. Biodegradation is likely to be an
DRAFT-September 1994 II-38
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Dipropylene Glycol Methyl Ether Acetate
important removal mechanism of dipropylene glycol methyl ether acetate from aerobic soil and
water based on screening studies from structurally similar glycol ether compounds. If released
to soil, dipropylene glycol methyl ether acetate is expected to display very high mobility.
Volatilization from dry soil surfaces will be important. In the atmosphere, dipropylene glycol
methyl ether acetate is expected to exist almost entirely in the gas-phase and reactions with
photochemically produced hydroxyl radicals should be fast (estimated half-life of 3.4 hrs).
Using a rapid biodegradation rate for dipropylene glycol methyl ether acetate in the STP fugacity
model results in 97 percent predicted removal from wastewater treatment plants; a moderate
rate corresponds to 83 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
Dodecyl Benzene Sulfonic Acid, Triethanol Amine Salt
Chemical Properties and Information
Dodecyl benzene sulfonic acid, triethanol amine salt
[benzenesulfonic acid, dodecyl-, compd. with
2,2',2"-nitrilotris[ethanol](1:1)]
CAS# 27323-41-7
Molecular weight: 475.5
Melting Point: Not available
Water Solubility: Low Solubility (E)
Vapor Pressure: <10"5 mm Hg (E)
LogKow:-1.49(E)
Henry's Law Constant: Not applicable
Chemistry of Use: Surfactant
C24H45N06S
Structure:
HN(CH,CH,OH),
Boiling Point: Not available
Density: 1.09g/cm3(M)
Flash Point: Not available
Koc: 10,000 (E)
Above data are either measured (M) or estimated (E)
This chemical exists in a pale yellow, slightly viscous paste, and has a bland odor.
This chemical is synthesized by reacting dodecyl benzene sulfonic acid with
triethanolamine.
Market Profile
In 1990, total U.S. production was 8.2 million pounds. Imports and exports of this
chemcial are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Dodecyl Benzene Sulfonic Acid, Triethanol Amine Salt
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, dodecyl benzene sulfonic acid, triethanol amine salt, is expected to
biodegrade under aerobic conditions, especially when acclimated organisms are present.
Although dodecyl benzene sulfonic acid, triethanol amine salt is an ionic compound, studies
have shown that dodecyl benzene sulfonic acid salts strongly adsorb to soil and that the force
dominating this process is the hydrophobic nature of the non-polar tail of the molecule.
Volatilization of dodecyl benzene sulfonic acid, triethanol amine salt from surface soil will not
be significant. If released to water, dodecyl benzene sulfonic acid, triethanol amine salt is
expected to biodegrade. It will also adsorb to sediment and particulate matter in the water
column. Volatilization of dodecyl benzene sulfonic acid, triethanol amine salt from water
should be insignificant. Experimental data indicate that similar dodecyl benzene sulfonic acids
do not bioconcentrate in fish and aquatic organisms. If released to the atmosphere, triethanol
amine salt, dodecyl benzene sulfonic acid will be associated with aerosols and be removed by
gravitational settling. Using a rapid biodegradation rate for the parent acid in the STP fugacity
model results in 97 percent predicted total removal for dodecyl benzene sulfonic acid,
triethanol amine salt from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethyl Acetate
Ethyl Acetate
Chemical Properties and Information
Ethyl acetate [Acetic ester]
CAS# 141-78-6
Molecular weight: 88
Melting Point: -83.6°C(M)
Water Solubility: 77g/l (E)
Vapor Pressure: 90 mm Hg (M) (25°C)
Log Kow= 0.730 (M)
Henry's Law Constant: 1.34 x 10"4 atm-m3/mole (M)
Chemistry of Use: Solvent
C4H802
Structure: CH,COOCH,CH
Boiling Point: 77.1°C(M)
Density: 0.884 g/ml (M)
FlashPoint: -4.4°C(M)
Koc: 9 (E)
Physical state: volatile liquid
Above data is either measured (M) or estimated (E)
Ethyl acetate is a volatile, flammable liquid with a characteristic fruity odor. It is found in
cereal crops, radishes, fruit juices, beer, and wine. The threshold limit value for air is 440
ppm. Ethyl acetate is miscible with most organic solvents.
Ethyl acetate occurs naturally, and recovery can be accomplished by steam distillation,
extraction or pressing, or a combination of these. Synthetic esters are generally prepared by
reaction of an alcohol and an organic acid in the presence of a catalyst such as sulfuric acid or
p-toluene sulfonic acid. Ethyl acetate thus may be prepared synthetically by the catalyzed
reaction of ethanol and acetic acid.
Market Profile
In 1991, total U.S. production was 245 million gallons. Imports were 12.3 million gallons
and exports were 96.2 million gallons. Total U.S. production quantity for use in screen
reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, ethyl acetate is expected to display high mobility. Biodegradation in
both aerobic and anaerobic soils is expected to be rapid. Volatilization of ethyl acetate from
both moist and dry soil to the atmosphere is expected to occur. If released to water, ethyl
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Ethyl Acetate
acetate is expected to rapidly degrade under both aerobic and anaerobic conditions. Five-day
theoretical BODs of 50 percent and 53 percent using an activated sludge seed and in seawater,
respectively, have been observed. Under anaerobic conditions using a water/sediment aquifer
slurry obtained from under a municipal landfill, 94 percent conversion to methane was
observed. Ethyl acetate is not expected to appreciably bioconcentrate in fish and aquatic
organisms or adsorb to sediment and suspended organic matter. Volatilization of ethyl acetate
from water to the atmosphere may also occur. If released to the atmosphere, ethyl acetate may
undergo oxidation by the gas-phase reaction with hydroxyl radicals with an estimated half-life of
approximately 8 days. It may also undergo atmospheric removal by wet deposition processes
because of its high water solubility. A pilot plant activated sludge system removed 100 percent
of the 167 mg/L of influent ethyl acetate with 93 percent lost through biodegradation and 7
percent lost though stripping.
Health Hazard
See Table II-6 and accompanying summary
Ethyl Lactate
Chemical Properties and Information
Ethyl lactate [(S)-Ethyl lactate; ethyl-2-hydroxypropanate;
Acytol]
CAS# 97-64-3
Molecular weight: 118.13
Melting Point: -26°C(M)
Water Solubility: Miscible
Vapor Pressure: 5 mm Hg (E) (25°C)
LogKow = -0.180(E)
Henry's Law Constant: 5.8 x 10"6 atm-m3/mole (E)
Chemistry of Use: Solvent
C5H1003
Structure: CH3CH(OH)COOCH2CH3
Boiling Point: 154°C(M)
Density: 1.042g/ml(M)
FlashPoint: 48°C(M)
Koc: 8 (E)
Physical state: Colorless, odorless liquid
Above data are either measured (M) or estimated (E)
Ethyl lactate is incompatible with oxidizing agents, bases and acids. It is miscible with
alcohols, ketones, esters, hydrocarbons and oils. Ethyl lactate is combustible. Ethyl lactate
has a fruity, buttery taste when used as a flavoring.
Ethyl lactate is primarily derived from lactonitrile by the esterification of lactic acid with
ethanol. It is also produced by combining acetaldehyde with hydrogen cyanide to form
acetaldehyde cyanohydrin, which is converted to ethyl lactate by treatment with ethanol and an
inorganic acid.
Market Profile
Market information for this chemical is not available.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethyl Lactate
Regulatory Status
Ethyl lactate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, ethyl lactate is expected to display very high mobility. Biodegradation
in acclimated aerobic soils may be rapid. Volatilization of ethyl lactate from the upper layers of
dry soil to the atmosphere may be significant although volatilization from moist soil may be
relatively slow. In basic soil with a pH greater thanS, chemical hydrolysis of ethyl lactate may
occur. If released to water, aerobic biodegradation may be rapid especially in acclimated
waters. Ethyl lactate is not expected to bioconcentrate in fish and aquatic organisms nor
adsorb to sediment and suspended organic matter. Volatilization of ethyl lactate from water to
the atmosphere may occur at a moderate rate. In basic waters, ethyl lactate may undergo
chemical hydrolysis with an estimated half-life of approximately 7 days at pH 8. If released to
the atmosphere, ethyl lactate may undergo oxidation by the gas-phase reaction with hydroxyl
radicals with an estimated half-life of approximately 6.4 days. It may also undergo atmospheric
removal by wet deposition processes. Using a rapid biodegradation rate for ethyl lactate in the
STP fugacity model results in 97 percent predicted total removal from wastewater treatment
plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Ethyl Oleate
Ethyl Oleate
Chemical Properties and Information
Ethyl oleate [9-octadecenoic acid; ethyl ester oleic acid]
CAS# 111-62-6
Molecular weight: 310.53
Melting Point: -32°C(M)
Water Solubility: 0.01g/l(E)
Vapor Pressure: 0.01 mm Hg (E) (25°C)
Log Kow = 8.51 (E)
Henry's Law Constant: 1.0 x 10"2 atm-m3/mole (E)
Chemistry of Use: Solvent
Structure: CH3(CH2)7CH=CH(CH
Boiling Point: 205-208°C(M)
Density: 0.870 g/ml (M)
FlashPoint: 175°C(M)
Koc: >10,000(E)
Physical state: Colorless, oily liquid
2,6CH2COOCH2CH3
Above data are either measured (M) or estimated (E)
Ethyl oleate is soluble in alcohol and ether. Ethyl oleate is combustible. It is
incompatible with strong oxidizing agents and is light-sensitive and air-sensitive.
Ethyl oleate is produced from the esterification of oleic acid. Oleic acid is derived from
fruits or plant seeds. Once refined, the fats are heated in the presence of a strong base, and
esterification occurs at the glycerol hydroxides. The reaction occurs with the appropriate
alcohol to provide the desired product.
Market Profile
In 1992, total U.S. production of salt and esters of oleic, linoleic, or linoleric acids was 36
million pounds. Greater specificity is not available due to the low number of companies
producing these products. Data for imported and exported amounts were not available. Total
U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
Ethyl oleate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment.
Environmental Fate
If released to soil, ethyl oleate is expected to be essentially immobile. Biodegradation in
acclimated aerobic soils may be rapid. Chemical hydrolysis of the ester group is not expected
to be significant except in highly basic soils (pH greater thanS). Volatilization of ethyl oleate
from moist soil to the atmosphere may be a significant process although it is likely to be
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Ethyl Oleate
relatively slow from dry soil. If released to water, aerobic biodegradation may be rapid
especially in acclimated waters. Bioconcentration in fish and aquatic organisms and
adsorption to sediment and suspended organic matter may also occur. Volatilization from
water to the atmosphere may be rapid although its expected strong adsorption to sediment and
suspended organic matter may significantly attenuate the rate of this process. Chemical
hydrolysis may occur in highly basic waters. If released to the atmosphere, ethyl oleate may
undergo rapid oxidation by the both the gas-phase reaction with hydroxyl radicals and ozone
with estimated half-lives of approximately 1.5 and 1.4 hours for the trans isomer, respectively,
with similar rates for the cis isomer. Using a either a rapid or moderate biodegradation rate for
ethyl oleate in the STP fugacity model results in greater than99 percent predicted total removal
from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Ethoxylated Castor Oil
Chemical Properties and Information
Ethoxylated castor oil [cosmetol, ricinus oil, neoloid
CAS# 61791-12-6
Molecular weight: 298.47 (ricinoleic) +135 (ethoxy)
Melting Point: 5.5°C(M)
Water Solubility: 0.003 g/L (E)
Vapor Pressure: <0.1 mm Hg at20°C (M)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Drying/coating agent
C18H3403 (ricinoleic) + (C2H50)3 (ethoxy)
Structure:
CH3(CH2)5CHCH2CHCH(CH2)7COOH (ricinoleic)
OCH2CH3 OCH2CH3
Boiling Point: 313°C(M)
Density: 0.961 (M)
FlashPoint: 299°C(M)
K • Not available
Above data are either measured (M) or estimated (E)
Ethoxylated castor oil is derived from the bean of the castor plant. The composition of
ethoxylated castor oil is ricinoleic acid, palmitic acid, stearic acids, oleic acids, and several
ethoxy groups. Ricinoleic acid comprises nearly 90 percent of castor oil. Ethoxylated castor oil
is a drying agent. It is soluble in ethyl alcohol and polar organic solvents.
Castor oil is recovered by use of hydraulic presses followed by solvent extraction. Oil
taken from mechanical presses requires refining steps to remove toxic proteins, improve the
color, and reduce the fatty acid content. Fatty acid content is reduced by treatment with caustic
soda solution. In the polyethoxylation reaction the hydroxyl groups undergo alkylation to
produce the polyethoxyl triglyceride fatty acid. Common catalysts for the dehydration
procedure are sulfuric acid and its acid salts.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethoxylated Castor Oil
Market Profile
In 1992, total U.S. production was 22.3 million gallons. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Ethoxylated castor oil does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, ethoxylated castor oil is expected to rapidly biodegrade as do linear
primarily alcohol ethoxylates. Biodegradation occurs by the p-oxidation of the alkyl chain,
scission of the hydrophobic and hydrophic moeties and step-wise removal of ethoxylate groups
to more hydrophobic metabolites. The mobility of ethoxylated castor oil will increase with
increasing number of ethoxylate groups although the expected rapid biodegradation of the
ethoxylate groups will reduce the importance of leaching. Volatilization from soil to the
atmosphere is not expected to occur. If released to water, ethoxylated castor oil is expected to
undergo rapid biodegradation. Experimental studies on other ethoxylated natural oils
possessing 3-20 ethoxylate groups have resulted in five-day theoretical BODs of up to 100
percent and those containing 50 or more ethoxylate groups are also amenable to
biodegradation. Shorter chain ethoxylates may also partition to sediment and particulate
matter in the water column. Volatilization of ethoxylated castor oil to the atmosphere is not
expected to occur. If released to the atmosphere by mechanical means, ethoxylated castor oil is
expected to undergo removal by both wet and dry processes due to its appreciable water
solubility and low expected vapor pressure, respectively. Using a rapid biodegradation rate in
the STP fugacity model results in 100 percent predicted total removal from wastewater
treatment plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Ethoxylated Nonylphenol
Ethoxylated Nonylphenol
Chemical Properties and Information
Ethoxylated nonylphenol [poly(oxy-1,2-ethanediyl), o
(nonylphenyl)-Q-hydroxy-; Antarox; polyethylene glycol
mono (nonylphenyl) ether]
CAS# 9016-45-9
Molecular weight: 630 (for n=9.5) (typical range 500 - 800)
Melting Point: -20 to+10°C(E)
Water Solubility: Soluble (M)
Vapor Pressure: <10"6 mm Hg (E)
LogKow:3.93(E)(np = 7)
Henry's Law Constant: 1.81X10'22 atm-m3/mole (E) (np = 7)
Chemistry of Use: Nonionic surfactant
C34H62010 (for n=9.5)
-0(CH,CH,0)H
I-\L L Branched- CQH1Q—(\ />-
Structure: 9 19 > //
Boiling Point: >300°C (E) (decomposes)
Density: 0.8g/cm3(E)
FlashPoint: 200-260°C(E)
Koc:0.64(E)(np = 7)
Above data are either measured (M) or estimated (E)
This chemical is colorless with a mild odor. It is stable under normal conditions. Its
properties vary with degree of ethoxylation. It is soluble in oil, alcohols, and aromatic solvents.
This chemical is synthesized by reacting branched nonylphenol with ethylene oxide.
Market Profile
In 1992, total U.S. production was 394.7 million gallons. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Ethoxylated nonylphenol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Ethoxylated nonylphenol has a high primary biodegradation rate which has been
demonstrated in wastewater treatment, river water, soil, and sediment. The rate of ultimate
degradation of ethoxylated nonylphenol, however, is low. Biodegradation proceeds by the step-
wise removal of ethoxylate groups, leading to the accumulation of more hydrophobic
metabolites, namely mono- and diethoxylates, nonylphenol, and mono- and dicarboxylates. The
mobility of ethoxylated nonylphenols varies with the number of ethoxy groups. Estimates
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethoxypropanol
based on molecular structure indicates that Koc is 110 for four ethoxylate groups. Longer chain
ethoxylates (n > 4) should therefore be fairly mobile in soil. The mobility of the mono- and
diethoxylate should be low. If released to soil, ethoxylated nonylphenol is expected to leach into
the soil and biodegrade. Volatilization from soil will be negligible. If released in water
ethoxylated nonylphenol should undergo rapid primary biodegradation. Shorter chain
ethoxylates may adsorb to sediment and particulate matter in the water column. Volatilization
will not be significant. If released to the atmosphere, vapor-phase ethoxylated nonylphenol
should degrade rapidly by reaction with photochemically-produced hydroxyl radicals (estimated
half-life of approximately 3.7 hours). However, it is anticipated that ethoxylated nonylphenols
will have very low vapor pressures and therefore would be associated with aerosols rather than
in the vapor. Using a rapid primary biodegradation rate in the STP fugacity model results in
100 percent predicted removal in wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Ethoxypropanol
Chemical Properties and Information
Ethoxypropanol [propylene glycol monoethyl ether]
CAS# 52125-53-8
Molecular weight: 104.1
Melting Point: -100°C(M)
Water Solubility: Completely miscible with water (M)
Vapor Pressure: 7.2 mm Hg (at 25°C) (M)
Log Kow: 0.002 (E)
Henry's Law Constant: 2.45X10'8 atm-m3/mole (E)
Chemistry of Use: Solvent
C5H1202
Structure: CH,CH,OCH,CHOHCH
Boiling Point: 132°C(M)
Density: 0.895 g/cm3(at25°C) (M)
Flash Point: 43°C (open cup) (M)
Koc: 24 (E)
Above data are either measured (M) or estimated (E)
Glycol ethers are both ethers and alcohols. Their hydroxyl groups can be etherified,
esterified, chlorinated, or otherwise modified. Miscible with acetone, benzene, carbon
tetrachloride, ethyl ether, petroleum ether.
This chemical is synthesized by reaction of ethanol with propylene oxide.
Market Profile
In 1991, total U.S. production of "other" P-series glycol ethers was 1 million gallons. This
category includes dipropylene glycol methyl ether acetate, ethoxypropanol, ethoxypropyl acetate,
and propylene glycol methyl ether acetate, among possibly others. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethoxypropanol
Regulatory Status
Ethoxypropanol does not trigger any federal environmental regulations. However, the
generic category of glycol ethers is listed as Hazardous Air Pollutants in the Clean Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, ethoxypropanol is expected to biodegrade under aerobic conditions and
it may be rapid if acclimated organisms are present. It is expected to display high mobility;
however, rapid biodegradation will decrease its potential of leaching through soil. Volatilization
of ethoxypropanol from both moist and dry soil to the atmosphere is not expected to be
important. If released to water, ethoxypropanol is expected to biodegrade under aerobic
conditions and it may be rapid if acclimated organisms are present. Neither bioconcentration
in fish and aquatic organisms, adsorption to sediment and suspended organic matter, nor
volatilization to the atmosphere are expected to be important. If released to the atmosphere,
ethoxypropanol is degraded rapidly by reaction with photochemically produced hydroxyl
radicals (typical half-life of 6.2 hours). Physical removal by wet deposition processes may also
occur because of its substantial water solubility; however, its short atmospheric residence time
suggests that wet deposition may be of limited importance. Using a rapid biodegradation rate
in the STP fugacity model results in 97 percent predicted total removal from wastewater
treatment plants; a moderate rate corresponds to 84 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Ethoxypropyl Acetate
Ethoxypropyl Acetate
Chemical Properties and Information
Ethoxypropyl acetate [propylene glycol, monoethyl ether
acetate, 2-propanol, 1-ethoxy-, acetate]
CAS# 54839-24-6
Molecular weight: 146.1
Melting Point: -100°C(E)
Water Solubility: Miscible
Vapor Pressure: 3.5 mm Hg (at 20°C) (E)
Log Kow: -0.46 (E)
Henry's Law Constant: 9.09X10'12 atm-m3/mole (E)
Chemistry of Use: Solvent
C7H1403
Structure: CH3CH2OCH2CHOOCCH3
CH3
Boiling Point: 153.2°C(E)
Density: 1.0g/cm3(E)
FlashPoint: 40°C(E)
Koc: 13(E)
Above data are either measured (M) or estimated (E)
Ethoxypropyl acetate is a glycol derivative that is both an ether and an ester. It is soluble
in organic solvents.
Ethoxypropyl acetate is prepared by hydrolysis of propylene oxide. Etherification is by
reaction with ethanol. Esterification is accomplished by reaction with acetic acid.
Market Profile
In 1991, total U.S. production of "other" P-series glycol ethers was 1 million gallons. This
category includes dipropylene glycol methyl ether acetate, ethoxypropanol, ethoxypropyl acetate,
and propylene glycol methyl ether acetate, among possibly others. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Ethoxypropyl acetate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, ethoxypropyl acetate is expected to biodegrade under aerobic
conditions and it may be rapid if acclimated organisms are present. It is expected to display
high mobility; however, rapid biodegradation will decrease its potential of leaching through soil.
Volatilization of ethoxypropyl acetate from moist soil to the atmosphere is not expected to be
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Ethoxypropyl Acetate
important although it may slowly volatilize from dry soil. If released to water, ethoxypropyl
acetate is expected to biodegrade under aerobic conditions and it may be rapid if acclimated
organisms are present. Chemical hydrolysis will be important only in very alkaline
environmental media (pH greater than 8.5). Neither bioconcentration in fish and aquatic
organisms, adsorption to sediment and suspended organic matter, nor volatilization to the
atmosphere are expected to be important. If released to the atmosphere, ethoxypropyl acetate
is degraded rapidly by reaction with photochemically produced hydroxyl radicals (typical
half-life of 6.2 hours). Physical removal by wet deposition processes may also occur because of
its substantial water solubility; however, its short atmospheric residence time suggests that wet
deposition may be of limited importance. Using a rapid biodegradation rate in the STP fugacity
model results in 97 percent predicted total removal from wastewater treatment plants; a
moderate rate corresponds to 84 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
Furfuryl Alcohol
Chemical Properties and Information
Furfuryl alcohol [2-Furanmethanol; 2-Furylcarbinol;
2-Hydroxymethylfuran]
CAS# 98-00-0
Molecular weight: 98.1
Melting Point: Not available
Water Solubility: Miscible (unstable) (M)
Vapor Pressure: 0.45 mm Hg (at 20°C) (M)
Log Kow: 0.28 (M)
Henry's Law Constant: 7.86X10'8 atm-m3/mole (E)
Chemistry of Use: Solvent
C5H602
Structure:
CH2OH
Boiling Point: 170°C(M)
FlashPoint: 75°C(M)
Above data are either measured (M) or estimated (E)
Furfuryl alcohol has a faint burning odor and bitter taste. It is very soluble in alcohol and
ether.
Furfuryl alcohol is prepared from furfural by the Cannizzaro reaction. It is prepared
industrially by the catalytic reduction of furfural using nickel and Cu-CrO catalysts.
Market Profile
In 1992, total U.S. production was 39.2 million gallons. Imports and exports of this chemical
are unknown. Total U.S. production quantity for use in sreen reclamation is unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Furfuryl Alcohol
Regulatory Status
Furfuryl alcohol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, furfuryl alcohol will be expected to exhibit very high mobility, based upon its
estimated soil adsorption coefficient. It may be subject to biodegradation in soil based upon results
observed in a laboratory aqueous biodegradation aerobic screening test using an activated sludge
inoculum. No information was found regarding its rate of biodegradation in soil. Volatilization of
furfuryl alcohol from moist soil should not be important. However, some volatilization would occur
from dry surface soil and other dry surfaces. If furfuryl alcohol is released to water, it would be
expected biodegrade according to results of laboratory screening studies. It should not adsorb to
sediment or suspended particulate matter in the water column or to bioconcentrate in aquatic
organisms. Furfuryl alcohol absorbs radiation greater than290 nm and therefore it may directly
photolyze in surface waters. According to its estimated Henry's Law constant, volatilization from
water will not be important. In the atmosphere, furfuryl alcohol will exist mainly in the vapor phase.
It will be rapidly degraded by reaction with photochemically-produced hydroxyl radicals (typical half-
life 3.7 hours). It may also undergo atmospheric degradation by direct photolysis. Physical removal
by rain would occur because of its miscibility in water. Using a rapid biodegradation rate in the STP
fugacity model results in 97 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Isobutyl Isobutyrate
Isobutyl Isobutyrate
Chemical Properties and Information
Isobutyl isobutyrate [propanoic acid, 2-methyl-, 2-
methylpropyl ester, isobutyric acid, isobutyl ester]
CAS# 97-85-8
Molecular weight: 144.21
Melting Point: -81°C(M)
Water Solubility: <1 g/L (M)
Vapor Pressure: 3.2 mm Hg (at 20°C) (M)
LogKow: 2.68 (E)Henry's Law Constant: 8.22 x 10'4atm-
m3/mole (M)
Chemistry of Use: Solvent
CRHlfiO.
16W2
Structure: (CH3)2CHCOOCH2CH(CH3)2
Boiling Point: 147°C(M)
Density: 0.855 g/cm3(at20°C) (M)
Flash Point: 38°C (closed cup) (M)
44°C (open cup) (M)
KOC:98(E)
Above data are either measured (M) or estimated (E)
This is a slow evaporating solvent, and is blush resistant. It is miscible with alcohol and
ether.
This chemical is prepared from the reaction of isobutyric acid and isobutyl alcohol.
Market Profile
Total U.S. production is unavailable. Imports and exports of this chemical are unknown.
Total U.S. production quantity for use in screen reclamation was estimated to be 2.63 million
gallons.
Regulatory Status
Isobutyl isobutyrate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, isobutyl isobutyrate is expected to biodegrade under aerobic conditions
and it may be rapid in acclimated soils. It is expected to display high mobility in the absence of
significant biodegradation. Volatilization of isobutyl isobutyrate from both moist and dry soil to
the atmosphere may be important. If released to water, it is expected to biodegrade under
aerobic conditions and it may be rapid if acclimated organisms are present. Neither
bioconcentration in fish and aquatic organisms nor adsorption to sediment and suspended
organic matter are expected to be important. Volatilization of isobutyl isobutyrate from water to
DRAFT-September 1994 II-53
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Isobutyl Oleate
the atmosphere may be relatively rapid. Chemical hydrolysis will be important only in very
alkaline environmental media (pH greater than 8.5). If released to the atmosphere, isobutyl
isobutyrate will degrade by reaction with photochemically produced hydroxyl radicals
(estimated half-life of 2.3 days). Using a rapid biodegradation rate in the STP fugacity model
results in 98 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Isobutyl Oleate
Chemical Properties and Information
Isobutyl oleate [Isobutyl ester oleic acid]
CAS# 10024-47-2
Molecular weight: 395
Melting Point: -26°C(M)
Water Solubility: 0.001 g/l (E)
Vapor Pressure: 0.01 mm Hg (E) (25°C)
Log Kow = 9.42 (E)
Henry's Law Constant: 2.5 x 10"2 atm-m3/mole (E)
Chemistry of Use: Numerous
C22H4202
Structure: CH3(CH2)7CH=CH(CH
Boiling Point: 226°C(M)
Density: 0.86 g/ml (M)
FlashPoint: 180°C(M)
Koc: >10,000(E)
Physical state: Oily liquid
2y6CH2COO-/-C4H11
Above data are either measured (M) or estimated (E)
Isobutyl oleate may be harmful if absorbed through the skin. Vapor and mist are
irritating to the respiratory tract and eyes. Isobutyl oleate is soluble in ethanol.
Isobutyl oleate is produced from the esterification of oleic acid. Oleic acid is derived by
mechanic means from the seeds of specific fruits and plants. Once refined, the oleate is heated
in the presence of a strong base and an alcohol. Esterification occurs at the glycerol hydroxides
of the oleic acid.
Market Profile
In 1992, total U.S. production of salt and esters of oleic, linoleic, or linoleric acids was 36
million pounds. Greater specificity is not available due to the low number of companies
producing these products. Data for imported and exported amounts were not available. Total
U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
Isobutyl oleate does not trigger any federal environmental regulations.
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II-54
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Isopropanol
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, isobutyl oleate is expected to be essentially immobile. Biodegradation
in acclimated aerobic soils may be rapid. Chemical hydrolysis of the ester group is not
expected to be significant except for highly basic soils (pH greater thanS) . Volatilization of
isobutyl oleate from moist soil to the atmosphere may be a significant process although it is
likely to be relatively slow from dry soil. If released to water, aerobic biodegradation may be
rapid, especially in acclimated waters. Bioconcentration in fish and aquatic organisms and
adsorption to sediment and suspended organic matter may also occur. Volatilization from
water to the atmosphere may be rapid although its expected strong adsorption to sediment and
suspended organic matter may attenuate the rate of this process. Chemical hydrolysis may
occur in highly basic waters. If released to the atmosphere, isobutyl oleate may undergo rapid
oxidation by the both the gas-phase reaction with hydroxyl radicals and ozone with estimated
half-lives of approximately 1.5 and 1.3 hours for the trans isomer, respectively, with similar
rates for the cis isomer. Using either a rapid or moderate biodegradation rate for isobutyl
oleate in the STP fugacity model results in greater than99 percent predicted total removal from
wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Isopropanol
Chemical Properties and Information
Isopropanol [Isopropyl alcohol; 2-propanol, dimethyl carbinol,
sec-propyl alcohol ]
CAS# 67-63-0
Molecular weight: 60.1
Melting Point: -88.5°C(M)
Water Solubility: Miscible
Vapor Pressure: 33 mm Hg (M) (20°C)
Log Kow = 0.05 (M)
Henry's Law Constant: 8.1 x 10"6 atm-m3/mole (M)
Chemistry of Use: Solvent
C3H80
Structure: (CH3)2CHOH
Boiling Point: 164°C(M)
Density: 0.7849 g/ml (M)
FlashPoint: Tag Open Cup: 17.2°C(M)
Closed Cup: 11.7°C(M)
KOC:25(E)
Physical State: Colorless, volatile, flammable liquid
Above data are either measured (M) or estimated (E)
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Isopropanol
Isopropanol is a colorless, volatile, flammable liquid. Its odor is slight, resembling a
mixture of ethyl alcohol and acetone. Isopropanol boils only 4°C higher than ethyl alcohol and
possesses similar solubility properties, and thus the two products compete for many solvent
applications. Because of its tendency to associate in solution, isopropanol forms azeotropes
with compounds from a variety of chemical groups. As an alcohol, it can be dehydrogenated,
oxidized, esterified, etherified, animated, halogenated, or otherwise modified.
Indirect hydration is the common process for commercial manufacture of isopropanol in
the United States. This two-step method involves: (1) formation of mono- and diisopropyl
sulfates by reacting propylene with sulfuric acid, and (2) hydrolysis of the sulfates to isopropyl
alcohol. The catalytic hydration process, increasingly used in Europe and Japan, uses
superheated steam and high pressures to directly convert propylene to isopropanol:
CH3CH = CH2 + H2O « (CH3)2CHOH
catalyst
Market Profile
In 1991, total U.S. production was 1.4 billion gallons. In 1992, imports were 91.5 million
gallons and exports were 416.9 million gallons. Total U.S. production quantity for use in
screen reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, biodegradation is expected to be an important removal process for
isopropanol. Adsorption to soil will not be important. In water, biodegradation is expected to
be fast, even under anaerobic conditions. Bioconcentration in fish, adsorption to sediment,
photolysis, and hydrolysis will not be important for isopropanol. Volatilization from water is
slow. In the atmosphere, isopropanol will photodegrade primarily by reaction with
photochemically produced hydroxyl radicals with a half-life of 1-2 days. Using a rapid and a
moderate biodegradation rate for isopropanol in the STP fugacity model results in about 97 and
83 percent, respectively, predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-56
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals d-Limonene
af-Limonene
Chemical Properties and Information
d-Limonene [1-methyl-4-(1-methylethenyl) cyclohexene;
carvene; citrene; 1,8-p-menthadiene; 4-isopropenyl-1-
methylcyclohexene cinene; cajeputene; kautschin]
CAS# 5989-27-5
Molecular weight: 136
Melting Point: -74°C(M)
Water Solubility: 0.014 g/L(M)
Vapor Pressure: 5 mm Hg (E) (25°C)
Log Kow = 4.83 (E)
Henry's Law Constant: 0.38 atm-m3/mole (E)
Chemistry of Use: Wetting and Dispersing Agent
C,nH
10' '16
Structure:
Boiling Point: 176°C(M)
Density: 0.84 g/ml (M)
FlashPoint: 48°C(M)
Koc: 1,000-4,800 (E)
Above data are either measured (M) or estimated (E)
d-Limonene is a terpenoid in a group of closely related compounds called p-
menthadienes. The p-menthadienes can all be hydrogenated to produce p-menthane, the
hydroperoxide of which is useful in the rubber industry. Limonene isomerizes rather slowly to
terpinolene, while the irreversible isomerization of terpinolene to a-terpinene is very rapid. The
physical state of limonene is a liquid with a fresh, citrus odor and taste.
d-Limonene is naturally occurring and is obtained from lemon and orange peel, dill,
cumin, neroli, bergamot, and caraway. The lemon oil that is obtained in 0.35 percent yield
from lemon peel is approximately 80 percent limonene (d and dl). Nonetheless, the
characteristic odor and flavor of lemon comes not from limonene, but from citral and other
compounds.
Market Profile
In 1988, total U.S. production was 28 million pounds. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation was
estimated to be 150,000 gallons.
Regulatory Status
d-Limonene does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT—September 1994 II-57
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Methanol
Environmental Fate
If released to soil, d-limonene is expected to exhibit low to slight mobility. It is expected
to rapidly volatilize from both dry and moist soil surfaces and biodegrade at a moderate rate in
soil. However, strong adsorption to soil may attenuate the rate of this process. If released to
water, d-limonene may bioconcentrate in fish and aquatic organisms and it may adsorb to
sediment and suspended organic matter. It is expected to rapidly volatilize from water to the
atmosphere. The estimated half-life for volatilization of d-limonene from a model river is 3.4
hrs, although adsorption to sediment and suspended organic matter may attenuate the rate of
this process. If released to the atmosphere, d-limonene is expected to rapidly undergo
gas-phase oxidation reactions with photochemically produced hydroxyl radicals and ozone, and
to react at night with nitrate radicals. Calculated half-lives for these processes are 2.3-2.6 hrs,
25-26 min and 3.1 min, respectively. Using a moderate biodegradation rate for d-limonene in
the STP fugacity model results in greater than99 percent predicted total removal from
wastewater treatment plants. Assuming no biodegradation in the STP fugacity model also
results in greater than99 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Methanol
Chemical Properties and Information
Methanol [methyl alcohol, carbinol, wood spirit, wood alcohol]
CAS# 67-56-1
Molecular weight: 32.04
Melting Point: -97.8°C(M)
Water Solubility: Miscible (M)
Vapor Pressure: 93.7 mm Hg (at 20°C) (M)
Log Kow: -0.770 (M)
Henry's Law Constant: 4.55X10'6 atm-m3/mole (M)
Chemistry of Use: Solvent
CH40
Structure: CH3OH
Boiling Point: 64.7°C(M)
Density: 0.792 g/cm3 (M)
Flash Point: 12°C (closed cup) (M)
K„„: not available
Above data are either measured (M) or estimated (E)
Pure methanol has a slight alcoholic odor, but more crude forms of methanol may have
repulsive odors. Methanol is generally a better solvent than ethanol. Methanol is flammable
and mobile. Methanol has an ignition temperature of 470°C. It is miscible with ethanol, ether,
benzene, ketones, and most other organic compounds.
Methanol is usually manufactured from hydrogen and carbon monoxide at high pressure
and temperature.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Methanol
Market Profile
In 1992, total U.S. production of methanol was 1.4 billion gallons. About 521 million
gallons were imported and 55 million gallons were exported. Total U.S. production quantity for
use in screen reclamation was estimated to be 610,000 gallons.
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, methanol is expected to rapidly biodegrade under aerobic conditions.
Methanol is also expected to slowly biodegrade under anaerobic conditions in soil. It is
expected to display very high mobility although its rapid rate of biodegradation limits its
potential to leach through soil. Volatilization of methanol from moist soil to the atmosphere is
not expected to occur although it may be important from dry soils. If released to water,
methanol is expected to rapidly biodegrade under aerobic conditions. Slow biodegradation in
anoxic sediments is also expected to occur. Neither volatilization to the atmosphere,
bioconcentration in fish and aquatic organisms, adsorption to sediment and suspended organic
matter, chemical hydrolysis, oxidation, nor photolysis are expected to occur. If released to the
atmosphere, methanol is expected to undergo a gas-phase reaction with photochemically
produced hydroxyl radicals; the estimated half life for this process is 11 days. Its substantial
water solubility indicates that wet deposition may also be an important atmospheric removal
process. Using a rapid biodegradation rate in the STP fugacity model results in 97 percent
predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-59
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Methoxypropanol Acetate
Methoxypropanol Acetate
Chemical Properties and Information
Methoxypropanol acetate [propylene glycol methyl ether
acetate]
CAS# 84540-57-8 (also 108-65-6)
Molecular weight: 132
Melting Point: -100°C(E)
Water Solubility: 200 g/L (M)
Vapor Pressure: 3.7 mm Hg (M)
Log Kow: 0.43 (M)
Henry's Law Constant: 4.2X10'6 atm-m3/mole (M)
Chemistry of Use: Solvent
CfiH,A
CH,0
Structure: CH,OCH,CHOCCH
Boiling Point: 140°C(M)
Density: 0.97g/cm3(M)
FlashPoint: 45°C(setaflash) (M)
Koc: 0.36 (M)
Above data are either measured (M) or estimated (E)
Methoxypropanol acetate is a glycol derivative that is both an ether and an ester. It is
combustible and has an ester like odor. It is soluble in organic solvents.
Propylene glycol methyl ether acetate is prepared by reacting propylene oxide with methyl
alcohol and esterifying with acetic acid or acetic anhydride.
Market Profile
In 1991, total U.S. production was 67.1 million gallons. About 6.9 million gallons were
exported. Total U.S. production quantity for use in screen reclamation was estimated to be
420,000 gallons.
Regulatory Status
Methoxypropanol acetate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, methoxypropanol acetate is expected to readily biodegrade.
Methoxypropanol acetate has a very low soil adsorption coefficient and is expected to be highly
mobile in soil. Volatilization of methoxypropanol acetate from dry surface soil and other
surfaces may be important, but volatilization from moist surface soil will be minimal. If
released to water, methoxypropanol acetate is expected to biodegrade. The estimated half-life
resulting from base-catalyzed chemical hydrolysis at pH 8 is 88 days and therefore chemical
DRAFT-September 1994 II-60
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Methyl Ethyl Ketone
hydrolysis would only be significant in highly alkaline water. The volatilization half-life of
methoxypropanol acetate from a model river is 10 days and therefore volatilization may occur
under some circumstances. Neither bioconcentration in aquatic organisms nor adsorption to
sediment and suspended organic matter should be significant. If released to the atmosphere,
methoxypropanol acetate is degraded by reaction with photochemically-produced hydroxyl
radicals (estimated half-life 34 hours). Using a rapid biodegradation rate in the STP fugacity
model results in 97 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Methyl Ethyl Ketone
Chemical Properties and Information
Methyl ethyl ketone [2-Butanone; Ethyl methyl ketone; Methyl
acetone; MEK]
CAS# 78-93-3
Molecular weight: 72.11
Melting Point: -87°C(M)
Water Solubility: 24 g/L (M)
Flash Point: -7°C
Log Kow = 0.29 (M)
Henry's Law Constant: 5.69 x 10"5 atm-m3/mole (M)
Chemistry of Use: Solvent
C4H80
Structure: H3CCH2COCH3
Boiling Point: 79.6°C(M)
Density: 0.8049420 g/ml (M)
Vapor Pressure: 77.5 mm Hg (M) (20°C) (M)
Koc: 5 (E)
Physical State: Clear colorless liquid
Above data are either measured (M) or estimated (E)
Methyl ethyl ketone is stable under normal laboratory conditions and is miscible in
ethanol, benzene, and diethyl ether. It is highly flammable. Forms a constant-boiling mixture
with water, b.p. 73.40° containing 11.3 percent water. Strong oxidizing agents can cause
spontaneous ignition and violent reaction; ignition on reaction with potassium t-butoxide; can
attack many plastics, resins, and rubber; incompatible with chlorosulfonic acid, chloroform,
hydrogen peroxide, and nitric acid.
Methyl ethyl ketone is mainly produced from sec-butanol and butylene.
Market Profile
In 1992, total U.S. production was 510 million gallons. Imports were 56.6 million gallons
and exports were 132.2 million gallons. Total U.S. production quantity for use in screen
reclamation was estimated to be 3.72 million gallons.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Methyl Lactate
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil surfaces, methyl ethyl ketone will either volatilize into the atmosphere,
directly photolyze, or leach into the ground where it will biodegrade. If methyl ethyl ketone
leaches to groundwater, biodegradability studies in anaerobic systems suggest slow
biodegradation after a long acclimation period. In surface waters, methyl ethyl ketone will
volatilize, photolyze, or biodegrade. Chemical hydrolysis, adsorption to sediment,
bioconcentration in aquatic organisms, and indirect photooxidation will not be important fate
processes for methyl ethyl ketone in water. If released to the atmosphere, gas-phase methyl
ethyl ketone will react with photochemically-produced hydroxyl radicals (estimated half-lives of
less than 10 days). Methyl ethyl ketone may be removed from air via wet deposition. Using a
rapid and a moderate biodegradation rate for methyl ethyl ketone in the STP fugacity model
results in 97 and 84 percent, respectively, predicted total removal from wastewater treatment
plants.
Health Hazard
See Table II-6 and accompanying summary
Methyl Lactate
Chemical Properties and Information
Methyl lactate [2-Hydroxypropanoicacid methyl ester; lactic
acid; methyl ester]
CAS# 547-64-8
Molecular weight: 104
Melting Point: -66°C(M)
Water Solubility: Miscible
Vapor Pressure: 7.7 mm Hg (E) (25°C)
Log Kow =-0.67 (E)
Henry's Law Constant: 8.5 x 10"9 atm-m3/mole (E)
Chemistry of Use: Solvent
Structure: CH3CH(OH)COOCH3
Boiling Point: 145°C(M)
Density: 1.0939 g/ml (M)
FlashPoint: 49°C(M)
Koc: 8 (E)
Physical State: Colorless liquid
Above data are either measured (M) or estimated (E)
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Methyl Lactate
Methyl lactate is acetylated with acetic anhydride to produce the acetyl derivative. Methyl
lactate is soluble in alcohol and ether. It is a dye solvent. A dye solvent has a high boiling
point, it is practically nonvolatile and maintains the dye in the solution long enough to stain the
wood. Methyl lactate decomposes in water.
Methyl lactate is a byproduct in the formation of lactic acid. Methyl lactate results from
the esterification of lactic acid with methyl alcohol. The methyl lactate is distilled and
hydrolyzed with a strong acid catalyst to produce semi-refined lactic acid. It is also produced
by hydrolyzing lactonitrile with sulfuric acid and purifying with methanol to form methyl
lactate.
Market Profile
Market information on this chemical is unavailable.
Regulatory Status
Methyl lactate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, methyl lactate is expected to display very high mobility. Biodegradation
in acclimated aerobic soils may be rapid. Volatilization of methyl lactate from the upper layers
of dry soil to the atmosphere may be significant although volatilization from moist soil will be
very slow. In basic soil with a pH greater thanS, chemical hydrolysis of methyl lactate may
occur. If released to water, aerobic biodegradation may be rapid, especially in acclimated
waters. Methyl lactate is not expected to bioconcentrate in fish and aquatic organisms nor is it
expected to adsorb to sediment and suspended organic matter. Volatilization of methyl lactate
from water to the atmosphere is expected to be very slow. In basic waters methyl lactate may
undergo chemical hydrolysis with an estimated half-life of approximately 7 days at pH 8. If
released to the atmosphere, methyl lactate may undergo oxidation by the gas-phase reaction
with hydroxyl radicals with an estimated half-life of approximately 6 days. It may also undergo
atmospheric removal by wet deposition processes. Using a rapid biodegradation rate for
methyl lactate in the STP fugacity model results in 97 percent predicted total removal from
wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Mineral Spirits (Naphtha, Heavy Straight-run)
Mineral Spirits (Naphtha, Heavy Straight-run)
Chemical Properties and Information
Mineral spirits [Many trade names by companies including
Amsco, Apco, Epesol, Exxon, Phillips, Shell, etc., most of
which include "mineral spirits" in the name]
CAS#64741-41-9
Molecular weight: 86 for n-hexane; 112 for
ethycyclohexane, for example
Melting Point: -60°C(E)
Water Solubility: 0.001 g/L(E)
Vapor Pressure: 1 mm Hg (E) (25°C)
LogKow = 3.4->6(E)
Henry's Law Constant: 1.5 x 10"3 -13 atm-m3/mole (E)
Chemistry of Use: Solvent
Molecular formula: CnH2n+2 (paraffin) and CnH2n
(cycloparaffin)
Structure: Typical structures include normal paraffins,
CH3(CH2)nCH3, branched paraffins, and cycloparaffins
Boiling Point: 160-200°C(M)
Density: 0.78 g/ml (M)
FlashPoint: 43°C(M)
Koc: 500 - >5000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
The term mineral spirits refers to a range of petroleum solvents consisting largely of
saturated hydrocarbons, including both straight-chain and branched paraffins, and
cycloparaffins, which may have alkyl side chains. Up to one-fourth of some mineral spirits
consists of aromatic hydrocarbons. A typical boiling range for mineral spirits is 160-200°C.
Mineral spirits are miscible with petroleum solvents.
Mineral spirits may be prepared by fractionation of straight-run, cracked, and reforming
petroleum distillates or fractionation of crude petroleum. The naphtha streams are generally
divided into heavy and light, and may then be further fractionated. The naphthas are usually
treated (chemically, with lye or other compounds, or hydrotreated) to remove sulfur
compounds and aromatic hydrocarbons, leaving the solvent consisting mostly of aliphatic
hydrocarbons.
Market Profile
No information is available on the production volumes of the numerous specific naphtha
fractions, excluding special naphthas. The production volume for all naphthas was 2.1 billion
pounds in 1991. The vast majority of naphthas are used in the production of gasoline and
other petroleum products and not directly as solvents. Data for imported and exported
amounts is not available. Total U.S. production for both mineral spirits (naphtha, heavy-
straight-run and distillates, hydrotreated light) use in screen reclamation was estimated to be
6.9 million gallons.
Regulatory Status
Mineral spirits does not trigger any federal environmental regulations.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Mineral Spirits (Distillates, Hydrotreated Light)
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Naphtha, heavy straight-run is a mixture of components chiefly C6-C12 cyclic and alicyclic
hydrocarbons. If released to soil, naphtha, heavy straight-run is expected to biodegrade at a
moderate rate under aerobic conditions, although some of the cycloalkanes may be resistant to
biodegradation. Some components of naphtha, heavy straight-run are expected to adsorb very
strongly to soil. Naphtha, heavy straight-run may rapidly volatilize from both moist and dry
soils to the atmosphere, although strong adsorption may significantly attenuate the rate of this
process. If released to water, naphtha, heavy straight-run is expected to biodegrade at a
moderate rate under aerobic conditions with the exception of some cycloalkanes. Some
components are expected to significantly bioconcentrate in fish and aquatic organisms and
strongly adsorb to sediment and suspended organic matter. The estimated half-life for
volatilization of naphtha, heavy straight-run components from a model river is approximately 1
hour while that from a model lake is greater than 100 days; the former model does not account
for the attenuating affect of strong adsorption. If released to the atmosphere, the dominant
atmospheric removal process for naphtha, heavy straight-run is expected to be oxidation by
hydroxyl radicals with an estimated half-life of 1-2 days. Using representative components that
either biodegrade rapidly and display moderate sludge adsorption and those that are
moderately biodegradable and display strong adsorption to sludge, the STP fugacity model
indicates that greater than 94 percent total removal from wastewater treatment plants may be
achieved.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Mineral Spirits (Distillates, Hydrotreated Light)
Mineral Spirits (Distillates, Hydrotreated Light)
Chemical Properties and Information
Mineral spirits [Many trade names by companies including
Amsco, Apco, Epesol, Exxon, Phillips, Shell, etc., most of
which include "mineral spirits" in the name]
CAS# 64741-47-8
Molecular weight: 86 for n-hexane; 112 for
ethycyclohexane, for example
Melting Point: -60°C(E)
Water Solubility: 0.001 g/L(E)
Vapor Pressure: 0.5-1 mm Hg (E) (25°C)
Log Kow = 4.76-8.25 (E)
Henry's Law Constant: 0.2 - 3.4 atm-m3/mole (E)
Chemistry of Use: Solvent
Molecular formula: CnH2n+2 (paraffin) and CnH2n
(cycloparaffin)
Structure: Typical structures include normal paraffins,
CH3(CH2)nCH3, branched paraffins, and cycloparaffins
Boiling Point: 140-180°C(M)
Density: 0.78 g/ml (M)
FlashPoint: <43°C(M)
Koc: 220 - >5000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
The term mineral spirits refers to a range of petroleum solvents consisting largely of
saturated hydrocarbons, including both straight-chain and branched paraffins, and
cycloparaffins, which may have alkyl side chains. Up to one-fourth of some mineral spirits
consists of aromatic hydrocarbons. A typical boiling range for mineral spirits is 160-200°C.
Mineral spirits are miscible with petroleum solvents.
Mineral spirits may be prepared by fractionation of straight-run, cracked, and reforming
petroleum distillates or fractionation of crude petroleum. The naphtha streams are generally
divided into heavy and light, and may then be further fractionated. The naphthas are usually
treated (chemically, with lye or other compounds, or hydrotreated) to remove sulfur
compounds and aromatic hydrocarbons, leaving the solvent consisting mostly of aliphatic
hydrocarbons.
Market Profile
No information is available on the production volumes of the numerous specific naphtha
fractions, excluding special naphthas. The production volume for all naphthas was 2.1 billion
pounds in 1991. The vast majority of naphthas are used in the production of gasoline and
other petroleum products and not directly as solvents. Data for imported and exported
amounts were not available. Total U.S. production quantity for both mineral spirits (naphtha,
heavy-straight-run and distillates, hydrotreated light) use in screen reclamation was estimated
to be 6.9 million gallons.
Regulatory Status
Mineral spirits does not trigger any federal environmental regulations.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Mineral Spirits (Distillates, Hydrotreated Light)
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Distillates, hydrotreated light is a mixture of components, chiefly C9-C16 cyclic and
alicyclic alkanes. If released to soil, distillates, hydrotreated light is expected to biodegrade at a
moderate rate under aerobic conditions although some cyclic paraffins may be resistant to
biodegradation. Some components of distillates, hydrotreated light may adsorb very strongly to
soil and some may rapidly volatilize from both moist and dry soils to the atmosphere although
strong adsorption may significantly attenuate the rate of this process. If released to water,
distillates, hydrotreated light is expected to biodegrade at a moderate rate under aerobic
conditions although some components may be resistant. Some components may significantly
bioconcentrate in fish and aquatic organisms and strongly adsorb to sediment and suspended
organic matter. The estimated half-life for volatilization of distillates, hydrotreated light
components from a model river is approximately 1.5 hours while that from a model lake is
greater than 100 days; the former model does not account for the attenuating affect of strong
adsorption. If released to the atmosphere, the dominant atmospheric removal process for
distillates, hydrotreated light is expected to be oxidation by hydroxyl radicals with an estimated
half-life of less than 1 day. Using representative components that either biodegrade rapidly and
display moderate sludge adsorption and those that are moderately biodegradable and display
strong adsorption to sludge, the STP fugacity model indicates that greater than 99 percent total
removal from wastewater treatment plants may be achieved.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-67
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
N-Methylpyrrolidone
N-Methylpyrrolidone
Chemical Properties and Information
N-methylpyrrolidone [1-methyl-2-pyrrolidone; 1-
methylazacyclopentan-2-one; N-methyl-Y-butyrolactam]
CAS# 872-50-4
Molecular weight: 99.13
Melting Point: -17 to-23°C(M)
Water Solubility: Miscible (M)
Vapor Pressure: 0.334 mm Hg (E) (25°C)
Log Kow =-0.73 (E)
Henry's Law Constant: 1.56 x 10"8 atm-m3/mole (E)
Chemistry of Use: Solvent
C5H9NO
Structure:
CH-,
Boiling Point: 202°C(M)
Density: 1.03g/ml(M)
FlashPoint: 96°C(M)
Koc: 10(E)
Physical State: Colorless liquid with mild amine odor
Above data are either measured (M) or estimated (E)
N-Methylpyrrolidone is a dipolar aprotic solvent. It is steam volatile and forms hydrates.
It dissolves many organic and inorganic compounds. N-methylpyrrolidone is soluble in ether
and acetone, miscible in castor oil, miscible with lower alcohols and ketones, ethyl acetate,
chloroform and benzene, and moderately soluble in aliphatic hydrocarbons.
N-Methylpyrrolidone is an N-substituted heterocycle. In addition to its chemical
synthesis, it may be a naturally occurring compound as it has been identified as a volatile
component of roasted nuts.
Market Profile
Total U.S. production in 1991 was 55 million gallons. In 1992, exports were 14.8 million
gallons. Data for imported amounts was not available. Total U.S. production quantity for use
in screen reclamation was estimated to be 38,000 gallons.
Regulatory Status
N-Methylpyrrolidone does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals 2-Octadecanamine, N,N-dimethyl-, N-oxide
Environmental Fate
If released to soil, N-methylpyrrolidone has the potential to biodegrade under aerobic
conditions. It is expected to display very high mobility in soil. N-Methylpyrrolidone may slowly
volatilize from dry soil to the atmosphere, but it is not expected to volatilize from moist soil. If
released to water, screening studies indicate that N-methylpyrrolidone will biodegrade under
aerobic conditions after a short lag period. N-Methylpyrrolidone is not expected to
bioconcentrate in fish and aquatic organisms nor is it expected to adsorb to sediment or
suspended organic matter. N-Methylpyrrolidone is not expected to volatilize from water to the
atmosphere. The estimated half-life for volatilization of N-methylpyrrolidone from a model river
is greater than2,000 days. If released to the atmosphere, N-methylpyrrolidone is expected to
undergo a gas-phase reaction with photochemically produced hydroxyl radicals with an
estimated half-life of 5.2 hrs. It may undergo atmospheric removal by wet deposition
processes; however, its short atmospheric residence time suggests that wet deposition is of
limited importance. Using a fast biodegradation rate for N-methylpyrrolidone in the STP
fugacity model results in 97 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
2-Octadecanamine, N,N-dimethyl-, N-oxide
Chemical Properties and Information
2-Octadecanamine, N,N-dimethyl-, N-oxide [2-
Octadecyldimethylamine oxide]
CAS# 71662-60-7
Molecular weight: 313.22
Melting Point: >200°C (decomposes) (E)
Water Solubility: Soluble (<10 g/L) / Dispersable (E)
Vapor Pressure. <10'6 mm Hg (E) Boi|jng pojnt m gpp|icgb|e
u°9V, lj , , QCov,n4 * 3i i ,o Density: Not available
Henry s Law Constant 3.62X10 atm-m /mole (E) Rgsh pojnt.
Chemistry of Use: Surfactant K . „„„ „„,, „-,
Structure:
o
— N— CH,
CH3(CH2)15CHCH3
Above data are either measured (M) or estimated (E)
This chemical is a surfactant. It is soluble in polar solvents.
This chemical is synthesized via oxidation of alkyl dimethyl amine.
Market Profile
No market information was available for this chemical.
DRAFT-September 1994 II-69
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Periodic Acid
Regulatory Status
2-Octadecanamine, N,N-dimethyl-, N-oxide does not trigger any federal environmental
regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Long chain dimethyl amine oxides degrade completely and rapidly in screening studies
and therefore, if released to soil, 2-octadecanamine, N,N-dimethyl-, N-oxide would be expected
to rapidly biodegrade. It would adsorb strongly to soil because of its long hydrophobic alkyl
chain. If released in water, 2-octadecanamine, N,N-dimethyl-, N-oxide would be expected to
rapidly biodegrade based on results of screening tests on analogous long chain dimethyl amine
oxides. Initially it would be expected to strongly adsorb to sediment and particulate matter in
the water column. Volatilization of 2-octadecanamine, N,N-dimethyl-, N-oxide to the
atmosphere should be important (estimated half-life from a model river 4.7 hours). If released
to the atmosphere, 2-octadecanamine, N,N-dimethyl-, N-oxide will be associated with aerosols
and will be removed by gravitational settling. Using a rapid biodegradation rate in the STP
fugacity model results in 100 percent predicted total removal from wastewater treatment
plants.
Health Hazard
See Table II-6 and accompanying summary
Periodic Acid
Chemical Properties and Information
Periodic Acid [Metaperiodic acid]
CAS# 13444-71-8
Molecular weight: 191.9
Melting Point: 130° C (M) decomposes
Water Solubility: 3,700 g/l (M)
Vapor Pressure: Negligible (E)
Chemistry of Use: Oxidizing agent
4
HIO,
Structure: HI04
Boiling Point: Not applicable
Density: 3.0g/ml(E)
Flash Point: Not applicable
Physical State: White crystals
Above data are either measured (M) or estimated (E)
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Periodic Acid
Periodic acid is a powerful oxidant especially in acid solution. It undergoes a potentially
explosive reaction with DMSO. It is soluble in alcohol and slightly soluble in ether.
Periodic acid is prepared by electrolytic oxidation of iodic acid in a diaphragm cell.
Alternatively, an alkaline solution of sodium iodate is oxidized with chlorine and the resulting
sodium periodate is converted to the acid via the barium salt.
Market Profile
The total U.S. production is unknown. Imports and exports for this chemical are
unknown. Total U.S. quantity for use in screen reclamation is estimated to be 1.02 million
pounds.
Regulatory Status
Periodic acid does not trigger any any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, the powerful oxidant periodic acid is expected to readily oxidize organic
matter and will be short-lived. If released to water, oxidation of organic matter is expected to be
sufficiently rapid to dominate all other potential fate pathways. If released to the atmosphere,
periodic acid is expected to undergo removal by both wet and dry deposition processes.
Depending on the composition of other components that may be present in the water droplets,
periodic acid may be transformed by oxidizing either organic, inorganic, or metallic species
present before deposition occurs. In wastewater treatment plants, periodic acid is expected to
undergo complete removal through the oxidation of numerous organic, inorganic, or metallic
species present in the wastewater.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Phosphoric Acid, Mixed Ester.
Phosphoric Acid, Mixed Ester with Isopropanol and Ethoxylated Tridecanol
Chemical Properties and Information
Phosphoric acid, mixed ester with isopropanol and
ethoxylated tridecanol [poly (oxy-1,2-ethanediyl) otridecyl-
03-hydroxy-, 1-methylethyl phosphate]
CAS# 68186-42-5
Molecular weight: >540
Melting Point: Not available
Water Solubility: Soluble/Dispersable
Vapor Pressure: <10"6 mm Hg (E)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Varies
Structure:
0 CHj
C, 3H27(OCH2CH2)nO — P — OCHCHj
OH
n = 5 to 20
Boiling Point: High Boiling (E)
Density: Not available
Flash Point: Not available
K • Not available
Above data are either measured (M) or estimated (E)
This chemical is a phosphate surfactant. It is soluble in polar solvents and alcohols
This chemical is synthesized via phosphorolation of ethoxylated alcohol.
Market Profile
Total U.S. production is unknown. The majority of this chemical was imported/exported.
Total U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
Phosphoric acid, mixed ester with isopropanol and ethoxylated tridecanol, does not
trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, phosphoric acid, mixed ester w/isopropanol and ethoxylated tridecanol
would be expected to biodegrade. Studies on a series of phosphate esters and ethoxylate
phosphates confirm that they are suseptible to primary biodegradation. Phosphoric acid,
mixed ester w/isopropanol and ethoxylated tridecanol is expected to be immobile in soil
because of the long hydrophobic alkyl group and because of complex formation with metal
cations, especially calcium and iron. Volatilization to the atmosphere is not expected to occur.
If released to water, phosphoric acid, mixed ester w/isopropanol and ethoxylated tridecanol
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Potassium Hydroxide
would be expected to biodegrade. Initially, it would be expected to adsorb to sediment and
particulate matter in the water column. It may bioconcentrate in aquatic organisms because of
its low water solubility, but this may be attenuated due to rapid biodegradation. Volatilization
from water would not be expected. If released to the atmosphere, phosphoric acid, mixed ester
w/isopropanol and ethoxylated will be associated with aerosols and will be removed by
gravitational settling. Using a rapid biodegradation rate in the STP fugacity model results in
100 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Potassium Hydroxide
Chemical Properties and Information
Potassium hydroxide [caustic potash]
CAS# 1310-58-3
Molecular weight: 56
Melting Point: 380°C(M)
Water Solubility: 1500g/L(E)
Vapor Pressure: Not applicable
Chemistry of Use: Caustic
KOH
Structure: KOH
Boiling Point: 1320-1324°C(M)
Density: 2.0 g/ml (E)
Flash Point: Not applicable
Physical State: Solid, white or slightly yellow lumps, rods,
pellets
Above data are either measured (M) or estimated (E)
Potassium hydroxide is strongly basic and highly caustic to tissue; a 0.1 M aqueous
solution has a pH of 13.5. It is extremely corrosive and toxic via ingestion. Potassium
hydroxide is soluble in 3 parts alcohol or 2.5 parts glycerol.
Potassium hyroxide is prepared industrially by electrolysis of potassium chloride. In
diaphragm cells, the product liquor contains potassium hydroxide (10-15 weight percent) and
potassium chloride. Most of the potassium chloride crystallizes during concentration by
evaporation and subsequent cooling, which results in purification of the potassium hydroxide
solution. The anode is constructed of titanium; the cathode is a flowing layer of metallic
mercury. Feed to the cells consists of brine, which is saturated with potassium chloride at a
moderate temperature. Water is added to the potassium-mercury amalgam that results, to
form potassium hydroxide and hydrogen.
Market Profile
In 1990, total U.S. production was 3.6 billion pounds. Imports were 8,740.6 million
pounds and exports were 1,140 million pounds. Total U.S. production quantity for use in
screen reclamation was estimated to be 1.06 million pounds.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Potassium Hydroxide
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The environmental fate of potassium hydroxide is that of its aqueous solution; the
dominant fate of solid potassium hydroxide release will be its dissolution in water. In aqueous
solution, potassium hydroxide will dissociate into potassium cations (K+) and the hydroxide
anion (OH). Potassium ions are naturally present in surface water, groundwater, and
rainwater as are hydroxide ions due to the ionization of water. Given that the components of
potassium hydroxide are naturally present and participate in the reactions of natural systems,
their fate will be determined by both the amount released and the composition of the receiving
medium. Depending on the size of the release and the buffering capacity of the receiving
medium, which is in a large part determined by the amount of naturally occurring acids such
as hydrogen sulfide, humic acids, and those produced from carbon dioxide (the carbonate
system), silica, and inorganic phosphates, the resulting pH may either increase or remain
constant. In those systems with limited buffering capacity, the increase in basicity with the
increase in the hydroxide ion concentration may lead to the formation and precipitation of
insoluble transition metal complexes such as iron, aluminum, and manganese hydroxides. In
soils with limited buffering capacity or a low organic content, potassium hydroxide may display
high mobility. Potassium hydroxide will not volatilize to the atmosphere but it or its aqueous
solutions may be released to the atmosphere by mechanical means during its production, use,
or transport. If released to the atmosphere, potassium hydroxide will undergo removal by
either wet or dry deposition processes. In wastewater treatment plants, potassium hydroxide
will undergo reactions similar to those described above with the net result being an increase in
the potassium ion concentration of the effluent.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Propylene Carbonate
Propylene Carbonate
Chemical Properties and Information
Propylene carbonate [1,2-Propylene carbonate; 4-methyl-1,3-
dioxolane-2-one]
CAS# 108-32-7
Molecular weight: 118
Melting Point: -55°C(M)
Water Solubility: 100g/L(E)
Vapor Pressure: 0.44 mm Hg (E) (25°C)
Log Kow= 0.54 (E)
Henry's Law Constant: 3.6 x 10"4 atm-m3/mole (E)
Chemistry of Use: Solvent
C4H603
Structure:
Boiling Point: 241.7°C(M)
Density: 1.20g/ml
FlashPoint: 132.2°C(M)
Koc: 6 (E)
Physical State: Colorless, odorless liquid
Above data are either measured (M) or estimated (E)
Propylene carbonate is combustible. It has a high solubility for CO2. This solubility
makes propylene carbonate widely used for drying natural gas. Propylene carbonate is miscible
with acetone, benzene, chloroform, ether and ethyl acetate.
Propylene oxide is reacted with carbon dioxide to yield propylene carbonate. Propylene
carbonate can be further hydrolyzed to propylene glycol. The reaction is catalyzed by
potassium iodide, calcium bromide or magnesium bromide.
Market Profile
In 1989, total U.S. production was 8.3 million gallons. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Propylene carbonate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, propylene carbonate is expected to display very high mobility.
Biodegradation in acclimated aerobic soils may be rapid. Volatilization of propylene carbonate
from both moist and dry soil to the atmosphere is expected to occur at a moderate rate. If
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Propylene Carbonate
released to water, aerobic biodegradation may occur and it may be rapid in acclimated waters.
Propylene carbonate is not expected to bioconcentrate in fish and aquatic organisms or to
adsorb to sediment and suspended organic matter. Volatilization of propylene carbonate from
water to the atmosphere is expected to be relatively rapid. If released to the atmosphere,
propylene carbonate may undergo oxidation by the gas-phase reaction with hydroxyl radicals
with an estimated half-life of approximately 2.5 days. It may also undergo atmospheric removal
by wet deposition processes. Using a rapid biodegradation rate for propylene carbonate in the
STP fugacity model results in 97 percent predicted total removal from wastewater treatment
plants. If a moderate biodegradation rate is used in this model, 84 percent predicted total
removal may be achieved.
Health Hazard
See Table II-6 and accompanying summary
Propylene Glycol
Chemical Properties and Information
Propylene glycol [1,2-propanediol, methyl glycol, 1,2-
dihydroxypropane, methylethylene glycol, trimethyl glycol]
CAS# 57-55-6
Molecular weight: 76.10
Melting Point: -60°C(M)
Water Solubility: Miscible
Vapor Pressure: 0.2 mm Hg at 20°C (M)
Log Kow: -.920 (M)
Henry's Law Constant: 1.3x10"8atm-m3/mole (E)
Chemistry of Use: Solvent
C3H802
Structure: HOCH(CH3)CH2OH
Boiling Point: 187.3°C(M)
Density: 1.038(M)
FlashPoint: 101°C(M)
Koc: 7 (E)
Above data are either measured (M) or estimated (E)
Propylene glycol is practically odorless with a slight taste. More volatile than ethylene glycol, it
is three times as viscous at room temperature. Although propylene glycol has a secondary hydroxyl
group, its chemistry parallels that of ethylene glycol. It is miscible with water and other polar
solvents.
Propylene glycol is produced by the hydrolysis of propylene oxide. The hydrolysis is carried
out under pressure at high temperature without catalysts. The proportion of products is controlled
by the ratio of water to propylene oxide.
Market Profile
In 1989, total U.S. production was 651 million gallons. In 1989, imports were 0.3 million
gallons. In 1988, exports were 144.5 million gallons. Total U.S. production quantity for use in
screen reclamation was estimated to be 203,000 gallons.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Propylene Glycol Methyl Ether
Regulatory Status
Propylene glycol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, propylene glycol may rapidly degrade under aerobic conditions. It is
expected to display very high mobility; however, its expected rapid biodegradation will decrease its
potential of leaching through soil. Volatilization of propylene glycol from moist soil to the atmosphere
will not be important although it may occur slowly from dry soils. If released to water, propylene
glycol may biodegrade rapidly under aerobic conditions. It may also slowly degrade under anaerobic
conditions. Neither volatilization to the atmosphere, bioconcentration in fish and aquatic organisms,
adsorption to sediment and suspended organic matter, chemical hydrolysis, nor oxidation are
expected to occur. If released to the atmosphere, propylene glycol is degraded rapidly by reaction
with photochemically produced hydroxyl radicals (typical half-life of 11 hours). Physical removal by
wet deposition processes may also occur because of its substantial water solubility; however, its
short atmospheric residence time suggests that wet deposition may be of limited importance. Using a
rapid biodegradation rate in the STP fugacity model results in 97 percent predicted total removal
from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Propylene Glycol Methyl Ether
Propylene Glycol Methyl Ether
Chemical Properties and Information
Propylene glycol methyl ether [Glycol ether PM]
CAS# 107-98-2
Molecular weight: 90.12
Melting Point: -95°C(M)
Water Solubility: Miscible
Vapor Pressure: 8.03 mm Hg (M) (20°C)
Log Kow= -0.49 (E)
Henry's Law Constant: 1.8 x 10"8 atm-m3/mole (E)
Chemistry of Use: Solvent
C4H1002
Structure: CH3OCH2CH(CH3)OH
Boiling Point: 121°C(M)
Density: 0.9234 g/ml (M)
Flash Point: Open cup: 36°C (M)
Closed Cup: 33°C(M)
Koc: 13(E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
Glycol ethers are both ethers and alcohols. Their hydroxyl groups can be etherified,
esterified, chlorinated, or otherwise modified. Propylene glycol methyl ether is miscible with
acetone, benzene, carbon tetrachloride, ethyl ether and petroleum ether. Glycol monoethers are
prepared by conventional etherification procedures, including the reaction of an alkali metal
glycolate with an alkyl halide, and reaction of propylene oxide with methanol.
Market Profile
In 1991, total U.S. production was 125 million gallons. Imports were less than 100,000
million gallons and exports were 28.7 million gallons. Total U.S. production quantity for use in
screen reclamation was estimated to be 418,000 gallons.
Regulatory Status
Propylene glycol methyl ether does not trigger any federal environmental regulations.
However, the generic category of glycol ethers is listed as Hazardous Air Pollutants in the Clean
Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Propylene glycol methyl ether is not expected to undergo hydrolysis or direct photolysis in
the environment. In water, volatilization, adsorption to sediments and suspended solids, and
bioconcentration in aquatic organisms are not expected to be important transport processes for
propylene glycol methyl ether. Biodegradation is likely to be the most important removal
mechanism of propylene glycol methyl ether from aerobic soil and water based on a 4-week
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Propylene Glycol Methyl Ether
BOD of 88-92 percent of theoretical. If released to soil, propylene glycol methyl ether is
expected to display very high mobility. Volatilization from dry soil surfaces will be important.
In the atmosphere, propylene glycol methyl ether is expected to exist almost entirely in the gas-
phase and reactions with photochemically produced hydroxyl radicals should be fast (estimated
half-life of 8.2 hrs). Physical removal of propylene glycol methyl ether from air by wet
deposition may occur; however, its short atmospheric residence time suggests that wet
deposition is of limited importance. Using a rapid biodegradation rate for propylene glycol
methyl ether in the STP fugacity model results in 97 percent predicted removal from
wastewater treatment plants; a moderate rate corresponds to 83 percent predicted removal.
Health Hazard
See Table II-6 and accompanying summary
Propylene Glycol Methyl Ether Acetate
Chemical Properties and Information
Propylene glycol methyl ether acetate[1-Methoxy-2-
acetoxypropane; 1-Methoxy-2-propyl acetate; 2-Acetoxy-1-
methoxypropane]
CAS# 108-65-6
Molecular weight: 132
Melting Point: -100°C(E)
Water Solubility: Miscible
Vapor Pressure: 2 mm Hg (E) (25°C)
Log Kow= 0.56 (M)
Henry's Law Constant: 4.26 x 10'6 atm-m3/mole (M)
Chemistry of Use: Solvent
C,H,,0,
Structure: CHqOCH,CHOCCH
Boiling Point: 140°C(E)
Density: 0.90 g/ml (E)
FlashPoint: 40°C(E)
Koc: 2 (M)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
Propylene glycol methyl ether acetate is a glycol derivative that is both an ether and an
ester. Propylene glycol methyl ether acetate is soluble in organic solvents.
Propylene glycol methyl ether acetate is made by reacting propylene oxide with methanol
followed by acetylation.
Market Profile
In 1991, total U.S. production of "other" P-series glycol ethers was 1 million pounds.
This category includes dipropylene glycol methyl ether acetate, ethoxypropanol, ethoxypropyl
acetate, and propylene glycol methyl ether acetate, among possibly others. Data for imported
and exported amounts were not available. Total U.S. production quantity for use in screen
reclamation was estimated to be 217,000 gallons.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Propylene Glycol Methyl Ether Acetate
Regulatory Status
Propylene glycol methyl ether acetate does not trigger any federal environmental
regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, propylene glycol methyl ether acetate is expected to display very high
mobility. Biodegradation in acclimated aerobic soils may be rapid. Hydrolysis of the ester
group is not expected to be significant except for highly basic soils (pH greater thanS).
Volatilization of propylene glycol methyl ether acetate from dry soil to the atmosphere may be
significant although it is likely to be a slow process from wet soil. If released to water, aerobic
biodegradation is likely to be the dominant removal process with 20-day BODs of 61 percent of
theoretical reported. Neither bioconcentration in fish and aquatic organisms, adsorption to
sediment and suspended organic matter, hydrolysis, nor volatilization to the atmosphere are
expected to be significant fate processes in surface water. If released to the atmosphere,
propylene glycol methyl ether acetate may undergo oxidation by the gas-phase reaction with
hydroxyl radicals with an estimated half-life of approximately 11 hours. It may also undergo
atmospheric removal by wet deposition processes; however, its short atmospheric residence
time suggests that wet deposition is of limited importance. Propylene glycol methyl ether
acetate is listed as degradable in the Japanese MITI test which uses an acclimated sludge seed
and it is expected to undergo significant removal in a wastewater treatment plant. Using a
rapid biodegradation rate for propylene glycol methyl ether acetate in the STP fugacity model
results in 97 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-80
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Silica
Silica
Chemical Properties and Information
Silica [silicon dioxide]
CAS# 7631-86-9
Molecular weight: 60
Melting Point: 1550°C(M)
Water Solubility: Practically insoluble; vitreous form more
soluble than quartz
Vapor Pressure: (E)
Log Kow: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Anticaking/defoaming agent
Si02
Structure: Occurs as a variety of minerals including quartz;
crystals are hexagonal
Boiling Point: Density: 2.65 (quartz) (M); 2.2 (amorphous)
Flash Point: (E)
Koc: Not applicable
Above data are either measured (M) or estimated (E)
Silica combines with many elements and oxides in the general realm of ceramic
chemistry. It occurs in nature as agate, amethyst, chalcedony, cristobalite, flint, quartz, sand,
tridymite, carnelian, onyx, and jasper; hydrated amorphous forms include opal, infusorial
earth, and diatomaceous earth. A common vitreous form is obsidian. It is practically insoluble
in acids, except aqueous HF, in which it readily dissolves, forming Si F4 and H2SiF6.
It is naturally occurring.
Market Profile
In 1992, total U.S. production was 1.8 billion pounds. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Silica does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, silica is expected to be essentially immobile. Although silica slowly
dissolves in water to a limited extent, adsorption to soil is expected through strong silica-soil
interactions. Experimental data to assess the degree of adsorption of silica to soil are not
available. Silica is not expected to biodegrade in soil nor volatilize to the atmosphere. Silica's
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Silica
ultimate fate in soil is expected to be chemical hydrolysis to silicic acid and participation in the
natural silicon cycle although this process occurs on a geological time scale. If released to
water, silica may slowly dissolve and may also undergo very slow chemical hydrolysis to silicic
acid. Its dominant aquatic fate process is expected to be adsorption to sediment although
ultimately it will enter the natural silicon cycle. Volatilization to the atmosphere,
biodegradation, and bioconcentration in fish and aquatic organisms are not expected to occur.
If released to the atmosphere as particulates, it is expected return to the earth via dry
deposition and rain-out. Removal of silica from wastewater treatment plants is expected to be
essentially complete due to its high degree of adsorption to sludge and complexation with
metals.
Health Hazard
See Table II-6 and accompanying summary
Silica, Fumed
(amorphous, crystalline-free)
Chemical Properties and Information
Silica, fumed [pyrogenic silica, aerosil, amorphous silica]
CAS# 112945-52-5
Molecular weight: 60
Melting Point: 1550°C(E)
Water Solubility: 0.1 g/L(E)
Vapor Pressure: Not applicable
Log Kow: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Thickener/reinforcer
Si02
Structure: Lack of crystalline structure
Boiling Point: 2950°C(E)
Density: 2.16g/cm3(M)
Flash Point: Not available
Koc: Not applicable
Above data are either measured (M) or estimated (E)
Fumed silica is an extremely pure form of silica. It is insoluble in all acids except HF (M).
Fumed silica is made by burning SiCl4 with H2 and O2 at 1000°C.
Market Profile
In 1992, total U.S. production was 48.6 million pounds. In 1992, about 2.6 million
pounds were imported and 2.0 million pounds were exported. Total U.S. production quantity
for use in screen reclamation is unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Silica, Fumed (amorphous, crystalline-free)
Regulatory Status
Silica, fumed, does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, fumed silica is expected to be essentially immobile. Although fumed
silica slowly dissolves in water to a limited extent, adsorption to soil is expected through strong
silica-soil interactions. Experimental data to assess the degree of adsorption of fumed silica to
soil are not available. Fused silica is not expected to biodegrade in soil nor volatilize to the
atmosphere. Fumed silica's ultimate fate in soil is expected to be chemical hydrolysis to silicic
acid and participation in the natural silicon cycle although this process will occur on a
geological time scale. If released to water, fumed silica may slowly dissolve and may also
undergo very slow chemical hydrolysis to silicic acid. Its dominant aquatic fate process is
expected to be adsorption to sediment although ultimately it will enter the natural silicon cycle.
Volatilization to the atmosphere, biodegradation, and bioconcentration in fish and aquatic
organisms are not expected to occur. If released to the atmosphere as particulates, it is
expected return to the earth via dry deposition and rain-out. Removal of fumed silica from
wastewater treatment plants is expected to be essentially complete due to its high degree of
expected adsorption to sludge and complexation with metals.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Bisulfate
Sodium Bisulfate
Chemical Properties and Information
Sodium bisulfate [sulfuric acid, monosodium salt,
monohydrate]
CAS# 10034-88-5
Molecular weight: 138
Melting Point: Decomposes (M)
Water Solubility: 1250g/L(M)
Vapor Pressure: Not applicable
Log Kow: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Salt
H3Na05S
Structure: HOSO,Na-H,0
Boiling Point: Not Applicable
Density: >2 g/cm3 (E)
Flash Point: Not applicable
Koc: Not applicable
Above data are either measured (M) or estimated (E)
This chemical changes to pyrosulfate when strongly heated. This chemical exists as
colorless, odorless crystals. This chemical is corrosive and its aqueous solution is strongly
acidic. It decomposes in alcohol.
This chemical is made by crystallization from an aqueous solution containing NaHSO4.
Market Profile
No information on production volumes of sodium bisulfate was available. In 1990, total
U.S. production of sodium sulfate was 812 million pounds. In 1991, about 34.6 million
pounds of sodium sulfate were imported and about 250 million pounds of sodium sulfate were
exported. Total U.S. production of sodium bisulfate for use in screen reclamation was
estimated to be 2.35 million pounds.
Regulatory Status
Sodium bisulfate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The environmental fate of sodium bisulfate is that of its aqueous solution; the dominant
fate of solid sodium bisulfate release will be its dissolution in water. In aqueous solution,
sodium bisulfate will ionize to sodium cations (Na+) and the bisulfate anion (HSO4). In water,
the bisulfate ion will rapidly dissociate to the sulfate ion (SO42) and a hydronium ion (H3O+).
Sodium ions are naturally present in surface water, groundwater, and rainwater as are sulfate
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Sodium Hexametaphosphate
ions. Sulfate ions are also important components of the sulfur cycle. Depending on the size of
the sodium bisulfate release and the buffering capacity of the receiving medium, the resulting
pH may either decrease or remain constant. In soil and water systems with limited buffering
capacity, the increase in acidity with the increase in hydronium ion concentration may lead to
the solubilization of metal complexes of phosphate, magnesium, calcium, iron, and aluminum.
Sodium bisulfate will not volatilize to the atmosphere but it may be released to the atmosphere
by mechanical means during its production, use, or transport. If released to the atmosphere,
sodium bisulfate will undergo removal by either wet deposition due to its appreciable water
solubility or dry deposition due to settling. In wastewater treatment plants, sodium bisulfate
will undergo rapid ionization and subsequent dissociation and will pass through the treatment
plant as the ions.
Health Hazard
See Table II-6 and accompanying summary
Sodium Hexametaphosphate
Chemical Properties and Information
Sodium hexametaphosphate [Metaphosphoric acid,
hexasodium salt; sodium polymetaphosphate; Graham's salt;
glassy sodium metaphosphate]
CAS# 10124-56-8
Molecular weight: 611.17
Melting Point: 628°C(M)
Water Solubility: Very Soluble
Vapor Pressure: Not applicable
Log Kow: Not applicable
Henry's Law Constant: Not available
Chemistry of Use: Corrosion inhibitor/dispersant
(NaP03)6
Structure: 12 member ring with alternating P and 0 atoms
Na+16(P6018)-6
Boiling Point: Not available
Density: 2.4g/cm3(E)
Flash Point: Not available
Koc: Not applicable
Above data are either measured (M) or estimated (E)
This chemical appears as a clear, hygroscopic glass. Sodium hexametaphosphate is a
mixture of polymeric metaphosphates, and is not a hexamer. It depolymerizes in aqueous
solution to form sodium trimetaphosphate and sodium ortho phosphates.
Sodium hexametaphosphate is prepared by rapidly chilling molten sodium
metaphosphate.
Market Profile
In 1989, total U.S. production was 88 million pounds. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Hexametaphosphate
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, sodium hexametaphosphate is expected to be essentially immobile due
to the formation of insoluble complexes with metal salts, particularly calcium and iron.
Sodium hexametaphosphate is expected to be unstable in soils and will eventually degrade to
orthophosphate. Degradation rates increase in clay containing soils resulting from metal
catalyzed processes. Volatilization to the atmosphere is not expected to occur. If released to
water, sodium hexametaphosphate will undergo slow chemical hydrolysis to orthophosphate
with a half-life of approximately 1 month at 40 °C at neutral pH. If organisms containing
phosphatase enzymes are present, sodium hexametaphosphate will undergo rapid hydrolysis in
environmental waters. In the absence of rapid hydrolysis, adsorption to sediment and
suspended organic matter may occur initially, followed by chemical degradation. Neither
volatilization to the atmosphere or bioconcentration in fish and aquatic organisms are expected.
If released to a wastewater treatment plants, complete removal of sodium hexametaphosphate
is expected from hydrolysis due to the relatively high local phosphatase concentration.
Available data indicate that metaphosphates in raw sewage are predominately hydrolyzed to
orthophosphate before they even reach the treatment plant
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Sodium Hydroxide
Sodium Hydroxide
Chemical Properties and Information
Sodium hydroxide [caustic soda; lye; sodium hydrate; soda
lye]
CAS# 1310-73-2
Molecular weight: 39.9
Melting Point: 323°C(M)
Water Solubility: 1,180g/L(E)
Vapor Pressure: Negligible (E)
1mmHg(M)(739°C)
Chemistry of Use: Caustic
NaOH
Structure: NaOH
Boiling Point: 1390°C(M)
Density: 2.13 g/ml (M)
Flash Point: Not applicable
Physical State: Deliquescent orthorhombic white powder
Above data are either measured (M) or estimated (E)
Sodium hydroxide is an important industrial alkali. It readily reacts with atmospheric
CO2 to form Na2CO3. It reacts with all the mineral acids to form the corresponding salts.
Sodium hydroxide is very soluble in ethanol and soluble in glycerol. It is insoluble in diethyl
ether and acetone.
Sodium hydroxide is manufactured either by electrolysis of brine (Castner-Kellner
process) or by treatment of Na2CO3 or NaHCO3 with CaO or Ca(OH)2. It can also be prepared
from sodium metal and water vapor at low temperature.
Market Profile
In 1991, total U.S. production was 25 billion pounds. In 1992, imports were 1,138
million pounds and in exports were 2,536 million pounds. Total U.S. production quantity for
use in screen reclamation was estimated to be 1.45 million pounds.
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The environmental fate of sodium hydroxide is that of its aqueous solution; the dominant
fate of solid sodium hydroxide release will be its dissolution in water. In aqueous solution,
sodium hydroxide will dissociate into sodium cations (Na+) and the hydroxide anion (OH).
Sodium ions are naturally present in surface water, groundwater, and rainwater as are
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Hypochlorite
hydroxide ions due to the ionization of water. Given that the components of sodium hydroxide
are naturally present and participate in the reactions of natural systems, their fate will be
determined by both the amount released and the composition of the receiving medium.
Depending on the size of the release and the buffering capacity of the receiving medium, which
is in a large part determined by the amount of naturally occurring acids such as hydrogen
sulfide, humic acids, and those produced from carbon dioxide (the carbonate system), silica,
and inorganic phosphates, the resulting pH may either increase or remain constant. In those
systems with limited buffering capacity, the increase in basicity with the increase in the
hydroxide ion concentration may lead to the formation and precipitation of insoluble transition
metal complexes such as iron, aluminum, and manganese hydroxides. In soils with limited
buffering capacity or a low organic content, sodium hydroxide may display high mobility.
Sodium hydroxide will not volatilize to the atmosphere but it or its aqueous solutions may be
released to the atmosphere by mechanical means during its production, use, or transport. If
released to the atmosphere, sodium hydroxide will undergo removal by either wet or dry
deposition processes. In wastewater treatment plants, sodium hydroxide will undergo
reactions similar to those described above with the net result being an increase in the sodium
ion concentration of the effluent.
Health Hazard
See Table II-6 and accompanying summary
Sodium Hypochlorite
Chemical Properties and Information
Sodium hypochlorite [chloric(l) acid, sodium salt;
hypochlorous acid, sodium salt; Clorox, Dazzle, Eau de
Labarraque]
CAS# 7681-52-9
Molecular weight: 74.4
Melting Point: 18° C (M) crystals decompose
Water Solubility: 260 g/l (M)
Vapor Pressure: Not applicable
Chemistry of Use: Oxidizing agent
NaOCI
Structure: NaOCI
Boiling Point: Not applicable
Density: 1.21g/ml(M)
Flash Point: Not applicable
Above data are either measured (M) or estimated (E)
Sodium hypochlorite is a strong oxidizing agent usually stored and used in solution.
There is a fire risk in contact with organic materials. It is highly reactive. The physical state of
sodium hypochlorite is a greenish yellow liquid (in solution) with a disagreeable sweetish odor.
Sodium hypochlorite is synthesized by bubbling C12 through aqueous NaOH in the
presence of CO2. It is manufactured by the electrolysis of brine.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Hypochlorite
Market Profile
In 1990, total U.S. production was 380 million gallons. In 1991, imports and exports
were believed to be negligible. Total U.S. production quantity for use in screen reclamation was
estimated to be 69,000 gallons.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The environmental fate of sodium hypochlorite is essentially that of its aqueous solutions;
the dominant fate of solid sodium hypochlorite release will be its dissolution in water. If
released to soil, sodium hypochlorite is expected to readily oxidize organic matter and is likely
to be short-lived. If released to water, sodium hypochlorite is expected to be short-lived
although its aquatic fate is partially dependent on the pH of receiving water. Sodium
hypochlorite is expected to dissociate to hypochlorous acid which may, in the presence of
additional chloride ions under acidic conditions, form chlorine. At pH 7.5, the hypochlorite ion
and hyperchlorous acid are at approximately equal concentrations; at pH 8.5, only 10 percent
of the added sodium hypochlorite would exist as hypochlorous acid. Hypochlorous acid and, if
formed, chlorine may undergo significant volatilization to the atmosphere. Sodium
hypochlorite itself is not expected to volatilize from water. Chlorine, hypochlorous acid, as well
as sodium hypochlorite are expected to readily oxidize organic compounds. Hypochlorous acid,
which is always in equilibrium with the hypochlorite ion, may also oxidize sulfur compounds,
nitrate ions, and certain metals such as Fe(II) an Mn(II). Hypochlorous acid may also
decompose under the influence of UV light. Reduction is ultimately expected to be the
dominant removal process for sodium hypochlorite in water. Sodium hypochlorite will not
volatilize to the atmosphere but it or its aqueous solutions may be released to the atmosphere
by mechanical means during its production, use, or transport. If released to the atmosphere,
sodium hypochlorite is expected to removed by both wet and dry deposition processes.
Depending on the composition of other components that may be present in the water droplets,
sodium hypochlorite may be transformed by oxidizing organics, certain metals, and some
inorganic species (such as nitrate ions) before deposition occurs. In activated sludge
wastewater treatment plants, sodium hypochlorite is expected to undergo rapid and complete
removal via the reductive pathways discussed above.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Lauryl Sulfate
Sodium Lauryl Sulfate
Chemical Properties and Information
Sodium lauryl sulfate [sulfuric acid monododecyl ester
sodium salt; sodium dodecyl sulfate; SDS; irium]
CAS# 151-21-3
Molecular weight: 288.38
Melting Point: Decomposes
Water Solubility: 100g/L(M)
Vapor Pressure: Not applicable
LogKow: L7(E)
Henry's Law Constant: Not available
Chemistry of Use: Detergent
C12H25Na04S
Structure: CHgfCH
Boiling Point: Decomposes
Density: 1 g/cm3 (E)
Flash Point: Not applicable
Koc: 80,000 (E)
Above data are either measured (M) or estimated (E)
Sodium lauryl sulfate has a mild fatty odor. It is an anionic detergent and lowers the
surface tension of aqueous solutions. It is soluble in alcohols and ethers.
Sodium lauryl sulfate is synthesized by sulfation of lauryl alcohol, followed by
neutralization with sodium carbonate.
Market Profile
No market information was available for this chemical.
Regulatory Status
Sodium lauryl sulfate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, sodium lauryl sulfate is expected to readily biodegrade under aerobic
conditions. The first step in the biodegradation pathway is believed to be hydrolysis to the
alcohol and inorganic sulfate. Sodium lauryl sulfate is chemically stable in neutral and alkaline
solutions, but readily hydrolyses in the presence of acids. Since the sodium bisulfate produced
in the hydrolysis is strongly acidic, once hydrolysis starts it is autocatalytic. Although sodium
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Sodium Metasilicate
lauryl sulfate is ionic, studies have shown that long chain alkyl sulfates strongly adsorb to soil
and that the force dominating this process is the hydrophobic nature of the non-polar tail of the
molecule. Volatilization of sodium lauryl sulfate from surface soil will not be significant. If
released to water, sodium lauryl sulfate is expected to rapidly biodegrade. It should also
adsorb to sediment and particulate matter in the water column. Volatilization of sodium lauryl
sulfate from water should be insignificant. Experimental data on similar long-chain alkyl
sulfates indicate that bioconcentration in fish and aquatic organisms is not an important
process. If released to the atmosphere, sodium lauryl sulfate will be associated with aerosols
and be removed by gravitational settling. Using a rapid biodegradation rate in the STP fugacity
model results in 100 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
Sodium Metasilicate
Chemical Properties and Information
Sodium metasilicate [waterglass]
CAS# 6834-92-0
Molecular weight: 122.08
Melting Point: 1089°C (decomposes) (M)
Water Solubility: Completely soluble in cold water (M)
Vapor Pressure: <10"8torr(E)
Log Kow: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Corrosion inhibitor
Na203Si
Structure:
2 Na
0
I
Si-
I
0
-2
Boiling Point: Not applicable
Density: 2.614 g/cm3(M)
Flash Point: Not available
Koc: Not applicable
Above data are either measured (M) or estimated (E)
This chemical is usually obtained as a glass, and sometimes as orthorhombic crystals. It
is hydrolyzed in hot water. It is insoluble in organics and alcohols. Sodium metasilicate is
prepared from sand (SiO2) and soda ash (Na2CO3) by fusion.
Market Profile
In 1992, total U.S. production was 106 million pounds. In 1992, for all metasilicates,
about 3,062 million pounds were imported and 23,058 million pounds were exported. Total
U.S. production quantity for use in screen reclamation is unknown.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Metasilicate
Regulatory Status
Sodium metasilicate does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, sodium metasilicate's mobility is likely dependent on both the silicate
species present and the type of soil. Highly polymerized forms of sodium metasilicate are not
expected to be mobile due to surface complexation with either active sites in soil via ion
exchange reactions or adsorption onto insoluble metal oxides. Mono and oligomeric silicates
are expected to display increased mobility yet may adsorb strongly onto clay soils due to
silicate-metal interactions. Experimental data to assess the degree of adsorption to soil are not
available. Sodium metasilicate is not expected to biodegrade nor volatilize to the atmosphere.
Alkaline earth silicates are one part of the natural buffer system of environmental waters and if
released to water, sodium metasilicate is expected to undergo typical acid/base reactions of
silicate buffers which, depending upon the pH of the receiving water, may include proton
exchange, polymerization, or depolymerization reactions. Volatilization to the atmosphere,
biodegradation, and bioconcentration in fish and aquatic organisms are not expected to occur.
The degree in which sodium metasilicate adsorbs to sediment is dependent on the same factors
influencing its adsorption to soil. The degree to which sodium metasilicate is removed from
wastewater treatment plants is also dependent on the nature of the silicates and the water being
treated. Highly polymerized soluble silicates are used in water treatment to precipitate metal
oxides and metal ions and these silicates are expected to be efficiently removed from wastewater
treatment plants via complexation with metals and adsorption to sludge. Mono and oligomeric
sodium metasilicates may not undergo significant removal in wastewater treatment plants.
Removal by biodegradation and volatilization of sodium metasilicate from wastewater treatment
plants is expected to be negligible.
Health Hazard
See Table II-6 and accompanying summary
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Sodium Periodate
Sodium Periodate
Chemical Properties and Information
Sodium periodate [sodium metaperiodate; sodium iodate(VII);
lodic(VII) acid, sodium salt; periodic acid, sodium salt]
CAS# 7790-28-5
Molecular weight: 213.8
Melting Point: 300° C (M) decomposes
Water Solubility: 140g/l(M)
Vapor Pressure: Negligible (E)
Chemistry of Use: Oxidizing agent
Nal04
Structure: Na+I04"
Boiling Point: Not applicable
Density: 3.865 g/ml (M)
Flash Point: Not applicable
Physical State: Colorless tetragonal crystals
Above data are either measured (M) or estimated (E)
Sodium metaperiodate is a strong oxidizer; contact with combustible or flammable
materials can cause fire or explosion. It is soluble in acetic acid. Sodium metaperiodate is
synthesized by direct oxidation of NaIO3 using O2 in the presence of an alkali at 300 °C and 34
atm. It is also a product of the thermal decomposition of NaH4IO6 • H2O.
Market Profile
The total U.S. production is unknown. Total U.S. quantity for use in screen reclamation
was estimated to be 11.7 million pounds.
Regulatory Status
Sodium periodate does not trigger any federal environmental regulations
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The environmental fate of sodium periodate is that of its aqueous solution; the dominant
fate of solid sodium periodate release will be its dissolution in water. If released to soil, sodium
periodate is expected to readily oxidize organic matter and will be short-lived. If released to
water, oxidation of organic matter is expected to be sufficiently rapid to dominate all other
potential fate pathways. If released to the atmosphere, sodium periodate is expected to undergo
removal by both wet and dry deposition processes. Depending on the composition of other
components that may be present in the water droplets, sodium periodate may be transformed
by oxidizing either organic, inorganic, or metallic species present before deposition occurs. In
wastewater treatment plants, sodium periodate is expected to undergo complete removal
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Sodium Salt, Dodecyl Benzene Sulfonic Acid
through the oxidation of numerous organic, inorganic, or metallic species present in the
waste water.
Health Hazard
See Table II-6 and accompanying summary
Sodium Salt, Dodecyl Benzene Sulfonic Acid
Chemical Properties and Information
Sodium salt, dodecyl benzene sulfonic acid [Sodium
dodecylbenzenesulfonate; Conoco C-50; Santomerse #1]
CAS# 25155-30-0
Molecular weight: 348.49
Melting Point: Not available
Water Solubility: Low Solubility (E); dispersible (E)
Vapor Pressure: <10"5 mm Hg (E)
LogKow: 1.96(M)
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
C18H29Na03S
Structure:
C12H25~S\ /
Boiling Point: Not available
Density: 0.5g/cm3(E)
Flash Point: Not available
Knc: 100,000 (M)
Above data are either measured (M) or estimated (E)
This chemical is synthesized by reacting dodecyl benzene sulfonic acid with sodium
carbonate.
Market Profile
In 1990, total U.S. production was 224.6 million pounds. Imports and exports of this
chemical are unknown. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
See Table II-3 and accompanying summary.
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Sodium Salt, Dodecyl Benzene Sulfonic Acid
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, sodium salt, dodecyl benzene sulfonic acid is expected to biodegrade
under aerobic conditions, especially when acclimated organisms are present. Although sodium
salt, dodecyl benzene sulfonic acid is ionic, studies have shown that dodecyl benzene sulfonic
acid salts strongly adsorb to soil and that the force dominating this process is the hydrophobic
nature of the non-polar tail of the molecule. Volatilization of sodium salt, dodecyl benzene
sulfonic acid from surface soil will not be significant. If released to water, sodium salt, dodecyl
benzene sulfonic acid is expected to biodegrade. It will also adsorb to sediment and particulate
matter in the water column. Volatilization of sodium salt, dodecyl benzene sulfonic acid from
water should be insignificant. Experimental data indicate that bioconcentration in fish and
aquatic organisms is not an important processes. If released to the atmosphere, sodium salt,
dodecyl benzene sulfonic acid will be associated with aerosols and be removed by gravitational
settling. Using a rapid biodegradation rate for the parent acid in the STP fugacity model results
in 97 percent predicted total removal of sodium salt, dodecyl benzene sulfonic acid from
wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-95
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Solvent Naphtha, Petroleum,
Light Aliphatic (VM&PNaptha)
Solvent Naphtha, Petroleum, Light Aliphatic (VM&P Naptha)
Chemical Properties and Information
Solvent naphtha, petroleum, light aliphatic [VM&P #66;
lacolene; rubber solvent; petroleum ether; naphtha; varnish
makers' and painters' solvent; VM&P Naphtha ]
CAS# 64742-89-8
Molecular weight: 86 for n-hexane; 112forethycyclohexane,
for example
Melting Point: <-80°C(M)
Water Solubility: 0.001 g/L(E)
Vapor Pressure: 20 mm Hg (E) (25°C)
Log Kow= 3.27->6(E)
Henry's Law Constant: 8.0 x 10"3 - 5 atm-m3/mole (E)
Chemistry of Use: Solvent
Molecular Formula: CnH2n+2 (paraffin) and CnH2n
(cycloparaffin)
Structure: Typical structures include normal paraffins,
CH3(CH2)nCH3, branched paraffins, and cycloparaffins
Boiling Point: 35-160°C(M)
Density: 0.7g/ml(E)
FlashPoint: 0°C(E)
Koc: 200 - >5,000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
These commercial products are all light aliphatic solvent naphthas with similar
compositions and properties. Most consist of 80 to 90 percent paraffins most of which are
straight- or branched-chain alkanes in the range of C5 through C10. Up to 10 percent is typically
aromatics, with only a fraction of this being C8 and above. They are miscible with petroleum
solvents.
Solvent naphthas are prepared by fractionation of straight-run, cracked, and reforming
distillates, or by fractionation of crude petroleum or natural gasoline. The naphtha streams are
divided into heavy and light, and may be further fractionated. The naphthas are usually treated
to remove sulfur, either chemically, with lye or other compounds, or by hydrotreating
processes. Aromatic hydrocarbons are also removed by solvent extraction or by destructive
hydrogenation.
Market Profile
Based on boiling range and other evidence, it has been assumed that this naphtha
fraction corresponds to "special naphthas." The 1990 production volume for this naphtha was
4.2 billion pounds. Data for imported and exported amounts were not available. Total U.S.
production quantity for use in screen reclamation was estimated to be 12.6 million pounds.
Regulatory Status
Solvent naphtha (petroleum), light aliphatic, does not trigger any federal environmental
regulations
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Solvent Naphtha, Petroleum,
Light Aliphatic (VM&PNaptha)
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Solvent naphtha, light aliphatic is a mixture of components, chiefly C5-C10 alkanes
typically with up to 10 percent aromatics. If released to soil, solvent naphtha, light aliphatic is
expected to biodegrade at a fast to moderate rate under aerobic conditions. Some components
of solvent naphtha, light aliphatic may adsorb very strongly to soil. Solvent naphtha, light
aliphatic may rapidly volatilize from both moist and dry soils to the atmosphere although
strong adsorption may significantly attenuate the rate of this process. If released to water,
solvent naphtha, light aliphatic is expected to biodegrade at a fast to moderate rate under
aerobic conditions. Some components may significantly bioconcentrate in fish and aquatic
organisms and strongly adsorb to sediment and suspended organic matter. The estimated half-
life for volatilization of solvent naphtha, light aliphatic components from a model river is
approximately 1 hour while that from a model lake is greater than 100 days; the former model
does not account for the attenuating affect of strong adsorption. If released to the atmosphere,
the dominant atmospheric removal process for solvent naphtha, light aliphatic is expected to be
oxidation by hydroxyl radicals with an estimated half-life of 1-3 days. Using representative
components that either biodegrade rapidly and display moderate sludge adsorption or are
moderately biodegradable and display strong adsorption to sludge, the STP fugacity model
indicates that greater than 94 percent total removal from wastewater treatment plants may be
achieved.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-97
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Solvent Naphtha, Petroleum, Light Aromatic
Solvent Naphtha, Petroleum, Light Aromatic
Chemical Properties and Information
Solvent naphtha, petroleum, light aromatic [Comsolv 100 ]
CAS# 64742-95-6
Molecular weight: 128 for naphthalene
Melting Point: -80°C(E)
Water Solubility: 0.03 g/L (M) for naphthalene
Vapor Pressure: 0.5 mm Hg (E) (25°C)
LogKow=3.0-3.5(E)
Henry's Law Constant: 4.8 x 10'4 - 8 x 10'3 atm-m3/mole (E)
Chemistry of Use: Solvent
C10H8 for naphthalene
Structure: Consist chiefly of aromatic hydrocarbons,
including small fused-ring compounds such
as naphthalene
Boiling Point: 135-210°C(E)
Density: 0.87 g/ml (E)
FlashPoint: 38°C(E)
Koc: 500 - 2,000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
The light aromatic solvent naphtha products are a complex combination of hydrocarbons
that consists chiefly of C8 through C10 aromatics, but they also may contain up to 30 percent
paraffins and cycloparaffins
Solvent naphthas are prepared by fractional distillation of petroleum. Sulfur compounds
are most commonly removed or converted to a harmless form by chemical treatment with lye or
other agent, or by hydrorefining processes.
Market Profile
No information is available on the production volumes of the numerous specific naphtha
fractions, excluding special naphthas. The production volume for all naphthas was 2,100
million pounds in 1991. The vast majority of naphthas are used in the production of gasoline
and other petroleum products and not directly as solvents. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Solvent naphtha (petroleum), light aromatic, does not trigger any federal environmental
regulations
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT—September 1994
II-98
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Solvent Naphtha, Petroleum, Light Aromatic
Environmental Fate
Solvent naphtha, light aromatic is a mixture of components, chiefly C8-C10 aromatics. If
released to soil, solvent naphtha, light aromatic is expected to biodegrade at a moderate rate
under aerobic conditions. Some components of solvent naphtha, light aromatic may adsorb
strongly to soil. Solvent naphtha, light aromatic may rapidly volatilize from both moist and dry
soils to the atmosphere although adsorption may significantly attenuate the rate of this process.
If released to water, solvent naphtha, light aromatic is expected to biodegrade at a moderate
rate under aerobic conditions. Some components may significantly bioconcentrate in fish and
aquatic organisms and adsorb to sediment and suspended organic matter. The estimated half-
life for volatilization of solvent naphtha, light aromatic components from a model river is
approximately 2 hours while that from a model lake is greater than 100 days; the former model
does not account for the attenuating affect of adsorption. If released to the atmosphere, the
dominant atmospheric removal process for solvent naphtha, light aromatic is expected to be
oxidation by hydroxyl radicals with an estimated half-life of 0.5-2 days. Using representative
components that biodegrade either at a rapid or moderate rate and display moderate sludge
adsorption, the STP fugacity model indicates that greater than 92 percent total removal from
wastewater treatment plants may be achieved.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 II-99
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Solvent Naphtha, Petroleum,
Heavy Aromatic (Aromatic 150)
Solvent Naphtha, Petroleum, Heavy Aromatic (Aromatic 150)
Chemical Properties and Information
Solvent naphtha, petroleum, heavy aromatic [Aromatic 150;
Comsolv150]
CAS# 64742-94-5
Molecular weight: 128 for naphthalene
Melting Point: -80°C(E)
Water Solubility: 0.03 g/L (M) for naphthalene
Vapor Pressure: 0.5 mm Hg (E) (25°C)
LogKow=3.5->5(E)
Henry's Law Constant: 8 x 10'4 - 8 x 10'3 atm-m3/mole (E)
Chemistry of Use: Solvent
C10H8 for naphthalene
Structure: Consist chiefly of aromatic hydrocarbons,
including small fused-ring compounds such
as naphthalene
Boiling Point: 150-290°C(E)
Density: 0.87 g/ml (E)
FlashPoint: 38°C(E)
Koc: 700 - >5,000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
The heavy aromatic solvent naphtha products consist chiefly of C8 through C16aromatics,
but they also may contain up to 30 percent paraffins and cycloparaffins. It is soluble in
petroleum solvents and other organics.
Solvent naphthas are prepared by fractional distillation of petroleum. Sulfur compounds
are most commonly removed or converted to a harmless form by chemical treatment with lye or
other agent, or by hydrorefining processes.
Market Profile
No information is available on the production volumes of the numerous specific naphtha
fractions, excluding special naphthas. The production volume for all naphthas was 2.1 billion
pounds in 1991. The vast majority of naphthas are used in the production of gasoline and
other petroleum products and not directly as solvents. Data for imported and exported
amounts were not available. Total U.S. production quantity for use in screen reclamation is
unknown.
Regulatory Status
Solvent naphtha (petroleum), heavy aromatic does not trigger any federal environmental
regulations
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Tall Oil, Special
Environmental Fate
Solvent naphtha, heavy aromatic is a mixture of components, chiefly C9-C16 aromatic
hydrocarbons. If released to soil, solvent naphtha, heavy aromatic is expected to biodegrade at
a moderate rate under aerobic conditions. Most components of solvent naphtha, heavy
aromatic are expected to adsorb strongly to soil. Solvent naphtha, heavy aromatic may
volatilize from both moist and dry soils to the atmosphere although its expected strong
adsorption may significantly attenuate the rate of this process. If released to water, solvent
naphtha, heavy aromatic is expected to biodegrade at a moderate rate under aerobic conditions.
Most components are expected to bioconcentrate in fish and aquatic organisms and strongly
adsorb to sediment and suspended organic matter. The estimated half-life for volatilization of
solvent naphtha, heavy aromatic components from a model river is approximately 2 hours
while that from a model lake is greater than 100 days; the former model does not account for
the attenuating affect of strong adsorption. If released to the atmosphere, the dominant
atmospheric removal process for solvent naphtha, heavy aromatic is expected to be oxidation by
hydroxyl radicals with an estimated half-life of 1-2.5 days. Using representative components
that biodegrade at a moderate to slow rate and display strong adsorption to sludge, the STP
fugacity model indicates that greater than 96 percent total removal from wastewater treatment
plants may be achieved.
Health Hazard
See Table II-6 and accompanying summary
Tall Oil, Special
Chemical Properties and Information
Tall oil, special [fatty acids, C18 and C18-unsatd., me esters,
methyl stearate, methyl oleate]
CAS# 68937-81-5
Molecular weight: 296-298
Melting Point: 36-39°C(E)
Water Solubility: Insoluble (M) (<0.1 g/L) (E)
Vapor Pressure: <10"3 mm Hg (E)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Solvent
C19H3602 and C19H3802
Structure: CH3(CH2)16COOCH3
and CH3(CH2)7CH=CH(CH2)7COOCH3
Boiling Point: 325°C(E)
Density: 0.88g/cm3(E)
FlashPoint: 200°C(E)
K • Not available
Above data are either measured (M) or estimated (E)
This chemical exists as white crystals. It is soluble in alcohol and ether. The methyl
oleate portion of this mixture is made by refluxing oleic acid with p-toluene sulfonic acid in
methanol.
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Tall Oil, Special
Market Profile
In 1987, total U.S. production of all tall oil was 1.892 million pounds. Information
specific to special tall oil was not available. Imports and exports of this chemical are unknown.
Total U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
Tall oil (special) does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
The long chain unsaturated acids and rosin acids that are the principal components of
special tall oil will adsorb strongly to soil because of their long hydrophobic alkyl chain. They
readily biodegrade by p-oxidation. Henry's Law constants estimated for the principal
components of special tall oil range from 2 x 105 to 7 x 106 atm-m3/mole. If released to soil,
special tall oil would initially be expected to adsorb strongly to soil and readily biodegrade. If
released in water, special tall oil would be expected to rapidly biodegrade based on results of
screening tests on its principal components and tall oil soaps. Initially it would be expected to
strongly adsorb to sediment and particulate matter in the water column. Volatilization of
special tall oil to the atmosphere may be significant (estimated half-lives of principal
components from a model river range from 3 to 12 days). If released to the atmosphere, special
tall oil will be associated with aerosols and be removed by gravitational settling. Using a rapid
biodegradation rate in the STP fugacity model results in 100 percent predicted total removal
from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-102
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Terpineols
Terpineols
Chemical Properties and Information
Terpineols [r-Butyrolactone; dihydro-2(3H)-furanone,
terpineo!318]
CAS# 8000-41-7
Molecular weight: 154
Melting Point: NA
Water Solubility: 2 g/L (M)
Vapor Pressure: 0.023 mm Hg (M) (20°C)
LogKow= 3.33-3.46 (E)
Henry's Law Constant: 3 x 10"6 atm-m3/mole (E)
Chemistry of Use: Cleaner/Disinfectant
C10H180
Structure: oterpineol
(98-55-5)
P-terpineol
(1380-87-4)
y-terpineol
(586-81-2)
Boiling Point: 218°C(M)
Density: 0.9412 g/ml (M)
FlashPoint: 75°C(E)
Koc: 60-1,800(E)
Physical State: Pure a-isomer is white, crystalline powder
Above data are either measured (M) or estimated (E)
The terpineols are 10-carbon alcohols of the structures shown above that are included in
a class of oxygenated isoprene derivatives called terpenes or terpenoids. Many of these
compounds, including terpineols, occur naturally in essential oils. All pine oils contain a-
terpineol as the main oxygenated component. Terpineols are soluble in propylene glycol and
are soluble in 1:8 proportion or more in 50 percent alcohol.
Terpineols are the major constituents in pine oils, which may be obtained in three ways:
(1) by steam distillation of the extract from aged pine stumps in the southeastern U.S.; (2) by
fractionation of crude sulfate turpentine; or (3) synthetically, by the acid-catalyzed hydration of
pinene, followed by distillation. High-grade perfumery a-terpineol is made by partial
dehydration of terpin hydrate under weakly acidic conditions. It may also be prepared from
isoprene and methyl vinyl ketone, using methyl magnesium iodide.
Market Profile
In 1991, total U.S. production for a-terpineols was 2.4 million pounds. In 1989, imports
were 0.8 million pounds. Data for exported amounts were not available. Terpineols are
important constituents of a number of chemical products, such as pine oils and lime oils; 1991
U.S. synthetic pine oil production, of which terpineol is a chief constituent, totaled 71 million
pounds. Thus, although unknown, the total volume of terpineols produced may be significantly
higher than the cited volume.
Total U.S. production quantity for use in screen reclamation was estimated to be 1.1
million pounds.
Regulatory Status
Terpineols do not trigger any federal environmental regulations
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Tetrahydrofurfuryl Alcohol
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to the atmosphere, gas-phase terpineol is expected to degrade by reaction with
photochemically produced hydroxyl radicals (estimated half-life of 4 hours). Reaction with
ozone molecules may also be an important fate process for terpineol in air. If released to soil,
terpineol is expected to exhibit low adsorption potential. One biological treatment study
suggests that biodegradation may be fast in soil and water; however, data are limited. In water,
hydrolysis, adsorption to sediment, and bioconcentration in aquatic organisms are not expected
to be important for terpineol. Volatilization half-lives for a-terpineol of 15 and 110 days have
been estimated for a model river (one meter deep) and a model environmental lake,
respectively. Using a fast biodegradation rate for terpineol in the STP fugacity model results in
99 percent predicted total removal from wastewater treatment plants; a moderate
biodegradation rate results in 92 percent total removal.
Health Hazard
See Table II-6 and accompanying summary
Tetrahydrofurfuryl Alcohol
Chemical Properties and Information
Tetrahydrofurfuryl alcohol [2-furanmethanol, tetrahydro,
aliphatic ether alcohol]
CAS# 97-99-4
Molecular weight: 102.13
Melting Point: <-80°C(M)
Water Solubility: Miscible with water (M)
Vapor Pressure: 0.64 mm Hg (20°C) (E)
LogKow:-0.11(E)
,, , , ^11 JAAV.IA9 i 31 i /i-% Density: 1 .0543 g/cm3 (M)
Henry's Law Constan 4.09X10'9 atm-m3/mole (E) * » ^
v ^ Vl v '
Chemistry of Use: Solvent
C5H1002
Structure:
CH2OH
Boiling Point: 178°C(M)
U-° [
Above data are either measured (M) or estimated (E)
This chemical is a hygroscopic and is colorless. It is flammable in air. It is miscible with
alcohol, ether, acetone, chloroform, benzene. Tetrahydrofurfuryl alcohol is manufactured by
catalytic hydrogenation of furfural or furfuryl alcohol.
DRAFT-September 1994 11-104
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Tetrahydrofurfuryl Alcohol
Market Profile
In 1992, total U.S. production was 14.2 million gallons. In 1992, about 0.1 million
gallons were imported and 4.4 million gallons were exported. Total U.S. production quantity
for use in screen reclamation is unknown.
Regulatory Status
Tetrahydrofurfuryl alcohol does not trigger any federal environmental regulations.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, tetrahydrofurfuryl alcohol will be expected to exhibit very high mobility,
based upon its estimated soil adsorption coefficient. Two biodegradation screening studies
have found tetrahydrofurfuryl alcohol to be readily biodegradable and biodegradation should be
the dominant degradative process in soil. Volatilization of tetrahydrofurfuryl alcohol from
moist soil should not be important, however, some volatilization would occur from dry surface
soil and other dry surfaces. Biodegradation is expected to be the dominant environmental fate
process for tetrahydrofurfuryl alcohol in water. Chemical hydrolysis, volatilization, adsorption
to sediment, and bioconcentration are not expected to be environmentally important. In the
atmosphere, tetrahydrofurfuryl alcohol is expected to exist almost entirely in the vapor phase.
It will degrade in the ambient atmosphere by reaction with photochemically-produced hydroxyl
radicals (estimated half-life of 13 hours). Physical removal from air via wet deposition is
probable since tetrahydrofurfuryl alcohol is miscible in water. Using a rapid biodegradation
rate in the STP fugacity model results in 97 percent predicted total removal from wastewater
treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-105
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Toluene
Toluene
Chemical Properties and Information
Toluene [Methylbenzene, Phenylmethane, Toluol]
CAS# 108-88-3
Molecular weight: 92.14
Melting Point: -95.0 to-93°C(M)
Water Solubility: 0.5 g/L (M)
Vapor Pressure: 55 mm Hg (M) (25°C)
Log Kow= 2.73 (M)
Henry's Law Constant: 6.64 x 10"3 atm-m3/mole (M)
Chemistry of Use: Solvent
C7H8
Structure:
ChU
Boiling Point: 110.6°C(M)
Density: 0.8660420 g/ml (M)
FlashPoint: 4°C(M)
Koc: 38-300 (M)
Physical State: Clear, colorless liquid
Above data are either measured (M) or estimated (E)
Chemical derivatives of toluene are formed by substitution of the hydrogen atoms of the
methyl group, by substitution of the hydrogen atoms of the ring, and by addition to the double
bonds of the ring. Toluene can also undergo a disproportionation reaction in which two
molecules react to yeld one molecule of benzene and one of xylene. Toluene has a TLV of 375.
It is highly flammable, and reacts violently with oxidants. It is stable under normal laboratory
storage conditions. Toluene is miscible in ethanol, chloroform, diethyl ether, acetone, and
acetic acid.
Toluene is generally produced along with benzene, xylenes and C9 aromatics by the
catalytic reforming of straight-run naphthas. The resulting crude reformate is extracted, most
frequently with sulfolane, to yield a mixture of benzene, toluene, xylenes and C9 aromatics,
which are then separated by fractionation. The catalyst may be Pt-Al2O3-based, or bimetallic,
containing both platinum and rhenium. Toluene was formerly produced from coke ovens and
coal-tar products.
Market Profile
In 1990, total U.S. production was 6 billion gallons. In 1991, imports were 520.8 million
gallons and exports were 438.8 million gallons. Total U.S. production quantity for use in
screen reclamation was estimated to be 2.67 million gallons.
Regulatory Status
See Table II-3 and accompanying summary
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Toluene
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If toluene is released to soil, it will be lost by evaporation from near-surface soil and is
expected to be very mobile. Biodegradation occurs at a moderate to rapid rate in soil and may
occur in acclimated groundwater, but at high concentrations, toluene may be toxic to
microorganisms. The presence of acclimated microbial populations may allow rapid
biodegradation in aerobic soil and water. It will not hydrolyze in soil or water under normal
environmental conditions. If toluene is released into water, its concentration will decrease due
to evaporation and biodegradation. This removal can be rapid or take several weeks,
depending on temperature, mixing conditions, and acclimation of microorganisms. It may
adsorb to sediment, but should not bioconcentrate in aquatic organisms. If toluene is released
to the atmosphere, it will degrade by reaction with photochemically produced hydroxyl radicals
(half-life 3 hr to slightly over 1 day) or be washed out in rain. It will not be subject to direct
photolysis. Using a fast biodegradation rate for toluene in the STP fugacity model results in 98
percent predicted total removal from wastewater treatment plants; a moderate biodegradation
rate corresponds to 92 percent predicted total removal.
Health Hazard
See Table II-6 and accompanying summary
1,1,1-Trichloroethane
Basic Chemical Properties
1,1,1-Trichloroethane [methyl chloroform; solvent 111; TCA;
chlorothene]
CAS# 71-55-6
Molecular weight: 133.42
Melting Point: -30.4°C(M)
Water Solubility: 4.4g/L(M)
Vapor Pressure: 127 mm Hg (M) (25°C)
Log Kow= 2.49 (M)
Henry's Law Constant: 1.72 x 10"2 atm-m3/mole (M)
Chemistry of Use: Solvent
C2H3CI3
Structure: CCI3CH3
Boiling Point: 74.2°C(M)
Density: 1.33g/ml(M)
Flashpoint: Not applicable
Koc: 107(M)
Physical State: Liquid with sweetish, chloroform-like odor
Above data are either measured (M) or estimated (E)
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals 1,1,1-Trichloroethane
Releases of 1,1,1-trichloroethane in water and soil volatilize or leach out. Releases to air
can travel long distances. Common routes of exposure are air and drinking water. Soluble in
acetone, benzene, methanol and carbon tetrachloride.
1,1,1-Trichloroethane is prepared by action of chlorine on 1,1-dichloroethane, or by
catalytic addition of hydrogen chloride to 1,1-dichloroethylene. It can be produced by
chlorination of vinyl chloride derived from 1,2-dichloroethane; hydrochlorination of vinylidene
chloride derived from 1,2-dichloroethane; or thermal chlorination of ethane.
Market Profile
In 1990, total U.S. production was 500 million gallons. In 1991, imports were 2.41
million gallons and exports were 101.8 million gallons. Total U.S. production quantity for use
in screen reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
If released to soil, 1,1,1-trichloroethane is expected to rapidly volatilize from both moist
and dry soil to the atmosphere. Biodegradation may occur slowly in both aerobic and
anaerobic soils. It has a high potential to leach into soil. If released to water, volatilization to
the atmosphere is expected to be the dominant fate process. Neither bioconcentration in fish
and aquatic organisms nor adsorption to sediment and suspended organic matter are expected
to be significant. The biodegradation of 1,1,1-trichloroethane in water has been well studied
and removal under aerobic conditions has not occurred to any significant extent. Experimental
half-lives for the anaerobic degradation of 1,1,1 -trichloroethane in water or water/sediment
systems range from 1 day to 16 weeks; high concentrations ( greater than 1 mg/L) were found to
be toxic to microorganisms. 1,1-Dichloroethane has been identified as the primary anaerobic
degradation product of 1,1,1-trichloroethane. If released to the atmosphere, 1,1,1-
trichloroethane is expected to persist for long periods of time. Half-lives for the gas-phase
reaction of 1,1,1 -trichloroethane with hydroxyl radicals ranging from 2 to 6 years have been
reported. Direct photolytic degradation of 1,1,1-trichloroethane in the troposphere does not
occur to any significant extent. It may undergo atmospheric removal by wet deposition
processes, although any 1,1,1-trichloroethane removed by this processes is expected to rapidly
re-volatilize to the atmosphere. In experimental studies using a model wastewater treatment
system, 1,1,1-trichloroethane underwent 99 percent removal due entirely to volatilization and
not biodegradation.
DRAFT-September 1994 11-108
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals 1,1,1-Trichloroethane
Health Hazard
See Table II-6 and accompanying summary
1,2,4-Trimethyl Benzene
Chemical Properties and Information
1,2,4-Trimethyl benzene [pseudocumene, trimethyl benzene,
asymmetrical trimethyl benzene]
CAS# 95-63-6
Molecular weight: 120.19
Melting Point: -43.78 °C(M)
Water Solubility: 0.02 g/l (E)
Vapor Pressure: 10.34 torr (at 54.4°C) (M)
Log Kow: 3.78 (M)
Henry's Law Constant: 6.16X10'3 atm-m3/mole (M)
Chemistry of Use: Solvent
C9H12
Structure:
0CH,
o
~..6 CH3
Boiling Point: 169-171°C(M)
Density: 0.876 g/cm3 (M)
FlashPoint: 54.4°C(M)
Koc: 440-2,700 (E)
Above data are either measured (M) or estimated (E)
This chemical occurs naturally in coal tar and in many petroleums. It is soluble in
alcohols, benzene, and ether.
1,2,4-Trimethyl benzene is synthesized by extraction from C9 hydrocarbon reformate by
superfractionation.
Market Profile
In 1992, total U.S. production of alkylbenzenes was 1.2 billion pounds. Information
specific to 1,2,4-trimethyl benzene was not available. Imports and exports of this chemical are
unknown. Total U.S. production quantity for use in screen reclamation is unknown.
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
DRAFT-September 1994 11-109
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
1,2,4-Trimethyl Benzene
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
In the atmosphere, gas-phase 1,2,4-trimethyl benzene will degrade by reaction with
photochemically produced hydroxyl radicals (estimated half-life of 7 hours). Removal from air
via wet deposition may also occur. If released to soil, 1,2,4-trimethyl benzene would have a
high adsorption potential and exhibit slight to medium soil mobility. Biodegradation should be
important in soil and water; however, this removal process may be hindered by high
adsorption. On terrestrial surfaces, volatilization will be an important removal process. In
surface waters, volatilization is expected to be the primary transport process with estimated
half-lives of 1.2 and 105 hours from a model river (1 meter deep) and a model lake,
respectively. Adsorption to sediment will also be important. Hydrolysis and photolysis are not
expected to be important fate processes for 1,2,4-trimethylbenzene in water. Bioconcentration
in fish may be important. Assuming a fast biodegradation rate for 1,2,4-trimethylbenzene in
the STP fugacity model results in greater than99 percent predicted total removal from
wastewater treatment plants; a moderate rate corresponds to 97 percent removal.
Health Hazard
See Table II-6 and accompanying summary
Tripropylene Glycol Methyl Ether
Chemical Properties and Information
Tripropylene glycol methyl ether [propanol, [2-(2-methoxy-
methylethoxy) methylethoxy]-, 2, 2, 2, Methoxypropoxy
propoxy propanol]
CAS# 25498-49-1
Molecular weight: 206.3
Melting Point: Not available
Water Solubility: Completely miscible in water (E)
Vapor Pressure: 0.022 torr (at75°C) (E)
0.002torr(at20°C)(E)
Log Kow: 0.56 (E)
Henry's Law Constant: 2.02x10'9atm-m3/mole (E)
Chemistry of Use: Solvent
C10H2204
Structure:
HOCH2CHOCH2CHOCH2CHOCH3
CH-
CH-
CH-
'3 3 3
Boiling Point: 242.4°C (at 1 atm) (E)
Density: 0.96g/cm3(E)
Flash Point: 260°C (open cup) (E)
Koc: 48 (E
Above data are either measured (M) or estimated (E)
DRAFT—September 1994
11-110
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Tripropylene Glycol Methyl Ether
The chemical properties were estimated by comparing this chemical to tripropylene glycol
monoethyl ether (2-Propanol, 1-[2-(2-methoxy-l-methyl ethoxy)-!-methyl ethoxy]-), which has
CAS number 20324-33-8. It is miscible with organics.
This chemical is synthesized by the addition of three moles of propylene oxide to
methanol.
Market Profile
In 1991, total U.S. production was about 4.3 million gallons. Of this quantity, 1.6 million
gallons were exported. Total U.S. production quantity for use in screen reclamation was
estimated to be 623,000 gallons.
Regulatory Status
Tripropylene glycol methyl ether does not trigger any federal environmental regulations.
However, the generic category of glycol ethers is listed as Hazardous Air Pollutants in the Clean
Air Act.
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Dipropylene glycol isopropyl ether is not expected to undergo hydrolysis or direct
photolysis in the environment. In water, volatilization, adsorption to sediments and suspended
solids, and bioconcentration in aquatic organisms are not expected to be important transport
processes for dipropylene glycol isopropyl ether. Biodegradation is likely to be the most
important removal mechanism of dipropylene glycol isopropyl ether from aerobic soil and water
based on screening studies of other glycol ether compounds. If released to soil, dipropylene
glycol isopropyl ether is expected to display very high mobility. Volatilization from dry soil
surfaces will be important. In the atmosphere, dipropylene glycol isopropyl ether is expected to
exist almost entirely in the gas-phase and reactions with photochemically produced hydroxyl
radicals should be fast (estimated half-life of 2.5 hrs). Using a rapid biodegradation rate for
dipropylene glycol isopropyl ether in the STP fugacity model results in 97% predicted removal
from wastewater treatment plants; a moderate rate corresponds to 83% predicted removal.
DRAFT-September 1994 11-111
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Tripropylene Glycol Methyl Ether
Health Hazard
See Table II-6 and accompanying summary
Trisodium Phosphate
Basic Chemical Properties
Trisodium phosphate [phosphoric acid, trisodium salt; sodium
phosphate; tribasic sodium phosphate; trisodium
orthophosphate; TSP; Oakite]
CAS# 7601-54-9
Molecular weight: 163.9
Melting Point: 75°C(M)
Water Solubility: 145g/L(M)
Vapor Pressure: Negligible (E)
Chemistry of Use: Caustic
Na3(P04)
Structure: Na3(PO,
Boiling Point: 1583°C(M)
Density: 2.5 g/ml (M)
Flashpoint: Not applicable
Physical State: Colorless crystals
Above data are either measured (M) or estimated (E)
Trisodium phosphate behaves as a moderately strong alkali; many of its applications are
based on this property. Trisodium phosphate commercially contains excess sodium hydroxide.
It readily forms a variety of double salts with other sodium compounds. Trisodium phosphate
is insoluble in alcohol and carbon disulfide.
Trisodium phosphate is synthesized from solid state reactions such as Na4P2O7 + Na2CO3
at 800° or Na2HPO4 + Na2CO3 at 600°, which provide the high-temperature form initially. It is
also manufactured by mixing soda ash and phosphoric acid in proper proportions to form
disodium phosphate and then adding caustic soda.
Market Profile
In 1991, total U.S. production was 46 million pounds. In 1989, imports were 2.8 million
pounds and in 1991, exports were 3.6 million pounds. Total U.S. production quantity for use
in screen reclamation was unknown.
Regulatory Status
See Table II-3 and accompanying summary
DRAFT-September 1994 11-112
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Trisodium Phosphate
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
Phosphorous is an essential nutrient for all organisms and trisodium phosphate is
expected to participate in the biological assimilation and mobilization inherent in the natural
phosphorous cycle. If released to soil, trisodium phosphate is expected to be quickly sorbed
and converted to less soluble metal salts which will become essentially immobile. The use of
phosphate as a soil fertilizer has shown that this fixation processes is appreciable in all but
very coarse-textured soils and that only one fourth of the applied phosphate is usable by plants
with the rest being lost to the occluded soil fraction. Trisodium phosphate may also be
removed from soil during its assimilation as a nutrient in the metabolism of other organic
compounds. Trisodium phosphate loss by volatilization to the atmosphere is expected to be
negligible. If released to water, trisodium phosphate will dissociate into H2PO4, HPO42, and
PO4 3 ions depending on the pH of the receiving medium. In seawater (pH = 8), 87 percent of
inorganic phosphate exists as HPO42, 12 percent as PO43, and 1 percent as H2PO4 and these
species can complex with metals other than sodium. There are significant bodies of data
indicating that inorganic phosphates are responsible for algal blooms; however, uptake by
aquatic plants may not remove phosphate from the aquatic system as it is available to
microorganisms in decaying alga. Dependent on the medium, insoluble salts of iron, calcium,
and aluminum may form resulting in the phosphate being deposited on sediment. If released to
the atmosphere, particulate trisodium phosphate is likely to undergo removal by both wet and
dry deposition processes. If released to a wastewater treatment plants, essentially complete
removal of trisodium phosphate by precipitation is expected when aluminum and iron salts are
added.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-113
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals
Xylene
Xylene
Basic Chemical Properties
Xylene [Dimethylbenzene; methyltoluene; xylol]
CAS# 1330-20-7
Molecular weight: 106.2
Vapor Pressure: 10 mm Hg (E) (25°C)
Water Solubility: 0.1g/L(E)
Melting Point: o: -25°C(M)
m: -48°C(M)
p: 13°C(M)
LogKow= 3.12-3.20 (M)
Henry's Law Constant: 5.18 x 10'3- 7.53 x 10'3 atm-m3/mole
(M)
Chemistry of Use: Solvent
Structure: o-xylene
CH
o
.CH
m-xylene
CH3
p-xylene
3
o-xylene
m —xylene
p —xylene
Boiling Point: 137-140°C(M)
Density: 0.864 g/ml (M)
FlashPoint: o: 17°C(M)
m: 29°C(M)
p: 27°C(M)
Koc: 25-166(M)
Physical State: Colorless liquid
Above data are either measured (M) or estimated (E)
The commercial product "mixed xylenes" is a technical product generally containing
approximately 40 percent m-xylene and 20 percent each of o-xylene, p-xylene, and ethylbenzene,
as well as small quantities of toluene. Xylene is produced in large quantities and is an agent of
major chemical and occupational significance. Xylene is miscible with absolute alcohol, ether,
and many other organic liquids.
Xylene is recovered from petroleum-derived catalytic reformate or pyrrolyis of gasoline. It
is recovered from crude light oil, a by product of coke manufacture. It is also synthesized by
the disproportionation of toluene.
Market Profile
In 1992, total U.S. production was 5.5 billion gallons. Imports were 305 million gallons
and exports were 318.8 million gallons. Total U.S. production quantity for use in screen
reclamation was estimated to be 6.88 million gallons.
Regulatory Status
See Table II-3 and accompanying summary
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Information on Individual Printing Chemicals Xylene
Hazard Summary
Aquatic Toxicity
See Table II-4, Table II-5 and accompanying summary
See Appendix M for the comprehensive methodology for this assessment
Environmental Fate
In the atmosphere, xylenes will degrade by reaction with photochemically produced
hydroxyl radicals. Half-lives for this reaction in air are typically 1-16 hours. Photolysis and
reaction with ozone will not be important. If released to water or soil surfaces, volatilization to
the ambient atmosphere will be the dominant removal process. Hydrolysis and
bioconcentration in aquatic organisms will not be important fate processes for xylenes in water.
Xylenes may partition from the water column to sediment. In soil, xylenes exhibit moderate
adsorption potential. Biodegradation will be important in soil and water where volatilization
does not occur. Xylenes are readily degradable in standard aerobic biodegradability tests using
a variety of inocula including sewage, activated sludge, and seawater. Under anaerobic
conditions, an acclimation period may be required for significant biodegradation. Using a
moderate biodegradation rate for xylenes in the STP fugacity model results in 94 percent
predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT-September 1994 11-115
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II. SCREEN RECLAMATION CHEMICALS
Federal Environmental Regulations that Affect Screen Reclamation Chemicals
CWA
Federal Environmental Regulations that Affect Screen Reclamation Chemicals
This section describes the federal environmental regulations that affect the use of screen
reclamation chemicals. Discharges of screen reclamation chemicals may be restricted by air,
water and solid waste regulations; in addition, facilities may be required to report releases of
some reclamation products subject to the federal toxic release inventory program. Table II-3
identifies federal regulations that govern releases of specific screen reclamation chemicals; in
addition, emissions or disposal of some chemicals may be regulated under general provisions.
Table 11-3
Screen Reclamation Use Cluster Chemicals
Which Trigger Federal Environmental Regulations^,
Chemical
Acetone
Butylacetate
Cyclohexanone
Dichloromethane
Ethyl acetate
Isopropanol
Methanol
Methyl ethyl ketone
Potassium hydroxide
Sodium hexametaphosphate
Sodium hydroxide
Sodium hypochlorite
Sodium salt, dodecyl benzene
sulfonic acid
1,1,1-Trichloroethane
Triethanol amine salt, dodecyl
benzene sulfonic acid
1,2,4-Trimethylbenzene
Trisodium phosphate
Toluene
Xylene
CAS#
67-64-1
123-86-4
108-94-1
75-09-2
141-78-6
67-63-0
67-56-1
78-93-3
1310-58-3
10124-56-8
1310-73-2
7681-52-9
25155-30-0
71-55-6
27323-41-7
95-63-6
7601-54-9
108-88-3
1330-20-7
CWA
Report able
Quantity (Ibs)
5,000
1,000
5,000
1,000
100
1,000
1,000
5,000
1,000
1,000
CWA
Priority
Pollutant
X
X
X
CAA
Hazardous Air
Pollutantb
X
X
X
X
X
X
CERCLA
Report able
Quantity (Ibs)
5,000
5,000
5,000
1,000
5,000
5,000
5,000
1,000
5,000
1,000
100
1,000
1,000
1,000
5,000
1,000
1,000
SARA 31 3
(TRI)
X
X
X
X
X
X
X
X
X
RCRA
Hazardous
Waste Code
U002
U057
U080
U112
U154
U159
0035°
U208
U220
U239
° See following pages for a description of each acronym and regulation.
b The generic category of glycol ethers are also listed as Hazardous Air Pollutants in the Clean Air Act Amendments.
0 In addition to being listed as a U waste, methyl ethyl ketone also exhibits a characteristic of toxicity which causes it to be considered hazardous waste.
DRAFT—September 1994
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II. SCREEN RECLAMATION CHEMICALS
Federal Environmental Regulations that Affect Screen Reclamation Chemicals CWA
CWA
The Clean Water Act (CWA) is the basic Federal law governing water pollution control in
the United States today.
Part 116 of the Federal Water Pollution Control Act (FWPCA) designates hazardous
substances under Section 311 (b) (2) (a) of the Clean Water Act, and Part 117 of the FWPCA
establishes the Reportable Quantity (RQ) for each substance listed in Part 116. When an
amount equal to or in excess of the RQ is discharged, the facility must provide notice to the
Federal government of the discharge, following Department of Transportation requirements set
forth in 33 Code of Federal Regulations (CFR) 153.203. This requirement does not apply to
facilities that discharge the substance under an National Permit Discharge Elimination System
(NPDES) Permit or a Part 404 Wetlands (dredge and fill) Permit, or to a Publicly Owned
Treatment Works (POTW), as long as any applicable effluent limitations or pretreatment
standards have been met.
The National Permit Discharge Elimination System permit program contains regulations
governing the discharge of pollutants to waters of the United States. The NPDES program
requires permits for the discharge of "pollutants" from any "point source" into "navigable
waters". The Clean Water Act defines all of these terms broadly, and a source will be required to
obtain an NPDES permit if it discharges almost anything directly to surface waters. A source
that sends its wastewater to a publicly owned treatment works (POTW) will not be required to
obtain an NPDES permit, but may be required to obtain an industrial user permit from the
POTW to cover its discharge.
In addition to other permit application requirements, facilities in the industrial category
of Printing and Publishing, and/or in Photographic Equipment and Supplies, will need to test
for all 126 priority pollutants listed in 40 CFR 122 Appendix D. Each applicant also must
indicate whether it knows or has reason to believe it discharges any of the other hazardous
substances, or non-conventional pollutants located at 40 CFR 122 Appendix D. Quantitative
testing is not required for the other hazardous pollutants; however, the applicant must describe
why it expects the pollutant to be discharged and provide the results of any quantitative data
about its discharge for that pollutant. Quantitative testing is required for the non-conventional
pollutants if the applicant expects them to be present in its discharge.
For the purpose of reporting on effluent characteristics in permit applications, there
exists a small business exemption (40 CFR 122.21 (g)(8)) for all applicants for NPDES permits
with gross total annual sales averaging less than $100,000 per year (in second quarter 1980
dollars). This exempts the small business from submitting quantitative data on certain organic
toxic pollutants (see 40 CFR 122.21 Table II, Appendix D). However, the small business must
still provide quantitative data for other toxic pollutants (metals and cyanides) and total phenols,
as listed in 40 CFR 122.21 Table III, Appendix D. The same regulations apply to the small
business concerning the other hazardous pollutants and non-conventional pollutants as for the
larger facilities (see previous paragraph).
CAA
The Clean Air Act (CAA), with its 1990 amendments, sets the framework for air pollution
control. Part 112 of the Clean Air Act establishes requirements that directly restrict the
emission of 189 hazardous air pollutants. The EPA is authorized to establish Maximum
DRAFT-September 1994 11-117
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II. SCREEN RECLAMATION CHEMICALS
Federal Environmental Regulations that Affect Screen Reclamation Chemicals CAA
Achievable Control Technology (MACT) standards for source categories that emit at least one of
the pollutants on the list. Currently, there is no MACT standard scheduled for proposal in the
commercial screen printing industry.
CERCLA
Comprehensive Environmental Response, Compensation and Liability Act (also known as
CERCLA, or more commonly as Superfund). CERCLA is the Act that created the Superfund and
set up a variety of mechanisms to address risks to public health, welfare, and the environment
caused by hazardous substance releases.
Substances deemed hazardous by CERCLA are listed in 40 Code of Federal Regulations
(CFR) 302.4. Based on criteria that relate to the possibility of harm associated with the release
of each substance, CERCLA assigns a substance-specific reportable quantity (RQ); RQs are
either 1, 10, 100, 1000, or 5000 pounds (except for radionuclides). Any person in charge of a
facility (or a vessel) must immediately notify the National Response Center as soon as a person
has knowledge of a release (within a 24-hour period) of an amount of a hazardous substance
that is equal to or greater than its RQ.1 There are some exceptions to this requirement,
including exceptions for certain continuous releases and for Federally permitted releases.
SARA 313
CERCLA was enacted in 1980 and, among other amendments, was amended in 1986 by
Title I of the Superfund Amendments and Reauthorization Act (SARA). Under SARA 313, a
facility that has more than 10 employees and that manufactures, processes or otherwise uses
more than 10,000 or 25,000 pounds per year of any toxic chemical listed in 40 Code of Federal
Regulations (CFR) 372.65 must file a toxic chemical release inventory (TRI) reporting form
(EPA Form R) covering releases of these toxic chemicals (including those releases specifically
allowed by EPA or State permits) with the EPA and a State agency. The threshold for reporting
releases is 10,000 or 25,000 pounds, depending on how the chemical is used (40 CFR 372.25).
Form R is filed annually, covers all toxic releases for the calendar year, and must be filed on or
before the first of July of the following year. Table II-3 lists chemicals used by facilities in
screen reclamation that are listed in the Toxic Release Inventory (TRI). Individual facilities may
use other chemicals which are listed in the TRI, but are not in Table II-3.
RCRA
One purpose of the Resource Conservation and Recovery Act (RCRA) of 1976 (as
amended in 1984) is to set up a cradle-to-grave system for tracking and regulating hazardous
waste. The EPA has issued regulations, found in 40 CFR Parts 260-299, which implement the
Federal statute. These regulations are Federal requirements. As of March 1994, 46 States have
been authorized to implement the RCRA program and may include more stringent
requirements in their authorized RCRA programs. In addition, non-RCRA-authorized States
(Alaska, Hawaii, Iowa and Wyoming) may have State laws that set out hazardous waste
1 The national toll-free number for the National Response Center is (800)-424-8802; in Washington, D.C., call (202)-426-
2675.
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II. SCREEN RECLAMATION CHEMICALS
Federal Environmental Regulations that Affect Screen Reclamation Chemicals RCRA
management requirements. A facility should always check with the State when analyzing which
requirements apply to their activities.
Assuming the material is a solid waste, the first evaluation to be made is whether it is
also considered a hazardous waste. Part 261 of 40 Code of Federal Regulations (CFR)
addresses the identification and listing of hazardous waste. The waste generator has the
responsibility for determining whether a waste is hazardous, and what classification, if any,
may apply to the waste. The generator must examine the regulations and undertake any tests
necessary to determine if the wastes generated are hazardous. Waste generators may also use
their own knowledge and familiarity with the waste to determine whether it is hazardous.
Generators may be subject to enforcement penalties for improperly determining that a waste is
not hazardous.
Wastes can be classified as hazardous either because they are listed by EPA through
regulation and appear in the 40 CFR Part 261 or because they exhibit certain characteristics.
Listed wastes are specifically named, e.g., discarded commercial toluene, spent non-
halogenated solvents. Characteristic wastes are defined as hazardous if they "fail" a
characteristic test, such as the RCRA test for ignitability.
There are four separate lists of hazardous wastes in 40 CFR 261. If any of the wastes
from a printing facility is on any of these lists, the facility is subject to regulation under RCRA.
The listing is often defined by industrial processes, but all wastes are listed because they
contain particular chemical constituents (these constituents are listed in Appendix VII to Part
261). Section 261.31 lists wastes from non-specific sources and includes wastes generated by
industrial processes that may occur in several different industries; the codes for such wastes
always begin with the letter "F." The second category of listed wastes (40 CFR 261.32) includes
hazardous wastes from specific sources; these wastes have codes that begin with the letter "K."
The remaining lists (40 CFR 261.33) cover commercial chemical products that have been or are
intended to be discarded; these have two letter designations, "P" and "U." Waste codes beginning
with "P" are considered acutely hazardous, while those beginning with "U" are simply considered
hazardous. Listed wastes from chemicals that are commonly used in the screen reclamation are
shown in Table II-3. While these exhibits are intended to be as comprehensive as possible,
individual facilities may use other chemicals and generate other listed hazardous wastes that
are not included in Table II-3. Facilities may wish to consult the lists at 40 CFR 261.31-261.33.2
Generator status defines how to dispose of a listed or characteristic waste. The
hazardous waste generator is defined as any person, by site, who creates a hazardous waste or
makes a waste subject to RCRA Subtitle C. Generators are divided into three categories:
o Large Quantity Generators -These facilities generate at least 1000 kg (approximately
2200 Ibs.) of hazardous waste per month, or greater than 1 kg (2.2 Ibs) of acutely
hazardous waste3 per month.
2 Lists of the "F, P, K and U" hazardous wastes can also be obtained by calling the EPA RCRA/Superfund/EPCRA Hotline at
(800) 424-9346.
3 The provisions regarding acutely hazardous waste are not likely to affect printers. Acutely hazardous waste includes
certain "F" listed wastes that do not apply to printers, and "P" listed wastes, none of which were identified as in use in the
commercial screen printing industry. (See 40 CFR 261.31-33 for more information).
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II. SCREEN RECLAMATION CHEMICALS
Federal Environmental Regulations that Affect Screen Reclamation Chemicals RCRA
o Small Quantity Generators (SQG) — These facilities generate greater than 100 kg
(approx. 220 Ibs.) but less than 1000 kg of hazardous waste per month, and up to
1 kg (2.2 Ibs) per month of acutely hazardous waste.
o Conditionally exempt small quantity generators (CESQG) — These facilities
generate no more than 100 kg (approx. 220 Ibs) per month of hazardous waste and
up to 1 kg (2.2 Ibs) per month of acutely hazardous waste.
Large and small quantity generators must meet many similar requirements. 40 CFR 262
provides that SQGs may accumulate up to 6000 kg of hazardous waste on-site at any one time
for up to 180 days without being regulated as a treatment, storage, or disposal (TSD) facility
and thereby having to apply for a TSD permit. The provisions of 40 CFR 262.34 (f) allow SQGs
to store waste on-site for 270 days without having to apply for TSD status provided the waste
must be transported over 200 miles. Large quantity generators have only a 90-day window to
ship wastes off-site without needing a RCRA TSD permit. Keep in mind that most provisions of
40 CFR 264 and 265 (for hazardous waste treatment, storage and disposal facilities) do not
apply to generators who send their wastes off-site within the 90- or 180-day window, whichever
is applicable.
Hazardous waste generators that do not meet the conditions for conditionally exempt
small quantity generators must (among other requirements such as record keeping and
reporting):
o Obtain a generator identification number;
o Store and ship hazardous waste in suitable containers or tanks (for storage only);
o Manifest the waste properly;
o Maintain copies of the manifest, a shipment log covering all hazardous waste
shipments, and test records;
o Comply with applicable land disposal restriction requirements; and
o Report releases or threats of releases of hazardous waste.
Summary of the Environmental Hazard Assessment for the Screen Reclamation
Chemicals
The chemicals in screen reclamation are divided into three groups: (1) discrete organic
chemicals, (2) petroleum products, and (3) inorganic chemicals. While the assessment process
is the same for all three groups, the methodology used to provide estimates of the aquatic
toxicity of the chemicals varies.
Methodology
The Environmental Effects Branch uses a standard assessment process (see Appendix M)
for assessing the hazards of chemicals to the aquatic environment. The process has been
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II. SCREEN RECLAMATION CHEMICALS
Summary of the Environmental Hazard Assessment
for the Screen Reclamation Chemicals Methodology
described and published in several publications, both inside and outside the Agency. A
summary of the hazard assessment process and references are in Appendix M. The
methodology involves the development of a standard hazard profile for each chemical consisting
of three acute toxicity values and three chronic values for aquatic species. The standard hazard
profile consists of the following toxicity values:
o Fish acute value (Usually a Fish 96-hour LC50 value)
o Aquatic invertebrate acute value (Usually a Daphnid 48-hour LC50 value)
o Green Algal Toxicity value (Usually an Algal 96-hour EC50 value)
o Fish Chronic value (Usually a Fish 28-day early life stage no effect concentration
(NEC).
o Aquatic Invertebrate Chronic value (Usually a Daphnid 21-day NEC.
o Algal Chronic value (Usually a Algal 96 hour NEC value for biomass)
The toxicity values may be obtained from the results of standard toxicity tests reported to
the Agency, published in the literature, or estimated using predictive techniques. For this
study, discrete organic chemicals were assessed using predictive equations called Structure
Activity Relationships (SARs) to estimate the inherent toxicity of these chemicals to aquatic
organisms.
The petroleum products such as mineral spirits and solvent naphtha are mixtures and do
not lend themselves readily to the standard hazard assessment process using SARs. The
chemical constituents and the percentage of each in the mixture varies. The constituents in
these products include linear and branched paraffins, cyclic paraffins with the total number of
carbons varying between 5 and 16. The toxicity of the petroleum products were determined by
estimating the toxicity of each individual constituent and then evaluating the potential hazard of
the product.
The estimates of toxicity for the inorganic chemicals was either based on information
extracted from a report by the U.S. Atomic Energy Commission (1973) or assessed using actual
data and nearest analog information taken from open literature.
Environmental Hazard Ranking
For the purpose of an overall assessment, the listed chemicals can be ranked according to
the estimated chronic value. This ranking is based on scoring the chemicals as High, Moderate
or Low concern for chronic effects according to the following criteria:
< 0.1 mg/L High
> 0.1 to < 10 mg/L Moderate
> 10 mg/L Low
See Appendix M for the basis and citations supporting these criteria.
DRAFT-September 1994 11-121
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of the Environmental Hazard Assessment
for the Screen Reclamation Chemicals Results
The results of this ranking are summarized in Table II-5. The chemicals are ranked from
the highest hazard potential to the lowest based on lowest of the three estimated chronic values
for each chemical. The petroleum products are rated as high hazard to aquatic organisms and
the concern is for chronic effects. Also included in the high hazard category are periodic acid
and sodium periodate, both which are strong oxiding agents and highly reactive. The concern
for trisodium phosphate is for phosphorus enrichment of receiving waters leading to algal
blooms.
This relative ranking of toxicity, provides guidance to the selection and use of chemicals
that are less hazardous to aquatic organisms.
A search for toxicity data in the AQUIRE database (AQUatic toxicity Information REtrieval
database) has been completed. The search indicates that some data were available for 22 of the
chemicals being assessed in the data set. These data were evaluated and the measured toxicity
values compared favorably with the predicted values.
Results
The toxicity values for acute and chronic effects to aquatic organisms were estimated
using predictive equations based on SARs, except for the inorganic chemicals. The values for
inorganic chemicals were obtained from published reports. The results are summarized in
Table II-4. The chemicals are listed alphabetically. For each chemical, the estimated toxicity
values in mg/L (ppm) for acute and chronic effects offish, daphnid and algae are given. The last
column shows the concern concentration set for the chemical in the water. This value is derived
by dividing the lowest of the three chronic values by a factor of 10. If the discharge of a chemical
to the aquatic environment results in a concentration equal to or greater than the concern
concentration set, then the chemical would be hazardous to aquatic organisms.
To assess the potential hazard of the petroleum products, toxicity values were estimated
for the individual components, i.e., C5 to C16 linear and branched paraffins and cyclic paraffins.
To estimate the toxicity of a product, the assumption is made that each component is present
as an equal percentage in the product and the geometric mean of the range of estimates
provides the best estimate of the toxicity. For example, for a C9 to C12 linear paraffin, the
estimated chronic values for the Daphnid Chronic are 0.019, 0.008, 0.004 and 0.002 mg/L and
the geometric mean is 0.006 mg/L. Based on these procedures the hazard potential of the
various products are discussed in the following paragraphs.
Mineral Spirits
Mineral spirits consist of linear and branched paraffins and cyclo paraffins. Based on the
information provided, the assessment was based on the estimated toxicity for n-hexane and
ethylcyclohexane. The linear form of n-hexane is approximately two times more toxic than cyclic
hexane. The lowest chronic value for n-hexane is 0.004 mg/L for fish and the lowest chronic
value for ethylcylohexane is 0.09 mg/L for fish.
DRAFT-September 1994 11-122
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of the Environmental Hazard Assessment for the Screen Reclamation Chemicals Hazard Ranking
Naphtha Solvents
The monomers associated with the various naphtha mixtures include linear and
branched paraffins, cyclic paraffins and aromatics such as naphthalene. The carbon chain
lengths vary from product to product and spans range from 5 to 16.
Inorganics
The toxicity values for the hydroxides of sodium and potassium are based on the inherent
toxicity of the compounds at pH 7.0. Sodium hypochlorite is a bleaching agent and the best
estimate of toxicity indicates acute toxicity values to fish and daphnids at or below 2 mg/L.
Periodic acid and sodium periodate are highly reactive and strong oxidizing agents and as such
are expected to be highly toxic at 1 mg/L or less. All estimates on the remaining inorganic
chemicals (sodium bisulfate, sodium hexametaphosphate, silica, silica (fumed), and trisodium
phosphate) were based on pH 7.0 test conditions. Fumed silica and silica were considered the
same and showed no effects at their aqueous water solubility limits.
DRAFT-September 1994 11-123
-------
Table 11-4
Estimated Aquatic Toxicity Values
(Values in mg/L)
CO
i
3
Si
Chemical
Acetone
Alcohols, C8-C10, Ethoxylated
Alcohols, C12-C14, Ethoxylated
Benzyl alcohol
2-Butoxyethanol
Butyl Acetate
Butyrolactone
Cyclohexanolt
Cyclohexanone
d-Limonene
Diacetone alcohol
Dichloromethane
Diethyl adipate
Diethyl glutarate
Diethylene glycol
Diethylene glycol monobutyl ether
Diethylene gylcol butyl ether acetate
Diisopropyl adipate
Dimethyl adipate
Fish
Acute
>1000
24
2.2
56.6
>1000
25
140
950
0.86
>1000
320
44
78
>1000
>1000
41
24
140
Daphnid
Acute
>1000
24
2.2
13.5
>1000
160
>1000
950
1.1
>1000
320
295
830
>1000
>1000
263
94
>1000
Algal
Acute
>1000
24
2.2
33.0
620
1.9
>1000
550
0.76
>1000
190
3.4
6.0
>1000
760
3.2
1.9
11
Fish
Chronic
490
2.4
0.22
8.2
120
2.5
14
100
0.16
745
36
4.4
7.8
>1000
140
4.1
2.4
14
Daphnid
Chronic
100
2.4
0.22
6.07
33
16
>100
29
0.14
154
12
29.5
83
>1000
41
26.3
9.4
>100
Algal
Chronic
76
2.4
0.22
2.0
32
1.4
7.5
28
0.27
124
13
2.6
4.6
656
40
3.1
1.5
8.4
Concern
Cone. a
7.6
0.24
0.020
0.20
0.32
0.14
0.75
1.4
2.8
0.014
12.4
1.2
0.26
0.46
70.0
4.0
0.31
0.15
0.84
CD
3
ffl
m
w
CD
CO
CO
CD
CO
8.
m
9
CD
o'
s?
o
O
o
s Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
t Data will be inserted in the final version.
m
N
m
3D
§
-------
Table 11-4 (cont.)
Estimated Aquatic Toxicity Values
(Values in mg/L)
Chemical
Dimethyl glutarate
Dimethyl succinate
Dipropylene glycol methyl ether
Dipropylene glycol methyl ether acetate
Dodecyl benzene sulfonic acid
Ethyl acetate
Ethyl lactate
Ethyl oleate
Ethoxylated castor oil
Ethoxylated nonylphenol
(np 4-9.5)
Ethoxypropanol
Ethoxypropyl acetate
Furfuryl alcohol
Isobutyl isobutyrate
Isobutyl oleate
Fish
Acute
246
165
>1000
674
2.6
64
143
N.E.S.
0.07
2.0
>1000
80.0
>1000
12.7
N.E.S.
Daphnid
Acute
>1000
>1000
>1000
>1000
2.6
>1000
>1000
N.e.s.
0.10
2.0
>1000
>1000
>1000
45.6
N.E.S.b
Algal
Acute
18.3
12.4
>1000
49
0.5
4.8
11
N.E.S.
0.08
2.0
>1000
6.1
>100
1.03
N.E.S.
Fish
Chronic
25.0
17.0
184
67.4
0.4
6.4
14.3
N.E.S.
0.02
0.2
>1000
8.0
147
1.3
N.E.S.
Daphnid
Chronic
650
530
149
>100
0.4
>100
>100
N.E.S.
0.03
0.2
311
102
31.6
4.6
N.E.S.
Algal
Chronic
13.6
9.2
877
36
0.13
3.6
8
N.E.S.
0.07
0.5
227
4.5
25.9
0.8
N.E.S.
Concern
Cone. a
1.0
1.0
14.9
3.6
0.01
0.36
0.8
N.E.S.
0.002
0.02
20.0
0.5
3.0
0.08
N.E.S.
a Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
b N.E.S. - No Adverse Effects expected in a saturated solution during the specified exposure period.
c Estimated toxicity at pH 7.0.
d Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United States Atomic Energy Commission, June 1973.
(Environmental Effects Files)
t Data will be inserted in the final version.
CO
i
3
Si
CD
3
ffl
en
CO
CD
CO
CO
CD
CO
70
o
m
CD
o'
8L
CO
o
O
o
m
N
m
§
-------
Table 11-4 (cont.)
Estimated Aquatic Toxicity Values
(Values in mg/L)
Chemical
Isopropanol
Methanol
Methoxypropanol acetate
1 -Methyl-4-(1 -methyl-ethenyl)
cyclohexane (limonene)
Methyl ethyl ketone
Methyl lactate
Mineral spirits (straight run naptha) C10
Linear
Mineral spirits (light hydro-treated) C10
Linear
N-methylpyrrolidone
2-Octadecanamine, N,N-dimethyl N-
oxidet
Periodic Acid
Phosphoric Acid, mixed ester, with
isopropanol and ethoxylated
tridecanolt
Potassium hydroxidec'd
Fish
Acute
>1000
>1000
305
0.86
>1000
243
N.E.S.
N.E.S.
>1000
<1
>1000
Daphnid
Acute
.1000
>1000
>1000
1.1
>1000
>1000
N.E.S.
N.E.S.
>1000
<1
>1000
Algal
Acute
>1000
>1000
22.4
0.76
>1000
18
0.02
0.02
>1000
<1
>1000
Fish
Chronic
285
111
30.5
0.16
224
24.3
0.004
0.004
>1000
<0.1
>100
Daphnid
Chronic
62
128
>1000
0.14
53
>100
0.008
0.008
373
<0.1
>100
Algal
Chronic
51
90.0
16.6
0.27
45
13
0.021
0.008
265
<0.1
>100
Concern
Cone. a
5.1
9.0
2.0
0.014
4.5
1.3
0.001
0.001
26.5
0.002
<0.01
0.018
>10
a Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
b Estimated toxicity at pH 7.0.
c Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United States Atomic Energy Commission, June 1973.
(Environmental Effects Files)
t Data will be inserted in the final version.
CO
i
3
Si
CD
3
ffl
en
CO
CD
CO
CO
CD
CO
70
o
m
CD
o'
8L
CO
o
O
o
m
N
m
§
-------
Table 11-4 (cont.)
Estimated Aquatic Toxicity Values
(Values in mg/L)
Chemical
Propylene carbonate
Propylene glycol
Propylene glycol methyl ether
Propylene glycol methyl ether acetate
Silica
Silica, fumed
Sodium bisulfate
Sodium hexameta-phosphate
Sodium hydroxideb'c
Sodium hypochloriteb'c
Sodium lauryl sulfate
Sodium metasilicatet
Sodium periodate
Sodium salt, dodecyl benzene sulfonic
acid
Solvent Naphtha light aliphatic C5 - C10
Fish
Acute
177
>1000
>1000
304
NES
NES
>100
>100
>1000
<1.7
2.6
<1
2.6
0.64
Daphnid
Acute
>1000
>1000
>1000
>1000
NES
NES
>100
>100
>1000
<2.0
2.6
<1
2.6
0.86
Algal
Acute
13
>1000
>1000
22
NES
NES
>100
<1.0
>1000
<2.0
0.5
<1
0.5
0.23
Fish
Chronic
17.7
>1000
>1000
30.4
NES
NES
10.0
0.1
>100
<0.17
0.4
<0.1
0.4
0.05
Daphnid
Chronic
>100
495
210
>100
NES
NES
10.0
>10.0
>100
<0.2
0.4
<0.1
0.4
0.05
Algal
Chronic
10
329
158
17
NES
NES
10.0
0.06
>100
<0.2
0.13
<0.1
0.13
0.11
Concern
Cone. a
1.0
30.0
15.8
1.7
NES
NES
1.0
0.006
>10
<0.02
0.01
d
<0.01
0.01
0.005
a Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
b Estimated toxicity at pH 7.0.
c Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United States Atomic Energy Commission, June 1973.
(Environmental Effects Files)
d No adverse effects expected in a saturated solution during prescribed test duration.
t Data will be inserted in the final version.
CO
i
3
Si
CD
3
ffl
en
CO
CD
CO
CO
CD
CO
70
o
m
CD
o'
8L
CO
o
O
o
m
N
m
§
-------
CO
i
3
Si
s?
o
Table IW(cont.)
Estimated Aquatic Toxicity Values
(Values in mg/L)
Chemical
Solvent Naphtha light aromatic C8 - C10
Solvent Naphtha heavy aromatic C8 -
C-16
Tall oil, special!
Terpineols (Mixed Isomers)
Tetrahydrofurfuryl alcohol
Toluene
1,1,1-Trichloroethane
1 ,2,4-trimethylbenzenet
Trisodium phosphateb
Xylenes, (mixed isomers)
Fish
Acute
5.6
5.6
28
>1000
14
34
>100
3.5
Daphnid
Acute
6.7
6.7
31
>1000
16
38
>100
4.1
Algal
Acute
4.5
4.5
20
>1000
10
24
<1
2.8
Fish
Chronic
0.9
0.9
4.0
268
2.0
4.8
.10
0.57
Daphnid
Chronic
0.6
0.6
2.1
64.6
1.1
2.4
>10
0.40
Algal
Chronic
1.0
1.0
3.0
56.7
1.6
3.2
0.06
0.64
Concern
Cone. a
0.06
d
0.21
6.0
0.11
0.24
0.015
0.006
0.04
a Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
b Estimated toxicity at pH 7.0.
c Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United States Atomic Energy Commission, June 1973.
(Environmental Effects Files)
t Data will be inserted in the final version.
CD
3
ffl
en
CO
CD
CO
CO
CD
CO
70
o
m
CD
o'
8L
CO
O
o
m
N
m
§
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of Aquatic Hazard Information for Screen Reclamation Chemicals
Table 11-5
Table 11-5
Ecological Hazard Ranking of Screen Reclamation Chemicals Based on the Estimated
Chronic Values
Chemical
Solvent naphtha (light aliphatic)
Mineral spirits (light hydrotreated)
Mineral spirits (straight run)
Trisodium phosphate
2-Octadecanamine, N,N-dimethly N-oxide
Alcohols, ethoxylated C12-C14
Periodic acid
Sodium periodate
Phosphoric Acid, mixed ester, with
isopropanol and ethoxylated tridecanol
1-methyl-4-(1-methylethenyl)cyclohexane
(limonene)
1,2,4-trimethyl benzene
Sodium hypochlorite
Xylenes
Solvent naphtha (light aromatic)
Solvent naphtha (heavy aromatic)
Toluene
Butyl acetate
Diisopropyl adipate
Terpineols
1,1,1-trichloroethane
Alcohols, ethoxylated, C8-C10
Diethyl adipate
Diethylene glycol butyl ether acetate
Ethyl acetate
Diethyl glutarate
Butyrolactone
Ethyl lactate
Dimethyl adipate
Propylene carbonate
Dichloromethane
Lowest Value (mg/L)
0.004
0.004
0.004
0.06
0.02
0.1
0.10
0.10
0.18
0.14
0.15
0.17
0.40
0.60
0.60
1.1
1.4
1.5
2.1
2.4
2.5
2.6
3.1
3.6
4.6
7.5
8.0
8.4
10
12
Chronic Eco Hazard Rank
H
H
H
H
H
H
H
H
H
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
L
DRAFT—September 1994
11-129
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of Aquatic Hazard Information for Screen Reclamation Chemicals
Table 11-5
Table 11-5
Ecological Hazard Ranking of Screen Reclamation Chemicals Based on the Estimated
Chronic Values
Chemical
Methyl lactate
Cyclohexanone
Cyclohexanol
Propylene glycol methyl ether acetate
2-Butoxyethanol
Dipropylene glycol methyl ether acetate
Diethylene glycol monobutyl ether
Methyl ethyl ketone
Isopropanol
Acetone
Sodium hydroxide
Potassium hydroxide
Tripropylene glycol methyl ether
Diacetone alcohol
Dipropylene glycol methyl ether
Propylene glycol methyl ether acetate
N-methylpyrrolidone
Isobutyl oleate
Ethyl oleate
Sodium metasilicate
Tall oil, special
Lowest Value (mg/L)
13
28
14
17
32
36
40
45
51
76
100
100
120
124
149
158
265
a
a
a
a
Chronic Eco Hazard Rank
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
' No adverse effects expected in a saturated solution during prescribed test duration.
Summary of Human Hazard Information for Screen Reclamation Chemicals
Table II-6 summarizes toxicity information obtained, to date, on the chemicals used in
screen reclamation. Initial literature searches were limited to secondary sources such as EPA's
Integrated Risk Information System (IRIS) and the National Library of Medicine's Hazardous
Substances Data Bank.
DRAFT—September 1994
11-130
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of Aquatic Hazard Information for Screen Reclamation Chemicals Table 11-5
Explanation of Table 11-6
The "TOX ENDPOINT" column lists adverse toxicological effects that have been reported
in the literature. This is simply a qualitative listing of reported effects and does not imply
anything about the severity of the effects nor the doses at which the effects occur. Furthermore,
an entry in this column does not necessarily imply that EPA has reviewed the reported studies
or that EPA concurs with the authors' conclusions. Toxicological effects are abbreviated as
follows:
o car = carcinogenicity
o dev = developmental toxicity, i.e. adverse effects on the developing embryo, fetus, or
newborn
o repro = reproductive toxicity, i.e. adverse effects on the ability of either males or
females to reproduce
o gene = genetic toxicity, such as point mutations or chromosomal aberrations
o neur = adverse neurological effects; includes a wide range of effects from serious
neuropathology to transient CNS depression commonly seen with high exposures to
solvents
o chron = chronic effects not otherwise listed; commonly includes target organ
toxicity such as liver and kidney effects.
"RfD/RfC" is the EPA Reference Dose or Reference Concentration. The RfD is an estimate
of a daily exposure to the human population that is likely to be without an appreciable risk of
deleterious noncancer effects during a lifetime. The RfD is usually expressed as an oral dose in
mg/kg/day. The RfC is an analogous value for continuous inhalation exposure, usually
expressed in mg/m3.
"NOAEL/LOAEL" is the no-observed-adverse-effect level or the lowest-observed-adverse-
effect level, respectively. The NOAEL is an exposure level at which there are no statistically or
biologically significant increases in the frequency or severity of adverse effects in the exposed
population. The LOAEL is the lowest exposure level at which adverse effects have been shown
to occur.
"SLOPE/UNIT RISK" is a measure of cancer potency derived from the dose-response curve
from a carcinogenicity study (usually an animal study). The slope factor is expressed as risk
per mg/kg-daily dose. Unit risk is a similar measure for air or water exposure levels and is
expressed as risk per ug/m3 in air or as risk per ug/1 in water.
"WOE" refers to the EPA weight-of-evidence classification for carcinogens. The WOE
categories are as follows:
o Group A - human carcinogen
o Group B - probable human carcinogen. Bl indicates limited human evidence; B2
indicates sufficient evidence in animals and inadequate or no evidence in humans.
o Group C - possible human carcinogen
DRAFT-September 1994 11-131
-------
II. SCREEN RECLAMATION CHEMICALS
Summary of Human Hazard Information
for Screen Reclamation Chemicals Explanation of Table 11-6
o Group D -- not classifiable as to human carcinogenicity
o Group E -- evidence of noncarcinogenicity for humans
DRAFT-September 1994 11-132
-------
Table 11-6
Human Health Hazard Effects
Chemical Name
Acetone
Alcohols, ethoxylated C8-C10
Alcohols, ethoxylated
C12-C14
Benzyl alcohol
2-Butoxyethanol
Butyl acetate
Butyrolactone
Cyclohexanol
Cyclohexanone
Diacetone alcohol
Cas No.
67-64-1
71060-57-6
68439-50-9
100-51-6
111-76-2
123-86-4
96-48-0
108-93-0
108-94-1
123-42-2
Tox
Endpoint
neur, chron
dev, neur,
chron
dev, chron
dev, neur,
chron
dev*, repro,
neur, chron
dev, repro,
neur, chron
gene.dev.rep
ro.neur.chron
neur, chron
RfD/RfC
-0.1 mg/kg/day
(kidney)
0.3 mg/kg/day
(forestom.
hyperplasia)
RfC in review
5 mg/kg/day
(decreased wt
gain)
NOAEL/
LOAEL
1000
ppm-N,650
ppm-N
Slope/
Unit Risk
WOE
D
Comment
no data found
not care in NTP
study;notmutag. in
several tests
NTP carcinogenicity
study in review
1 000 ppm NOAEL for
repro tox, 650 ppm
NOAEL for dev tox
co =
i
3
Si
•<
o
m
m
O m
| =•
S ?
a> 3
o
o
o
g
w
-------
Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Name
Dichloromethane
Diethyl adipate
Diethyl glutarate
Diethylene glycol
Diethylene glycol monobutyl
ether
Diethylene glycol butyl ether
acetate
Diisopropyl adipate
Dimethyl adipate
Dimethyl glutarate
Cas No.
75-09-2
141-28-6
818-38-2
111-46-6
112-34-5
124-17-4
6938-94-9
627-93-0
1119-40-0
Tox
Endpoint
car, gene,
dev, neur,
chron
gene, dev
dev, neur,
chron
dev, chron
dev, chron
dev, chron
chron
RfD/RfC
0.06 mg/kg/day
(liver)
NOAEL/
LOAEL
51
mg/kg/day-
L, 2000
mg/kg/day-
N
Slope/
Unit Risk
4.7E-7/ug/
m3
WOE
B2
Comment
RfC in review
negative in Salmonella
mutagenicity test
LOAEL for chronic,
dermal NOAEL for dev
tox
RfC in review, sec. 4
data
chron, repro(- result)
studies on mixture of
dibasic esters
chron, dev(- result),
repro(-) studies on
mixture of dibasic esters
co =
i
3
Si
•<
o
m
m
O m
| =•
S ?
a> 3
o
o
o
g
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Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Name
Dimethyl succinate
Dipropylene glycol methyl
ether
Dipropylene glycol methyl
ether acetate
Dodecyl benzene sulfonic
acid, TEA salt
Ethoxylated castor oil
Ethoxylated nonylphenol
Ethoxypropanol
Ethoxypropyl acetate
Ethyl acetate
Ethyl lactate
Ethyl oleate
Ethylene glycol propyl ether
Furfuryl alcohol
Cas No.
106-65-0
34590-94-8
88917-22-0
27323-41-7
61791-12-6
9016-45-9
52125-53-8
54839-24-6
141-78-6
97-64-3
111-62-6
2807-30-9
98-00-0
Tox
Endpoint
chron
neur, chron
dev, chron
neur, chron
neur*
dev, chron
neur
RfD/RfC
0.7 mg/kg/day
NOAEL/
LOAEL
Slope/
Unit Risk
WOE
Comment
chron, dev(- result),
repro(-) studies on
mixture of dibasic esters
health effects at high
concentrations
only acute toxicity data
found
very little data
dev tox at high doses
health effects at high
dose
NIOSH 40 mg/m3 TWA;
60 mg/m3 STEL (skin);
NTP care in progress
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Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Name
Isobutyl isobutyrate
Isobutyl oleate
Isopropanol
d-Limonene
Methanol
Methyl ethyl ketone
Methyl lactate
Mineral spirits (straight run
naphtha)
Mineral spirits (light
hydrotreated)
N-methylpyrrolidone
2-Octadecanamine,
N,N-dimethyl, N-oxide
Cas No.
97-85-8
10024-47-2
67-63-0
5989-27-5
67-56-1
78-93-3
547-64-8
64741-41-9
64742-47-8
872-50-4
71662-60-7
Tox
Endpoint
dev, neur,
chron
dev, chron
gene, dev,
neur, chron
dev, neur,
chron
dev, repro,
chron
RfD/RfC
0.5 mg/kg/day
(liver)
0.6 mg/kg/day,
1.0mg/m3
NOAEL/
LOAEL
150
mg/kg/day
LOAEL
175
mg/kg/day
NOAEL
Slope/
Unit Risk
WOE
D
Comment
no effects in subchronic
rat study up to 1000
mg/kg/day
limited chronic data
LOAEL on kidney effect
in review at NTP
RfD/RfC on
developmental toxicity
NOAEL on
developmental toxicity
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Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Name
Periodic acid
Phosphoric acid, mixed ester
w/isopropanol and ethoxilated
tridecanol
Potassium hydroxide
Propylene carbonate
Propylene glycol
Propylene glycol methyl ether
Propylene glycol methyl ether
acetate
Silica
Silica, fumed
Sodium bisulfate
Cas No.
13444-71-8
68186-42-5
1310-58-3
108-32-7
57-55-6
107-98-2
108-65-6
7631-86-9
112945-52-5
10034-88-5
Tox
Endpoint
corrosive
chron
dev, neur
care, chron
corrosive
RfD/RfC
20 mg/kg/day
RfD 0.7
mg/kg/day, RfC
2.0 mg/m3
NOAEL/
LOAEL
3000 ppm-L
Slope/
Unit Risk
WOE
Comment
oxidizer
CTFA assess; tech
grade may contain
propylene oxide, a
carcinogen
negative Genetox for
SCE and cell
transformation
LOAEL on dev, RfC on
neur, RfD on liver,
kidney
crystalline silica is IARC
2A carcinogen
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Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Name
Sodium hexametaphosphate
Sodium hydroxide
Sodium hypochlorite
Sodium lauryl sulfate
Sodium metasilicate
Sodium periodate
Naphtha, light aliphatic
Naphtha, light aromatic
Sodium salt, dodecyl
benzenesulfonic acid
Solvent naphtha, heavy
aromatic
Tall oil, special
Cas No.
10124-56-8
1310-73-2
7681-52-9
151-21-3
6834-92-0
7790-28-5
64742-89-8
64742-95-6
25155-30-0
64742-94-5
68937-81-5
Tox
Endpoint
chron
corrosive
gene, dev,
chron
dev, chron
dev,
corrosive
dev
RfD/RfC
NOAEL/
LOAEL
300
mg/kg/day,
400
mg/kg/day-
N
Slope/
Unit Risk
WOE
Comment
not mutagenic in
Salmonella or S.
cerevisiae; chron effects
at high doses
oxidizer
NOAELS are 300
mg/kg/day dev't tox and
400 mg/kg/day chronic
tox
oxidizer
developmental toxicity
data on C9 fraction
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Chapter III
Background Information on Methodologies Used In Screen
Reclamation Risk, Performance and Cost Evaluation
This chapter is intended to serve as a reference section for the CTSA document and
contains details of data collection and methodologies used in the CTSA risk assessment,
performance demonstration and cost evaluation. The methodologies and assumptions
underlying the evaluations in Chapter 5 are outlined in this chapter, including:
o Screen Printing Workplace Practices Questionnaire
o Occupational Exposures (inhalation and dermal)
o Environmental Releases
o Population Exposure Assessments
o Risk Assessments
o Performance Evaluations
o Cost Estimates
Overview of Data from the Screen Printing Industry Used in Risk Assessment
In August and September 1993, screen printers were surveyed on the workplace practices
associated with the screen cleaning/reclamation process. The survey tool was the "Workplace
Practices Questionnaire for Screen Printers" (Appendix B), developed by the Screen Printing
Association International (SPAI), the University of Tennessee Center for Clean Products and
Clean Technologies and staff of the EPA Design for the Environment Program. The survey was
developed to characterize typical screen printing facilities and workplace practices associated
with the screen cleaning/reclamation process. This information was needed to estimate the
amounts and types of environmental releases from the screen cleaning/reclamation process and
to estimate exposure from the process. The results were also used to help identify pollution
prevention opportunities for screen printers.
SPAI distributed the workplace practices questionnaire to approximately 300 printers,
focusing on printers with 20 or fewer employees. Respondents mailed completed
questionnaires to SPAI, which sent them to the University of Tennessee Center for Clean
Products and Clean Technologies, where they were entered into a data base using FOXPRO
software. The University of Tennessee, under a research grant from the EPA Office of Pollution
Prevention and Toxics, developed a summary of responses to the questionnaire. Respondents
to the survey were guaranteed anonymity and their identities withheld from the computerized
database provided to EPA and from the summary of results.
All facilities that received the questionnaire were asked to respond to pages one, two and
11 of the questionnaire, which included a business profile, major products produced, general
facility information, equipment and materials use, and pollution prevention opportunities for
DRAFT-September 1994 111-1
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment
screen printers. Only screen printers who used solvent or UV-based inks printed on
plastic/vinyl substrates were asked to respond to the remainder of the questionnaire.
Appendix C presents the summary of responses to the questionnaire. A total of 1 15
screen printers responded to the questionnaire, which represents an approximate 38 percent
response rate. Representatives from SPAI and the screen printers who participated in the
survey should be congratulated for this exceptionally high response rate to a direct mail
questionnaire. Of the total, 107 respondents were screen printers who primarily use solvent or
UV-based inks printed on plastic/vinyl substrates.
Environmental Releases and Occupational Exposure Assessment
Specific quantities for environmental releases and occupational exposure to chemicals
can be determined for a particular system used in screen reclamation. This summary provides
an overview of the releases and exposure and methodology used in determining the releases
and exposure for the traditional ink remover, emulsion remover, and haze remover products.
While the greatest environmental releases and occupational exposure occur during the
actual process of screen reclamation, releases and exposure also occur from volatilization from
open containers, transfer operations, sampling operations, and waste rags. Air releases and
the inhalation exposures occur as a result of volatilization during these operations. Releases to
air occur by volatilization of chemicals from open containers, from the surface of the screen as
it is being cleaned, and from rags used in the cleaning process. Estimation of releases to land
and water is based on a mass balance relationship. Dermal exposures can also be estimated
based on operations, formulation concentrations, and established dermal exposure models.1
It is assumed that workers perform the following activities during each step of the screen
reclamation process. Some of these steps are not necessary or are altered for certain methods
assessed here. See Figure 1-2 for an outline of the steps involved in each method.
Step 1 . Ink removal
o Open 55-gallon drum of ink remover
o Pour ink remover into 5-gallon pail
o Dip rag or brush into pail
o Remove ink from screen
o Toss rag into laundry pile
o Drum waste ink for disposal
Step 2. Emulsion removal
o Open container of emulsion remover
o Dip brush into container
o Remove emulsion from screen
o Rinse screen
'U.S. EPA. Dermal Exposure Assessment: Principles and Applications. Office of Health and Environmental Assessment,
Jan. 1992, Document no. EPA/600/8-9/01 IF.
DRAFT-September 1994 III-2
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment
Step 3. Haze removal
o Open container of haze remover
o Dip brush into container
o Remove haze from screen
o Rinse screen
To support the assessments, numerous sources of information were used in gathering
data. Preliminary information was collected from the 1 1-page Screen Printing Workplace
Practices Questionnaire. Meetings with printers to discuss the basic data assumptions used in
the assessment were held at Screen Print '93 in New Orleans in October 1993 and at the SPAI
Environmental Committee Meeting in January 1994. Information was also verified though
facilities participating in the Screen Printing Performance Demonstration from February to May
1 994 . These operation assumptions and data are presented in Table III- 1 .
Table 111-1
Assumptions and Data from Industry and Trade Groups
Type of Data
Number of employees involved in ink removal
Hours per employee per day in ink removal
Number of employees in screen reclamation
Hours per employee per day in screen reclamation
Average number of screens cleaned per day
Average screen size
Size of combined screen reclamation/ink removal area
Amount of ink remover per screen
Amount of emulsion remover per screen
Amount of haze remover per screen
Average value
Number
3
1
2
1.5
6
2,127
80
8 (traditional)
4 (alternative)
3.5
3
Units
employees
hours
employees
hours
screens
in2
ft2
oz
oz
oz
a Normalized from Workplace Practices Questionnaire to remove printing establishments larger
than 20 employees.
Estimation Methodology
In general, in evaluating traditional and alternative screen reclamation systems, it is
assumed that all releases to air, land, or water occur via the four scenarios described below.
Using this assumption cleaning fluid usage has been partitioned to air, land, and water with
concentrations of mass. Volatilization is estimated using a number of established models as
DRAFT—September 1994
III-3
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment _ Estimation Methodology
documented below. Water and land releases are estimated to be all cleaning fluids not
volatilized. The exposure/release scenarios are defined as follows:
o Scenario I. Actual screen cleaning operations. Air releases are due to volatilization
of chemicals from the screen surface. Unvolatilized material is assumed to be
disposed to land or water. Ink, emulsion, and haze removal for 6 screens a day;
each screen is approximately 2100m2.
o Scenario II. Releases to the atmosphere from pouring of 1 oz of material for
sampling. This is assumed to take place over 15 minutes each day.
o Scenario III. Releases to the atmosphere from pouring of cleaning mixtures from a
55-gallon drum into a 5 gallon pail.
o Scenario IV. Releases from rags stored in a two-thirds empty drum. The water
releases in this case occur in a commercial laundry. The drum is opened to add
more rags once per day and to transfer the rags from the storage drum to a
laundry. Rags are used only for the ink removal step.
Releases shown in the above scenarios will occur during the use of Reclamation Methods
1,2, and 4 of Exhibit 1-2. In addition to these releases, in Method 3 (SPAI Workshop Process),
an ink degradant is applied after the ink remover, followed by a water rinse; a screen degreaser
is then applied prior to use of the emulsion remover. For the purposes of this assessment,
Method 3 is evaluated only in conjunction with system Omicron.
Assumptions for Environmental Releases
The environmental releases model prepared for this report assumes that releases to air
equal the total airborne concentration of chemicals from:
o volatilization of solvents from screens
o emissions from transfer operations
o emissions from sampling operations
volatilization from waste dirty rags
o
The following assumptions and sources of information were used in the model:
o typical airborne concentrations
o typical ventilation rates
o emission factors from EPA (AP-42) (an EPA compendium of emission factors from
the Office of Air)
o formulation data and physical properties
o average amounts of ink, haze, and emulsion remover used per site-day of 36
ounces, 21 ounces, and 18 ounces
DRAFT-September 1994 III-4
-------
III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment _ Estimation Methodology
The model addresses releases to three media: air, water, and land. Releases to air result
from volatilization from the screens during cleaning, and fluid sampling and transfers.
Releases for all systems studied were associated with ink removal, emulsion removal, and haze
removal.
Water releases result primarily from the emulsion removal phase which is typically a
rinse step using a water and sodium hypochlorite or sodium periodate solution for the
traditional systems, and a water and sodium periodate solution for the alternative systems.
The emulsion removal phase may also generate a contaminated rinsewater. In either phase,
waste water results from screen rinsing and the spray or rag application of haze and emulsion
removers.
Off-site releases to land result from the cleaning of non-disposable rags and the landfilling
of disposable rags. It is assumed that rags are used only to remove the ink. The model
assumes that non-disposable rags sent to a laundry contain 0.75 grams of ink remover per 18
rags. This assumption is based on:
o limited data on how much material stays on a damp shop rag with mineral spirits
o the average number of rags used to remove ink per screen (3 per screen)
o the average number of screens cleaned per day (6 screens)
The model assumes weekly laundering of non-disposable shop rags and 250 days of use per
year. Similarly, rags sent to a landfill are assumed to contain 0.75 grams of ink remover per 18
rags.
For Systems Omicron and Beta, which have ink remover products that are water-
miscible, it was assumed that nonlaunderable rags were used and the discharge to water
occurred at the screen printing facility. This assumption was made given that a water rinse is
used with these products in removing ink.
For aqueous solutions, the density of all components is assumed equal to 1 g/cm3. For
nonaqueous solutions, ideal solution behavior is assumed and the density of each component is
used to find the amount of the component in 4 ounces of ink remover. (See Appendix D for a
further explanation) .
Assumptions for Occupational Exposure
In order to estimate occupational exposure to chemicals during the screen cleaning
process, an inhalation model and a dermal exposure model was developed. The assumptions
underlying each model are described below.
Inhalation Model
The inhalation model used in the CTSA is a mass balance model. It assumes that the
amount of a chemical in a room equals the amount leaving the room minus any generated in the
room. The model is valid for estimating the displacement of vapors from containers, and the
volatilization of liquids from open surfaces. Assumptions include:
o incoming room air is contaminant-free
DRAFT-September 1994 III-5
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment _ Estimation Methodology
o generation and ventilation rates are constant over time
o room air and ventilation air mix ideally
o Raoult's law is valid (i.e., the volatilization and interaction of vapors)
o ideal gas law applies (i.e., the interaction of vapors)
o inhaled doses of each chemical were based on "typical case" ventilation parameters,
since these seem to give the best fit to the highest observed values (see below) .
Actual ventilation conditions are unknown.
o median values were used for the composition; worst case evaluation for air releases
would include the most volatile compound at its maximum concentration.
We used the following assumptions for the frequency and duration of inhalation exposure for
ink, emulsion, and haze removal:
o 6 screens cleaned per day
o 1 to 3 workers per site
o 3 hours per day exposure total
o 250 days per year
The four scenarios described on page III-4 were modelled for assessing inhalation exposure.
Inhalation exposures occur as a result of volatilization during these scenarios. The model
assumes that shop workers do not wear respirators in any of the four scenarios.
Dermal Model
Dermal exposure is caused by contact with the material. Contact with the material
includes touching damp rags, dipping hand(s) into a pail of ink remover, and manually
applying the brush or rag to the screen to loosen the ink. Two scenarios, routine contact with
two hands and routine immersion with two hands, were modelled for assessing dermal
exposure. Routine contact occurs from touching rags and manually applying the brush or rag
to the screen. Routine immersion occurs from dipping hand(s) into a pail or ink, haze, or
emulsion remover.
Dermal contact models from the CEB handbook (CEB, 1991) were used by adjusting the
concentration of the chemical in the mixture. Dermal exposure assumes no gloves or barrier
creams will be used. Although exposure was estimated for the emulsion removers or haze
removers containing sodium hypochlorite or sodium hydroxide, it is usually expected that use
of these chemicals would result in negligible exposure given that use of these solutions without
gloves causes irritation and corrosivity effects.
Overview of Methodology
CEB (Chemical Engineering Branch) models the evaporation of chemicals from open
surfaces, such as the surface of a screen, using the following model:
DRAFT-September 1994 III-6
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment _ Overview of Methodology
0.02MP
G=-
RT
D ,v
7TZ
(1)
where
G = Volatilization rate, g.m 2.s '
M = Molecular weight, g.mol '
P = Vapor pressure, mm Hg
R = Gas constant, 0.0624 mmHg.mlmol'.K1
T = Temperature, K
Dab = Diffusivity, cm2.s '
vz = Air velocity, m.s1
z = Distance along pool surface, m
The air velocity is assumed to be vz = 100 ft.min '. Since Dab is not available for many of the
chemicals of interest to CEB, the following estimation equation is used:
(2)
where
Dab = Diffusion coefficient in air, cm2. sec '
T = Temperature, K
M = Molecular weight, g.mol '
Pt = Total pressure, atm
This equation is based on kinetic theory and generally gives values of Dab that agree closely with
experimental data. The value of G computed from eqs (1) and (2) above is used in the following
mass balance expression to compute the airborne concentration in the breathing zone:
where
Cv = Airborne concentration, ppm
T = Ambient temperature, K
G = Vapor generation rate, g.m 2.sec '
M = Molecular weight, g.mol '
A = Area of surface, m2
Q = Ventilation rate, ft3.min '
k = Mixing factor, dimensionless
The mixing factor accounts for slow and incomplete mixing of ventilation air with room air.
CEB sets this factor to 0.5 for the typical case and 0.1 for the worst case. CEB commonly uses
values of the ventilation rate Q from 500 ft3.min ' to 3,500 ft3.min '. An effective ventilation rate
of 250 ft3/min was used, which was equal to the mixing factor of 0.5 multiplied by the lowest
ventilation rate (500 ft3/min) . The value of Cv from equation (3) is converted to mass/volume
units as follows:
DRAFT-September 1994 III-7
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Releases and Occupational Exposure Assessment _ Overview of Methodology
r -r M
c»rCvT7 (4)
where
Cm = Airborne concentration, mg.m 3
Cv = Airborne concentration, ppm
M = Molecular weight, g.mol '
Vm = Molar volume of an ideal gas, l.mol '
At 25 °C, Vm has the value 24.45 l.mol '. Since a worker can be assumed to breathe about 1.25
m3 of air per hour, it is a straightforward matter to compute inhalation exposure once Cm has
been determined. Equations (3) and (4) can be combined to yield the following, given the
"typical case" choice of ventilation parameters:
I=QA8GAt (5)
where
I = Total amount inhaled, mg.day '
G = Vapor generation rate, g.m 2.s '
A = Area of surface, m2
t = Duration of exposure, s
The advantage of equation (5) is that the quantity GAt is often known beforehand, since it is
equal to the total amount of the chemical released to the atmosphere. It is also useful when
computing the total dose due to a sudden release of material, such as occurs when a container
is opened. In this case, it is difficult to ascertain the duration of exposure, but it is a simple
matter to estimate the amount of vapor in the container's headspace.
Example 1. Estimate the vapor generation rate and worker exposure during removal of ink
from a printing screen using 100 percent toluene. The worker cleans screens for 1 hour each
day in a room with a ventilation rate of 3,000 ft3. mm1. The screen area is 2,21 7 in2. Assume
a mixing factor ofk = 0.5.
Toluene has the following physical properties:
Molecular weight: 92. 14 g.mol '
Vapor pressure: 28 mmHg at 25 °C
Diffusion coefficient: 0.076 cm2. sec '
Using these values in equation (1) gives:
Generation rate G: 0.28 g.s '.m2
Airborne concentration: 141 ppm (Cv)
534 mg.m 3 (CJ
Exposure over 1 hour: 667 mg
If the CEB worst-case parameters are used in equation (2), i.e., a mixing factor of k = 0.1 and a
ventilation rate of 500 ft3.min ', then the estimated airborne concentration is Cv = 4,216 ppm.
Exposures and volatilization rates are calculated by multiplying the pure-component values
DRAFT-September 1994 III-8
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment _ Uncertainties
from Exhibit 4 by the mole fraction of that component in the liquid phase. A typical screen has
an area of 2127 in2 = 1.37 m2. Each worker cleans screens for 1 hour per day. Amounts
released should be checked against amount used to ensure mass balance.
Example 2. If a worker cleans 6 screens using 8 oz/screen of mineral spirits, the amount of
spirits used will be:
6 x 8 x 29.57 fluid oz/cc x 0.78 g/cc = 1 107 g
The amount volatilized will be:
0.01087 g.m2.s ' x 3600 s x 1.37 m2 = 53 g
Thus, the amount volatilized is not limited by the amount used. For the case of the traditional
haze remover, however, volatilization is limited by the amount used. If 3 oz of haze remover
containing 30 wt percent (32 volume percent or 21 mole percent) acetone is used per screen,
the total amount available is:
6 x 3 x 0.32 x 29.57 fluid oz/cc x 0.79 = 133 g
The amount that would volatilize over 1 hour is:
1.49x 1. 37 x 3600s = 7,350 g
Uncertainties
Occupational Exposure: Uncertainties
Determining occupational exposure levels associated with screen cleaning requires
making assumptions about the cleaning process, the workplace environment, health and safety
practices, and waste management practices. This section describes the uncertainties involved
in assessing occupational exposure for screen cleaning. It also explains the assumptions
underlying the exposure assessment model developed for the CTSA.
EPA has published Guidelines for Exposure Assessment in the Federal Register. These
are guidelines for the basic terminology and principles by which the Agency is to conduct
exposure assessments. There are several important issues relevant to this assessment. If the
methodology is one which allows the assessor to in some way quantify the spectrum of
exposure, then the assessor should assess typical exposures, as well as high end exposures or
bounding exposures. Typical exposures refer to exactly that, how much the typical person is
exposed to the particular substance in question. High end refers to a person exposed to
amounts higher than 90 percent of the people (or ecological species of interest) exposed to the
substance. Bounding estimates are judgements assuming that no one will be exposed to
amounts higher than that calculated amount. However, in many cases, all we can do is give a
picture of what the exposure would be under a given set of circumstances, without
characterizing the probability of these circumstances actually occurring. These are called "What
if scenarios. They do not try to judge where on the exposure scale the estimate actually falls.
All of the exposure assessments fall into the "What if" category for this assessment.
DRAFT-September 1994 III-9
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment _ Uncertainties
Although the screen cleaning process is relatively straightforward, occupational exposure
levels will differ in actual shop environments because of many variables such as variations in:
o toxicity of the chemicals used
o amount of chemicals applied
o how the chemicals are applied
o compliance with health and safety and waste management procedures
o equipment operating time
o ventilation conditions and shop lay-out
o temperature conditions (ambient and solvent)
All of these variables will influence the impacts of chemicals used in the screen cleaning
process on shop workers. Based on studies of screen printing operations conducted by the
National Institute for Occupational Safety and Health (NIOSH), it appears that many of the
small to medium sized operations do not follow health and safety precautions.2 Specifically,
workers were observed performing screen reclamation without protective gloves or proper
breathing apparatus. Nor did shop workers wear protective aprons to reduce dermal exposure.
According to one study, some workers used solvent to wash their arms and hands after
completing the screen cleaning process. In another study, rags and paper towels contaminated
with solvent were placed in an open trash can. Both of these practices will also increase
exposure levels significantly.
There are also differences in how screen printers wash the screens; this affects
occupational exposure. Some shops use automated screen washers which blast the screens
with solvent or hot water in an enclosed system . Others use a hose in a sink to flush the
screens by hand or the cleaner is spread on the screen by hand, and the worker uses a rag or
paper towel to wipe down the screen. Exposure levels will differ if individual workers use more
(or less) cleaner than specified, and if they allow it to remain on the screen longer than
specified.
During research to support this assessment a NIOSH Health Hazard Evaluation (HHE)
document on screen washing was located and used to validate exposure estimates. CEB
initially estimated occupational exposures by applying the relatively conservative models that
are normally used for review of new chemicals. The resulting exposure estimates were high in
comparison to actual monitoring data. These data indicated that, after necessary corrections
were made, the exposures predicted by the CEB model were within the range of the NIOSH
observations, as long as the "typical case" ventilation parameters were chosen. Use of the "worst
case" ventilation parameters in the CEB model leads to results that exceed the range of the
experimental data by about an order of magnitude. The theoretical basis of the CEB model was
investigated and a standard engineering formula for mass transfer in laminar boundary layers
was found to provide a closer approximation to the upper end of NIOSH data when used with
the same "worst case" ventilation parameters.
Both the CEB model (when used with the "typical case" ventilation parameters) and the
boundary-layer approach can provide estimates of inhalation exposures which agree with the
experimental data within one order of magnitude or better. It is difficult to obtain better
agreement than this without knowing a great deal more about each exposure scenario, such as
2Sources: Health Hazard Evaluation Report No. HETA 84-299-1543, (Chicago, IL:Impressions Handprinters). Health
Hazard Evaluation Report No. HETA 81-383-1151, (Chicago, IL:Main Post Office).
DRAFT-September 1994 111-10
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment _ Uncertainties
the details of the screen cleaning process at each site, the solvent temperature, the air
temperature, and the ventilation pattern in the screen cleaning area. These items are not
routinely recorded by NIOSH investigative teams. A report documenting an alternative
volatilization and exposure model based on laminar boundary layers is provided in Appendix
E.
Dermal Exposure Model
The dermal exposure model is based on the concentration of material contacting the skin
and the surface area contacted. Dermal exposure levels will differ in actual shop environments
because of many variables such as variations in:
o type of worker activity
o likelihood or type of contact (i.e., routine or immersion)
o frequency of contact (i.e., routine or incidental)
o potential surface area contacted
o likelihood and effectiveness of protective equipment being used
o amount of chemical remaining on the skin
o evaporation rate of the chemical
In estimating dermal exposure, it was assumed that gloves were not worn. However,
assuming that gloves are worn, dermal exposure is assumed to be negligible to none depending
on the chemical in question. In situations where the chemical is corrosive (e.g., sodium
hypochlorite) , dermal exposure to shop workers using gloves is zero. The model assumes that
one hand (surface area 650 cm2) is routinely exposed during the screen cleaning process (1 to 3
mg/cm2 typically remaining on the skin)3
Environmental Releases: Uncertainties
Determining environmental releases associated with screen cleaning requires making
assumptions about the cleaning process, the workplace environment, and waste management
practices. This section describes the uncertainties involved in assessing environmental releases
associated with screen cleaning. It also explains the assumptions underlying the environmental
release assessment model developed for the CTSA.
Uncertainties
Uncertainties related to environmental releases overlap with the uncertainties associated
with occupational exposure. They include variations in:
o toxicity of the chemicals used
o amount of chemicals applied
o how the chemicals are applied
o compliance with waste management procedures
o equipment operating time
o ventilation conditions and shop lay-out
o temperature conditions (ambient and solvent)
3Source: U.S. Environmental Protection Agency, Chemical Engineering Branch Manual for the Preparation of
Engineering Assessments, (February 28, 1991), p. 4-36.
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment Release Amounts
_ vs. Occupational Exposures
Release Amounts vs. Occupational Exposures
Air releases were computed in two different ways, depending on the particular scenario
under consideration. For Scenario I (evaporation from a screen) and Scenario II (evaporation
during sampling), the equations used for computing the total mass of material volatilized can be
condensed into the following expression:
8.24x l(T8Ma WP( — +—)a V' 5At
GAt=
-0.05 0. 5p 0. 5
J z rt
where:
GAt = Mass released (= flux x area x time)
M = Molecular weight (g.mol')
P = Vapor pressure (mmHg)
vz = Air velocity (ft.min ')
A = Area of surface (cm2)
t = Duration of release (s)
T = Air temperature (K)
z = Length of surface (cm)
Pt = Total pressure (atm)
For all cases of interest here, the temperature T, total pressure Pt, and air velocity vz are
assigned fixed values. These are 298 K, 1 atmosphere, and 100 ft.min ', respectively. In
addition, the surface is taken to be square, so that z = A0'5. Thus, the mass of material
released has the following dependencies:
-_j_+_j_\o.25
29 M
(8)
(9)
For Scenario III (releases from pouring) and Scenario IV (releases from drum of rags), the
vapor space of the container was assumed to be saturated. The model used can be represented
as:
MPV
(10)
l '
(24.45)(760)
where:
M = Molecular weight (g.mol ')
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment Release Amounts
_ vs. Occupational Exposures
P = Vapor pressure (mmHg)
V = Volume of container (1)
For each scenario, the container volume is fixed, so that:
QAt^M (11)
QAt^P (12)
Releases to water and/or land disposal are computed by a mass balance approach; any
chemical not volatilized is assumed to be disposed to one of these two media.
The amount of each chemical inhaled by workers is given by the following expression:
where
7 = Inhaled dose (mg.day')
Q = Ventilation rate (ft3.min ')
k = Mixing factor (dimensionless)
In this report, Q is fixed at 3,000 ftlmin ' and k = 0.5. Thus,
I=QASGAt (14)
Thus, the inhaled dose has the same dependencies as the amount released, no additional
variables being introduced.
Based on the above expressions, the amount released to the atmosphere in Scenarios I and II is
approximately proportional to JVf 835P. For Scenario III and IV, the dependence is
approximately MP. The vapor pressure is generally lower for compounds with higher molecular
weights. An idea of the sensitivity of vapor pressure to molecular weight can be obtained from a
molecular model of the liquid state. According to Fowler and Guggenheim (Statistical
Thermodynamics, Cambridge, 1956), for a liquid whose intermolecular potential energy can be
represented by the Lennard-Jones function:
--- (15)
r
the vapor pressure can be estimated to be:
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Environmental Release and Occupational Exposure Assessment Release Amounts
vs. Occupational Exposures
«-1 1 ^S_^_£> ~& 136(e/£Z)
^-lliS—e -^ (16\
a
As noted in the development of an expression for Dab, the diffusivity, in Appendix K of the CEB
Manual, the quantities e and o can be roughly correlated with molecular weight. When these
parameters are regressed against experimental data for CrC9 and substituted into the
expression for vapor pressure, a relationship of the following form is observed:
p-M^e^1 (17)
Somewhat different dependencies will be found with different sets of experimental data, but all
of the resulting expressions will show that vapor pressure falls off rapidly with molecular
weight within a homologous series of compounds. Thus, the amount of chemical volatilized
and the resulting inhaled dose will be approximately proportional to
Ma6Vrfa (18)
Population Exposure Assessment for Screen Reclamation Processes
The purpose of a general population exposure assessment is to account for amounts of
chemicals with which people who are not directly involved in the screen printing process may
be in contact. There are several ways that the general population may be exposed to substances
used in the screen reclamation process. People may breathe the air containing vapors which
have been carried away by air currents from a screen printing facility. The vapors would be
environmental releases stemming from evaporation of products at the screen printing facility.
People may drink water which contains residues from the reclamation products, which can
originate with the facility discharging the products down the drain. People may also drink well
water that contains contaminants which have migrated from a landfill where wastes are
disposed. The amount which a person may come in contact with varies with how far away they
are located from the facility, how many of the different routes of contact they actually have (such
as drinking, breathing, touching), how long the chemical has been in the environment and how
the chemical moves through the environment. The amounts also depend on such
environmental conditions as the weather or the amount of water that is flowing in the receiving
stream or river where the facility's discharges go.
EPA has published Guidelines for Exposure Assessment in the Federal Register. These
are guidelines for the basic terminology and principles by which the Agency is to conduct
exposure assessments. There are several important issues relevant to this assessment. If the
methodology is one which allows the assessor to in some way quantify the spectrum of
exposure, then the assessor should assess typical exposures, as well as high end exposures or
bounding exposures. Typical exposures refer to exactly that, how much the typical person is
exposed to the particular substance in question. High end refers to a person exposed to
amounts higher than 90 percent of the people (or ecological species of interest) exposed to the
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes
substance. Bounding estimates are judgements assuming that no one will be exposed to
amounts higher than that calculated amount. However, in many cases, all we can do is give a
picture of what the exposure would be under a given set of circumstances, without
characterizing the probability of these circumstances actually occurring. These are called "What
if scenarios. They do not try to judge where on the exposure scale the estimate actually falls.
All of the exposure assessments fall into the "What if" category for this assessment.
The fate of the chemical in the environment is how we refer to the breakdown
(transformation) and mobility of the chemical through air, water and land. There is a different
chemical fate for release through a waste water treatment facility as opposed to an air release or
a landfill release. There are also different processes by which degradation may occur. For
example, in air, a chemical may be broken down by sunlight (by either direct photolysis or
photooxidation) or by reaction with water in the atmosphere (hydrolysis) . In water and soil, an
important degradation process is biodegradation, where the substance may be decomposed by
bacteria and other biota in the environment. Each of these processes will have its own rate
(speed) at which it occurs, and this may vary with the concentration of the chemical in the
system. Often the way we present the fate for a chemical is by giving a half-life value. This term
simply means the amount of time it takes for one-half of the substance initially present to be
lost by degradation. There are other ways to present fate. If we are interested in how much of a
chemical is removed from water during its trip through a waste water treatment facility (such as
a POTW - Publicly Owned Treatment Works), we will give a removal amount, usually in percent.
There are summaries in Chapter 2 of the chemical fate of all of the chemicals identified as being
used in screen reclamation products.
There are two perspectives to address when handling exposure concerns for any
commercial process. The first is best described as a local point of view, i.e., a single facility in
normal operation will have certain releases which affect a specific area and specific local
population. Since we do not have information for each screen printing facility, we use a "model
facility" approach to calculate typical releases and environmental concentrations. This will not
allow us to specify the number of people around the facility, because the population varies
considerably depending on the location of the screen printing facility. The other perspective is
to view the overall impact, i.e., what is the impact of all of the printing facilities for the general
population. While one facility may not be releasing very much of any given chemical, the
cumulative effect of all of the printers in an area could be serious.
For this assessment, we have tried to present a view of the local concerns by presenting
exposures for a standard set of conditions, by which we are trying to simulate a single facility
for all of the methods and systems. The overall perspective is presented only for the traditional
systems, which are the systems which are considered to already be in common use. It was felt
that it would far too hypothetical to do an overall perspective for the alternative formulations
since we do not have a basis for predicting how many screen printers might use any given
formulation.
The effects of a chemical may be a short-term (acute) effect, such as the effect a poison
would have on the body, or it could be long-term, such as a carcinogen. For long-term (chronic)
effects, it is most helpful to have average, or typical, exposures, since the effect will vary with
the cumulative exposure. For acute effects, a peak exposure estimate would be more helpful.
This can then be compared to levels at which the chemical is known to give immediate health
problems. In general for this assessment, average concentrations are calculated.
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes Overview by Media
Overview by Media
Air
Releases to air are from evaporation of chemicals during the process. This may be from
allowing screens to dry during reclamation, or from rags or open drums of chemicals located
around the facility. These vapors are then carried and mixed with outside air. The air
concentration will depend on weather conditions. Stagnant conditions will not move vapors
away quickly, so local concentrations will be higher than the concentrations of the chemical
farther from the plant. There is the potential that everyone outside the facility could be affected.
The chemical concentrations will decrease with distance, but the number of people may
increase with distance, depending on the location of the screen printing facility. Usually the
exposure assessor will use a computer program to determine the number of people around a
known facility by using census data. Since the locations of all the screen printing facilities
across the country are not known to us, we use the model facility approach, and do not count
population for the model facility.
For our model facility, we assume a building height of three meters, and a width of 10
meters. This is a building approximately the size of a garage. We then pick sample weather
conditions, usually from San Bernardino, to determine what the air concentration of a chemical
will be at a set distance from the printing facility. We use San Bernardino because the weather
conditions there will give the highest average concentrations around the facility of any of the
approximately 500 weather stations in the United States. However, none of the average
concentrations across the country will be even ten times less than the average concentrations at
San Bernardino. If the highest concentration were 10 ug/m3, then anywhere in the country the
concentration would be greater than 1 ug/m3. We would say that there is less than an order of
magnitude difference.
Methodology References
Air Modeling Parameters for ISCLT90
MODEL - Industrial Source Complex. Long Term: US EPA, Office of Air and
Radiation, Office of Air Quality Planning and Standards, Research Triangle
Park, NC 27711, version 90, as implemented by the Office of Pollution
Prevention and Toxics in the Graphical Exposure Modeling System, GEMS
Atmospheric Modeling Subsection.
The following default parameters were used:
o Regulatory default setting for ISCLT.
o Facility location at 34° latitude, 117° longitude
o The Star Station (meteorological) data from the station
closest to the point of release, San Bernardino, CA.
o Urban Mode (U3)
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes _ Overview by Media
o Standard Polar grid, with 3 calculations per segment.
o Single point of release at the facility location.
Release height of 3 meters for fugitive releases from an area
source of 1 0 meters by 1 0 meters ( 1 00 m2) .
Surface Water
Releases to surface water are those releases discharged through a drain at a screen
printing facility that end up going to public sewers or Publicly Owned Treatment Works
(POTWs) . This discharge is treated before being released, and the effectiveness of the treatment
determined, so that the amount actually getting through to the receiving water body can be
calculated. The receiving water will dilute the discharge from the POTW, and a stream
concentration can be calculated using stream flow information.
We use average stream concentrations to calculate average drinking water consumption.
We assume that people actually drink the two liters a day that is recommended for good health.
If the chemical is one that will accumulate in animals or plants, we calculate ingestion of the
chemical from eating fish.
The other issue for surface water is the effect that a chemical may have on aquatic
organisms, from algae to fish. If the food chain is broken in a stream, the consequences are
dire. No algae, no fish. A healthy stream with numerous organisms will also have a better
ability to handle chemical releases than one whose quality is already compromised. The
organisms lower on the food chain, such as algae, tend to have shorter lives, making shorter
exposure time periods more critical. Since concentrations will vary with the stream flow, there
may be periods of lower flow conditions where the same amount released as on a regular flow
situation will cause problems. We use historical stream data to try to predict how often this
will happen.
Cumulative releases to the same POTW may be estimated by counting the number of
screen printers in an area and distributing the releases across all the POTWs in the area. We
have to assume that the releases are for the same products, or very similar products. As for
air, this cumulative number is expected to be far more significant than the amount for any
single screen printer.
Methodology Reference
Single Site
Concentration = Chemical Loading / Streamflow
In general, the concentration will be in ug/L, and the chemical loading is in
grams or kilograms. The streamflow used is the harmonic mean streamflow
in Million Liters per Day (MLD) for drinking water concerns, if the location is
known. Otherwise, the streamflow will be assumed to be 1000 MLD.
US-Wide Water Releases
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes _ Overview by Media
The methodology used is outlined in its entirety in a report from VERSAR, Inc
for Task 1-1 1, sub task 101, from Contract 68-D3-0013. Copies of this report
are available from either VERSAR, Inc or from Sondra Hollister at EPA.
Septic Systems
There appears to be a significant minority of screen printers who do not release water to
a waste water treatment plant. These printers are assumed to release to septic systems. The
releases of this type are not modeled in this assessment. There are some general guidelines
that may be used to determine if there will be exposure to any of the screen reclamation
chemicals from septic system seepage. Each chemical will have an estimated potential
migration to ground water, which is usually used for landfill assessments. This can be directly
applied to septic systems, because the potential to migrate to ground water will be the same. Of
course the individual characteristics of the system will determine the actual speed that each
chemical travels into the ground water. If the septic system is relatively leaky, and the ground
water table is relatively high, the time that a chemical takes to get into the ground water will be
shorter than for a septic system which is sealed well and where the ground water table is low.
Landfill
Our usual techniques for estimating exposures from landfill releases are not applicable to
printing. For a typical situation, we would assume one facility sending waste to a landfill. For
the printing industry, the use of landfills cannot be so simplified. A lack of data limits the
determination of exposures. We do not know how many printers are sending what types of
wastes to any given landfill. There also is no way to account for a printer sending a portion of
their wastes to a hazardous waste handler, and sending another portion to the county landfill,
or how many printers will be sending to any given landfill. For these reasons, even though the
exposures from landfill releases may be significant, we will not be able to calculate exposures
from landfill seepage and migration into ground water. However, we can give the expected fate
of the chemical in the landfill -- will the chemical migrate to ground water rapidly, moderately
or negligibly.
Background on Risk Assessment for Screen Reclamation Processes
Human Health Risk
Assessment of the human health risks presented by chemical substances includes the
following components of analysis:
o Hazard Identification is the process of determining whether exposure to a
chemical can cause an adverse health effect and whether the adverse health effect is
likely to occur in humans.
o Dose-response Assessment is the process of defining the relationship between the
dose of a chemical received and the incidence of adverse health effects in the
exposed population. From the quantitative dose-response relationship, toxicity
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes _ Methodology References
values are derived that are used in the risk characterization step to estimate the
likelihood of adverse effects occurring in humans at different exposure levels.
o Exposure Assessment identifies populations exposed to a chemical, describes their
composition and size, and presents the types, magnitudes, frequencies, and
durations of exposure to the chemical.
o Risk Characterization integrates hazard and exposure information into
quantitative and qualitative expressions of risk. A risk characterization includes a
description of the assumptions, scientific judgments, and uncertainties embodied in
the assessment.
Quantitative Expressions of Hazard and Risk
The manner in which estimates of hazard and risk are expressed depends on the nature
of the hazard and the types of data upon which the assessment is based. For example, cancer
risks are most often expressed as the probability of an individual developing cancer over a
lifetime of exposure to the chemical in question. Risk estimates for adverse effects other than
cancer are usually expressed as the ratio of a toxicologic potency value to an estimated dose or
exposure level. A key distinction between cancer and other toxicologic effects is that most
carcinogens are assumed to have no dose threshold; that is, no dose or exposure level can be
presumed to be without some risk. Other toxicologic effects are generally assumed to have a
dose threshold; that is, a dose or exposure level below which a significant adverse effect is not
expected.
Cancer Hazard and Risk
EPA employs a "weight-of-evidence" approach to determine the likelihood that a chemical
is a human carcinogen. Each chemical evaluated is placed into one of the five weight-of-
evidence categories listed below.
o Group A - human carcinogen
o Group B - probable human carcinogen. Bl indicates limited human evidence; B2
indicates sufficient evidence in animals and inadequate or no evidence in humans.
o Group C - possible human carcinogen
o Group D - not classifiable as to human carcinogenicity
o Group E - evidence of noncarcinogenicity for humans
When the available data are sufficient for quantitation, EPA develops an estimate of the
chemical's carcinogenic potency. EPA "slope factors" express carcinogenic potency in terms of
the estimated upper-bound incremental lifetime risk per mg/kg average daily dose. "Unit risk"
is a similar measure of potency for air or drinking water concentrations and is expressed as
risk per ug/m3 in air or as risk per ug/1 in water for continuous lifetime exposures.
Cancer risk is calculated by multiplying the estimated dose or exposure level by the
appropriate measure of carcinogenic potency. For example an individual with a lifetime average
DRAFT-September 1994 111-19
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes _ Methodology References
daily dose of 0.3 mg/kg of a carcinogen with a potency of 0.02/mg/kg/day would experience a
lifetime cancer risk of 0.006 from exposure to that chemical. In general, risks from exposures
to more than one carcinogen are assumed to be additive, unless other information points
toward a different interpretation.
Chronic Health Risks
Because adverse effects other than cancer and gene mutations are generally assumed to
have a dose or exposure threshold, a different approach is needed to evaluate toxicologic
potency and risk for these "systemic effects." "Systemic toxicity" means an adverse effect on any
organ system following absorption and distribution of a toxicant to a site in the body distant
from the toxicant's entry point. EPA uses the "Reference Dose" approach to evaluate chronic
(long-term) exposures to systemic toxicants. The Reference Dose (RfD) is defined as "an
estimate (with uncertainty spanning perhaps an order of magnitude) of a daily exposure to the
human population (including sensitive subgroups) that is likely to be without appreciable risk
of deleterious effects during a lifetime" and is expressed as a mg/kg/day dose. The RfD is
usually based on the most sensitive known effect; that is, the effect that occurs at the lowest
dose. EPA calculates a comparable measure of potency for continuous inhalation exposures
called a Reference Concentration or RfC, expressed as a mg/m3 air concentration. Although
some RfDs and RfCs are based on actual human data, they are most often calculated from
results obtained in chronic or subchronic animal studies. The basic approach for deriving an
RfD or RfC involves determining a "no-observed-adverse-effect level (NOAEL) " or "lowest-
observed-adverse-effect level (LOAEL)" from an appropriate toxicologic or epidemiologic study
and then applying various uncertainty factors and modifying factors to arrive at the RfD/RfC.
RfDs and RfCs can be used to evaluate risks from chronic exposures to systemic
toxicants. EPA defines an expression of risk called a "Hazard Quotient" which is the ratio of the
estimated chronic dose/exposure level to the RfD/RfC. Hazard Quotient values below unity
imply that adverse effects are very unlikely to occur. The greater the Hazard Quotient exceeds
unity, the greater is the level of concern. However, it is important to remember that the Hazard
Quotient is not a probabilistic statement of risk. A quotient of 0.001 does not mean that there
is a one-in-a-thousand chance of the effect occurring. Furthermore, it is important to
remember that the level of concern does not necessarily increase linearly as the quotient
approaches or exceeds unity because the RfD/RfC does not provide any information about the
shape of the dose-response curve.
An expression of risk that can be used when an RfD/RfC is not available is the "Margin-of-
Exposure (MOE)." The MOE is the ratio of a NOAEL or LOAEL (preferably from a chronic
study) to an estimated dose or exposure level. Very high MOE values such as values greater
than 100 for a NOAEL-based MOE or 1000 for a LOAEL-based MOE imply a very low level of
concern. As the MOE decreases, the level of concern increases. As with the Hazard Quotient, it
is important to remember that the MOE is not a probabilistic statement of risk.
Developmental Toxicity Risks
Because of the many unique elements associated with both the hazard and exposure
components of developmental toxicity risk assessment, these risks are treated separately from
other systemic toxicity risks.
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Population Exposure Assessment for Screen Reclamation Processes _ Methodology References
EPA defines developmental toxicity as adverse effects on the developing organism that
may result from exposure prior to conception, during prenatal development, or postnatally to
the time of sexual maturation. Adverse developmental effects may be detected at any point in
the life span of the organism. The major manifestations of developmental toxicity include: (1)
death of the developing organism, (2) structural abnormality, (3) altered growth, and (4)
functional deficiency.
There is a possibility that a single exposure may be sufficient to produce adverse
developmental effects. Therefore, it is assumed that, in most cases, a single exposure at any of
several developmental stages may be sufficient to produce an adverse developmental effect. In
the case of intermittent exposures, examination of the peak exposure(s) as well as the average
exposure over the time period of exposure is important.
EPA has derived Reference Doses and Reference Concentrations for developmental
toxicants in a similar manner to the RfDs and RfCs for other systemic toxicants. The RfDDT or
RfCDT is an estimate of a daily exposure to the human population that is assumed to be without
appreciable risk of deleterious developmental effects. The use of the subscript DT is intended
to distinguish these terms from the more common RfDs and RfCs that refer to chronic
exposure situations for other systemic effects.
Developmental toxicity risk can be expressed as a Hazard Quotient (dose or exposure
level divided by the RfDDT or RfCDT) or Margin-of-Exposure (NOAEL or LOAEL divided by the
dose or exposure level), with careful attention paid to the exposure term, as described above.
NOTE: The closely related area of reproductive toxicity is also an important aspect of systemic
toxicity. For purposes of this report, toxicity information on adult male and female
reproductive systems will be assessed as part of the chronic toxicity risk.
Assumptions and Uncertainties
Estimated doses assume 100 percent absorption. The actual absorption rate may be
significantly lower, especially for dermal exposures to relatively polar compounds. The
assessment used the most relevant toxicological potency factor available for the exposure under
consideration. In some cases the only potency factor available was derived from a study
employing a different route of exposure than the exposure being evaluated. For example, oral
RfD values were sometimes used to calculate Hazard Quotients for inhalation and dermal
exposures. For the occupational risk assessment, RfC values were converted to units of dose
assuming a breathing rate of 20 m3/day and a body weight of 70 kg. This conversion was done
because occupational inhalation exposures were calculated as a daily dose rather than as an
average daily concentration. The general population risk estimates compare RfC values directly
to average daily concentrations because continuous exposure is assumed for the general
population. Most of the Margin-of-Exposure calculations presented in the assessment are
based on toxicity data that have not been formally evaluated by the Agency. Simple esters of
glycol ethers were assumed to present the same hazards at approximately the same potencies
as the corresponding alcohol. The same potency data were used in risk estimates for each
alcohol and its corresponding ester unless specific data for each compound were available.
All risk estimates are based on release and exposure values estimated from information
on product usage and work practices obtained from industry surveys. No actual measures of
chemical release or exposure levels were available.
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Background and Methodology for Performance Demonstrations _ Background
Certain formulation components are described in the CTSA by their category name, such
as propylene glycol series ethers. However, all risk calculations in the CTSA are based on
chemical-specific hazard and exposure data. Thus, risk values may appear for some category
members but not others because of limitations in available data.
Ecological Risk
The basic elements of ecological risk assessment are similar to those employed in human
health risk assessment. This report will address only ecological risks to aquatic species.
Quantitative evaluation of aquatic risks involves deriving an "ecotoxicity concern concentration
(ECO CC)" for chronic exposures to aquatic species. The ECO CC may be based either on
actual toxicologic test data on the subject chemical or on quantitative structure- activity relation
analysis of test data on similar chemicals. The ECO CC is typically expressed as a mg/1 water
concentration. Concentrations below the ECO CC are assumed to present low risk to aquatic
species. A notation of "N.E.S." rather than a numeric estimate of the ECO CC indicates that no
adverse effects are expected in a saturated solution during the specified exposure period.
For further background on the determination of ecological hazard, see Appendix M.
Background and Methodology for Performance Demonstrations
Background
One purpose of the DfE Printing Project was to collect and disseminate to printers
information concerning the performance of several screen reclamation alternatives. This
section of the CTSA summarizes performance information collected during laboratory and
production run performance demonstrations with alternative screen reclamation products
carried out between January and April 1994. Performance data collected includes time spent
on ink removal, volume used, and appearance of the screen following each step. Information
from the performance demonstrations, taken in conjunction with risk, cost and other
information in the CTSA, provides a more complete assessment of product systems than has
otherwise been available from one source. DfE participants believe that this information will
allow printers to make a number of comparisons that were not previously possible. For
example, printers can compare cost, risk and performance between screen reclamation systems
currently used and alternative systems as well as across the alternative systems evaluated
during the performance demonstrations.
In a joint and collaborative effort, EPA and the Screen Printing Association International
(SPAI) organized and conducted the performance demonstrations of 11 screen reclamation
product systems and one alternative technology.4 The DfE project staff contacted all known
product manufacturers to request submission of product systems. The industry participants
and the internal EPA workgroup decided to request that alternative product systems contain no
stratospheric ozone depleting substances and no chlorinated compounds. This is due, in part,
4Product systems are whatever combination of specific ink removers, emulsion removers, and haze removers the participating
manufacturer submitted or recommended.
DRAFT-September 1994 III-22
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Background and Methodology for Performance Demonstrations _ Background
to the expectation that impending regulations may effect market availability and use of these
substances. The DfE Project Staff did not solicit those products containing chlorinated
compounds due to the scheduled phase-out of many of these chemicals under the 1990 Clean
Air Act Amendments.
Performance data were collected for each product system in a laboratory setting at the
Screen Printing Technical Foundation (SPTF) and also in production runs at 23 volunteer
facilities. The performance demonstration protocol was developed by consensus with the
involvement of EPA, product manufacturers, and screen printers. The protocol was designed
to allow the evaluation of the maximum number of product systems given the resources
available to the project. The intent of the SPTF evaluations was to assure that the product
systems sent to printers would provide an acceptable level of performance. This screening level
evaluation also provided another set of observations to compare with in-facility demonstration
results. In-facility testing was undertaken at the request of printers participating in the DfE
project so that product systems would be evaluated during production runs at printing
facilities. It should be noted that the performance demonstrations are not rigorous scientific
investigations. Instead, the performance information in Chapter 5 documents the printers'
experiences with and opinions of these products as they were used in production runs at their
facilities.
Methodology
Performance evaluations were conducted in two distinct phases of the project. SPTF
evaluated products under very controlled and consistent conditions. Volunteer printing
facilities nationwide collected much of the same information, but did so under more variable
conditions during production. The methodologies for data collection at SPTF and at the
printing facilities are outlined below.
SPTF Evaluations
At SPTF, each product system was tested on three imaged screens; one with solvent-
based ink, one with LJV-cured ink and one with water-based ink. One of the most important
aspects of the SPTF methodology is that all evaluations were conducted under consistent screen
conditions (e.g., tension, mesh type, emulsion type, thread count, image) for all screens. In
addition, the same technician conducted the evaluations for all product systems at SPTF. The
technician at SPTF recorded the following information: amount of product used, time spent on
each reclamation step, level of effort required, and a qualitative assessment of product
effectiveness and screen condition. (See Appendix L for SPTF methodology.)
Printing Facility Demonstrations
SPAI recruited volunteer screen printers who print on plastic and vinyl substrates from
across the country. EPA and SPAI staff matched the submitted product systems to volunteer
printing facilities based on existing equipment, ink type, and current practices. Most products
were scheduled to be evaluated in two or three facilities to provide performance data from
different operating and ambient conditions. Prior to shipping product systems to printers,
SPTF repackaged products or removed identifying marks and brand names so that those
printers (and the DfE observers) evaluating the products did not know the manufacturer or
product name. Masked MSDSs were also developed and shipped along with the product
systems to be evaluated.
DRAFT-September 1994 III-23
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Background and Methodology for Performance Demonstrations _ Background
The appropriate staff at each volunteer facility were asked to:
o provide background information on the facility, its screen printing operations, and
its current screen reclamation process and products;
o participate in a one-day site visit in which a DfE observer would observe and
document current practices, introduce facility staff to data recording and reporting
needs of the project and allow the observation of screen reclamation using the
alternative system;
o record information on product performance over a four-week period; and
o participate in a weekly telephone call with the DfE observer.
In designing the protocol and record-keeping, every effort was made to keep volunteer printers'
burden low and to minimize production disruptions.
The printers recorded the same performance information as described in the SPTF
methodology. Following the receipt of a facility background questionnaire sent by SPAI, the DfE
observer called each facility to review the details of their operation and to schedule a site visit.
(See Appendix G.) Alternative product systems, MSDSs, application instructions, and spray
bottles were shipped to each facility prior to the DfE observer's site visit.
DfE observers were not EPA employees, but were drawn from staff from Abt Associates,
Inc., and its subcontractor, Radian Corporation. They conducted the initial site visits to all
facilities. During these visits, the observer documented current screen reclamation procedures
and the performance of current product systems, as well as three screen reclamations with the
alternative system. Printers were asked to comment on the effectiveness of each product (ink
remover, emulsion remover and haze remover) and to determine if screen cleanliness was
sufficient for future re-imaging and printing. (See Appendix H for an example of the site visit
evaluation sheet.) After the observer's visit, the facility continued to use the alternative systems
for one month. During this time, facility staff recorded performance information (including
subsequent print image quality) on the alternative systems for approximately 12 screen
reclamations per week, using the standardized observation forms. (See Appendices I and J for
examples of the evaluation sheets for ink removal and for haze and emulsion removal.) Where
possible, facilities tracked the screens used in the demonstration to collect information on the
long-term performance and effects of these products. Each week, the DfE observer called the
facility staff for an update on the product system's performance, as well as to identify any
changes in the way the products were used. These calls were documented in telephone logs.
(See Appendix K for an example.)
A more detailed explanation of the methodology and product review protocols is provided
in Appendix L.
Data Col lection
The information summarized in chapters 4 and 5 comes from five sources.
o Each product system was evaluated at SPTF using ink types compatible with the
product system (up to three types: solvent-based, UV-cured, and water-based).
DRAFT-September 1994 III-24
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Background and Methodology for Performance Demonstrations _ Background
o Each facility completed a background questionnaire profiling printing and
reclamation operations. The questionnaire was typically either completed or
reviewed with the DfE observer during the initial site visit.
o DfE observers visited each facility. During the visits they observed a reclamation
with the current product system and up to three reclamations using the alternative
system.
o The facility staff completed as many as 12 observation forms per week for four
weeks.
o Weekly follow-up calls made by the DfE observers.
Data Summary and Analysis
Summaries and analyses were prepared for each product system keeping each facilities'
experiences with that product system separate. A number of statistics correlations were
attempted for each facility but the results are typically not statistically significant due to small
sample size. Correlations included:
o the effectiveness of ink removal compared with variables, such as, effort/time spent
on ink removal, ink color, number of impressions
o the condition of screen after emulsion removal step compared with variables, such
as, effort/time spent on emulsion removal, prior ink coverage
o the condition of screen after all reclamation steps are complete (is screen reusable
for all types of print jobs) compared with effort/time spent on haze removal,
effectiveness of previous steps
Where appropriate, these results are included within the text summaries in Chapter 5 of
each product system. Some summary statistics, such as average amount of product used, are
presented in accompanying tables.
Limitations
As noted previously, the inclusion of widely variable conditions across and within
facilities and the short duration of the performance demonstrations does not allow the results
to be interpreted as definitive performance assessments of the product systems. In addition,
some facilities did not provide the full complement of observation forms for several reasons
including, unacceptable performance of the product system, personnel problems, insufficient
volume of products supplied, and lost records of the performance demonstrations.
As mentioned above, the performance demonstrations are not scientifically rigorous but
are subjective assessments which reflect the conditions and experience of two to three
individual facilities. There are a number of reasons why the results of performance
demonstrations for one particular product system may differ from one facility to another and/or
from the SPTF results. Among these reasons are:
DRAFT-September 1994 III-25
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Background and Methodology for Performance Demonstrations _ Background
o Variability of screen conditions. Because performance demonstrations were carried
out during production runs, many factors which affect the performance of
reclamation products were not controlled during the performance demonstrations
including age of screen, ink color, ink coverage, image size, ink type and drying time
prior to reclamation.
o Variability of ambient conditions. Conditions, such as temperature and humidity,
were recorded but not controlled during performance demonstrations. Many
screen printers reported that ambient conditions affect performance of products
they use (e.g., temperature effect on drying of ink on screens).
o Chemical interactions with products used previously on screen. Printers and
manufacturers have reported that the use of several different types of chemicals
previously applied to clean a screen can affect the performance of products
currently used to clean the screen. Product systems are often designed for chemical
compatibility during the screen reclamation process; if another product is added to
the product system that is chemically incompatible, cleaning performance of the
system may be affected. This may occur when a particular chemical, such as
lacquer thinner, is used to remove ink at press-side during a print run (such as
removing ink while the printer stops for lunch); if a printer is using a water-based
screen reclamation product system, chemical incompatibilities can affect product
system performance. If a printer has been using a variety of hydrocarbon solvents,
such as acetone and xylene, to clean a screen, prior to demonstrating the
effectiveness of an alternative system, the performance of the alternative system may
be affected by a residue of hydrocarbons on the surface of the screen. In the second
case, the testing would be more effective if a new screen was used; however, this
was typically not the case in the performance demonstration. In either case, the
performance demonstration may have been affected by (1) residue chemicals on the
surface of the screen or (2) the chemical "conditioning" of the screen.
o Variability of staff involved in performance demonstrations. At SPTF, the same
technician conducted and recorded all testing. At the volunteer facilities, more than
one individual often conducted the reclamations during which data were collected.
Reclaimers' past experience also differs and can affect their perception of
performance. For example, a screen reclaimer who has only used highly effective
ink removers may differ in their opinion of "moderate scrubbing effort" from a
reclaimer whose current ink remover instructions call for one to two minutes of
scrubbing with a brush.
Product System Summaries
A performance summary of each product system is detailed in Chapter 5. In each is a
general summary of product performance, a description of the product application method,
results from the evaluation at SPTF, details of product performance reported separately for
each volunteer printing facility, and facility background information. For each product system,
a table is also included which provides certain summary statistics from the performance
demonstrations at the volunteer printing facilities and at SPTF (for three ink types) . For a
quick summary of the results, the table providing summary statistics is very helpful.
DRAFT-September 1994 III-26
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Chemical Volume Estimates
Chemical Volume Estimates
Volumes for chemicals used within screen reclamation were estimated. Volumes of the
chemicals produced within the nation, export volumes, and import volumes were estimated
from information obtained from the following sources: Chemical Economics Handbook5, US
ITC6, Mansville7, US EPA reports8, Kirk-Othmer9, and industry sources. In some cases,
volumes reported represent broader categories than the individual chemical. Volumes for the
portion of the chemicals used within screen reclamation was not readily available.
The Workplace Practices Questionnaire,10 SPAI's 1990 Survey,11 and expert opinion
estimates were used to develop an estimate of the chemical volumes. The following
methodology summarizes the assumptions and calculations used to estimate the annual
national totals of chemicals used in screen reclamation.
The information needed to develop the estimates included the average screen size, the per
screen volume of each type of reclamation product, market shares, the number of screens
cleaned yearly, and the number of screen printing operations. This information, and its
sources, is summarized in Table III- 1 .
The screen size, in conjunction with the amount of product used or purchased and the
number of screens cleaned, was used to determine the per screen product usage. Typical
formulations were then used to determine the chemical breakdown of the reclamation
products. Combining this information resulted in estimates of the volumes of chemicals used
for screen reclamation. Additional detail of the methodology is given below.
Average Screen Size
Estimated from the Workplace Practices survey, observations were weighted by the
number of screens cleaned per day. This is a normalization technique which incorporates the
frequency of screen cleaning as well as the size of the screens. The average screen size was
5SRI. selected reports from 1985 to 1993. Chemical Economics Handbook. SRI International, Menlo Park, CA.
6USITC. 1993 and 1994 Synthetic Organic Chemicals: United States Production and Sales. 1991. U.S. International
Trade Commission, Washington, DC.
7Manville. selected reports from 1990 - 1993. Manville Chemical Products Corporation, Asbury Park, NJ.
8US EPA reports, including the Toxic Substances Control Act Chemical Substance Inventory (1985), "Aqueous and
Terpene Cleaning" (1990), "Economic Analysis of Final Test Rules for DGBE and DGBA" (1987), "Glycol Ethers: An
Overview" (1985)
9Kirk-Othmer, 1981, "Oils,essential." Om: Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., vol 16. New York:
Wiley.
10The Workplace Practices Questionnaire was developed by EPA, SPAI and the University of Tennessee in 1993. It
contains information on 115 screen printing facilities' operating and work practice characteristics. See Appendix B for a
reproduction of the blank questionnaire and Appendix C for a summary of responses.
"Screen Printing Association International, 1990 Industry Profile Study, (Fairfax, Va.: 1991).
DRAFT-September 1994 III-27
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Screen Reclamation Chemical Usage _ Number of Screens Cleaned
estimated to be 2,916 square inches. This value differs from the average in the appendix due to
this normalization to incorporate incomplete responses.
Per Screen Product Usage
Usage levels for three types of reclamation products were calculated using information
collected through the Workplace Practices Survey: ink remover, emulsion remover, and haze
remover. Information used included average screens printed per day, volumes of products
purchased each year, and the unit price of the products. Certain observations such as those
from facilities carrying out in-plant recycling, were excluded from the calculations as these
would distort the average volume used per screen of one-time ink removal operations. The
average volume used per screen was calculated by dividing the annual amount of product
purchased by the number of screens cleaned per year (assuming 252 working days and the
midpoint of the range of screens cleaned per day) .
Derivation of Market Share of Traditional and Alternative Screen Reclamation Products
Current use of screen reclamation products is divided between traditional products,
generally high VOC solvents, and alternative products, usually low or no VOC content products.
To calculate the market share represented by each type of product, data was collected from the
Work Practices Survey (see Appendices B and C). In the calculation, market share is not based on
volume used but rather on total screen area cleaned since traditional and alternative products may
require very different quantities to clean the same screen area.
The formula used to calculate market share is as follows:
Market ShareAlt = AAlt/AAlt+Tra Market ShareTra = ATra/AAlt+Tra
Where:
Alt denotes Alternative Product
Tra denotes Traditional Product F
A = total screen area cleaned daily = S [# of screens cleaned daily x area of screens]
n
F = number of facilities cleaning screens
Ink Removers
A simplistic decision rule, based on expert opinion, was used to classify ink removers as
alternative or traditional. If the price of an ink remover in the Work Practices Survey was below
$5.60/gallon then it was considered traditional. If the unit price was above $ 18.90/gallon then the
product was considered to be alternative. An additional seven ink removal products were assigned
as traditional or alternative based on having a brand name in common with a product assigned
DRAFT-September 1994 III-28
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Screen Reclamation Chemical Usage _ Number of Screens Cleaned
using the price thresholds.12 As the Work Practices Survey collected brand names, we did not
know the composition of the product and had no other method to determine which category the
products fit into. Once facilities were identified as using either traditional or alternative products,
the screen area cleaned per day for each facility was estimated.13 The screen area cleaned per day
is then summed across facilities within product types. To estimate market share, the screen area
cleaned using each type of product was then divided by the total screen area cleaned daily with both
types of products. The results indicate that the percentage of total screen area cleaned using
traditional products equals 65.6% and the percentage of total screen area cleaned using alternative
products equals 34.4%.
Emulsion Removers
As there is little difference among emulsion removers used in the Work Practices survey no
distinction was made between traditional and alternative emulsion removers.
Haze Removers
The market share of haze removers used by printing operations that is considered to be
traditional and the market share that is considered to be alternative is not known. Consequently,
in the cost analysis, it was assumed that all haze removers currently used are traditional products.
Number of Screens Cleaned
The number of screens cleaned per year was taken from SPAI's 1990 survey, where facilities
reported which range they fit into. In order to use this information for our calculations, an average
value was chosen to represent each range. For the top range of 41 screens or more, 50 screens per
day was used. The remaining figures are reported in Table III-1.
Using an SPAI estimate of 20,000 screen printing facilities (excluding textile printers), the
total number of screens cleaned per day can be estimated. For example, 57 percent of facilities
clean one to ten screens, or an average of 5.5, a day, resulting in 62,700 screens a day for that
particular range. Continuing the analysis results in an estimate of 272,710 screens cleaned per
day.
12 A substantial portion (~ 70%) of screen area reported in the Work Practices survey could not be assigned to traditional or
alternative products and were, therefore, not included in the above calculation.
13 Data reported in the Work Practices Survey was limited to the total volume of alternative and traditional products
purchased annually and the total number of screens cleaned per day at the facility. The number of screens cleaned per day with
each type of product was not indicated. As a result, the average price of the ink remover was calculated and used to establish
which type of product the facility was using.
DRAFT-September 1994 III-29
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Screen Reclamation Chemical Usage
National Estimates of Screen Reclamation Products
Table 111-2
Information for Screen Reclamation
Chemical Volume Estimates
Description
Average screen size3
Per screen product usage3
Ink remover market share3>d
Screens cleaned per dayb
Number of screen printing facilities0
Number of screens cleaned per dayd
Data
2916 sc
Product
Ink remover (traditional)
Ink remover (alternative)
Emulsion remover
Haze remover
in
Oz/Screen (Gal/Screen)
98 (0.7663)
22(0.1731)
8.8 (0.0685)
2(0.0160)
Traditional - 65.6%
Alternative - 34.4%
Range of # of Screens
1to10
11 to 20
21 to 30
31 to 40
41 or more
Value used
5.5
15.5
25.5
35.5
50
% of facilities
57.0
23.2
9.8
4.1
5.9
20,000
272,710
3Based on raw data from WPQ for screen printing adjusted for incomplete responses.
"SPAI's 1990 Industry Profile.
CSPAI estimate.
Calculated value.
National Estimates of Screen Reclamation Products
Multiplying product usage per screen by market share by the total number of screens cleaned
per year provides estimates of the amount of screen reclamation products used nationally. All
facilities are assumed to use ink remover, emulsion remover, and haze remover; this may result
in an overestimate of chemicals used as not all facilities use haze remover, at least not on all
screens. Market share estimates, developed by EPA in consultation with industry experts, are
provided in Table III-3.
DRAFT—September 1994
III-30
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Screen Reclamation Chemical Usage
National Estimates of Screen Reclamation Products
Table 111-3
Estimated Market Share for Screen Reclamation Products
Chemical
Ink Remover, Traditional Formulations
Xylene
Mineral spirits
Acetone
Lacquer thinner3
Market Sh are (%)
20
20
20
40
Ink Remnver Alternative Formulations
Propylene glycol methyl ether
Methoxypropanol acetate
Dibasic estersb
Diethylene glycol
Propylene glycol methyl ether acetate
Terpineols/d-limonene (50/50)
Propylene glycol
Tripropylene glycol methyl ether
Diethylene glycol butyl ether
Cyclohexanone
10
10
30
3
5
1
5
15
10
5
Fmulfiinn Remnver
Bleach (sodium hypochlorite) (12% solution in water)
Sodium metaperiodate (4% solution in water)
Periodic acid (10% solution in water)
Sodium bisulfate (50% solution in water)
Ha7e Remnver
Sodium hydroxide (20% solution in water)
Potassium hydroxide (20% solution in water)
Sodium hypochlorite (12% solution in water)
Mixture of 65% Glycol ethers0 and 35% N-methylpyrrolidone
10
80
5
5
25
25
10
10
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111-31
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Screen Reclamation Chemical Usage _ Estimates of Chemical Usage for Screen Reclamation
Table 1 1 1-3
Estimated Market Share for Screen Reclamation Products
Chemical
Mixture of 10% d-limonene, 20% Sodium hydroxide, and 70% water
Mixture of 10% Xylene, 30% Acetone, 30% Mineral spirits, and 30% Cyclohexanone
Market Sh are (%)
10
20
aThe formulation for Lacquer thinner is as follows:
CAS# Percentage
(1) Methyl ethyl ketone 78933 30%
(2) n-butyl acetate 123-86-4 15%
(3) Methanol 67561 5%
(4) Solvent naphtha, light aliphatic 64742-89-8 20%
(5) Toluene 108883 20%
(6) Isobutyl isobutyrate 97858 10%
bThis category includes dimethyl glutarate, dimethyl adipate, dimethyl succinate in a 2:1:1 ratio.
This category includes propylene glycol methy ether, methoxypropanol acetate, propylene glycol methyl ether acetate,
tripropylene glycol methyl ether, and diethylene glycol mono butyl ether in equal portions.
Estimates of Chemical Usage for Screen Reclamation
To estimate the amount of individual chemicals used, the product volumes estimated earlier
were combined with the market share estimates to determine the amount of individual chemicals
used. Chemicals that are solids at room temperature are reported in units of mass (pounds) and
those that are liquids are reported in units of volume (gallons). The estimated amount of chemicals
is reported in Table III-4. Many of the chemicals do not have estimates; the chemical's specific
information provided for this analysis (reported in Table III-2) is an overview and, therefore, did
not cover all of the chemicals used in screen reclamation. We were unable to collect volume
information directly from reclamation product manufacturers.
DRAFT-September 1994 III-32
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Screen Reclamation Chemical Usage
Estimates of Chemical Usage for Screen Reclamation
Table 111-4
Estimated Annual Amount of Chemicals Currently Used in Screen Reclamation
(Liquids are reported by volume, solids by weight)
Chemical
Acetone
Alcohols, C8-C10, ethoxylated
Alcohols, C12-C14, ethoxylated
Benzyl alcohol
2-Butoxyethanol
n-Butyl acetate
Butyrolactone
Cyclohexanol
Cyclohexanone
Diacetone alcohol
Dichloromethane
Diethyl adipate
Diethyl glutarate
Diethylene glycol
Diethylene glycol monobutyl ether
Diethylene glycol butyl ether acetate
Diisopropyl adipate
Dimethyl adipate
Dimethyl glutarate
Dimethyl succinate
Dipropylene glycol methyl ether
Dipropylene glycol methyl ether acetate
Dodecyl benzene sulfonic acid, triethanol amine salt
Ethoxylated castor oil
Ethoxylated nonylphenol
Ethyl acetate
Ethvl lactate
Volume
(Gallons)
6,920,000
NAa
NA
NA
NA
1,920,000
NA
NA
270,000
NA
NA
NA
NA
122,000
420,000
NA
NA
609,000
304,000
NA
NA
NA
NA
NA
NA
NA
Weight
(Pounds)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
2,700,000
5,500,000
NA
NA
NA
NA
NA
NA
NA
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III-33
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Screen Reclamation Chemical Usage
Estimates of Chemical Usage for Screen Reclamation
Table 111-4
Estimated Annual Amount of Chemicals Currently Used in Screen Reclamation
(Liquids are reported by volume, solids by weight)
Chemical
Ethyl oleate
Fumed silica
Furfuryl alcohol
Isobutyl isobutyrate
Isobutyl oleate
Isopropanol
d-Limonene
Methoxypropanol acetate
Methanol
Methyl ethyl ketone
Methyl lactate
Mineral Spirits
N-Methyl pyrrolidone
2-Octdecanamine, N.Ndimethyl, Noxide
Periodic acid
Phosphoric acid, mixed ester w/isopropanol and ethoxylated tridecanol
Potassium hydroxide
Propylene carbonate
Propylene glycol
Propylene glycol methyl ether
Propylene gycol methyl ether acetate
Silica
Silica, fumed (amorphous, crystalline-free)
Sodium bisulfate
Sodium hexametaphosphate
Sodium hydroxide
Sodium hypochlorite
Volume
(Gallons)
NA
NA
NA
2,630,000
NA
NA
420,000
610,000
3,720,000
NA
6,920,000
38,000
NA
NA
NA
203,000
418,000
217,000
NA
NA
NA
69,000
Weight
(Pounds)
NA
NA
NA
NA
NA
1,100,000
NA
NA
1,020,000
NA
1,060,000
NA
NA
NA
2,350,000
NA
1,450,000
DRAFT—September 1994
III-34
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Screen Reclamation Chemical Usage
Estimates of Chemical Usage for Screen Reclamation
Table 111-4
Estimated Annual Amount of Chemicals Currently Used in Screen Reclamation
(Liquids are reported by volume, solids by weight)
Chemical
Sodium lauryl sulfate
Sodium metasilicate
Sodium periodate
Sodium salt, dodecylbenzene sulfonic acid
Solvent naphtha, heavy aromatic
Solvent naphtha, light aliphatic
Solvent naphtha, light aromatic
Special tall oil
Terpineols
Tetrahydrofurfuryl alcohol
Toluene
1,1,1-Trichloroethane
1 ,2,4-Trimethylbenzene
Triethanolamine salt, dodecyl benzene sulfonic acid
Tripropylene glycol methyl ether
Trisodium phosphate
Xylene
Volume
(Gallons)
NA
NA
NA
NA
2,160,000
NA
NA
NA
2,670,000
NA
NA
NA
623,000
NA
6,880,000
Weight
(Pounds)
NA
NA
11,700,000
NA
NA
NA
NA
1,100,000
NA
NA
NA
NA
NA
aNot available. Some chemical amounts were not estimated; sufficient information on the use of those chemicals in the screen
printing industry was not available.
Cost Analysis Methodology
The following methodology was used to estimate the costs of baseline screen reclamation as
well as the cost of six alternative chemical, technological and work practice substitutes. The cost
estimation methodology is intended to reflect standard industry practices and representative data
for the given screen reclamation substitutes. The performance demonstrations conducted during
production runs at 23 volunteer facilities in early 1994 were the predominant source of
information for the cost estimates. Information from the performance demonstrations was
supplemented by several other sources, including (1) product evaluations undertaken by the
Screen Printing Technical Foundation (SPTF), (2) equipment specifications from manufacturers
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III-35
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology _ General Description of Costing Methodology
and distributors, (3) industry statistics collected by trade groups, (4) EPA's risk assessment work
undertaken as part of the CTSA, and (5) industry experts and suppliers.
For each substitute method, annual facility costs and per screen costs were estimated for
individual facilities (those involved in the performance demonstrations) whose operations were
characteristic of the given substitute method. For the hypothetical baseline facility, the total annual
cost and per screen cost were estimated for reclaiming six screens (2, 127 in2) per day. In addition,
each facility's costs were normalized to allow cross-facility comparisons, particularly with the
baseline scenario. Normalized values adjust product usage, number of screens cleaned, and
number of rags laundered at demonstration facilities to reflect the screen size and number of
screens cleaned per day under the baseline scenario.
A general description of the cost estimation methodology and data sources used is presented
below. The second section presents additional details for the baseline scenario and each of the six
substitute screen reclamation methods.
General Description of Costing Methodology
The baseline screen reclamation scenario and substitutes are defined as follows:
o Baseline. Traditional chemical formulations for ink removal, emulsion removal and
haze removal.
o Method 1. Chemical substitutes for ink removal and emulsion removal. No haze
removal required.
o Method 2. Chemical substitutes for ink removal, emulsion removal and haze removal.
o Method 3. SPAI Workshop Process -- Chemical substitutes for ink removal, ink
degradant, degreasing and emulsion removal. No haze removal required.
o Method 4. Technology substitute of high pressure wash for ink removal; technology
substitute and reclamation products used for emulsion and haze removal.
o Technology substitute. Use of automatic screen washer for ink removal.
o Work practice substitute. Screen disposal in lieu of reclamation.
In general, the cost estimate for each reclamation method was composed of the sum of six
distinct cost elements: labor, reclamation products, materials, resource use, equipment, and waste
disposal.
o Labor. The printer's staff time spent on each reclamation step (e.g., ink removal,
emulsion removal, haze removal and degreasing) was collected or estimated from
various sources. The total time estimate does not include collecting screens from
printing areas, waiting for product reactions as might be specified in the
manufacturers^ application instructions, maintenance of reclamation area, or handling
of segregated waste materials. The labor cost was calculated as the total time spent
multiplied by (1) the average wage rate for screen reclaimers of $6.53/hour (as reported
in SPAI's 1993 Wage Survey Report for the Screen Printing Industry) and (2) an
DRAFT-September 1994 III-36
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Cost Analysis Methodology
General Description of Costing Methodology
industry multiplier of 2.01 (calculated from SPAI's 1992 Operating Ratios Study) to
account for fringe and overhead costs.
Reclamation products. The average usage per screen was calculated for each product
(i.e., ink remover, emulsion remover, haze remover, and degreaser) used by a
particular facility. Because of wide variations, no attempt was made to average across
facilities or product systems within the same substitute method. For comparative
purposes, "normalized" average quantities were calculated by multiplying actual usage
with the ratio of the baseline screen size of 2,127 in2 to the recorded screen size.
Multiplying usage with the unit cost of each product (provided by each participating
manufacturer and summarized in Table III-5) yielded the reclamation product costs.
Costs associated with special storage requirements for products were not considered
in the cost analysis.
Table 111-5
Alternative Screen Printing Systems: Manufacturer Pricing
System
Alpha
Beta
Chi
Delta
Epsilon
Gamma
Mu
Phi
Omicron
Theta
Ink Remover
$18.18/gallon
(5gallons/$91)
(55 gallons/$850)
$15.10/gallon
$31.20/gallon
(5gallons/$156)
(55gallons/$1,315)
$20.00/gallon
(5gallons/$100)
(55 gallons/$900)
$7.80/gallon
(5 gallons/$39)
$10.90/gallon
(25 liters/$72)
(5 gallons/$55)
($7.76/gallon)
(20liters/$41)
(5 gallons/$39)
$24.95/gallon
$13.40/gallon
(5 gallons/$67)
(55 gallons/$540)
No ink remover costs
Other costs: $5,170
Emulsion Remover
$4.00/gallon
Ink remover only
$32.00/gallon
(5gallons/$160)
(15gallons/$438)
(55gallons/$1,238)
$32.00/gallon
(5gallons/$160)
(15gallons/$438)
(55gallons/$1,238)
$13.54/gallon
(5kg/$149)
$1.60/lb
(15kg/$53)
$10.34/gallon
(3 five liter units/$41)
(5 gallons/$52)
$24.95/gallon
$11.00/gallon
(5 gallons/$55)
(55 gallons/$530)
$21.95/gallon
Haze Remover
$9.39/gallon
(5 kg/$50)
Ink remover only
$31.20/gallon
(5gallons/$156)
(55gallons/$1,315)
$20.00/gallon
(5gallons/$100)
(55 gallons/$900)
$1.09/gallon
(15kg/$36)
$9.39/gallon
(25 liters/$62)
(5 gallons/$52)
$7.57/gallon
(5 five liter units/$50)
(5gallons/$189)
$39.95/gallon
$18.00/gallon
(5 gallons/$90)
$43.00/gallon
DRAFT—September 1994
III-37
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology _ General Description of Costing Methodology
Table 1 1 1-5
Alternative Screen Printing Systems: Manufacturer Pricing
System
Zeta
Ink Remover
$23.00/gallon
Emulsion Remover
$23.00/gallon
Haze Remover
$30.00/gallon
Note: Volume conversions were made using 3.785 liters/gallon.
The price of the greatest volume in the table (e.g., 55 gallons) was used when estimating cost for a particular system.
o Materials (e.g.. rags, screens). This element is most important for the work practice
substitute of screen disposal. A supplier quote was used for the unit cost of screen
mesh (40" wide, 260 threads per square inch). Wastage was assumed to be 10 percent
of the screen size. For all methods, rag use was estimated or recorded for the baseline
and all substitute methods. It was assumed that rags were leased and laundered at
a cost of $0.15/rag. Changes in the number of application brushes between the
baseline and substitute methods is considered inconsequential.
o Resource Use. The cost of electricity and water was addressed quantitatively only for
Method 4 (high pressure wash). The equipment was assumed to be in operation only
for the recorded time spent on ink removal. Equipment specifications for flow rate
and electrical rating provided by the manufacturer allow the calculation of water and
electricity use. The cost of water, electricity and sewer were estimated using utility
rates in the Northeast, a generally conservative assumption. For all other methods,
changes in resource use are considered inconsequential.
o Equipment. Equipment costs were considered for Method 4 (high pressure wash) and
the automatic screen washer only. Equipment costs common to all the methods and
the baseline were excluded from the analysis. The capital costs were amortized over
a ten-year period, the estimated engineering life of the equipment. An interest rate of
7 percent for small business loans was used (which represents the marginal rate of
return on capital). The annualized cost of equipment was adjusted (using a marginal
tax rate of 34 percent) to reflect the nontaxable nature of interest and (10-year)
depreciation for such equipment.
o Waste disposal. Hazardous waste disposal costs were assumed only if the reclamation
products contain RCRA-listed chemicals or if the products are defined as characteristic
wastes due to their ignitable nature (See Table III-6). For each product system,
hazardous waste generation rates (in g/day for 6 screens), were estimated by chemical
engineers on EPA's staff. This methodology does not consider the possible effect
residual inks may have on the waste's hazard classification. It also assumes that other
wastestreams at the facility are hazardous; thus, the labor cost of training and
managing hazardous wastes is not associated with screen reclamation only. Given that
filtration systems used to remove residual inks and reclamation products from spent
wash water (spent filters must be disposed of) may be required for both baseline and
alternative systems, filtration system and filter disposal costs were not included in the
cost analysis. The analysis focuses on quantifying cost differences among reclamation
methods.
DRAFT-September 1994 III-38
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
EVALUATION
Cost Analysis Methodology
Details Related to Data Sources and Methodological Approach
Table 111-6
Alternative Screen Printing Systems: Determination of RCRA Hazardous Waste Listing
System
Alpha
Beta
Chi
Delta
Epsilon
Gamma
Mu
Phi
Omicron (AE &
AF)
Theta
Zeta
Ink remover
RCRA Characteristic waste (ignitable)
Flashpoint = 101°F/38°C
None
None
None
RCRA Listed waste (cyclohexanone - all
other components qualify as listed under
mixture rule). Also Characteristic waste
(ignitable)
Flashpoint = 46°C/1 15° F
None
RCRA Characteristic waste (ignitable)
Flashpoint = 131°F/55°C
None
None
No ink remover
RCRA Characteristic waste (ignitable)
Flashpoint = 101°F/38°C
Emulsion remover
None
Ink remover only
None
None
None
None
None
None
None
None
None
Haze remover
None
Ink remover only
None
None
1:1 dilution with ink remover. All
components quality as hazardous
waste under mixture rule.
None
None
None
None
RCRA Listed waste (cyclohexanone
- all other components qualify as
listed under mixture rule)
None
All information on flashpoint was gathered from masked MSDSs submitted by supplier. None of the above information should
be used for compliance purposes. None of the chemicals in these formulations is listed as toxic characteristic contaminants and
were not treated as such in the cost analysis; however, printers should use the Toxicity Characteristic Leaching Procedure
(TCLP) to determine the applicability of the toxicity characteristic to their particular waste stream.
Details Related to Data Sources and Methodological Approach
In addition to the methodological approach outlined above, there a number of important
assumptions and differences specific to the cost estimations of each screen reclamation method.
Details related to data sources and the methodological approach used to estimate the cost of each
reclamation method are presented below.
Baseline Screen Reclamation
Four traditional systems are defined in Chapter 5, the primary distinction among them being
the chemical constituents of the ink remover, emulsion remover and haze remover. Traditional
System #4 was used to estimate baseline costs, as it was expected to be more representative of
systems currently in use. The baseline products used are described as follows:
Ink remover
Emulsion remover
Haze remover
lacquer thinner
1.25% sodium periodate in water
10% xylene (by weight)
30% acetone
DRAFT—September 1994
III-39
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology _ Details Related to Data Sources and Methodological Approach
30% mineral spirits
30% cyclohexanone
For ink remover, time and volume information was taken from SPTF testing. An average
price for lacquer thinner was calculated from prices reported in the Workplace Practices
Questionnaire conducted by SPAI and the University of Tennessee. Time, volume, and price
information for baseline emulsion removal was taken from the Zeta system used in performance
demonstrations. Time and volume information for the four-chemical baseline haze remover was
not available from the performance demonstrations and had to be estimated based on the SPTF
evaluation of a similar haze remover, resulting in a time of 11.5 minutes. A volume of 3 ounces for
haze removal was taken from the application instructions developed for SPTF. A price for
purchasing this formulation in a 5 5 -gallon drum quantity was quoted by Ashland Chemical.
A second baseline scenario was developed which excluded the haze removal step. The second
baseline reflects the fact that between 27 and 80 percent of facilities regularly use a haze remover.
The second baseline also allowed comparisons of Method 1 (no haze removal) with a similar
baseline.
DRAFT-September 1994 III-40
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology Details Related to Data Sources and Methodological Approach
Substitute Method 1: Chemical Substitutes for Ink Removal and Emulsion Removal. No
Haze Removal Required.
Two assumptions affect the cost analysis of Substitute Method 1. Eliminating haze removal
avoids both the material and labor costs of haze removal. The estimated cost difference between
Substitute Method 1 and the baseline may also be affected by the assumption that the baseline
facility uses haze remover during all screen reclamations; however, industry figures indicate that
haze removal is undertaken on between 27 and 80 percent of reclamations. Therefore, the baseline
used in the analysis of this alternative method excludes haze removal. The amount of ink remover
and emulsion remover used and time spent on reclamation were taken from performance
demonstrations. Product prices were provided by participating suppliers. Performance
demonstration results from product systems Chi (excluding the haze removal step) and Beta
(including an emulsion removal step from System Zeta) were used to estimate the cost of Substitute
Method 1.
Substitute Method 2: Chemical substitutes for ink removal, emulsion removal and haze
removal.
The amount of each reclamation product used and time spent on reclamation were available
from the performance demonstrations. Product prices were provided by participating suppliers.
Performance demonstration results for product systems Alpha, Chi, Delta, Epsilon, Gamma, Mu,
Phi, Omicron-AE, Omicron-AF, and Zeta were used to estimate the cost of Substitute Method 2.
Substitute Method 3: SPAI Workshop Process - Chemical substitutes for ink removal,
ink degradant, degreasing and emulsion removal. No haze removal required.
The amounts of ink and emulsion removers used were available from performance
demonstrations of product system Omicron. Based on information about the SPAI Workshop
Process, which indicated that the overall time spent reclaiming screens would not change
appreciably from a typical reclamation process, the average time spent (including 5 minutes for
treatment with ink degradant and degreasing) from the evaluation of product system Omicron by
four facilities was used to estimate labor costs. Documentation of the SPAI Workshop Process was
used to estimate the amount of ink degradant (3 ounces) and degreaser (3 ounces) used. Product
prices were available from participating suppliers.
Substitute Method 4: Technology substitute of high pressure wash for ink removal;
technology substitute and reclamation products used for emulsion and haze removal.
Data collected by SPTF staff during a facility visit and equipment specifications provided by
the manufacturer were used to develop the cost for this method. The capital cost of this equipment
was annualized by the method described above and added to the recurring operating and
maintenance costs and divided by the number of screens reclaimed per year to arrive at the per
screen equipment costs. Water, wastewater and electrical usage costs were included in the cost
estimate for this method only. As in all other cost estimations, the cost of a filtration system was
not included as the analysis was focused on quantifying cost differences between reclamation
systems, without accounting for filtration costs that could be expected to occur in all cases.
DRAFT-September 1994 11141
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology _ Details Related to Data Sources and Methodological Approach
Technology Substitute of Automatic Screen Washer for Ink Removal
Although several suppliers of automatic screen washers were asked to participate in
performance demonstrations, none accepted. As information on automatic screen washers was,
therefore, not collected as part of the performance demonstrations, it was gathered from other
sources, including an equipment supplier and a printer. Two cost estimates were developed which
reflect the baseline facility's operations and size and the range of equipment available. Typically,
automatic screen washers substitute for the ink removal step; emulsion removal and haze removal
may still be required.
Automatic Screen Washer # 1 was a large capacity (in terms of the maximum size of screen)
enclosed washer with a fully automated feed system to move the screens through separate wash
and rinse areas. It was assumed that mineral spirits were in both reservoirs. As mineral spirits
were used in the ink removal step, the cost analysis of automatic screen washer # 1 assumes the
same emulsion and haze removal costs as in the baseline. Its purchase price was assumed to be
$95,000, the original manufacturer's list price, although the printer purchased the equipment at
auction. The only operating costs were related to solvent make-up (daily) and replacement of the
reservoirs' contents 70 gallons (every eight to nine months) . Information on other operating costs
was not available; it was assumed that these costs would be minimal as compared to the
equipment costs. Time spent loading and unloading the washers was taken from manufacturer's
documentation of the equipment. As the equipment's electrical rating was not available from
information provided by the distributor, electrical costs were not included. The price of mineral
spirits ($4.00/gallon) was taken from the Work Practice Survey. Emulsion removal and haze
removal costs were assumed to be similar to those of the baseline system.
Automatic Screen Washer #2 is a smaller unit. Screens must be loaded and unloaded by
hand. Because it uses a solvent with lower volatile fraction than # 1 , more solvent remains on the
screen and must be washed off following ink removal. Time spent loading and unloading the
washers was taken from manufacturer's documentation of the equipment. Two pumps operate
using compressed air which is reportedly available from other sources at the facility; the cost of
a generator was not included in the cost analysis. The price of the ink remover was provided by
the equipment supplier. Emulsion removal costs were assumed to be similar to those of the
baseline system. The manufacturer indicated that a haze remover was not required given the
formulation of the ink remover.
Work Practice Substitute of Screen Disposal
The cost estimate of screen disposal was developed for comparison to other reclamation
methods. Information on screen disposal was not collected as part of the performance
demonstrations. Consequently, one cost estimate was developed which reflects the baseline
facility's operations and size. It should be noted that screen disposal is most cost effective under
two circumstances not assumed for the model facility's operations: where production runs
approach the useful life of a screen and where the size of the screen is relatively small. A number
of assumptions were used to estimate the cost of this substitute method, including:
o No other changes in operations or equipment were required.
o Waste screens do not need to be handled as hazardous waste under RCRA which
would greatly increase the estimated cost.
DRAFT-September 1994 III42
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Cost Analysis Methodology _ Details Related to Data Sources and Methodological Approach
o The replacement of screens (after reaching the end of the useful life of the mesh) was
not considered in the baseline nor in any of the other reclamation methods; it is
estimated to be approximately $0.60/screen reclaimed. Consequently, this value was
deducted from the total cost of this method.
o The average wage rate of screen stretchers ($6.87), which is slightly higher than for
screen reclaimers, was used to calculate labor costs for this method.
DRAFT-September 1994 III-43
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Chapter IV
Screen Reclamation Products: Functional Groups
The intent of this chapter is to define the characteristics associated with each ink remover,
emulsion remover and haze remover. Because of the specific functions these three types of
products perform, they have been designated as functional groups in a screen reclamation system.
Information on the characteristics associated with each of these functional groups is presented in
a format that will allow comparison of several types of products within each functional group. For
example, given a hazard summary, purchase cost, exposure analysis and risk characterization for
several different types of ink removers, decisions regarding which one of these products would
work best in an individual facility could be made. However, to gain a better understanding of all
the issues associated with the ink removers, performance information in Chapter V should be
referenced. In this chapter information about the different ink removers is combined with
emulsion and haze removers, forming a product system by which they are typically sold. In this
way the variables of performance and total cost can be fully evaluated.
In the sections below, characteristics of many of the different formulations associated with
ink, emulsion and haze removers are described. However, these formulations are not all-inclusive;
other formulations may be available commercially. These particular formulations were selected
by a workgroup consisting of screen printing manufacturers who participated in the performance
demonstration, SPAI and DfE staff. For the purposes of this document, an ink remover has been
defined as any chemical, set of chemicals, process or technology that removes ink from the screen
surface. Ink removers can also be referred to as ink degradants. Because the final screen
reclamation process is being considered, not press-side in-process activities, some of the ink
removers may also remove emulsions. An emulsion or stencil remover has been defined as any
chemical, set of chemicals, process or technology that removes an emulsion from the screen
surface. Lastly, a haze remover has been defined as any chemical, set of chemicals, process or
technology that can remove the residual pigment and resin in screen mesh so as to eliminate ghost
images.
Each functional group is evaluated as follows:
o Hazard Summary and Cost
o Occupational Exposure
o Occupational Risk Conclusions and Observations
o Environmental Releases in Screen Cleaning Operations
o Ecological Risks from Water Releases
o General Population Exposure Conclusions and Observations
At the end of this chapter is a brief discussion of the process of manufacturing screen
reclamation chemical products and a general source release assessment on product formulation.
Energy and natural resources use in product formulation is also discussed. Information on these
areas could not be discussed for each formulation or technology due to limited data availability.
Information about pollution prevention opportunities through workpractice changes and
equipment modifications is discussed in Chapter VI.
DRAFT-September 1994 IV-1
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IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function Substitute Comparative Assessment
Ink Removal Function
Substitute Comparative Assessment
Table IV-1 below lists some of the chemical ink removers that are available to screen printers.
In addition to chemical ink removers, specific technologies, such as high-pressure water wash
systems, are commercially available. Reference Method 4 in Chapter V for a discussion of this
option. In Table IV-1, a brief hazard summary and a list of purchase prices is included for each
ink remover. For information on the chemical properties and industrial synthesis of the bulk
chemicals, refer to Chapter II and for performance information on these products in a given system
see Chapter V. Market information on the volume of specific ink remover products sold is not
available.
DRAFT-September 1994 IV-2
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IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Substitute Comparative Assessment
Table IV-1
Hazard Summaries and Costs: Ink Removers
Formulation
Traditional Systems
System 1
100% Mineral spirits
System 2
100% Acetone
Svstem 3 & Svstem 4
100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% Butyl acetate
5% Methanol
20% Naphtha, light aliphatic
20% Toluene
10% Isobutyl isobutyrate
%voc
Flash Pt.
V.P.a
100 %
109 F
1 mm Hg
100 %
OF
185mm Hg
100 %
Hazard Summary
Health Effects
Description
limited hazard data
neurotoxicity; chronic
toxicity
developmental toxicity;
genetic toxicity?;
neurotoxicity; chronic
toxicity
Aquatic
Hazard
Rankingsb
High
Low
Low
Medium
Low
High
Medium
Medium
Purchase Cost
$4.00/gallon
$3.00/gallon
$3.50/gallon
Alternative Systems
Alpha
Aromatic solvent naphtha
Propylene glycol series ethers
Beta
2-Octadecanamine, N,N-dimethyl-, N-
oxide or a modified amine from
unsaturated soy bean oil fatty acid
Water
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
100 %
101 F
< 4mm Hg
0%
205 F
NAC
96%
<200F
<0.1 mm Hg
94%
<200F
< 1.0mm Hq
developmental toxicity;
neurotoxicity
limited hazard data
developmental toxicity;
reproductive toxicity;
neurotoxicity; chronic
toxicity
developmental toxicity;
chronic toxicity
Low
Low/Medium
High
Low/Medium
Low/Medium
Low
Medium
Medium
Low/Medium
Medium
$18.18/gallon
(5 gallons/ $91
55 gallons/ $850)
$15.10/gallon
(estimated)
$31.20/gallon
(5 gallons/$156
55
gallons/$1,315)
$20.00/gallon
(5 gallons/$100
55 gallons/$900)
DRAFT—September 1994
IV-3
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IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Substitute Comparative Assessment
Table IV-1
Hazard Summaries and Costs: Ink Removers
Formulation
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
Gamma
Tripropylene glycol methyl ether
Diethylene glycol butyl ether acetate
Dibasic esters
Fatty alcohol ethers
Derivatized plant oil
Mu
Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Ehi
Dibasic esters
Omicron AE & Omicron AF
Diethylene glycol butyl ether
Propylene glycol
Zeta
Propylene glycol series ethers
%voc
Flash Pt.
V.P.a
65%
115F
unknown
40%
76 F
10.9 mm Hg
50%
131 F
< 0.3 mm Hg
NA
<160F
NA
30%
214F
0.04 mm Hg
100 %
101 F
0.4-10.5 mm
Hg
Hazard Summary
Health Effects
Description
developmental toxicity;
reproductive toxicity;
genetic toxicity;
neurotoxicity; chronic
toxicity
developmental toxicity;
chronic toxicity
developmental toxicity;
chronic toxicity
developmental toxicity;
chronic toxicity
developmental toxicity;
chronic toxicity
developmental toxicity;
neurotoxicity; chronic
toxicity
Aquatic
Hazard
Rankingsb
Low
Medium
Low
Medium
Low
Medium
Low/High
Low
Medium
Medium
Medium/High
Low/High
Medium
Medium
Medium
High
Low/High
Medium
Low
Low
Low/Medium
Purchase Cost
$7.80/gallon
(5 gallons/$39)
$10.90/gallon
(25 liters/$72)
$7.76/gallon
(20liters/$41)
$24.95/gallon
$13.40/gallon
(5 gallons/$67
55 gallons/$540)
$23.00/gallon
aV.P. means vapor pressure.
bThe hazard rankings shown identify the categories (low, medium, or high) into which the individual components of the product system fall. The aquatic hazard
ranking for each chemical is listed on the same line as the chemical name. When an alternative system includes chemicals from a chemical category (see Table
II-2), the hazard ranking shown is the range of the rankings of all of the individual chemicals comprising the category. This analysis did not estimate the aquatic
hazard ranking of the product systems as mixtures.
°NA means not available.
DRAFT—September 1994
IV-4
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IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Exposure Analysis & Risk Characterization
For specific assumptions and details of the occupational exposure, environmental releases
and risk assessment, please reference Chapter III.
Table IV-2
Occupational Exposures: Ink Removers
System
Traditional Systems
System 1
Mineral spirits- light hydrotreated
System 2
Acetone
Systems 3 & 4
Methyl ethyl ketone
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Inhalation Exposures, by Scenario
(mg/day)
I
26
539
165
44
27
98
110
7
II
0.1
11
5.3
1.3
4.7
1.6
2.3
0.4
III
0
5
3
1
2
1
1
0
IV
0.3
38
20
5.3
15
6.2
9.2
1.7
Dermal Exposures, (mg/day)
Routine
1560
1560
468
234
78
312
312
156
Immersion
7280
7280
2180
1090
364
1460
1460
728
Alternative Systems
Alpha
Aromatic solvent naphtha
Propylene glycol series ethers
Beta
2-Octadecanamine, N,N-dimethyl-, N-oxide
or a modified amine from unsaturated soy
bean oil fatty acid
Water
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
13
56
292
0
0
0
3
0
2
0
0
0.1
0.6
4.3
0
0
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0.2
2.6
0
0
0
0
0.1
0
0.1
0
0
1250
312
1530
31
312
858
312
78
702
780
78
5820
1460
7130
146
1456
4000
1460
364
3280
3640
364
DRAFT—September 1994
IV-5
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-2
Occupational Exposures: Ink Removers
System
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Gamma
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Mu
Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
EM
Dibasic esters
Omicron AE & Omicron AF
Diethylene glycol butyl ether
Propylene glycol
Zeta
Propylene glycol series ethers
Method 5 (Automatic Screen Washer)
Ink remover solvent (mineral spirits or
lacquer thinner)3
Inhalation Exposures, by Scenario
(mg/day)
1
39
17
0
0.1
0.1
1.6
4.6
0
0
0.2
0.4
1.3
3
31
21
0
0
4
0
17
139
II
0.3
0.4
0
0
0
0.1
0.1
0
0
0
0
0
0
0.4
0.6
0
0
0
0
0.1
0.6
III
0.2
0.2
0
0
0
0
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IV
1.4
1.7
0
0
0.2
0.2
0.4
0
0
0.2
0.1
0.2
0.2
1.7
2.4
0
0.2
0.2
0
0.4
2.8
266
Dermal Exposures, (mg/day)
Routine
468
234
312
101
55
156
234
62
780
62
187
468
1014
312
156
94
62
1561
984
576
1560
Immersion
2180
1090
1460
473
255
728
1090
291
3640
291
873
2184
4728
1460
728
437
291
7270
4590
2690
7280
3900
Occupational exposure from automatic screen washers are estimated to be the same for either mineral spirits or lacquer
thinner. See traditional system 3 for the composition of lacquer thinner. This analysis did not consider alternative exposure
routes for automatic screen washers.
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
DRAFT—September 1994
IV-6
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-3
Occupational Risk Conclusions and Observations:
Ink Removers
System
Observations
Traditional Systems
System 1
System 2
Systems 3 & 4
Dermal exposures to workers using mineral spirits in ink removal can be very high, although the risks
from mineral spirits could not be quantified because of limitations in hazard data.
Hazard quotient calculations indicate clear concerns for chronic dermal and inhalation exposures to
workers using acetone in ink removal.
Hazard quotient calculations indicate clear concerns for both toluene and methyl ethyl ketone with
respect to chronic dermal and inhalation exposures to workers using these chemicals in ink removal.
Hazard quotient calculations indicate marginal concerns for chronic inhalation exposure to workers
using methanol in ink removal.
Alternative Systems
Alpha
Beta
Chi
Delta
Hazard quotient calculations indicate marginal concerns for chronic inhalation exposure to workers
using propylene glycol series ethers in ink removal. Possible concerns also exist for chronic dermal
exposure to propylene glycol series ethers based on the calculated hazard quotients, which assume
100% dermal absorption. If the actual dermal absorption rate of propylene glycol series ethers is
significantly lower, this concern would be significantly reduced or eliminated.
Inhalation exposures to propylene glycol series ethers also present possible concerns for
developmental toxicity risks, based on margin-of-exposure calculations.
Dermal exposures to other chemicals used in ink removal or haze removal can be high, although the
risks could not be quantified because of limitations in hazard data.
Both inhalation and dermal exposures to workers using 2-octadecanamine, N,N-dimethyl-, N-oxide in
ink removal can be high, although the risks could not be quantified because of limitations in hazard
data.
Clear concerns exist for chronic dermal exposures to diethylene glycol series ethers used in ink
removal based on the calculated margins-of-exposure.
Concerns exist for developmental toxicity risks from dermal exposures to N-methylpyrrolidone based
on the calculated margin-of-exposure. Similar calculations for inhalation exposures to N-
methylpyrrolidone indicate very low concern.
Inhalation exposures to other ink remover components are very low.
Dermal risks from other ink remover components could not be quantified because of limitations in
hazard data, but exposures can be high.
Although no risks could be quantified because of limitations in hazard data, relatively high dermal
exposures to ink remover components could occur.
Inhalation exposures to all components are very low.
DRAFT—September 1994
IV-7
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-3
Occupational Risk Conclusions and Observations:
Ink Removers
System
Observations
Epsilon
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures to
cyclohexanone and benzyl alcohol during ink removal. Similar calculations for inhalation exposures
to cyclohexanone and benzyl alcohol indicate low concern.
Margin-of-exposure calculations indicate a marginal concern for developmental toxicity risk from
inhalation exposures to cyclohexanone during ink removal. Reproductive and developmental toxicity
risks from dermal exposures to cyclohexanone could not be quantified.
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures and low
concern for chronic inhalation exposures to methoxypropanol acetate.
Risks from other ink remover components could not be quantified because of limitations in hazard
data, although dermal exposures to all components could be relatively high.
Gamma
Clear concerns exist for chronic dermal exposures to diethylene glycol butyl ether acetate used in ink
removal based on the calculated margin-of-exposure.
Developmental toxicity risks from dermal exposures to diethylene glycol butyl ether acetate are very
low based on the calculated margin-of-exposure.
Risks from other ink remover components could not be quantified because of limitations in hazard
data, although dermal exposures to all components could be relatively high.
Inhalation exposures to all components are very low.
Mu
Concerns exist for chronic risks from both inhalation and dermal exposures to d-limonene during ink
removal based on the calculated margins-of-exposure.
Hazard quotient calculations for methoxypropanol acetate used in ink removal indicate a marginal
concern for chronic dermal exposures and low concern for chronic inhalation exposures.
Margin-of-exposure calculations show possible concerns for developmental toxicity risks from
inhalation exposures to methoxypropanol acetate.
Risks from other ink remover components could not be quantified because of limitations in hazard
data, although dermal exposures to all components could be relatively high.
Phi
Risks from ink remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
Inhalation exposures to all components are very low.
DRAFT—September 1994
IV-8
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-3
Occupational Risk Conclusions and Observations:
Ink Removers
System
Observations
Omicron AE &
Omicron AF
Margin-of-exposure calculations indicate clear concerns for chronic dermal exposures to workers
using diethylene glycol butyl ether in ink removal.
Margin-of-exposure calculations also show possible concerns for developmental toxicity risks from
dermal "immersion" exposures to diethylene glycol butyl ether. Routine dermal exposures, however,
represent a very low concern for developmental toxicity risks.
Hazard quotient calculations for inhalation and dermal exposures to propylene glycol during ink
removal indicate very low concern.
Inhalation exposures to other components are very low.
Risks from other components could not be quantified because of limitations in hazard data, although
dermal exposures to all components could be relatively high.
Zeta
Hazard quotient calculations indicate marginal concerns for chronic inhalation exposure to workers
using propylene glycol series ethers in ink removal. Possible concerns also exist for chronic dermal
exposure to propylene glycol series ethers based on the calculated hazard quotients, which assume
100% dermal absorption. If the actual dermal absorption rate of propylene glycol series ethers is
significantly lower, this concern would be significantly reduced or eliminated.
Inhalation exposures to propylene glycol series ethers also presents possible concerns for
developmental toxicity risks, based on margin-of-exposure calculations.
Inhalation exposures to other components are very low.
Risks from other ink remover components could not be quantified because of limitations in hazard
data, although dermal exposures to all components could be relatively high.
DRAFT—September 1994
IV-9
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-3
Occupational Risk Conclusions and Observations:
Ink Removers
System
Observations
Method 5
(Automatic Screen
Washer)
Mineral spirits
Inhalation exposures were significantly lower (reduced by about 70%) than the exposures during
manual use of this system. Risks could not be quantified because of limitations in hazard data.
Dermal exposures can still be relatively high.
Lacquer Thinner
Hazard quotient calculations indicate marginal concerns for chronic inhalation exposures to toluene,
methyl ethyl ketone, and methanol.
Hazard quotient calculations indicate clear concerns for chronic dermal exposures to toluene and
methyl ethyl ketone and marginal concerns for dermal exposures to methanol.
The risks described above are slightly lower than the corresponding risks during manual use of this
system.
Risks from other components could not be quantified because of limitations in hazard data, although
dermal exposures to all components could be relatively high.
DRAFT—September 1994
IV-10
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-4
Environmental Releases in Screen Cleaning Operations:
Ink Removers
System
Traditional Systems
System 1
Mineral spirits - light hydrotreated
System 2
Acetone
Systems 3 & 4
Methyl ethyl ketone
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Release Under Each Scenario
(g/day)
I
Air
54
1120
344
92
57
204
229
15
Water
0
0
0
0
0
0
0
0
Land
1050
0
0
80
0
25
0
100
II
Air
0.2
22
11
2.6
9.8
3.2
4.8
0.8
III
Air
0.1
11
5.7
1.5
4.1
1.7
2.6
0.5
IV
Air
0.6
80
42
11
30
13
19
3.4
Water
1350
1270
363
191
37
257
251
132
Alternative Systems
Alpha
Aromatic solvent naphtha
Propylene glycol series ethers
Beta
2-Octadecanamine, N,N-dimethyl-, N-
oxide or a modified amine from
unsaturated soy bean oil fatty acid
Water
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
27
117
609
0
0.1
0.1
6.8
0
3.7
0.1
0
0
0
0
0
0
0
0
0
0
0
0
473
8
0
12
138
381
132
35
319
359
36
0.1
1.3
9.1
0
0
0
0.1
0
0
0
0
0.1
0.7
6.3
0
0
0
0
0
0
0
0
0.5
5.4
0
0
0
0
0.2
0
0.2
0
0
1080
265
0
0
270
742
270
67
608
675
67
DRAFT—September 1994
IV-11
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Ink Removal Function
Exposure Analysis & Risk Characterization
Table IV-4
Environmental Releases in Screen Cleaning Operations:
Ink Removers
System
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Gamma
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Mu
Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
EM
Dibasic esters
Omicron AE & Omicron AF
Diethylene glycol butyl ether
Propylene glycol
Zeta
Propylene glycol series ethers
Method 5 (Automatic Screen Washer)
Usina Mineral Spirits
Mineral Spirits
Release Under Each Scenario
(g/day)
1
Air
82
36
0
0.2
0.2
3.2
9.6
0
0.1
0.3
0.8
2.7
5.1
64
43
0
0.3
8.1
0
35
290
15.1
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NAa
Land
126
68
138
45
24
66
94
28
355
28
84
210
446
75
27
42
27
766
440
222
375
NA
II
Air
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0.1
0
0
0
0.8
1.2
0
0.1
0
0
0.2
1.4
NA
III
Air
0.4
0.5
0
0
0
0.1
0.1
0
0
0
0
0
0
0.5
0.7
0
0
0
0
0.1
0.8
NA
IV
Air
2.9
3.6
0
0
0.3
0.5
0.8
0
0
0.3
0.1
0.3
0.3
3.6
5.1
0
0.3
0.3
0
0.7
5.8
NA
Water
402
199
270
88
47
135
202
54
675
54
162
405
877
266
130
81
54
1349
852
497
1345
NA
DRAFT—September 1994
IV-12
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Substitute Comparative Assessment
Table IV-4
Environmental Releases in Screen Cleaning Operations:
Ink Removers
System
Method 5 (Automatic Screen Washer)
Usina Lacquer Thinner
Methyl ethyl ketone
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Release Under Each Scenario
(g/day)
1
Air
335
27.7
91.5
57.7
80.7
4.6
Water
NAa
NA
NA
NA
NA
NA
Land
NA
NA
NA
NA
NA
NA
II
Air
NA
NA
NA
NA
NA
NA
III
Air
NA
NA
NA
NA
NA
NA
IV
Air
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
aThis analysis did not estimate releases to water or land from automatic screen washing.
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
Ecological Risks from Water Releases of Screen Reclamation Chemicals
o Cumulative releases of mineral spirits from Traditional System 1 present a concern
for risk to aquatic species. The largest contributor to these releases is the hypothetical
commercial laundry that launders the shop rags used by the area's screen printers.
o None of the other components of any of the four traditional systems reached an
ecotoxicity concern concentration, even when considering the cumulative releases from
all shops in the area.
o None of the single facility releases of either traditional or alternative systems reach an
ecotoxicity concern concentration.
General Population Exposure Conclusions and Observations
o Health risks to the general population from both air and water exposures are very low
for all of the ink removers evaluated.
Emulsion Removal Function
Substitute Comparative Assessment
Table IV-5 below lists some of the chemical emulsion removers that are available to screen
printers. Table IV-5 includes a summary of key physical properties, a brief hazard summary, and
a list of purchase prices for each emulsion remover. For information on the chemical properties
DRAFT—September 1994
IV-13
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Substitute Comparative Assessment
and industrial synthesis of the bulk chemicals, refer to Chapter II. Market information on the
volume of specific emulsion remover products sold is not available.
Table IV-5
Hazard Summaries and Cost: Emulsion Removers
Formulations
%voc,
Flash Pt.,
V.P.b,
(per
formulation)
Hazard Summary
Health Effects
Description
Aquatic
Hazard
Rankingsc
Purchase Cost
Traditional Systems
Systems 1. 2. & 3
12% Sodium hypochlorite (bleach)
88% Water
System 4
1% Sodium periodate
99% Water (as applied)
0%
NA
NA
0%
NA
NA
developmental
toxicity; genetic
toxicity; chronic
toxicity
NA
Medium
High
$1.80/gallon
$23.00/gallon (5%
sodium periodate)
Alternative Systems
Alpha
Sodium periodate
Water
Chi
Sodium periodate
Water
Delta
Sodium periodate
Water
Epsilon
Sodium periodate
Sulfate salt
Water
Gamma
Sodium periodate
Sulfate salt
Phosphate salt
Water
0%
NA
0%
NA
NA
0%
NA
NA
0%
NA
unknown
0%
NA
23.4mmHg
(water)
NA
NA
NA
corrosive
chronic toxicity;
corrosive
High
High
High
High
Medium
High
Medium
High
$4.00/gallon
$32.00/gallon
(5 gallons/$160
15gallons/$438
55gallons/$1,238)
$32.00/gallon
(5 gallons/$160
15gallons/$438
55gallons/$1,238)
$13.54/pound
(5kg/$149)
$1.60/pound
(15kg/$53)
DRAFT—September 1994
IV-14
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Substitute Comparative Assessment
Table IV-5
Hazard Summaries and Cost: Emulsion Removers
Formulations
Mu
Periodic acid
Water
EM
Sodium periodate
Ethoxylated nonylphenol
Other
Water
Omicron AE & Omicron AF
Sodium periodate
Ethoxylated nonylphenol
Water
Theta
Sodium periodate
Water
Zeta
Sodium periodate
Water
%voc,
Flash Pt.,
V.P.b,
(per
formulation)
0%
NA
NA
0%
NA
23.4mmHg
(water)
0%
NA
23.4mmHg
(water)
0%
NA
NA
0%
NA
9D mm Hn
Hazard Summary
Health Effects
Description
NA
NA
NA
NA
NA
Aquatic
Hazard
Rankingsc
High
High
Medium
Low
High
Medium
High
High
Purchase Cost
$10.34/gallon
(three 5-liter units/$41
(5gallons/$51.73))
$24.95/gallon
$11.00/gallon
(5 gallons/$55
55 gallons/$530)
$21.95/gallone
$23.00/gallon
aWhile many of these formulations may seem similar, they may vary in the composition of specific components.
bV.P. means vapor pressure.
bThe hazard rankings shown identify the categories (low, medium, or high) into which the individual components of the product
system fall. The aquatic hazard ranking for each chemical is listed on the same line as the chemical name. When an
alternative system includes chemicals from a chemical category (see Table II-2), the hazard ranking shown is the range of the
rankings of all of the individual chemicals comprising the category. This analysis did not estimate the aquatic hazard ranking of
the product systems as mixtures.
dNA means not available.
Troduct system also requires a fixed cost of $13,165. Reference Method 4 in Chapter V.
Exposure Analysis & Risk Characterization
For specific assumptions and details of the occupational exposure, environmental releases
and risk assessment, please reference Chapter III.
DRAFT—September 1994
IV-15
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Substitute Comparative Assessment
Table IV-6
Occupational Exposures: Emulsion Removers
System
Traditional Product Systems
Systems 1 & 3 (Bleach)3
Sodium hypochlorite (12%)
Water
Systems 2 & 4 (Zeta diluted 1 :4)
Sodium periodate (1%)
Water
Inhalation Exposures, by Scenario
(mg/day)
I
0
0
0
0
II
0
0
0
0
III
0
0
0
0
IV
0
0
0
0
Dermal Exposures, (mg/day)
Routine
187
1370
16
1540
Immersion
874
6410
73
7210
Alternative Systems
Alpha (diluted to 0.8%)
Sodium periodate
Water
Chi (diluted 1:4)
Sodium periodate
Water
Delta (diluted 1:4)
Sodium periodate
Water
Epsilon (3% chemicals. 97% water)
Sodium periodate
Sulfate salt
Water
Gamma
Sodium periodate
Sulfate salt
Phosphate salt
Other
Water
Mu
Periodic acid
Water
Ehi
Sodium periodate
Water
Ethoxylated nonylphenol
Other
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
12
1550
16
1540
39
1520
23
23
1510
39
16
117
117
1270
156
1400
47
1210
123
181
58
7220
73
7210
182
7100
109
109
7060
182
73
546
546
5930
728
6550
218
5640
575
844
DRAFT—September 1994
IV-16
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Exposure Analysis & Risk Characterization
Table IV-6
Occupational Exposures: Emulsion Removers
System
Omicron AE & Omicron AF
Sodium periodate
Ethoxylated nonylphenol
Water
Zeta (diluted 1:4)
Sodium periodate
Water
Theta (Method 41"
Sodium periodate
Water
Theta (Method 4Hdiluted 1:31
Sodium periodate
Water
Inhalation Exposures, by Scenario
(mg/day)
1
0
0
0
0
0
0
0
0
0
II
0
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
IV
0
0
0
0
0
0
0
0
0
Dermal Exposures, (mg/day)
Routine
47
31
1480
16
1540
1250
312
312
1250
Immersion
218
146
6920
73
7210
5820
1460
1460
5820
aDermal exposures presented are worst-case and the use of gloves is expected due to irritation and corrosive effects.
bThis system can be used with or without diluted emulsion remover, depending on the needs of the facility.
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
Occupational Risk Conclusions and Observations
All of the systems that employ an emulsion remover use either a strong oxidizer such as
hypochlorite or periodate or a strong base such as sodium hydroxide. The haze removers in Alpha,
Epsilon, Gamma, Mu, Omicron, and Theta also contain these compounds. All of these materials
present a high concern for skin and eye irritation and tissue damage if workers are exposed in the
absence of proper protective clothing. None of the emulsion removers present significant
inhalation risks.
DRAFT—September 1994
IV-17
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Emulsion Removal Function
Exposure Analysis & Risk Characterization
Table IV-7
Environmental Releases in Screen Cleaning Operations:
Emulsion Removers
System
Traditional Product Systems
Systems 1 & 3 (Bleach)
Sodium hypochlorite
Water
Svstem 2 &4(Zeta diluted 1:4)
Sodium periodate
Water
Release Under Each Scenario
(g/day)
I
Air
0
0
0
0
Water
75
546
6
615
Land
0
0
0
0
II
Air
0
0
0
0
III
Air
0
0
0
0
IV
Air
0
0
0
0
Water
0
0
0
0
Alternative Systems
Alpha (diluted to 0.8%)
Sodium periodate
Water
Chi (diluted 1:4)
Sodium periodate
Water
Delta (diluted 1:4)
Sodium periodate
Water
Epsilon (diluted to 3%)
Sodium periodate
Sodium salt
Water
Gamma
Sodium periodate
Sulfate salt
Phosphate salt
Other
Water
Mu
Periodic acid
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5
616
6
615
16
605
9
9
602
16
6
47
47
506
62
559
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DRAFT—September 1994
IV-18
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Substitute Comparative Assessment
Table IV-7
Environmental Releases in Screen Cleaning Operations:
Emulsion Removers
System
Ehi
Sodium periodate
Water
Ethoxylated nonylphenol
Other
Omicron AE & Omicron AF
Sodium periodate
Ethoxylated nonylphenol
Water
Zeta (diluted 1:41
Sodium periodate
Water
Theta (Method 4)
Sodium periodate
Water
Theta (Method 4Hdiluted 1:31
Sodium periodate
Water
Release Under Each Scenario
(g/day)
1
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
19
481
49
72
19
13
603
6
615
177
44
44
177
Land
0
0
0
0
0
0
0
0
0
0
0
0
0
II
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
III
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
IV
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
General Population Exposure Conclusions and Observations
o Health risks to the general population from both air and water exposures are very low
for all of the emulsion removers evaluated.
Ecological Risks from Water Releases of Screen Reclamation Chemicals
o None of the single facility releases of emulsion removers reach an ecotoxicity concern
concentration.
DRAFT—September 1994
IV-19
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Substitute Comparative Assessment
Haze Removal Function
Substitute Comparative Assessment
Table IV-8 below lists some of the chemical haze removers that are available to screen
printers. Table IV-8 includes a summary of key physical properties, a brief hazard summary, and
a list of purchase prices for each emulsion remover. For information on the chemical properties
and industrial synthesis of the bulk chemicals, refer to Chapter II. Market information on the
volume of specific haze remover products sold is not available.
Table IV-8
Hazard Summaries and Cost: Haze Removers
Formulation
Traditional Product Systems
Systems 1.2. 3. & 4
10%Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
%voc
Flash Pt.
V.P.a
100%
Hazard Summary
Health Effects Description
developmental toxicity;
reproductive toxicity; genetic
toxicity; neurotoxicity;
chronic toxicity
Aquatic
Hazard
Rankingsb
Medium
Low
High
Low
Purchase Cost
$5.12/gallon
Alternative Systems
Alpha
Alkali/caustic
Tetrahydrofurfuryl alcohol
Water
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
< 15 %
183 F
NAC
94%
<200F
<0.1 mm Hg
94%
<200F
< 1.0mm Hq
corrosive
developmental toxicity;
reproductive toxicity; chronic
toxicity
developmental toxicity;
chronic toxicity
Low
Medium
Low/Medium
Low/Medium
Low
Medium
Medium
Low/Medium
Medium
$9.39/gallon
(5 kg/$50)
$31.20/gallon
(5 gallons/$156
55gallons/$1,315)
$20.00/gallon
(5 gallons/$100
55 qallons/$900)
DRAFT—September 1994
IV-20
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Substitute Comparative Assessment
Table IV-8
Hazard Summaries and Cost: Haze Removers
Formulation
Epsilon
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Sodium hydroxide
Derivatized plant oil
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
Water
Gamma
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Water
Mu
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Water
Ehi
N-methyl pyrrolidone
Dibasic esters
Omicron AE
Ethoxylated nonylphenol
Phosphate surfactant
Other
Water
Omicron AF
Ethoxylated nonylphenol
Phosphate surfactant
Alkali/caustic
Other
Water
%voc
Flash Pt.
V.P.a
unknown
NA
unknown
0%
NA
<0.2mmHg
(@70F)
0%
NA
NA
NA
>185F
0.195
unknown
210 F
0.1 mm Hg
unknown
unknown
< 1 mm Hg
Hazard Summary
Health Effects Description
developmental toxicity;
reproductive toxicity; genetic
toxicity; neurotoxicity;
chronic toxicity; corrosive
developmental toxicity;
genetic toxicity; chronic
toxicity; corrosive
developmental toxicity;
genetic toxicity; chronic
toxicity; corrosive
developmental toxicity;
reproductive toxicity; chronic
toxicity
limited hazard data
corrosive
Aquatic
Hazard
Rankingsb
Medium
Medium
High
Low
Low/High
Low
Medium
Low
Medium
Low
Medium
Low/High
Medium
Low
Medium
Medium
Low
Medium
Low
Medium
Medium
High
Low
Medium
High
Low
Low
Purchase Cost
$1.09/lb
(15kg/$36)
$9.39/gallon
(25 liters/$62))
$7.57/gallon
(five 5-liter
units/$50))
$39.95/gallon
$18.00/gallon
(5 gallons/$90)
$18.00/gallon
5 gallons/$90
DRAFT—September 1994
IV-21
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-8
Hazard Summaries and Cost: Haze Removers
Formulation
Theta
Alkali/caustic
Cyclohexanone
Furfuryl alcohol
Zeta
Alkali/caustic
Propylene glycol
Water
%voc
Flash Pt.
V.P.a
unavailable
171 F
NA
100 %
101 F
0.4-10.5 mm
Hn
Hazard Summary
Health Effects Description
developmental toxicity;
reproductive toxicity; genetic
toxicity; neurotoxicity;
chronic toxicity; corrosive
corrosive
Aquatic
Hazard
Rankingsb
Medium
Low
Medium
Low
Low
Purchase Cost
$43.00/gallond
$30.00/gallon
aV.P. means vapor pressure.
bThe hazard rankings shown identify the categories (low, medium, or high) into which the individual components of the product
system fall. The aquatic hazard ranking for each chemical is listed on the same line as the chemical name. When an
alternative system includes chemicals from a chemical category (see Table II-2), the hazard ranking shown is the range of the
rankings of all of the individual chemicals comprising the category. This analysis did not estimate the aquatic hazard ranking of
the product systems as mixtures.
CNA means not available.
dProduct system also requires a fixed cost of $13,165. Reference Method 4 in Chapter V.
Exposure Analysis & Risk Characterization
For specific assumptions and details of the occupational exposure, environmental releases
and risk assessment, please reference Chapter III.
DRAFT—September 1994
IV-22
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-9
Occupational Exposures: Haze Removers
System
Traditional Systems
Systems 1.2. 3. and 4
Xylenes (mixed)
Acetone
Mineral spirits-light hydrotreated
Cyclohexanone
Inhalation Exposures, by Scenario
(mg/day)
I
21
64
7
27
II
0.9
11
0.1
0.3
III
1
5
0
0
IV
0
0
0
0
Dermal Exposures, (mg/day)
Routine
156
468
468
468
Immersion
728
2180
2180
2180
Alternative Systems
Alpha
Alkali/caustic3
Tetrahydrofurfuryl alcohol
Water
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Alkali/caustic3
Water
Gamma
Sodium hypochlorite3
Alkali/caustic3
Water
Sodium alkyl sulfate
0
1
0
0
0
3
0
2
0
0
12
5.2
0
0
0
0.5
1.4
0
0
0
0
0
0
0
0
0
0
0.1
0
0
0
0
0
0
0
0
0.3
0.4
0
0
0
0.1
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.2
0.2
0
0
0
0
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
390
234
936
312
858
312
78
702
780
78
234
117
156
51
27
78
62
140
62
117
408
109
585
39
827
109
1820
1090
4370
1456
4000
1460
364
3280
3640
364
109
546
728
273
127
364
291
655
291
546
1890
510
2730
182
3860
510
DRAFT—September 1994
IV-23
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-9
Occupational Exposures: Haze Removers
Mu System
Sodium hypochlorite3
Alkali/caustic3
Water
Sodium alkyl sulfate
Ehi
N-methylpyrrolidone
Dibasic esters
Omicron AE
Other
Ethoxylated nonylphenol
Phosphate surfactant
Water
Omicron AF
Ethoxylated nonylphenol
Alkali/caustic3
Phosphate surfactant
Other
Water
Zeta
Alkali/caustic3
Propylene glycol
Water
Theta (Method 4)
Alkali/caustic3
Cyclohexanone
Furfural alcohol
Inhalation Exposures, by Scenario
(mg/day)
0
0
0
0
6
1
0
0
0
0
0
0
0
0
0
0
0
0
0
25
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0
0
0.3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Dermal Exposures, (mg/day)
585
39
827
109
780
780
109
16
78
1360
16
156
78
109
1200
234
62
1260
515
515
530
2730
182
3860
510
3640
3639
510
73
364
6330
73
728
364
510
5610
1090
291
5900
2400
2400
2480
"Dermal exposures presented are worst-case and the use of gloves is expected due to irritation and corrosive effects.
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
DRAFT—September 1994
IV-24
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-10
Occupational Risk Conclusions and Observations:
Haze Removers
System
Observations
Traditional Product Systems
Systems 1 .
2.3. & 4
Hazard quotient calculations indicate clear concerns for chronic dermal and inhalation exposures to workers
using acetone in haze removal.
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures to workers using
xylene and cyclohexanone in haze removal.
Margin-of-exposure calculations indicate very low concern for developmental and reproductive toxicity risks
from inhalation of cyclohexanone. Reproductive and developmental toxicity risks from dermal exposures to
cyclohexanone could not be quantified.
Dermal exposures to workers using mineral spirits in haze removal can be very high, although the risks from
mineral spirits could not be quantified because of limitations in hazard data.
Alternative Systems
Alpha
Chi
Delta
Epsilon
Dermal exposures to other chemicals used in haze removal can be high, although the risks could not be
quantified because of limitations in hazard data.
Clear concerns exist for chronic dermal exposures to diethylene glycol series ethers used in haze removal
based on the calculated margins-of-exposure.
Concerns exist for developmental toxicity risks from dermal exposures to N-methylpyrrolidone based on the
calculated margin-of-exposure. Similar calculations for inhalation exposures to N-methylpyrrolidone indicate
very low concern.
Inhalation exposures to other haze remover components are very low.
Dermal risks from other haze remover components could not be quantified because of limitations in hazard
data, but exposures can be high.
Although no risks could be quantified because of limitations in hazard data, relatively high dermal exposures
to haze remover components could occur.
Inhalation exposures to all components are very low.
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures to cyclohexanone and
benzyl alcohol during haze removal. Similar calculations for inhalation exposures to cyclohexanone and
benzyl alcohol indicate low concern.
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures and low concern for
chronic inhalation exposures to methoxypropanol acetate.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
althouah dermal exposures to all components could be relatively hiah.
DRAFT—September 1994
IV-25
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-10
Occupational Risk Conclusions and Observations:
Haze Removers
System
Observations
Gamma
Developmental and chronic toxicity risks from dermal exposures to sodium alkyl sulfate in haze remover are
very low based on the calculated margin of exposure.
Inhalation exposures to all components are very low.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
Mu
Developmental and chronic toxicity risks from dermal exposures to sodium alkyl sulfate in haze remover are
very low based on the calculated margin of exposure.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
Dermal exposures to N-methylpyrrolidone during haze removal present a concern for developmental toxicity
risk based on the calculated margins-of-exposure. Similar estimates for inhalation exposures to N-
methylpyrrolidone indicate very low concern.
Inhalation exposures to all other components are very low.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
Omicron AE
Inhalation exposures to components are very low.
Risks from components could not be quantified because of limitations in hazard data, although dermal
exposures to all components could be relatively high.
Omicron AF
Inhalation exposures to components are very low.
Risks from components could not be quantified because of limitations in hazard data, although dermal
exposures to all components could be relatively high.
Zeta
Hazard quotient calculations for chronic inhalation and dermal exposures to propylene glycol during haze
removal indicate very low concern.
Inhalation exposures to other components are very low.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
DRAFT—September 1994
IV-26
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-10
Occupational Risk Conclusions and Observations:
Haze Removers
System
Observations
Theta
Method
Hazard quotient calculations indicate marginal concerns for chronic dermal exposures and very low concern
for chronic inhalation exposures to cyclohexanone during haze removal.
Margin-of-exposure calculations show low concern for developmental and reproductive toxicity risks from
inhalation exposures to cyclohexanone. Reproductive and developmental toxicity risks from dermal
exposures to cyclohexanone could not be quantified.
Inhalation exposures to other components are very low.
Risks from other haze remover components could not be quantified because of limitations in hazard data,
although dermal exposures to all components could be relatively high.
DRAFT—September 1994
IV-27
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-11
Environmental Releases in Screen Cleaning Operations:
Haze Removers
System
Traditional Product Systems
Systems 1.2. 3. & 4
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Release Under Each Scenario
(g/day)
I
Air
44
133
15
57
Water
0
0
119
76
Land
0
0
0
0
II
Air
1.9
22
0.2
0.7
III
Air
1.1
11
0.1
0.4
IV
Air
0
0
0
0
Water
0
0
0
0
Alternative Systems
Alpha
Alkali/caustic
Tetrahydrofurfuryl alcohol
Water
Chi
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Delta
Dibasic esters
Tripropylene glycol series ethers
Ethoxylated nonylphenol
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Alkali/caustic
Water
Phosphate salt
0
1.5
0
0.1
0.1
6.8
0
3.7
0.1
0
25
11
0
0.1
0.1
1
2.9
0
0
0
0
0
133
78
319
104
286
97
26
239
269
27
55
29
53
17
9.3
26
37
48
21
138
37
21
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0
0
0
0.1
0
0
0
0
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0
0
0
0
0.1
0
0
0
0
0
0
0
0
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.4
0.5
0
0
0
0.1
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DRAFT—September 1994
IV-28
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Haze Removal Function
Exposure Analysis & Risk Characterization
Table IV-11
Environmental Releases in Screen Cleaning Operations:
Haze Removers
System
Gamma
Sodium hypochlorite
Alkali/caustic
Water
Sodium alkyl sulfate
Mu
Sodium hypochlorite
Alkali/caustic
Water
Sodium alkyl sulfate
Ehi
N-methylpyrrolidone
Dibasic esters
Omicron AE
Other
Ethoxylated nonylphenol
Phosphate surfactant
Water
Omicron AF
Ethoxylated nonylphenol
Alkali/caustic
Phosphate surfactant
Other
Water
Zeta
Alkali/caustic
Propylene glycol
Water
Theta (Method 4)
Alkali/caustic
Cyclohexanone
Furfural alcohol
Release Under Each Scenario
(g/day)
I
Air
0
0
0
0
0
0
0
0
12
3.1
0
0
0
0
0
0
0
0
0
0
0.7
0
0
53
0
Water
200
13
282
37
200
13
282
37
270
279
43
6.2
31
540
5.6
56
28
39
428
80
21
431
291
239
300
Land
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
II
Air
0
0
0
0
0
0
0
0
0.1
0
0
0
0
0
0
0
0
0
0
0
0.2
0
0
0.7
0
III
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0
0
0.4
0
IV
Air
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = transferring waste rags from a storage drum to a "laundry bag."
DRAFT—September 1994
IV-29
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Manufacturing of Screen Reclamation Chemical Products Manufacturing Process
General Population Exposure Conclusions and Observations
o Health risks to the general population from both air and water exposures are very low
for all of the haze removers evaluated.
Ecological Risks from Water Releases of Screen Reclamation Chemicals
o None of the single facility releases of haze removal chemicals reach an ecotoxicity
concern concentration.
Manufacturing of Screen Reclamation Chemical Products
Manufacturing Process
Most screen reclamation chemical products are formulated in facilities outside of the United
States.1 The basic process description that follows is based primarily on conversations with two
formulation manufacturers in the United States and may not describe the range of manufacturing
processes used by formulation manufacturers elsewhere.2 3
Screen reclamation chemical products typically consist of a mixture of two or more liquid
and/or solid chemicals. In some cases, the mixture may include water used as a diluent or to
dissolve solids and facilitate the spray application of the product. Regardless of whether the
product is an ink remover, emulsion remover or haze remover, the basic manufacturing process
is the same, as described below.
Chemical ingredients are received from a chemical manufacturer or distributor in small (55
gallon drums or 350 gallon totes) or large (tanker trucks) quantities and stored on-site. Small
quantities are typically stored on pallets or racks on the process floor in a designated area without
separate ventilation. Large quantities may be stored in dedicated storage tanks.
Chemicals are pumped or emptied by weight into a mixing vessel. The mixing vessel is
covered and ingredients are agitated or mixed using turbine or rotary blade/propeller mixing,
aeration and shear dispersion. The addition of heat or pressure is not normally required to
accomplish the mixing step. Typically, mixing vessels do not have a separate ventilation system
(e.g., ventilation is to the process room).
Products are usually packaged in 55 gallon drums, 15 gallon drums, 5 gallon pails and one
gallon jugs, although other sizes are available if requested by the customer. Containers are filled
manually with a hand-held pump and semi-automated fillers or by pouring from smaller mixing
'Correspondence between Marci A. Kinter, SPAI, and Lori Kincaid, University of Tennessee, June
1994.
Correspondence between Oliver Nichols, Nichols and Associates, and Dean Menke, University of
Tennessee, June 1994.
Correspondence between Clark King, Kiwo, and Dean Menke, University of Tennessee, June
1994.
DRAFT-September 1994 IV-30
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Manufacturing of Screen Reclamation Chemical Products Energy and Natural Resources Issues
vessels (e.g., 55 gallon drums). Employees wear gloves, goggles, and respirators when needed.
Packaged products may be inventoried on the process floor, in a separate designated area or stored
outside of the process area pending distribution.
Source Release Assessment: Product Formulation
Process air emissions of volatile organic compounds from product formulation processes can
originate from the venting of mixing vessels. Fugitive air emissions can result when process fluid
leaks from plant equipment such as pumps, compressors and process valves. Air emissions from
storage and handling operations can also occur where screen reclamation products are formulated.
Other potential sources of environmental releases or transfers include:
• wastewater discharges from a facility into rivers, streams or other bodies of water or
transfers to a publicly-owned treatment works (POTW);
• on-site releases to landfills, surface impoundments, land treatment or another mode
of land disposal; and
• transfer of wastes to off-site facilities for treatment, storage or disposal.
Energy and Natural Resources Issues
The use of different chemical products, processes or technologies in a use cluster can result
in changes in the rate of energy and natural resources consumption, either in the product use
stage, manufacture stage, or other life cycle stages (e.g., extraction of raw materials, transportation,
disposal, etc.). The processes used to formulate traditional versus alternative screen reclamation
chemical products appear to be similar, however, with no differences that would significantly
influence the rate of energy or natural resources consumption during product manufacturing. The
following lists potential energy and natural resources issues that should be considered when
choosing among alternatives.
• The energy required to manufacture the chemical ingredients of screen reclamation
products can vary substantially. For example, the energy required to manufacture
solvents derived from plants using a cold-press process may be less than that required
in a hot-press process.
• Products manufactured from petrochemicals have an energy equivalence, as do other
products with sufficient energy content to be used as fuel. The amount of
petrochemicals used to manufacture screen reclamation products, however, is small
compared to other uses of petroleum-based products.
• Products manufactured from petrochemicals are also derived from a nonrenewable
resource, petroleum. However, products manufactured from renewable resources,
such as plants, frequently use petrochemicals at some point in the chemical
manufacturing process. In either case, the amount of petrochemicals used to
manufacture screen reclamation products is small compared to other uses of
petroleum-based products.
DRAFT-September 1994 IV-31
-------
IV. SCREEN RECLAMATION PRODUCTS: FUNCTIONAL GROUPS
Manufacturing of Screen Reclamation Chemical Products Energy and Natural Resources Issues
• Products that are formulated using heat or pressure to dissolve product ingredients
or cause a chemical reaction consume more energy than those manufactured using
simple mixing processes.
• Compared to undiluted products, formulations that are diluted with water prior to
shipping result in greater energy consumption during transportation of the product
from the manufacturer to the printing facility.
DRAFT-September 1994 IV-32
-------
Chapter V
Substitute Comparative Assessment, Screen Reclamation
Methods
Introduction
Chapter 5 provides a comprehensive assessment of screen reclamation methods 1-4 and
the automatic screen washer. When available, information is provided for each method and
technology on occupational exposure and risk, population exposure and risk, performance of
traditional and alternative systems, and the cost analysis of traditional and alternative systems.
The discussion of the details of each method or technology includes an explanation of the
particular advantages or disadvantages of that method or technology. The details, assumptions
and uncertainties of each of the methodologies in this chapter are discussed in Chapter 3;
referencing this chapter while reading Chapter 5 may eliminate the confusion that may occur
due to the numerous exhibits.
Method 1: Traditional Reclamation
Method 1 encompasses the use of only ink removal and emulsion removal chemical
products to reclaim screens. The action of these two products must eliminate the use of a haze
remover. Some screen printers are able to reclaim screens without the need for a haze
remover. Because a haze remover is not used in screen reclamation in Method 1, source
reduction, the highest priority in the pollution prevention hierarchy, is achieved. However,
simply because the haze remover is not used does not mean that occupational and population
risk is low. The intrinsic hazard of the particular chemicals used in ink and emulsion remover
products must be combined with worker and general exposure to the chemicals to generate a
risk assessment. In the following discussion of Method 1, data detailing occupational and
population exposure are presented to support overall risk conclusions for 6 systems comprised
of only ink and emulsion removal products: Traditional Systems 1, 2, 3 and 4, Alternative
System Chi, and Alternative Ink remover Beta. Limited performance and/or cost information is
available for Traditional Systems 1, 2, 3 and 4, and Alternative System Chi. Figure V-l
provides a schematic illustration of the product groups used in the two steps required under
Method 1.
Traditional System 1
Formulation
Ink Remover: 100% Mineral spirits
Emulsion Remover: 12 wt% Sodium hypochlorite/ 88% water
DRAFT-September 1994 V-1
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Figure V -1
Process Steps Included in Method 1
Ink Removal
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Emulsion
Removal/Water
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
DRAFT—September 1994
V-2
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Occupational Exposure
Table V-1
Occupational Exposure Estimates for Method 1, Traditional System 1
Ink Remover
Mineral spirits- light hydrotreated
Emulsion Remover
Sodium hypochlorite
Water
Inhalation (mg/day)
I
26
0
0
II
0.1
0
0
III
0
0
0
IV
0.3
0
0
Dermal (mg/day)
Routine
1560
187
1370
Immersion
7280
874
6410
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III =
transferring chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Estimates
Quantitative risk estimates could not be determined for this system due to insufficient
data. See risk conclusions for areas of concern for this system.
Occupational Risk Conclusions and Observations
Ink Remover
o Dermal exposures to workers using mineral spirits in ink removal can be very high,
although the risks from mineral spirits could not be quantified because of
limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT—September 1994
V-3
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Environmental Releases
Table V-2
Estimated Environmental Releases for Screen Cleaning Operations
Method 1, Traditional System 1
System
Ink Remover
Mineral spirits- light hydrotreated
Emulsion Remover
Sodium hypochlorite
Water
Release Under Each Scenario
(g/day)
I
Air
54
0
0
Water
0
75
546
Land
1050
0
0
II
Air
0.2
0
0
III
Air
0.1
0
0
IV
Air
0.6
0
0
Water
1350
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Table V-3
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 1, Traditional System 1
Substance
Mineral Spirits
Sodium Hypochlorite
To Air
54.9 g/day
To Water
1350g/daya
75 g/day
To Landfill
1050g/daya
a1,350 g/day is estimated to be released from the rags. This release from the rags will be either to landfill or to water. If
the release is to water through the laundry (launderable rags), then the landfill column is blank. If the release is to landfill
(disposable rags), then the landfill column will be 1,050 g/day. This is true of all of the ink remover chemicals. For our
purposes, the rest of the assessment assumes release to water only, since we are not assessing landfill releases.
DRAFT—September 1994
V-4
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Releases to Water from a Single Facility
Table V-4
Estimated Releases to Water from Traditional Formulations from Screen Reclamation at a
Single Facility
Screen Reclamation Method 1, Traditional System 1
Substance
Mineral Spirits
Sodium Hypochloriteb
Amount Released
to Water from
Facility
1350g/dayat
laundry
75 g/day
Waste water
Treatment
Removal
Efficiency
94%
100 %
Amount to Water
After Waste Water
Treatment
81 g/day
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
8x10'2
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Concentrated solutions of sodium hypochlorite will kill the biota which degrade organic chemicals (the other substances listed
in the table) during waste water treatment. This could cause problems at the waste water treatment plant, reducing the waste
water treatment efficiency for the other compounds sent to the plant.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
DRAFT—September 1994
V-5
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Table V-5
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 1, Traditional System 1
Substance
Mineral Spirits
Sodium Hypochlorite
Total Amount
Released to Water
from All Facilities
182 kg/day at
laundry
10 kg/day
Waste Water
Treatment
Removal
Efficiency
94%
100 %
Amount to Water
After Waste water
Treatment
1 1 kg/day
0
Average Concentration
in Meramec River,
ug/L (ppb)
1
0
Releases to Air from Individual Screen Printing Facilities
Table V-6
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Screen Reclamation Method 1, Traditional System 1
Substance
Mineral Spirits
Amount of Releases per
day
54.9 g/day
Highest Aver age
Concentration 100 M
away
1 x 10'1 ug/m3
Annual Potential Dose,
mg/yeara
7x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 1, Traditional System 1.
Because of the low concentration estimate found from single source releases, multiple
facility impacts are note likely to significantly raise concentration estimates. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2, and Alternative System Chi in Method 2; please reference these sections
as illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
DRAFT—September 1994
V-6
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 1
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o Cumulative releases of mineral spirits from Traditional System 1 present a concern
for risk to aquatic species. The largest contributor to these releases is the
hypothetical commercial laundry that launders the shop rags used by the area's
screen printers.
o None of the other components of Method 1, Traditional System 1 reached an
ecotoxicity concern concentration, even when considering the cumulative releases
from all shops in the area.
o None of the single facility releases of Method 1, Traditional System 1 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 1. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-7
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 1, Traditional System 1
Substance
Mineral Spirits
Sodium
Hypochlorite
Total Amount
Released to
Water from All
Facilities
16 kg/day +
182 kg/day at
laundry
10 kg/day
Waste water
Treatment
Removal
Efficiency
94%
100 %
Amount to Water
After Waste water
Treatment
960 g/day
11 kg/day
0
Daily Stream
Cone, in
Meramec
River, ug/L
(ppb)
1 x 10'1
1
0
ECOCC
(ug/i)
1
<20
ECO Risk
Indicator
(Stream
Cone/
ECO CC)
1.1
0
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
Cost
Because the performance of this system was not determined in this project, the total cost
of using this system was also not calculated.
DRAFT—September 1994
V-7
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 2
Traditional System 2
Formulation
Ink Remover: 100% Acetone
Emulsion Remover: 1% Sodium periodate/ 99% water
Occupational Exposure
Table V-8
Occupational Exposure Estimates for Method 1, Traditional System 2
System
Ink Remover
Acetone
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Inhalation (mg/day)
I
539
0
0
II
11
0
0
III
5
0
0
IV
38
0
0
Dermal (mg/day)
Routine
1560
16
1540
Immersion
7280
73
7210
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover
o Hazard quotient calculations indicate clear concerns for chronic dermal and
inhalation exposures to workers using acetone in either ink removal or haze
removal.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT—September 1994
V-8
-------
Table V-9
Occupational Risk Estimates for Method 1, Traditional System 2.
o
Q.
a>
o-
CO
Name
Ink Remover
Acetone
Emulsion Remover (Zeta diluted
M
Sodium periodate
Water
Hazard Quotient
Inhalation
84
NA
NA
Dermal
Routine
22
NA
NA
Immersion
1,040
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
LOAELd
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard
Quotient values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
Q.
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
m
g.
5'
3
8L
CO
2-
S"
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 2
Environmental Releases
Table V-10
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Traditional System 2
System
Ink Remover
Acetone
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Release Under Each Scenario
(g/day)
I
Air
1120
0
0
Water
0
6
615
Land
0
0
0
II
Air
22
0
0
III
Air
11
0
0
IV
Air
80
0
0
Water
1270
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Table V-11
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 1, Traditional System 2
Substance
Acetone
Sodium Periodate
To Air
1,233 g/day
To Water
1,270a g/day
6 g/day
To Landfill
1,270a g/day
a1,270 g/day is estimated to be released from the rags. This release from the rags will be either to landfill or to water. If the
release is to water through the laundry, then the landfill column is blank. If the release is to landfill, then the landfill column will
be 1,270 g/day and the water column will be empty. This is true of all of the ink remover chemicals. For our purposes, the rest
of the assessment assumes release to water only, since we are not assessing landfill releases.
DRAFT—September 1994
V-10
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 2
Releases to Water from a Single Facility
Table V-12
Estimated Releases to Water from Method 1, Traditional System 2
Substance
Acetone
Sodium Periodate
Amount Released
to Water from
Facility
1270g/day
6 g/day
Waste Water
Treatment
Removal
Efficiency
87%
100%
Amount to Water
After Waste water
Treatment
165 g/day
0 g/day
Daily Stream
Concentration, ug/La
for 1,000 MLD
Receiving Water
0.2
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
Table V-13
Estimated Cumulative Releases to Water for St. Louis County, MO
Method 1, Traditional System 2
Substance
Acetone
Sodium
Periodate
Total Amount
Released to Water
from All Facilities
171 kg/day
810 g/day
Waste water
Treatment
Removal
Efficiency
87%
»99%
Amount to Water
After Waste water
Treatment
22.3 kg/day
«8.1 g/day
Average Concentration
in Meramec River, ug/L
(ppb)
3
«8x10'4
• is very much greater than, « is very much less than.
DRAFT—September 1994
V-11
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Traditional System 2
Releases to Air from Individual Screen Printing Facilities
Table V-14
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Method 1, Traditional System 2
Substance
Acetone
Amount of Releases per
day
1233g/day
Highest Average
Concentration 100 M
away
3ug/m3
Annual Potential Dose,
mg/yeara
20
aThis estimates doses for people living 100 Meters from hypothetical facility. The actual number of people who would fall into
this range can be determined from census data, if the facility location is known. The model is more completely explained in the
Overview by Media-Air Section in Chapter III. To calculate the annual potential dose, the concentration is multiplied by the
amount a person will breathe (20 m3/day) and the number of days per year (365), and the units are converted to mg/year by
dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 1, Traditional System 2.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2, and Alternative System Chi in Method 2; please reference these sections
as illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the components of Method 1, Traditional System 2 reached an ecotoxicity
concern concentration, even when considering the cumulative releases from all
shops in the area.
o None of the single facility releases of Method 1, Traditional System 2 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 2. The analogous figures for single facilities show much lower exposure
and risk levels.
DRAFT-September 1994 V-12
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 2
Table V-15
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 2, Traditional System 2
Substance
Acetone
Sodium
Periodate
Total Amount
Released to
Water from All
Facilities
171 kg/day
810g/day
Waste
water
Treatment
Removal
Efficiency
87%
»99%
Amount to Water
After Waste
water Treatment
22.3 kg/day
«8.1 g/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
3
«8x10'4
ECOCC
(ug/L)
7600
<10
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
4x1 0'4
~io-5
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
Cost
Because the performance of this system was not determined in this project, the total cost
of using this system was also not calculated.
DRAFT—September 1994
V-13
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Traditional System 3
Formulation
Ink Remover: 100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% n-butyl acetate
5% Methanol
20% Naphtha, light aliphatic
20% Toluene
10% Isobutyl isobutyrate
Emulsion Remover: 12 wt% Sodium hypochlorite, 88% water
Occupational Exposure
Table V-16
Occupational Exposure Estimates for Method 1, Traditional System 3
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Inhalation (mg/day
I
165
44
27
98
110
7
0
0
II
5.3
1.3
4.7
1.6
2.3
0.4
0
0
III
3
1
2
1
1
0
0
0
IV
20
5.3
15
6.2
9.2
1.7
0
0
Dermal (mg/day)
Routine
468
234
78
312
312
156
187
1370
Immersion
2180
1090
364
1460
1460
728
874
874
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover
o Hazard quotient calculations indicate clear concerns for both toluene and methyl
ethyl ketone with respect to chronic dermal and inhalation exposures to workers
using these chemicals in ink removal.
DRAFT—September 1994
V-14
-------
Table V-17
Occupational Risk Estimates for Method 2, Traditional System 3.
o
Q.
a>
o-
CO
Name
Ink Remover
Methyl ethyl ketone (2-butanone)
Butyl acetate normal
Methanol
Aromatic solvent naphtha
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Hazard Quotient
Inhalation
9.2
NA
1.4
NA
17.
NA
NA
NA
Dermal
Routine
22
NA
2.2
NA
44.
NA
NA
NA
Immersion
103
NA
10
NA
208.
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
Q.
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
m
g.
5'
3
8L
CO
2-
S"
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
Environmental Releases
Table V-18
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Traditional System 3
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Release Under Each Scenario
(g/day)
I
air
344
92
57
204
229
15
0
0
water
0
0
0
0
0
0
75
546
land
0
80
0
25
0
100
0
0
II
air
11
2.6
9.8
3.2
4.8
0.8
0
0
III
air
5.7
1.5
4.1
1.7
2.6
0.5
0
0
IV
air
42
11
30
13
19
3.4
0
0
water
363
191
37
257
251
132
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-16
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Table V-19
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 1, Traditional System 3
Substance:
Methyl ethyl ketone
n-butyl Acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium hypochlorite
To Air:
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7 g/day
To Water:
363 g/day at laundry
191 g/day at laundry3
37 g/day at laundry
257 g/day at laundry
251 g/day at laundry
132 g/day at laundry
75 g/day
To Landfill:
80 g/daya
25 g/day
100 g/day
aThe landfill number is the amount estimated to be released from the rags. This release from the rags will be either to landfill or
to water. If the release is to water through the laundry, then the landfill column is blank. This is true of all of the ink remover
chemicals. For our purposes, the rest of the assessment assumes release to water only, since we are not assessing landfill
releases.
DRAFT—September 1994
V-17
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Releases to Water from a Single Facility
Table V-20
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Method 1, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium Hypochloriteb
Amount Released
to Water from
Facility
363 g/day at
laundry
191 g/day at
laundry
37 g/day at laundry
257 g/day at
laundry
251 g/day at
laundry
132 g/day at
laundry
75 g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
100 %
Amount to Water
After Waste water
Treatment
58 g/day
5.7 g/day
1.1 g/day
15 g/day
20 g/day
2.6 g/day
0
Mean Daily
Concentration, ug/La
for 1000 MLD
Receiving Water
6x10'2
6x10'3
1 x 10'3
2x10'2
2x10'2
3x10'3
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Concentrated solutions of sodium hypochlorite will kill the biota which degrade organic chemicals (the other substances listed
in the table) during waste water treatment. This could cause problems at the waste water treatment plant, reducing the waste
water treatment efficiency for the other compounds sent to the plant.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
DRAFT—September 1994
V-18
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Table V-21
Estimated Cumulative Releases to Water for St. Louis County, MO
Method 1, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium Hypochlorite
Total Amount
Released to Water
from All Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
10 kg/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
» 99%
Amount to Water
After Waste water
Treatment
7.8 kg/day
8 x10'1 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
«100g/day
Average Concentration
in Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
«1 x 10'2
DRAFT—September 1994
V-19
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Releases to Air from Individual Screen Printing Facilities
Table V-22
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Method 1, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Amount of Releases per
day
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7
Highest Average
Concentration 100 M away
8x10'1ug/m3
2x10'1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
Annual Potential
Dose, mg/yeara
6
1
1
3
4
0.3
aThis estimates doses for people living 100 Meters from hypothetical facility. The actual number of people who would fall into
this range can be determined from census data, if the facility location is known. The model is more completely explained in the
Overview by Media-Air Section in Chapter III. To calculate the annual potential dose, the concentration is multiplied by the
amount a person will breathe (20 m3/day) and the number of days per year (365), and the units are converted to mg/year by
dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are
estimated to be very low for Method 1, Traditional System 3.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1.
Hazard Quotient values below one indicate very low risk. Margin-of-Exposure (MOE) values
above 100 for a NOAEL or above 1000 for a LOAEL indicate very low risk.
DRAFT—September 1994
V-20
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
Table V-23
Risks from Potential Drinking Water Exposures
Screen Reclamation Method 1, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium Hypochlorite
Daily Stream
Concentration in
Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
«1 x 10'2
Daily dose from
Drinking Water
(mg/kg)
3x1 0'5
3x1 0'6
6x1 0'7
9x1 0'6
9x1 0'6
1x10'6
«3x10'7
RfD (mg/kg)
0.6
not available
0.5
not available
0.2
not available
not available
Hazard
Quotient
(dose/RfD)
5x1 0'5
1x10'6
4x1 0'5
Table V-24
Estimated Risks from Ambient Air Releases from a Single Model Facility
Screen Reclamation Method 1, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphthajight aliphatic
Toluene
Isobutyl isobutyrate
Highest Avg
Concentration 100 M
away
8x10'1ug/m3
2x10'1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
Daily Potential
Dose, (mg/kg)
2x1 0'4
4x1 0'5
4x1 0'5
1x10'4
2x1 0'4
1x10'5
RfD/RfC (mg/kg,
mg/rm)
1 mg/m3
not available
0.5 mg/kg
not available
0.4 mg/m3
not available
Hazard
Quotient(dose
or conc/RfDor
RfC)
8x1 0'4
8x1 0'5
1x10'3
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the components of Method 1, Traditional System 3 reached an ecotoxicity
concern concentration, even when considering the cumulative releases from all
shops in the area.
o None of the single facility releases of Method 1, Traditional System 3 reach an
ecotoxicity concern concentration.
DRAFT—September 1994
V-21
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 3
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 3. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-25
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 1, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light
aliphatic
Toluene
Isobutyl isobutyrate
Sodium Hypochlorite
Total Amount
Released to
Water from All
Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
10 kg/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
» 99%
Amount to
Water After
Waste water
Treatment
7.8 kg/day
8 x10'1 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
«100g/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
«1 x 10'2
ECOCC
(ug/L)
4500
140
9000
5
110
80
<20
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
2x1 0'4
7x1 0'4
2x1 0'6
0.06
3x1 0'3
5x1 0'4
-0.05
Performance
The performance of a similar system was demonstrated at the Screen Printing Technical
Foundation; the performance demonstration differed from this product system in that it
included the use of a haze remover containing potassium hydroxide and tetrahydrofurfuryl
alcohol. Reference Traditional System 3 in Method 2 for a complete description of the
performance of this system with a haze remover.
Cost
Because the performance of this particular system was not determined in this project, the
total cost of using this system was not determined.
DRAFT—September 1994
V-22
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Traditional System 4
Formulation
Ink Remover: 100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% n-butyl acetate
5% Methanol
20% Naphtha, light aliphatic
20% Toluene
10% Isobutyl isobutyrate
Emulsion Remover: 1% Sodium periodate, 99% water
Occupational Exposure
Table V-26
Occupational Exposure Estimates for Method 1, Traditional System 4
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Inhalation (mg/day)
I
165
44
27
98
110
7
0
0
II
5.3
1.3
4.7
1.6
2.3
0.4
0
0
III
3
1
2
1
1
0
0
0
IV
20
5.3
15
6.2
9.2
1.7
0
0
Dermal (mg/day)
Routine
468
234
78
312
312
156
16
1540
Immersion
2180
1090
364
1460
1460
728
73
7210
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover
Hazard quotient calculations indicate clear concerns for both toluene and methyl
ethyl ketone with respect to chronic dermal and inhalation exposures to workers
using these chemicals in ink removal.
DRAFT—September 1994
V-23
-------
Table V-27
Occupational Risk Estimates for Method 1, Traditional System 4
o
Q.
a>
o-
CO
Name
Ink Remover
Methyl ethyl ketone (2-butanone)
Butyl acetate normal
Methanol
Aromatic solvent naphtha
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted
M
Sodium periodate
Water
Hazard Quotient
Inhalation
9.29
NA
1.4
NA
17
NA
NA
NA
Dermal
Routine
22
NA
2.2
NA
46
NA
NA
NA
Immersion
103
NA
10.4
NA
210
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
a.
5'
3
8L
o_
m
m
o'
CD
•o
Q)
I
CD
CO
CO
CD
I
Q)
a
o
Q.
CO
m
g.
5'
3
8L
CO
2-
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
Environmental Releases
Table V-28
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Traditional System 4
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Release Under Each Scenario
(g/day)
I
air
344
92
57
204
229
15
0
0
water
0
0
0
0
0
0
6
615
land
0
80
0
25
0
100
0
0
II
air
11
2.6
9.8
3.2
4.8
0.8
0
0
III
air
5.7
1.5
4.1
1.7
2.6
0.5
0
0
IV
air
42
11
30
13
19
3.4
0
0
water
363
191
37
257
251
132
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-25
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Table V-29
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 1, Traditional System 4
Substance:
Methyl ethyl ketone
n-butyl Acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium periodate
To Air:
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7 g/day
To Water:
363 g/day at laundry
191 g/day at laundry3
37 g/day at laundry
257 g/day at laundry
251 g/day at laundry
132 g/day at laundry
6 g/day
To Landfill:
80 g/daya
25 g/day
100 g/day
a191 g/day is estimated to be released from the rags if the rags are laundered. This release from the rags will be either to
landfill or to water. If the release is to water through the laundry, then the landfill column is blank. If the release is to landfill,
then the landfill column will be 80 g/day and the water column will be blank. This is true for all of the ink remover chemicals.
For our purposes, the rest of the assessment assumes release to water only, since we are not assessing landfill releases.
DRAFT—September 1994
V-26
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Releases to Water from a Single Facility
Table V-30
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Method 1, Traditional System 4
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium periodate
Amount Released
to Water from
Facility
363 g/day at
laundry
191 g/day at
laundry
37 g/day at laundry
257 g/day at
laundry
251 g/day at
laundry
132 g/day at
laundry
6 g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
100 %
Amount to Water
After Waste Water
Treatment
58 g/day
5.7 g/day
1.1 g/day
15. 4 g/day
20 g/day
2.6 g/day
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
6x10'2
6x10'3
1 x 10'3
2x10'2
2x10'2
3x10'3
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
DRAFT—September 1994
V-27
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Table V-31
Estimated Cumulative Releases to Water for St. Louis County, MO
Method 1, Traditional System 4
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium Periodate
Total Amount
Released to Water
from All Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
810g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
» 99%
Amount to Water
After Waste water
Treatment
7.8 kg/day
0.8 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
«8.1 g/day
Average Concentration
in Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
«1 x 10'3
These stream concentrations will be put into perspective in the risk integration section of
this document. Please refer to that section for information on how to interpret these
concentrations.
DRAFT—September 1994
V-28
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Releases to Air from Individual Screen Printing Facilities
Table V-32
Air Release, Concentration and Potential Dose Estimates for
a Single Model Facility
Method 1, Traditional System 4
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Amount of Releases per
day
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7
Highest Average
Concentration 100 M away
8x10'1ug/m3
2x10'1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
Annual Potential
Dose, mg/yeara
6
1
1
3
4
3x10'1
aThis estimates doses for people living 100 Meters from hypothetical facility. The actual number of people who would fall into
this range can be determined from census data, if the facility location is known. The model is more completely explained in the
Overview by Media-Air Section in Chapter III. To calculate the annual potential dose, the concentration is multiplied by the
amount a person will breathe (20 m3/day) and the number of days per year (365), and the units are converted to mg/year by
dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 1, Traditional System 4.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2, and Alternative System Chi in Method 2; please reference these sections
as illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the components of Method 1, Traditional System 4 reached an ecotoxicity
concern concentration, even when considering the cumulative releases from all
shops in the area.
o None of the single facility releases of Method 1, Traditional System 4 reach an
ecotoxicity concern concentration.
DRAFT—September 1994
V-29
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 4. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-33
Estimated Cumulative Releases for St. Louis County, MO
Screen Reclamation Method 1, Traditional System 4
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light
aliphatic
Toluene
Isobutyl isobutyrate
Sodium Periodate
Total Amount
Released to
Water from All
Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
810g/day
Waste
water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
» 99%
Amount to Water
After Waste
water Treatment
7.8 kg/day
0.8 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
«8.1 g/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
«1 x 10'3
ECOCC
(ug/L)
4500
140
9000
5
110
80
<10
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
2x1 0'4
7x1 0'4
2x1 0'6
0.06
3x1 0'3
5x1 0'4
~io-4
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
DRAFT—September 1994
V-30
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Traditional System 4
Cost
Table V-34
Method 1: Summary of Cost Analysis for Baseline
(Traditional System 4 Minus Haze Remover)
Cost Element Description
Traditional
System 4
(minus Haze
Remover)
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost ($)
12.9
2.82
3
0.45
8.0
0.22
3.5
0.13
—
34
0.02
Totals
Total Cost($/Screen)
Total Cost($/year)
3.63
5,446
DRAFT—September 1994
V-31
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Chi
Alternative System Chi
Formulation
Ink Remover:
Emulsion Remover:
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
Water
Occupational Exposure
Table V-35
Occupational Exposure Estimates for Method 1, Alternative System Chi
System
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol methyl ether
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Inhalation (mg/day)
I
0
0
3
0
0
0
II
0
0
0
0
0
0
III
0
0
0
0
0
0
IV
0
0
0.1
0
0
0
Dermal (mg/day)
Routine
312
858
312
78
16
1540
Immersion
1456
4000
1460
364
73
7210
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover
Clear concerns exist for chronic dermal exposures to the diethylene glycol series
ethers used in ink removal based on the calculated margins-of-exposure.
Concerns exist for developmental toxicity risks from dermal exposures to N-
methylpyrrolidone based on the calculated margin-of-exposure. Similar
calculations for inhalation exposures to N-methylpyrrolidone indicate very low
concern.
DRAFT—September 1994
V-32
-------
Table V-36
Occupational Risk Estimates for Method 1, System CHI
o
Q.
a>
o-
CO
Name
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Hazard Quotient
Inhalation
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
NA
NA
NA
NA
NA
Immersion
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
3,600
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
1,800
NA
39
NA
NA
NA
LOAEL
46
NA
NA
NA
NA
NA
Immersion
NOAEL
380
NA
8.4
NA
NA
NA
LOAEL
9.8
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
Q.
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
O
Q.
f
5T
O
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Chi
o Inhalation exposures to other ink remover components are very low.
o Dermal risks from other ink remover components could not be quantified because
of limitations in hazard data, but exposures can be high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
Environmental Releases
Table V-37
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Alternative System Chi
System
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Release Under Each Scenario
(g/day)
I
air
0.1
0.1
6.8
0
0
0
water
0
0
0
0
6
615
land
138
381
132
35
0
0
II
air
0
0
0.1
0
0
0
III
air
0
0
0
0
0
0
IV
air
0
0
0.2
0
0
0
water
270
742
270
67
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-34
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Chi
Table V-38
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 1, Alternative System Chi
Substance:
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium Periodate
To Air:
0.1 g/day
0.1 g/day
7.1 g/day
To Water:
270 g/day at laundry
742 g/day at laundry
270 g/day at laundry
67 g/day at laundry
6 g/day
To Landfill:
138 g/day
381 g/day
132 g/day
35 g/day
Releases to Water from a Single Facility
Table V-39
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 1, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
Amount
Released to
Water from
Facility
270 g/day at
laundry
742 g/day at
laundry
270 g/day at
laundry
67 g/day at
laundry
6 g/day
Waste water
Treatment
Removal
Efficiency
83%
83-97%
97%
100%
»99%
Amount to Water
After Waste water
Treatment
46 g/day
126 g/day
8.1 g/day
0 g/day
«.06 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
4x10'2
1 x 10'1
8x10'3
0
«6x10'5
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-35
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Chi
Releases to Air from Individual Screen Printing Facilities
Table V-40
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 1, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Amount of Releases
per day
0.1 g/day
0.1 g/day
7.1 g/day
Highest Average
Concentration 100 M
away
2x10'4ug/m3
2x10'4ug/m3
1x10'2ug/m3
Annual Potential
Dose, mg/yeara
1 x 10'3
1 x 10'3
1 x 10'1
aThis estimates doses for people living 100 Meters from hypothetical facility. The actual number of people who would fall into
this range can be determined from census data, if the facility location is known. The model is more completely explained in the
Overview by Media-Air Section in Chapter III. To calculate the annual potential dose, the concentration is multiplied by the
amount a person will breathe (20 m3/day) and the number of days per year (365), and the units are converted to mg/year by
dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Alternative System Chi.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Alternative System Chi in
Method 2. Hazard Quotient values below one indicate very low risk. Margin-of-Exposure
(MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 1, Alternative System Chi reach an
ecotoxicity concern concentration.
Performance
The performance of System Chi, with the ink remover also in use as a haze remover, was
demonstrated at the Screen Printing Technical Foundation and at two volunteer printing
facilities. Reference Product System Chi in Method 2 for details of these performance
evaluations. The information reported from Facility 21 will be particularly applicable to Method
1 as Facility 21 was able to use the ink remover/emulsion remover combination and achieve
acceptable performance. Facility 21 noted that all screens could be reused for future jobs and
that this system worked particularly well in removing metallic inks.
DRAFT—September 1994
V-36
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Chi
Cost
Table V-41
Method 1: Summary of Cost Analysis for Method 1, Alternative System Chi
Cost Element Description
Baseline
(Traditional
System 4-
Haze Remover)
Alternative System Chi
Facility 3
Facility 21
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
1,977
15
1,088
23
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
12.9
2.82
3
0.45
8.0
0.22
3.5
0.13
—
34
0.02
9.4
2.07
1.2
0.18
1.1
0.21
2.1
0.07
—
0
0
4.5
0.98
1.2
0.19
1.1
0.21
1.5
0.05
—
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Nnrmali7firia
3.63
3.63
5,466
5,446
2.53
2.83
9,497
4,245
1.43
1.95
8,005
2,918
formalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-37
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Beta
Alternative System Beta
Unlike other manufacturers who participated in the project, this manufacturer submitted
only an ink remover, rather than a product system consisting of ink remover, emulsion
remover and haze remover. To accommodate the screen reclamation methods identified in this
CTSA and develop a risk assessment based on a product system, an emulsion remover
product was arbitrarily added to ink remover Beta to form Product System Beta. While the risk
and cost assessment include this other product, the performance of the ink remover was
profiled at a single facility (12) which used their standard emulsion and haze remover to
completely clean their screens. Due to a lack of information about the standard emulsion and
haze remover products used by Facility 12, the risk assessment for these products was not
undertaken.
Formulation
Ink Remover:
Emulsion Remover:
2-octadecanamine, N, N-dimethyl-, N-oxide or a modified amine
from unsaturated soy bean oil fatty acid/ water
Water
Sodium periodate
Occupational Exposure
Table V-42
Occupational Exposure Estimates for Method 1, Alternative Beta
System
Ink Remover
2-Octadecanamine, N, N-dimethyl, N-oxide
Water
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Inhalation (mg/day)
I
292
0
0
0
II
4.3
0
6
615
III
3
0
0
0
IV
0
0
0
0
Dermal (mg/day)
Routine
1530
31
0
0
Immersion
7130
146
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Estimates
Quantitative risk estimates could not be determined for this system due to insufficient
data. See risk conclusions for areas of concern for this system.
DRAFT—September 1994
V-38
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Beta
Occupational Risk Conclusions and Observations
Ink Remover
o Both inhalation and dermal exposures to workers using 2-octadecanamine, N,N-
dimethyl-, N-oxide in ink removal can be high, although the risks could not be
quantified because of limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
Environmental Releases
Table V-43
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Alternative System Beta
System
Ink Remover
2-Octadecanamine, N,N-dimethyl, N-
oxide
Water
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Release Under Each Scenario
(g/day)
I
air
609
0
0
0
water
0
0
6
615
land
0
12
0
0
II
air
9.1
0
0
0
III
air
6.3
0
0
0
IV
air
0
0
0
0
water
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-39
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Beta
Table V-44
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 1, Alternative System Beta
Substance:
2-octadecanamine, N,N-dimethyl, N-
oxide
Sodium periodate
To Air:
624 g/day
To Water:
5 g/day
To Landfill:
Releases to Water from a Single Facility
Table V-45
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 1, Alternative System Beta
Substance
Sodium periodate
Amount Released
to Water from
Facility
5 g/day
Waste water
Treatment
Removal
Efficiency
100 %
Amount to Water
After Waste water
Treatment
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-46
Air Releases, Concentrations and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 1, Alternative System Beta
Substance
2-Octadecanamine, N,N-dimethyl, N-oxide
Amount of Releases
per day
624 g/day
Highest Aver age
Concentration 100 M away
1.3ug/m3
Annual Potential
Dose, mg/yeara
9
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
DRAFT—September 1994
V-40
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product System Beta
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 1, Alternative System Beta.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2, and Alternative System Chi in Method 2; please reference these sections
as illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 1, Alternative System Beta reach an
ecotoxicity concern concentration.
Performance
General Summary of Ink Remover Beta Performance, and Related Variables
Facility 12 used ink remover Beta during the performance demonstrations. Unlike the
Product Systems submitted by other manufacturers, the manufacturer of Beta supplied the ink
remover only. The facility used the alternative ink remover Beta, along with their standard
emulsion remover and haze remover to reclaim their screens. During the demonstrations, the
performance of ink remover Beta was recorded for 17 screens with solvent-based inks over a
three week period. Facility 12 prints graphic overlays, labels, and flexible membrane switches,
and all products are primarily printed on plastics.
Ink remover Beta was also sent to two other facilities who were not able to participate in
the Performance Demonstrations. One facility could not use the product because they send all
their screens out to be reclaimed; they only use ink removers as an in-process cleaner. Since
this project is intended to evaluate ink removers used for screen reclamation, not for in-process
ink removal, this facility did not participate. The second facility felt they could not use the
alternative system because of an on-going EPA inspection. The printer regretted not being able
to participate, however, the EPA was in the process of testing his waste water, so he did not
want to add any new chemicals to his waste stream.
Facility 12 reported that the ink remover removed the ink on most screens, but it also left
an oily residue on the screen. Prior to the demonstration, this facility used an acetone and
toluene blend that left no residue on the screen. The printer found that the ink wiped off more
easily when it was wet, however it was very time-consuming to remove dried ink. On some
screens, it took 30 minutes to remove the ink.
Alternative Ink Remover Beta Profile
The manufacturer recommends applying ink remover Beta as follows:
DRAFT-September 1994 V-41
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product System Beta
Water Resistant Emulsions: Card off the excess ink from the screen. Using a spray
bottle, apply the ink remover to the screen. After a short penetration time (only for dried
inks) use high pressure water and rinse all the ink residue from the screen. For tests
done at SPTF, a 1000 psi spray was used for rinsing the ink remover.
Non Water Resistant Emulsions: Card off the excess ink from the screen. Using a spray
bottle, spray the ink remover directly onto the screen. Clean the screen with a cloth
slightly dampened with ink remover. Dry both sides of the screen with a dry and
absorbent cloth.
Alternative System Performance at SPTF
Ink remover Beta was tested at SPTF on three screens (one with a solvent-based ink, one
with a UV-curable ink, and one with a water-based ink). On all three screens, the technician
reported that the ink dissolved well, however a fair amount of wiping was required. For the
screen with the solvent-based ink, seven wipes were needed. Six wipes were used on the UV
ink screen, and eight wipes were required to remove the ink from the water-based ink screen.
On all three screens, the technician noticed that the ink remover affected the stencil image in
the half tone area. The color of the stencil appeared on the rag, which also indicated that the
product was deteriorating the emulsion.
Alternative System Performance Details
Performance Details from Facility 12
Facility 12 felt the ink remover Beta sufficiently removed the ink from most screens,
however, it took a long time to remove the ink and the product left an oily haze on the screen.
In some cases, they reported ink residue or ink stains were also left in the mesh. The oily film
and the ink residue were both removed during emulsion removal and haze removal steps, and
all screens were reusable for all types of printing jobs.
Unlike all of the other facilities in the Performance Demonstrations, an observer did not
visit this facility to introduce them to the project and to the alternative system. This lack of in-
person guidance may have affected the results. During the first week, the printer sprayed on
the ink remover, rubbed it in with a brush and pressure washed the screen to remove the ink.
This application method was very messy and did not effectively remove the ink. For the
remainder of the demonstrations, the printer changed his application method and used rags to
wipe the ink off the screen. This second method removed the ink much more easily, but took a
long time (an average of 25 minutes per screen). Two or three rags were used on each screen.
While wiping the screen with the rags, the printer noticed that the emulsion started to
deteriorate. He also mentioned that he needed to replace his filters on the ink removal sink
waste water more frequently when using the alternative system.
In reviewing the data, there did not appear to be any correlations between the product
performance and the screen conditions, however, the printer felt it was much easier to remove
wet ink and light colored inks, than dried on and black ink.
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the ink remover and the
relevant conditions at the demonstration facility. In addition to the field demonstrations data,
results of the product tests performed at SPTF are also summarized in this table.
DRAFT-September 1994 V-42
-------
Table V47
Performance Summary for Ink Remover BETA
•o_
CD"
CD
System
Component
Performance
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh
type;
Thread
count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
12
Ink remover
3.9±8.2hrs
(n=15)
4.2±1.5oz.
(n=17)
24.6 ± 5.4
mins (n=17)
Moderate
Removed ink but
took a long time
and left an oily
residue.
•Not
demonstrated as
part of a system.
Solvent-
based ink
Capillary film
Polyester,
abraded;
195-390
threads/
inch
1089 in2
Laboratory Testing at SPTF
SPTF
Solvent-
based Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based Ink
Ink Remover
Ink Remover
Ink Remover
15mins
15mins
15mins
2.5 oz.
2.5 oz.
3.0 oz.
9.1 mins
6.3 mins
12.0 mins
Moderate
Moderate
Moderate
Ink dissolved well, but 7 rags were
needed and the stencil started to
deteriorate.
Ink dissolved well, but 6 rags were
needed and the stencil started to
deteriorate.
Ink dissolved well, but it took a long time
(8 rags were needed) and the stencil
started to deteriorate.
Solvent-
based
UV-
curable
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
260
threads/
inch
Polyester;
390
threads/
inch
Polyester;
260
threads/
inch
360 in2
360 in2
360 in2
o
Q.
m
Q.
o_
m
m
o'
co_
rt^
c
CD"
ff
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CD
s
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8-
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5T
CD
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product System Beta
Facility Profiles
General Facility Background for Facility 12
Facility 12 prints graphic overlays, labels, and flexible membrane switches on plastics,
paper, and metals. Their typical run length is one hour, and approximately 70% of their orders
are repeat orders. There are about 10 employees involved in screen printing at this location,
and approximately 4 are involved in screen reclamation. Solvent-based vinyl and polyester inks
used at this facility. Screens with mesh counts of 195 - 390 threads/inch and capillary film
emulsions were used during the demonstrations. The average screen size at this facility is 9 ft2
and 10-15 screens are reclaimed daily.
Screen Reclamation Area in Facility 12
Ink removal is done in a spray booth where a local, mechanical system provides
ventilation. Screen reclamation is done in a high-pressure (2700 psi) water blaster booth.
Waste water from the wash of the emulsion remover and haze remover is filtered prior to
discharge to the sewer. Filters and spent solvent from the ink removal area are disposed of as
hazardous waste.
Current Screen Reclamation Products at Facility 12
This facility uses a solvent blend ink remover containing 50% toluene and 50% acetone.
Their emulsion remover consists primarily of sodium periodate. For haze removal, they use a
proprietary solvent blend which includes sodium hydroxide and cyclohexanone.
Current Screen Reclamation Practices in Facility 12
Using their standard products, this facility reclaims their screens following the procedure
described below. Personal protective equipment worn by operators includes gloves, eye
protection, respiratory protection, and rubber boots (for haze removal).
o Ink Remover: Card off the excess ink. Spray the ink remover onto the screen from
a low pressure tank (60 psi). Wipe off the dissolved ink with disposable rags (one
or two rags are used on each screen).
o Emulsion Remover: Spray the emulsion remover onto both sides of the screen.
Brush the emulsion remover into the screen. Pressure rinse and allow to air dry.
o Haze Remover: Dip a brush into the container of haze remover and rub it into the
screen. Rinse with the high-pressure water blaster.
DRAFT-September 1994 V-44
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method! Traditional Reclamation
Product System Beta
Cost
Table V-48
Method 1: Summary of Cost Analysis for Alternative Beta
Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
System 4 minus
Haze Remover)
2,127
6
Alternative
System Betas
Facility 12
1,089
15
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost ($)
12.9
2.82
3
0.45
8.0
0.22
3.5
0.13
—
34
0.02
29.4
6.43
2.2
0.34
4.2
0.50
1.8
0.06
—
0
0
Total Costs
Total Cost ($/screen)
Normalized11
Total Cost ($/year)
Nnrmali7i=Hb
3.63
3.63
5,446
5,446
17.33
7.97
27,477
11,958
aThe emulsion removal use and cost per screen were taken from performance demonstration results for
product system Zeta.
bl\lormalized values adjust product usage, number of screens cleaned, and number of rags laundered at
demonstration facilities to reflect the screen size and number of screens cleaned per day under the baseline
scenario. Labor costs, however, are not normalized. Normalization allows a comparison between the
baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-45
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 1
Method 2: Traditional Reclamation With Haze Remover
In a typical screen printing facility, ink remover, emulsion remover and haze remover are
all used in the process of screen reclamation. Method 2 incorporates the most common
practices in screen reclamation; it differs from Method 1 in that printers are assumed to use a
haze remover (see Figure V-2). For the purposes of determining occupational exposure to the
haze remover, it was assumed that screen reclaimers only used haze remover on 1-2 screens of
the estimated six screens reclaimed daily in the average small/medium screen printing facility.
Because Method 2 is most representative of current screen reclamation practices, the
majority of alternative systems are included in this category. A total of fourteen systems are
assessed, including four traditional systems and ten alternative systems. The alternative
systems were submitted by manufacturers who volunteered to participate in the project. These
systems were named Alpha, Chi, Delta, Epsilon, Gamma, Mu, Phi, Omicron-AE, Omicron-AF
and Zeta. Printers who are interested in further exploration of the merits of one of these
systems should contact the manufacturers listed in the acknowledgements section of the
document.
Although three chemical products are used in Method 2, as opposed to two chemical
products in Method 1, pollution prevention can still be achieved through a combination of
improved workplace practices and equipment modifications. Chapter 6 should be referenced
to best determine which pollution prevention practices are most appropriate for a particular
facility. In Chapter 6, a discussion of workplace practices reported by printers as a means of
reducing or preventing pollution is followed by an overview of spray applicator systems,
washout booths, filtration systems, recirculation systems and distillation units. All of these
modifications can be used in combination with Method 2 to prevent pollution.
Traditional System 1
Formulation
Ink Remover: 100% Mineral spirits
Emulsion Remover: 12% Sodium hypochlorite (bleach)
Haze Remover: 10%Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
DRAFT-September 1994 V-46
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Figure V - 2
Process Steps Included in Method 2
Ink Removal
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Emulsion
Removal/Water
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
Haze Removal/
Water Wash
Product Groups
Include:
• GLYCOL ETHERS
• CAUSTICS
• DIBASIC ESTERS
• SOLVENTS
• SURFACTANTS
DRAFT—September 1994
V-47
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Occupational Exposure
Table V-49
Occupational Exposure Estimates For Method 2, Traditional System 1
System
Ink Remover
Mineral spirits- light hydrotreated
Emulsion Remover
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed)
Acetone
Mineral spirits-light hydrotreated
Cyclohexanone
Inhalation Exposures, by
Scenario (mg/day)
I
26
0
0
21
64
7
27
II
0.1
0
0
0.9
11
0.1
0.3
III
0
0
0
1
5
0
0
IV
0.3
0
0
0
0
0
0
Dermal Exposures, (mg/day)
Routine
1560
187
1370
156
468
468
468
Immersion
7280
874
6410
728
2180
2180
2180
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III =
transferring chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Hazard quotient calculations indicate clear concerns for chronic dermal and
inhalation exposures to workers using acetone in haze removal.
o Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures to workers using xylene and cyclohexanone in haze removal.
o Margin-of-exposure calculations indicate very low concern for developmental and
reproductive toxicity risks from inhalation of cyclohexanone. Reproductive and
developmental toxicity risks from dermal exposures to cyclohexanone could not be
quantified.
o Dermal exposures to workers using mineral spirits in ink removal can be very high,
although the risks from mineral spirits could not be quantified because of
limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide.
DRAFT—September 1994
V-48
-------
Table V-50
Occupational Risk Estimates for Method 2, Traditional System 1
Name
Ink Remover
Mineral spirits- light hydrotreated
Emulsion Remover
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Hazard Quotient
Inhalation
NA
NA
0.2
11
NA
0.08
Dermal
Routine
NA
NA
NA
1.1
66
NA
1.3
Immersion
NA
NA
NA
5.2
311
NA
6.2
Margin Of Exposures
Inhalation
NOAELb
NA
NA
NA
NA
NA
NA
180
LOAELc
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
o
Q.
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a.
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8L
c?
o.
m
m
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CO
CD
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Q)
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CD
CO
CO
CD
I
Q)
a
o
Q.
CO
aNA means Not Available.
bNOAEL means No Observed Adverse Effect Level.
10AEL means Lowest Observed Adverse Effect Level.
m
g.
5'
3
8L
CO
2-
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
The haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain these
compounds. All of these materials present a high concern for skin and eye irritation and tissue
damage if workers are exposed in the absence of proper protective clothing. None of the
emulsion removers present significant inhalation risks.
Environmental Releases
Table V-51
Estimated Environmental Releases in Screen Cleaning Operations
Method 2, Traditional System 1
System
Ink Remover
Mineral spirits- light hydrotreated
Emulsion Remover
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Release Under Each Scenario
(g/day)
I
air
54
0
0
44
133
15
57
water
0
75
546
0
0
119
76
land
1050
0
0
0
0
0
0
II
air
0.2
0
0
1.9
22
0.2
0.7
III
air
0.1
0
0
1.1
11
0.1
0.4
IV
air
0.6
0
0
0
0
0
0
water
1350
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-50
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Table V-52
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility:
Traditional System 1
Substance
Mineral Spirits
Sodium Hypochlorite
Acetone
Xylene
Cyclohexanone
To Air
69.5 g/day
167g/day
47.5 g/day
58.1 g/day
To Water
119 g/day
1350g/daya
74.5 g/day
76.5 g/day
To Landfill
1053g/daya
aThis release is either to water from the printing facility, or is sent with wastes to a waste handler to go to a landfill or to
incineration. For our purposes, the rest of the assessment assumes release to water only, since we are not assessing
landfill releases.
Releases to Water from a Single Facility
Table V-53
Estimated Releases to Water from Screen Reclamation at a Single Facility
Traditional System 1
Substance
Mineral Spirits
Xylenes
Cyclohexanone
Sodium Hypochloriteb
Amount Released to
Water from Facility
119 g/day
1350 g/day at laundry
76.5 g/day
74.5 g/day
Waste water
Treatment Removal
Efficiency
99%
75%
90%
»c 99%
Amount to Water
After Waste water
Treatment
1 .2 g/day
13.50 g/day
7.6 g/day
« .7 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
1.2x10'3
7.6 x10'3
«7x10'4
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Concentrated solutions of sodium hypochlorite will kill the biota which degrade organic chemicals (the other substances listed
in the table) during waste water treatment. This could cause problems at the waste water treatment plant, reducing the waste
water treatment efficiency for the other compounds sent to the plant.
c» is very much greater than, « is very much less than.
DRAFT—September 1994
V-51
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even though the release from one screen printing
facility is not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes as it is
at the release point.
Table V-54
Estimated Cumulative Releases for St. Louis County, MO
Traditional System 1
Substance
Mineral Spirits
Cyclohexanone
Sodium Hypochlorite
Total Amount Released
to Water from All
Facilities
16 kg/day + 182 kg/day at
laundry
10 kg/day
10 kg/day
Waste water
Treatment
Removal
Efficiency
99%
90%
» 99%
Amount to Water
After Waste water
Treatment
160g/day
1 .8 kg/day
1 g/day
«100g/day
Daily Stream
Concentration in
Meramec River,
ug/L (ppb)
1.6x10'1
1.8
1 x 10'3
«1 x 10'1
Releases to Air from Individual Screen Printing Facilities
DRAFT—September 1994
V-52
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Table V-55
Air Release, Concentration and Potential Dose Estimates From a Single Model
Facility
Traditional System 1
Substance
Mineral Spirits
Acetone
Xylene
Cyclohexanone
Amount of Releases
per day
69.5 g/day
167g/day
47.5 g/day
58.1 g/day
Highest Average
Concentration 100 M away
3x10'1ug/m3
23 ug/m3
9x10'2ug/m3
1 x 10'1 ug/m3
Annual Potential Dose,
mg/yeara
1.1
2.6
0.7
0.9
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who
would fall into this range can be determined from census data, if the facility location is known. The model used to
calculate concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To
calculate the annual potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day)
and the number of days per year (365), and the units are converted to mg/year by dividing by 1000.
The following graphic depicts the population near San Bernardino, CA, and the lines
(isopleths) are equal average concentration of acetone from a hypothetical facility at 34 ° latitude
and 117° longitude. The concentrations do not vary in concentric circles from the release
point, but in patterns which depend on the weather and terrain.
Table V-56
Population Risk Estimates for Traditional System 1
Chemical Name
Mineral spirits
Sodium hypochlorite
Xylene
Acetone
Cyclohexanone
Ambient Air
(Health)
See note 1
Air releases not expected
Hazard Quotient = ~ 10'5
Hazard Quotient = ~ 10'3
Hazard Quotient = ~ 10'5
Ambient Water
(Health)
See note 1
See note 2
Water releases not
expected
Water releases not
expected
Hazard Quotient = ~ 10'8
Ambient Water
Conc/Eco CC
2
~io-3
Water releases not
expected
Water releases not
expected
~io-7
Note 1: Risks resulting from exposures to mineral spirits could not be quantified.
Note 2: Human health risks from the release of hypochlorite to water are expected to be very low, but cannot be quantified
because of limitations in the available hazard data. Estimated concentrations of hypochlorite in ambient water are much
lower than hypochlorite concentrations in typical drinking water supplies.
DRAFT—September 1994
V-53
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 1
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Traditional System 1.
o Risks to the general population from ambient air and drinking water exposures are
very low for Method 2, Traditional System 1.
o The major health impact on the general population for this type of product is
probably its release of volatile organic compounds that contribute to the formation
of photochemical smog in the ambient air.
o A marginal concern exists for risks to aquatic species resulting from the release of
mineral spirits from a commercial laundry that launders shop rags from all of the
screen printing facilities in the area. Aquatic risks from all of the chemicals are low
with respect to direct water releases from the screen printing facilities.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
DRAFT-September 1994 V-54
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Figure V-3
Acetone Concentration Patterns Around a "Typical" Screen Print Facility
ISOPLETH # CONCENTRATION.
ug/m3
5.4 x 104
5.Ox 104
l.Ox 104
5.Ox 105
1.8x 105
* = Population Centroid - Weighted center of population of one census block group.
There are roughly 800 to 1200 people represented by each centroid.
Distances are in kilometers
1
2
3
4
5
DRAFT—September 1994
V-55
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o Cumulative releases of mineral spirits from Traditional System 1 present a concern
for risk to aquatic species. The largest contributor to these releases is the
hypothetical commercial laundry that launders the shop rags used by the area's
screen printers.
o None of the components of Method 2, Traditional System 1 reached an ecotoxicity
concern concentration, even when considering the cumulative releases from all
shops in the area.
o None of the single facility releases of Method 2, Traditional System 1 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 1. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-57
Estimated Cumulative Releases for St. Louis County, MO
Screen Reclamation Method 2, Traditional System 1
Substance
Mineral Spirits
Cyclohexanone
Sodium Hypochlorite
Total Amount
Released to
Water from All
Facilities
16 kg/day +
182 kg/day at
laundry
10 kg/day
10 kg/day
Waste
water
Treatment
Removal
Efficiency
94%
83%
100 %
Amount to Water
After Waste
water Treatment
960 g/day
11 kg/day
1 .7 kg/day
0
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
1 x 10'1
1
2x10'1
0
ECOCC
(ug/i)
1
2800
<20
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
1.1
7x1 0'5
0
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
DRAFT—September 1994
V-56
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 1
Cost
Because the performance of this system was not determined in this project, the total cost
of using this system was also not calculated.
Traditional System 2
Formulation
Ink Remover
Emulsion Remover
Haze Remover
100% Acetone
12% Sodium hypochlorite (bleach)
10%Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
Occupational Exposure
Table V-58
Occupational Exposure Estimates for Method 2, Traditional System 2
System
Ink Remover
Acetone
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Inhalation (mg/day)
1
539
0
0
21
64
7
27
II
11
0
0
0.9
11
0.1
0.3
III
5
0
0
1
5
0
0
IV
38
0
0
0
0
0
0
Dermal (mg/day)
Routine
1560
187
1370
156
468
468
468
Immersion
7280
874
6410
728
2180
2180
2180
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-57
-------
Table V-59
Occupational Risk Estimates for Method 2, Traditional System 2
o
Q.
IS3
CO
Name
Ink Remover
Acetone
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Hazard Quotient
Inhalation
84
NA
NA
0.2
11
NA
0.07
Dermal
Routine
23
NA
NA
1.1
66
NA
1.3
Immersion
1,040
NA
NA
5.2
311.
NA
6.2
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
180
LOAELd
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
0
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
0
LOAEL
NA
NA
NA
NA
NA
NA
0
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
a.
5'
3
8L
c?
o.
m
m
o'
CD
•o
Q)
I
CD
CO
CO
CD
I
Q)
a
o
Q.
CO
m
g.
5'
3
8L
CO
2-
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 2
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Hazard quotient calculations indicate clear concerns for chronic dermal and
inhalation exposures to workers using acetone in either ink removal or haze
removal.
o Hazard quotient calculations indicate marginal concerns for dermal exposures to
workers using xylene and cyclohexanone in haze removal.
o Margin-of-exposure calculations indicate very low concern for developmental and
reproductive toxicity risks from inhalation of cyclohexanone. Reproductive and
developmental toxicity risks from dermal exposures to cyclohexanone could not be
quantified.
o Dermal exposures to workers using mineral spirits in haze removal can be high,
although the risks from mineral spirits could not be quantified because of
limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover (all systems except Beta) use
either a strong oxidizer such as hypochlorite or periodate or a strong base such as
sodium hydroxide. The haze removers in Alpha, Epsilon, Gamma, Mu, Omicron,
and Theta also contain these compounds. All of these materials present a high
concern for skin and eye irritation and tissue damage if workers are exposed in the
absence of proper protective clothing. None of the emulsion removers present
significant inhalation risks.
DRAFT-September 1994 V-59
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Environmental Releases
Table V-60
Estimated Environmental Releases in Screen Cleaning Operations
Method 2, Traditional System 2
System
Ink Remover
Acetone
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Release Under Each Scenario
(g/day)
1
air
1120
0
0
44
133
15
57
water
0
75
546
0
0
119
76
land
0
0
0
0
0
0
0
II
air
22
0
0
1.9
22
0.2
0.7
III
air
11
0
0
1.1
11
0.1
0.4
IV
air
80
0
0
0
0
0
0
water
1270
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-60
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Estimated Environmental Releases from Screen Reclamation Processes
Method 2, Traditional Screen Reclamation System 2
From Ink Removal Operations:
Acetone
1233g/day to air
1270 g/day to water
From Emulsion Remover:
Sodium Hypoclorite
75 g/day to water
From Haze Remover:
Acetone:
166 g/day to air
Xylenes:
47 g/day to air
Mineral Spirits:
15.3 g/day to air
119 g/day to water
Cyclohexanone:
58.1 g/day to air
76 g/day to water
Table V-61
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 2, Traditional System 2
Substance:
Acetone
Sodium Hypoclorite
Mineral Spirits
Xylenes
Cyclohexanone
To Air:
1,399 g/day
15.3 g/day
47 g/day
58.1 g/day
To Water:
1270a g/day
75 g/day
119 g/day
76 g/day
To Landfill:
1270a g/day
a1270 g/day is estimated to be releases from the rags. This release from the rags will be either to landfill or to water. If the
release is to water through the laundry, then the landfill column is blank. If the release is to landfill, then the landfill column will
be 1270 g/day and the water column will be empty. This is true of all of the ink remover chemicals. For our purposes, the rest
of the assessment assumes release to water only, since we are not assessing landfill releases.
DRAFT—September 1994
V-61
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Releases to Water from a Single Facility
Table V-62
Estimated Releases to Water from Method 2, Traditional System 2
Substance
Acetone
Cyclohexanone
Mineral spirits
Sodium Hypoclorite
Amount Released
to Water from
Facility
1270g/day
76 g/day
119g/day
75 g/day
Waste water
Treatment
Removal
Efficiency
87%
83%
94%
»99%
Amount to Water
After Waste water
Treatment
165 g/day
12.9 g/day
7. 14 g/day
«1 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
0.2
1 x 10'2
7x10'3
«1 x 10-3
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
DRAFT—September 1994
V-62
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Table V-63
Estimated Cumulative Releases for St. Louis County, MO
Method 2, Traditional System 2
Substance
Acetone
Mineral Spirits
Cyclohexanone
Sodium
Hypochlorite
Total Amount
Released to Water
from All Facilities
171 kg/day
16.1 kg/day
10.3 kg/day
10.1 kg/day
Waste water
Treatment
Removal
Efficiency
87%
94%
83%
»99%
Amount to Water
After Waste water
Treatment
22.3 kg/day
964 g/day
1 .7 kg/day
« 100 g/day
Average Concentration
in Meramec River, ug/L
(ppb)
3
0.1
0.2
« 1 x 10'1
» is very much greater than, « is very much less than.
Releases to Air from Individual Screen Printing Facilities
Table V-64
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Method 2, Traditional System 2
Substance
Mineral Spirits
Acetone
Xylenes
Cyclohexanone
Amount of Releases per
day
15.3 g/day
1399 g/day
47 g/day
58.1 g/day
Highest Average
Concentration 100 M
away
3x10'2ug/m3
3ug/m3
9x10'2ug/m3
1 x 10'1 ug/m3
Annual Potential Dose,
mg/yeara
0.2
20
0.7
0.7
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Traditional System 2.
DRAFT—September 1994
V-63
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the other components of Method 2, Traditional System 2 reached an
ecotoxicity concern concentration, even when considering the cumulative releases
from all shops in the area.
o None of the single facility releases of Method 2, Traditional System 2 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 2. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-65
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 2, Traditional System 2
Substance
Acetone
Mineral Spirits
Cyclohexanone
Sodium
Hypochlorite
Total Amount
Released to
Water from All
Facilities
171 kg/day
16.1 kg/day
10.3 kg/day
10.1 kg/day
Waste water
Treatment
Removal
Efficiency
87%
94%
83%
»99%
Amount to
Water After
Waste water
Treatment
22.3 kg/day
964 g/day
1 .7 kg/day
« 100 kg/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
3
0.1
0.2
« 1 x 10'1
ECOCC
(ug/L)
7600
1
2800
20
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
4x1 0'4
0.1
7x1 0'5
«1 x 10'2
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
DRAFT—September 1994
V-64
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 2
Cost
Because the performance of this system was not determined in this project, the total cost
of using this system was also not calculated.
Traditional System 3
Formulation
Ink Remover:
Emulsion Remover:
Haze Remover:
100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% n-butyl acetate
5% Methanol
20% Naphtha light aliphatic
20% Toluene
10% Isobutyl isobutyrate
12 wt% Sodium hypochlorite/88 % water
10%Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
DRAFT—September 1994
V-65
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Occupational Exposure
Table V-66
Occupational Exposure Estimates for Method 2, Traditional System 3
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Inhalation (mg/day
1
165
44
27
98
110
7
0
0
21
64
7
27
II
5.3
1.3
4.7
1.6
2.3
0.4
0
0
0.9
11
0.1
0.3
III
3
1
2
1
1
0
0
0
1
5
0
0
IV
20
5.3
15
6.2
9.2
1.7
0
0
0
0
0
0
Dermal (mg/day)
Routine
468
234
78
312
312
156
187
1370
156
468
468
468
Immersion
2180
1090
364
1460
1460
728
874
874
728
2180
2180
2180
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
Hazard quotient calculations indicate clear concerns for both toluene and methyl
ethyl ketone with respect to chronic dermal and inhalation exposures to workers
using these chemicals in ink removal.
Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
Hazard quotient calculations indicate clear concerns for chronic dermal and
inhalation exposures to workers using acetone in haze removal.
DRAFT—September 1994
V-66
-------
Table V-67
Occupational Risk Estimates for Method 2, Traditional System 3
Name
Ink Remover
Methyl ethyl ketone (2-butanone)
Butyl acetate normal
Methanol
Aromatic solvent naphtha
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Hazard Quotient
Inhalation
9.29
NA
1.4
NA
17
NA
NA
NA
0.2
11
NA
0.07
Dermal
Routine
23
NA
2.2
NA
44
NA
NA
NA
1.1
66
NA
1.3
Immersion
103
NA
10
NA
208
NA
NA
NA
5.2
311
NA
6.2
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
180
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
"Margin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
Q.
IS3
m
a.
5'
3
8L
c?
o.
m
m
o'
CO
CD
•o
Q)
I
CD
CO
CO
CD
I
Q)
a
o
Q.
CO
m
g.
5'
3
8L
CO
2-
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 3
o Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures to workers using cyclohexanone in haze removal.
o Margin-of-exposure calculations indicate very low concern for developmental and
reproductive toxicity risks from inhalation of cyclohexanone. Reproductive and
developmental toxicity risks from dermal exposures to cyclohexanone could not be
quantified.
o Dermal exposures to workers using mineral spirits in haze removal can be high,
although the risks from mineral spirits could not be quantified because of
limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover (all systems except Beta) use
either a strong oxidizer such as hypochlorite or periodate or a strong base such as
sodium hydroxide. The haze removers in Alpha, Epsilon, Gamma, Mu, Omicron,
and Theta also contain these compounds. All of these materials present a high
concern for skin and eye irritation and tissue damage if workers are exposed in the
absence of proper protective clothing. None of the emulsion removers present
significant inhalation risks.
DRAFT-September 1994 V-68
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Environmental Releases
Table V-68
Estimated Environmental Releases in Screen Cleaning Operations
Method 2, Traditional System 3
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Bleach)
Sodium hypochlorite
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Release Under Each Scenario
(g/day)
1
air
344
92
57
204
229
15
0
0
44
133
15
57
water
0
0
0
0
0
0
75
546
0
0
119
76
land
0
80
0
25
0
100
0
0
0
0
0
0
II
air
11
2.6
9.8
3.2
4.8
0.8
0
0
1.9
22
0.2
0.7
III
air
5.7
1.5
4.1
1.7
2.6
0.5
0
0
1.1
11
0.1
0.4
IV
air
42
11
30
13
19
3.4
0
0
0
0
0
0
water
363
191
37
257
251
132
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-69
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Table V-69
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 2, Traditional System 3
Substance:
Methyl ethyl ketone
n-butyl Acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Bleach
Mineral Spirits
Acetone
Xylenes
Cyclohexanone
To Air:
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7 g/day
15.3 g/day
166 g/day
47 g/day
58.1 g/day
To Water:
363 g/day at laundry
191 g/day at laundry3
37 g/day at laundry
257 g/day at laundry
251 g/day at laundry
132 g/day at laundry
75 g/day
119 g/day
76 g/day
To Landfill:
80 g/daya
25 g/day
100 g/day
aThe landfill number is the amount estimated to be releases from the rags. This release from the rags will be either to landfill or
to water. If the release is to water through the laundry, then the landfill column is blank. This is true of all of the ink remover
chemicals. For our purposes, the rest of the assessment assumes release to water only, since we are not assessing landfill
releases.
DRAFT—September 1994
V-70
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Releases to Water from a Single Facility
Table V-70
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Method 2, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Hypochloriteb
Amount Released
to Water from
Facility
363 g/day at
laundry
191 g/day at
laundry
37 g/day at laundry
257 g/day at
laundry
251 g/day at
laundry
132 g/day at
laundry
119 g/day
76 g/day
75 g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
100 %
Amount to Water
After Waste water
Treatment
58 g/day
5.7 g/day
1.1 g/day
15 g/day
20 g/day
2.6 g/day
7.1 g/day
13 g/day
0
Mean Daily
Concentration, ug/La
for 1000 MLD
Receiving Water
6x10'2
6x10'3
1 x 10'3
2x10'2
2x10'2
3x10'3
7x10'3
1 x 10'2
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Concentrated solutions of sodium hypochlorite will kill the biota which degrade organic chemicals (the other substances listed
in the table) during waste water treatment. This could cause problems at the waste water treatment plant, reducing the waste
water treatment efficiency for the other compounds sent to the plant.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
DRAFT—September 1994
V-71
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
Table V-71
Estimated Cumulative Releases for St. Louis County, MO
Method 2, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Hypochlorite
Total Amount
Released to Water
from All Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
16 kg/day
10 kg/day
10 kg/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
» 99%
Amount to Water
After Waste water
Treatment
7.8 kg/day
8 x10'1 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
960 g/day
1.7 kg/day
« 100 g/day
Average Concentration
in Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
1 x 10'1
2x10'1
«1 x 10'2
DRAFT—September 1994
V-72
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Releases to Air from Individual Screen Printing Facilities
Table V-72
Air Release, Concentration and Potential Dose Estimates from a Single Model Facility
Method 2, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Acetone
Xylenes
Cyclohexanone
Amount of Releases per
day
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7
15.3 g/day
166 g/day
47 g/day
58.1 g/day
Highest Average
Concentration 100 M away
8x10'1ug/m3
2x10'1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
3x10'2ug/m3
3x10'1ug/m3
9x10'2ug/m3
1 x 10'1 ug/m3
Annual Potential
Dose, mg/yeara
6
1
1
3
4
0.3
0.2
2
0.7
0.7
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Traditional System 3.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1.
Hazard Quotient values below one indicate very low risk. Margin-of-Exposure (MOE) values
above 100 for a NOAEL or above 1000 for a LOAEL indicate very low risk.
DRAFT—September 1994
V-73
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Table V-73
Risks from Potential Drinking Water Exposures
Screen Reclamation Method 2, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Hypochlorite
Daily Stream
Concentration in
Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
1 x 10'1
2x10'1
«1 x 10'2
Daily dose from
Drinking Water
(mg/kg)
3x1 0'5
3x1 0'6
6x1 0'7
9x1 0'6
9x1 0'6
1x10'6
3x1 0'6
6x1 0'6
«3x10'7
RfD (mg/kg)
0.6
not available
0.5
not available
0.2
not available
not available
5
not available
Hazard
Quotient
(dose/RfD)
5x1 0'5
1x10'6
4x1 0'5
1x10'6
DRAFT—September 1994
V-74
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Table V-74
Risk Estimates from Ambient Air Releases from a Single Model Facility
Screen Reclamation Method 2, Traditional System 3
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Acetone
Xylenes
Cyclohexanone
Highest Avg
Concentration 100 M
away
8x10'1ug/m3
2x10-1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
3x10'2ug/m3
3x10'1ug/m3
9x10'2ug/m3
1 x 10'1 ug/m3
Daily Potential
Dose, (mg/kg)
2x1 0'4
4x1 0'5
4x1 0'5
1x10'4
2x1 0'4
1x10'5
8x1 0'6
8x1 0'5
3x1 0'5
3x1 0'5
RfD/RfC (mg/kg,
mg/m 3)
1 mg/m3
not available
0.5 mg/kg
not available
0.4 mg/m3
not available
not available
0.1 mg/kg
2 mg/kg
5 mg/kg
Hazard
Quotient(Dose
or Conc/RfD or
RfC)
8x1 0'4
8x1 0'5
1x10'3
8x1 0'4
1x10'5
6x1 0'6
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the other components of Method 2, Traditional System 3 reached an
ecotoxicity concern concentration, even when considering the cumulative releases
from all shops in the area.
o None of the single facility releases of Method 2, Traditional System 3 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 3. The analogous figures for single facilities show much lower exposure
and risk levels.
DRAFT—September 1994
V-75
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 3
Table V-75
Estimated Cumulative Releases for St. Louis County, MO
Screen Reclamation Method 2, Traditional System 3
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha light
aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Hypochlorite
Total Amount
Released to
Water from All
Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
16 kg/day
10 kg/day
10 kg/day
Waste
water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
» 99%
Amount to Water
After Waste
water Treatment
7.8 kg/day
8 x10'1 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
960 g/day
1 .7 kg/day
« 100 g/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
1 x 10'1
2x10'1
«1 x 10'2
ECOCC
(ug/L)
4500
140
9000
5
110
80
1
2800
<20
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
2x1 0'4
7x1 0'4
2x1 0'6
0.06
3x1 0'3
5x1 0'4
0.1
7x1 0'5
-0.05
Performance
General Summary of Traditional System 3 Performance
The performance of Traditional System 3 was demonstrated at SPTF. This product
system consisted of an ink remover (lacquer thinner), an emulsion remover (sodium
hypochlorite or bleach), and a haze remover. The ink remover and the haze remover were
selected based on general chemical formulations that were identified by manufacturers as the
most common types of products currently used in the screen printing industry. SPTF did not
use the haze remover suggested by the manufacturers due to concerns about the volatility and
hazards of the product; instead a commonly used, commercially available haze remover
containing potassium hydroxide and tetrahydrofurfuryl alcohol was used. Unlike the
alternative systems, Traditional Product System 3 was only tested at SPTF; no demonstrations
were conducted at volunteer printing facilities. Traditional System 3 was tested following the
same procedure as was used for alternative system testing at SPTF (see Appendix F for details
of the testing methodology and test parameters).
Overall, SPTF described the ink remover (lacquer thinner) as very difficult to work with,
and incompatible with water-based ink systems. Using bleach as an emulsion remover was
also inefficient: it required a lot of time and effort to remove the stencil. The haze remover
worked very well on the screens with solvent-based ink and UV ink, but it was not tested on the
screen with water-based ink.
DRAFT—September 1994
V-76
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 3
Traditional System 3 Profile
The products in Traditional System 3 were used to reclaim screens as follows:
o Ink Removal Card up the excess ink from the screen with cardboard or plastic
squeegees. Spray the screen surface with the ink remover and wipe up the
dissolved ink and solvent with an absorbent rag or cloth. Repeat spraying on the
product and wiping off the ink until the ink is removed and little comes off on the
cloth.
o Emulsion Removal Place the screen in the washout sink and spray both sides of
the stencil area so that the product evenly covers the stencil. Use a soft brush to
loosen the stencil. Scrub with the brush until the stencil is broken up in all areas.
Apply more product if necessary. Wash away the stencil with a hard spray of water,
preferably with a pressure washer.
o Haze Removal Mix the haze remover paste thoroughly. Brush the product on the
stained areas on both sides of the wet mesh. Let stand for a maximum of 8
minutes. Rinse off the residue with a gentle water spray, followed by a high
pressure water spray to remove the stain.
Traditional System 3 Performance by SPTF
Traditional System 3 was tested by SPTF on three screens (one with a solvent-based ink,
one with a UV-curable ink, and one with a water-based ink). The performance of the products
varied greatly with the different ink types.
On the screen with the solvent-based ink, the lacquer thinner removed the ink, but left a
gray haze over the screen. The technician noted that the lacquer thinner was very difficult to
use: it required a lot of wiping effort and ten rags were used to remove the ink. The stencil was
affected during ink removal, either from the lacquer thinner itself or from the excessive wiping
that was required to remove the ink. The emulsion remover was also very difficult to use.
Three applications of the bleach were required, along with vigorous scrubbing for over 10
minutes to remove the stencil. When the stencil finally did dissolve and the screen was
pressure washed, ink residue and stain remained in the image areas. The haze remover easily
removed all of the ink residue and the ink stain. The screen was then left in the laboratory
testing area overnight. The next day, the technician noticed that the screen had ripped
sometime after the test was complete.
The performance of the traditional system was similar on the screen with UV ink. The
lacquer thinner left a gray haze on the screen and the stencil started to deteriorate during the
ink removal step. The UV ink screen did not require quite as much scrubbing effort as the
solvent-based ink screen, and seven rags were used. The bleach performance was the same as
with the solvent-based ink screen: the stencil dissolved very slowly, and an excessive amount of
scrubbing, effort, and rinsing were needed to remove the stencil. After the rinse, ink residue
remained in the image areas. As with the solvent-based ink screen, the haze remover easily
removed the ink residue and no latent image was visible.
On the screen with the water-based ink, the lacquer thinner proved to be completely
incompatible. All of the ink on the screen solidified when the lacquer thinner was applied. At
DRAFT-September 1994 V-77
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 3
that point, the test had to be aborted and the emulsion remover and haze remover were not
applied.
Traditional System 3 Performance Table
The following table highlights the observed performance of Traditional Product System 3
during the product tests performed at SPTF.
Cost
Although the performance of this system was demonstrated at SPTF, the total cost of this
system was not calculated. It was determined that a cost analysis with a sodium periodate-
based emulsion remover would be more representative of the products that are currently being
used at screen printers. Subsequently, the traditional system cost baseline was based on
Traditional System 4, not System 3.
DRAFT-September 1994 V-78
-------
•o_
CD"
CD
Table V-76
Performance Summary For Traditional Product System 3
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Overall System Performance
Demonstration Conditions
Ink type
Emulsion
type
Mesh type;
Thread count
Average
Screen Size
Laboratory Testing at SPTF
Solvent-
based Ink
UV-
curable
Ink
Water-
based Ink
Ink Remover
Emulsion
Remover
Haze Remover3
Ink Remover
Emulsion
Remover
Haze Remover1
Ink Remover
Emulsion
Remover
Haze Remover
15mins
24 hours
Omins
15mins
24 hours
0 mins
15mins
not used
not used
3.5 oz.
3.0 oz.
1.5oz.
2.5 oz.
3.0 oz.
1 Ooz
not recorded
not used
not used
8.7 mins
22.5 mins
11. Omins
7.4 mins
17.7 mins
120mins
not recorded
not used
not used
High
High
Low
Moderate
High
Low
not recorded
not used
not used
Removed ink with a lot of scrubbing.
Gray haze remained on entire screen.
Stencil dissolved slowly with vigorous
scrubbing. Heavy ink residue and
stain remained in image areas.
Removed all residue and stain.
Removed ink with moderate
scrubbing. A gray haze remained on
the screen.
Stencil dissolved slowly with vigorous
scrubbing and excessive rinsing. Ink
residue and stain remained in image
areas.
Removed all residue and stain
The ink solidified across the entire
screen when the ink remover was
applied. Testing was stopped at this
point.
Test aborted after ink remover failure.
Test aborted after ink remover failure.
Solvent-
based
UV-cured
Water-
based
Dual-cure
direct
Dual-cure
direct
Dual-cure
direct
Polyester; 245
threads/inch
Polyester;
390
threads/inch
Polyester; 245
threads/inch
360 in2
360 in2
360 in2
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m
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Traditional System 4
Formulation
Ink Remover:
Emulsion Remover:
Haze Remover:
100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% n-butyl acetate
5% Methanol
20% Naphtha light alipahtic
20% Toluene
10% Isobutyl isobutyrate
1% Sodium periodate/ 99% water
10%Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
Occupational Exposure
DRAFT—September 1994
V-80
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Table V-77
Occupational Exposure Estimates for Method 2, Traditional System 4
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Inhalation (mg/day)
I
165
44
27
98
110
7
0
0
21
64
7
27
II
5.3
1.3
4.7
1.6
2.3
0.4
0
0
0.9
11
0.1
0.3
III
3
1
2
1
1
0
0
0
1
5
0
0
IV
20
5.3
15
6.2
9.2
1.7
0
0
0
0
0
0
Dermal (mg/day)
Routine
468
234
78
312
312
156
16
1540
156
468
468
468
Immersion
2180
1090
364
1460
1460
728
73
7210
728
2180
2180
2180
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
Hazard quotient calculations indicate clear concerns for both toluene and methyl
ethyl ketone with respect to chronic dermal and inhalation exposures to workers
using these chemicals in ink removal.
Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
Hazard quotient calculations indicate clear concerns for chronic dermal and
inhalation exposures to workers using acetone in haze removal.
Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures to workers using cyclohexanone in haze removal.
DRAFT—September 1994
V-81
-------
Table V-78
Occupational Risk Estimates for Method 2, Traditional System 4
Name
Ink Remover
Methyl ethyl ketone (2-butanone)
Butyl acetate normal
Met hand
Aromatic solvent naphtha
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted 1 :4)
Sodium periodate
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Hazard Quotient
Inhalation
9.3
NA
1.4
NA
17
NA
NA
NA
0.2
11
NA
0.07
Dermal
Routine
22
NA
2.2
NA
44
NA
NA
NA
1.1
66
NA
1.3
Immersion
103
NA
10
NA
208
NA
NA
NA
5.2
310
NA
6.2
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
180
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
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"Margin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
'Hazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less than 1 imply that adverse effects
are very unlikely to occur.
°NOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
m
g.
5'
3
8L
CO
2-
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 4
o Margin-of-exposure calculations indicate very low concern for developmental and
reproductive toxicity risks from inhalation of cyclohexanone. Reproductive and
developmental toxicity risks from dermal exposures to cyclohexanone could not be
quantified.
o Dermal exposures to workers using mineral spirits in haze removal can be high,
although the risks from mineral spirits could not be quantified because of
limitations in hazard data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-83
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Environmental Releases
Table V-79
Estimated Environmental Releases in Screen Cleaning Operations
Method 2, Traditional System 4
System
Ink Remover
Methyl ethyl ketone( 2-butanone)
Butyl acetate, normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
Water
Haze Remover
Xylenes (mixed isomers)
Acetone
Mineral spirits- light hydrotreated
Cyclohexanone
Release Under Each Scenario
(g/day)
I
air
344
92
57
204
229
15
0
0
44
133
15
57
water
0
0
0
0
0
0
6
615
0
0
119
76
land
0
80
0
25
0
100
0
0
0
0
0
0
II
air
11
2.6
9.8
3.2
4.8
0.8
0
0
1.9
22
0.2
0.7
III
air
5.7
1.5
4.1
1.7
2.6
0.5
0
0
1.1
11
0.1
0.4
IV
air
42
11
30
13
19
3.4
0
0
0
0
0
0
water
363
191
37
257
251
132
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-84
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Table V-80
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 2, Traditional System 4
Substance:
Methyl ethyl ketone
n-butyl Acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Sodium periodate
Mineral Spirits
Acetone
Xylenes
Cyclohexanone
To Air:
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7 g/day
15.3
166 g/day
47 g/day
58.1 g/day
To Water:
363 g/day at laundry
191 g/day at laundry3
37 g/day at laundry
257 g/day at laundry
251 g/day at laundry
132 g/day at laundry
6 g/day
119 g/day
76 g/day
To Landfill:
80 g/daya
25 g/day
100 g/day
a191 g/day is estimated to be releases from the rags if the rags are laundered. This release from the rags will be either to
landfill or to water. If the release is to water through the laundry, then the landfill column is blank. If the release is to landfill,
then the landfill column will be 80 g/day and the water column will be blank. This is true for all of the ink remover chemicals.
For our purposes, the rest of the assessment assumes release to water only, since we are not assessing landfill releases.
DRAFT—September 1994
V-85
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Releases to Water from a Single Facility
Table V-81
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Method 2, Traditional System 4
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium periodate
Amount Released
to Water from
Facility
363 g/day at
laundry
191 g/day at
laundry
37 g/day at laundry
257 g/day at
laundry
251 g/day at
laundry
132 g/day at
laundry
119 g/day
76 g/day
6 g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
100 %
Amount to Water
After Waste water
Treatment
58 g/day
5.7 g/day
1.1 g/day
15. 4 g/day
20 g/day
2.6 g/day
7.1 g/day
13 g/day
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
6x10'2
6x10'3
1 x 10'3
2x10'2
2x10'2
3x10'3
7x10'3
1 x 10'2
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Water from Multiple Screen Printers
The concentrations listed in the chart above are relatively low. However, in the local area
there may be many screen printers, all of which are connected to the same waste treatment
facility. The concentration in the stream would be the combined amounts of all of the releases
in the stream, which could be significant, even if the release from one screen printing facility is
not.
To demonstrate the combined effects, the multiple screen printing facilities in St. Louis
County, Missouri were picked as an example. The Dun and Bradstreet data shows 135 screen
printing facilities in St. Louis County. We are assuming that the waste water from all of these
is going to the St. Louis County Sewer Company, which releases into the Meramec River. Less
than five kilometers downstream is the Kirkwood Water Department, and just about ten
kilometers downstream is an intake for the St. Louis County Water company. These service an
estimated 28 thousand people and one million people, respectively. The mean flow of the river
is 7895 million liters per day (MLD), and is not any larger at the drinking water intakes than it
is at the release point.
DRAFT—September 1994
V-86
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Table V-82
Estimated Cumulative Releases for St. Louis County, MO
Method 2, Traditional System 4
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Periodate
Total Amount
Released to Water
from All Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
16 kg/day
10 kg/day
810g/day
Waste water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
» 99%
Amount to Water
After Waste water
Treatment
7.8 kg/day
0.8 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
960 g/day
1.7 kg/day
«8.1 g/day
Average Concentration
in Meramec River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
1 x 10'1
2x10'1
«1 x 10'3
DRAFT—September 1994
V-87
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Releases to Air from Individual Screen Printing Facilities
Table V-83
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Method 2, Traditional System 4
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Acetone
Xylene
Cyclohexanone
Amount of Releases per
day
403 g/day
107g/day
101 g/day
222 g/day
255 g/day
19.7
15.3 g/day
166 g/day
47 g/day
58.1 g/day
Highest Average
Concentration 100 M away
8x10'1ug/m3
2x10'1ug/m3
2x10'1ug/m3
4x10'1ug/m3
5x10'1ug/m3
4x10'2ug/m3
3x10'2ug/m3
3x10'1ug/m3
9x10'2ug/m3
1 x 10'1 ug/m3
Annual Potential
Dose, mg/yeara
6
1
1
3
4
3x10'1
2x10'1
2
7x10'1
7x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Traditional System 4.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
DRAFT—September 1994
V-88
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the other components of Method 2, Traditional System 4 reached an
ecotoxicity concern concentration, even when considering the cumulative releases
from all shops in the area.
o None of the single facility releases of Method 2, Traditional System 4 reach an
ecotoxicity concern concentration.
The following table summarizes the exposure and risk estimates for cumulative releases
of Traditional System 4. The analogous figures for single facilities show much lower exposure
and risk levels.
Table V-84
Estimated Cumulative Releases for St. Louis County, MO
Screen Reclamation Method 2, Traditional System 4
Substance
Methyl ethyl ketone
n-butyl acetate
Methanol
Naphtha, light
aliphatic
Toluene
Isobutyl isobutyrate
Mineral Spirits
Cyclohexanone
Sodium Periodate
Total Amount
Released to
Water from All
Facilities
49 kg/day
26 kg/day
5 kg/day
35 kg/day
34 kg/day
18 kg/day
16 kg/day
10 kg/day
810g/day
Waste
Water
Treatment
Removal
Efficiency
84%
97%
97%
94%
92%
98%
94%
83%
» 99%
Amount to Water
After Waste
water Treatment
7.8 kg/day
0.8 kg/day
150g/day
2.1 kg/day
2.7 kg/day
360 g/day
960 g/day
1 .7 kg/day
«8.1 g/day
Daily
Stream
Cone, in
Meramec
River, ug/L
(ppb)
1
1 x 10'1
2x10'2
3x10'1
3x10'1
4x10'2
1 x 10'1
2x10'1
«1 x 10'3
ECOCC
(ug/L)
4500
140
9000
5
110
80
1
2800
<10
Eco Risk
Indicator
(Stream
Cone/
ECO CC)
2x1 0'4
7x1 0'4
2x1 0'6
0.06
3x1 0'3
5x1 0'4
0.1
7x1 0'5
~io-4
Performance
The performance of this system was not demonstrated at the Screen Printing Technical
Foundation or at volunteer printing facilities. Since this system is commonly used in many
screen printing shops, it was decided to use the limited resources available for a performance
demonstration to evaluate alternatives to the traditionally used product systems.
DRAFT—September 1994
V-89
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Traditional System 4
Cost
Table V-85
Baseline (Traditional System 4)
Cost Element Description
Traditional
System 4
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost ($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
Totals
Total Cost ($/screen)
Total Cost ($/year)
6.27
9,399
Note: For additional information regarding product performance see
performance demonstration summaries.
DRAFT—September 1994
V-90
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Alpha
Product System Alpha
Formulation
Ink Remover:
Emulsion Remover:
Haze Remover:
Aromatic solvent naphtha
Propylene glycol series ethers
Sodium periodate/water
Alkali/Caustic
Tetrahydrofurfuryl alcohol
Water
Occupational Exposure
Table V-86
Occupational Exposure Estimates for Method 2, Alternative System Alpha
System
Ink Remover
Aromatic solvent naphtha
Propylene glycol series ethers
Emulsion Remover (diluted to 0.8%)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Tetrahydrofurfuryl alcohol
Water
Inhalation (mg/day)
1
13
56
0
0
0
1
0
II
0.1
0.6
0
0
0
0.1
0
III
0
0
0
0
0
0
0
IV
0.2
2.6
0
0
0
0
0
Dermal (mg/day)
Routine
1250
312
12
1550
390
234
936
Immersion
5820
1460
58
7220
1820
1090
4370
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-91
-------
Table V-87
Occupational Risk Estimates for Alternative System Alpha
o
Q.
IS3
CO
Name
Ink Remover
Aromatic solvent naphtha
Propylene glycol series ethers
Emulsion Remover (diluted to 0.8%)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Tetrahydrofurfuryl alcohol
water
Hazard Quotient
Inhalation
NA
1.4
NA
NA
NA
NA
NA
Dermal
Routine
NA
7.4
NA
NA
NA
NA
NA
Immersion
NA
34
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
LOAELd
NA
230
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
m
Q.
c?
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
Q.
f
5T
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using propylene glycol series ethers in ink removal. Possible
concerns also exist for chronic dermal exposure to propylene glycol series ethers
based on the calculated hazard quotients, which assume 100% dermal absorption.
If the actual dermal absorption rate of propylene glycol series ethers is significantly
lower, this concern would be significantly reduced or eliminated.
o Inhalation exposures to propylene glycol series ethers also present possible
concerns for developmental toxicity risks, based on margin-of-exposure
calculations.
o Dermal exposures to other chemicals used in ink removal or haze removal can be
high, although the risks could not be quantified because of limitations in hazard
data.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-93
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Alpha
Environmental Releases
Table V-88
Estimated Environmental Releases in Screen Cleaning Operations
Method 2, Alternative System Alpha
System
Ink Remover
Aromatic solvent naphtha
Propylene glycol series ethers
Emulsion Remover (diluted to 0.8%)
Sodium periodate
Water
Alpha - Haze Remover
Alkali/Caustic
Tetrahydrofurfuryl alcohol
Water
Release Under Each Scenario
(g/day)
1
air
27
117
0
0
0
1.5
0
water
0
0
5
616
133
78
319
land
473
8
0
0
0
0
0
II
air
0.1
1.3
0
0
0
0.1
0
III
air
0.1
0.7
0
0
0
0.1
0
IV
air
0.5
5.4
0
0
0
0
0
water
1080
265
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Table V-89
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Alpha
Substance:
Aromatic solvent naphtha
Propylene glycol series ethers
Sodium periodate
Alkali/caustic
Tetrahydrofurfuryl alcohol
To Air:
27.7 g/day
124 g/day
1 .7 g/day
To Water:
1080 g/day at laundry
265 g/day at laundry
5 g/day
133 g/day
78 g/day
To Landfill:
473 g/day
8 g/day
DRAFT—September 1994
V-94
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Alpha
Releases to Water from a Single Facility
Table V-90
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Alpha
Substance
Aromatic solvent naphtha
Propylene glycol series ethers
Sodium periodate
Alkali/caustic
Tetrahydrofurfuryl alcohol
Amount Released
to Water from
Facility
1080g/dayat
laundry
265 g/day at
laundry
5 g/day
133 g/day
78 g/day
Waste water
Treatment
Removal
Efficiency
92-96 %
83-84 %
100 %
100 %
97%
Amount to Water
After Waste water
Treatment
43 g/day
45.1 g/day
0
0
2.3 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
4x10'2
5x10'2
2x10'3
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-91
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Alpha
Substance
Aromatic solvent naphtha
Propylene glycol series ethers
Tetrahydrofurfuryl alcohol
Amount of Releases
per day
27.7 g/day
124 g/day
1 .7 g/day
Highest Average
Concentration 100 M away
5.6x10-2ug/m3
2.5x10-1ug/m3
3x10'3ug/m3
Annual Potential
Dose, mg/yeara
4x10'1
2
2x10'2
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
DRAFT—September 1994
V-95
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Alternative System Alpha.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Alternative System Alpha reach an
ecotoxicity concern concentration.
Performance
General Summary of Alternative System Alpha Performance, and Related Variables
This product system consisted of an ink remover, emulsion remover, and a haze remover.
The products were demonstrated at Facilities 8, 13, and 14. Facility 8 prints labels,
nameplates, and graphic overlays. They reclaimed 48 screens over 4 weeks of demonstrations
using solvent-based inks. Facility 13 prints store displays, decals, and outdoor signs, and they
reclaimed 13 screens using UV-cured and solvent-based inks during the 2 weeks they
participated in the demonstrations. Facility 14 prints metal nameplates, vinyl pressure
sensitive decals, and signs. They used solvent-based inks during the three weeks they used
Alternative System Alpha and they reclaimed 36 screens.
Facility 8 reported that the ink remover worked well most of the time, but results were
inconsistent and some extra scrubbing was required to achieve the desired results.
Performance was improved if the ink remover was sprayed on both the scrubbing rag and the
screen. The ink remover did not seem to work at all with epoxy inks. Facility 13 also
reported that the ink remover required more time and scrubbing than their usual product.
Facility 14 reported that the ink remover worked as well as their usual product. One screen
reclamation employee at this facility reported that the ink remover worked particularly well
with their vinyl inks.
At Facility 8, the emulsion remover worked satisfactorily only if the screen was rinsed
with hot water before applying the product. Facility 13 reported that the emulsion remover did
not work as efficiently as their usual product, taking more time to dissolve the stencil and more
scrubbing, even at full strength. Facility 14 reported that the emulsion remover worked as well
as their usual product and required less effort than the regular product with the same positive
results. The only negative feature mentioned by Facility 14 was that the emulsion remover left a
slight green tint on the screen, but this tint was removed by the alternative haze remover.
The haze remover performance varied between the three facilities. At Facility 8, the haze
remover removed the ink stain on most of the screens, however, it did not sufficiently remove
haze from about 20% of the screens. These screens had to be cleaned again with their standard
DRAFT-September 1994 V-96
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
product. Facility 13 thought that the haze remover did not work at all, and required extra
scrubbing and follow up use with their regular product. Facility 14 initially reported that the
haze remover performance was average, but another reclaimer said that it did not work as well
as their usual product.
Alternative System Alpha Profile
The manufacturer recommends applying Product System Alpha as follows:
o Ink Remover. Card up as much ink as possible with plastic squeegees or
cardboard. Spray the screen surface with the ink remover and wipe up the
dissolved ink and solvent with an absorbent rag or cloth. Repeat spraying on the
ink remover and wiping it off until the ink is removed, and little comes off on the
cloth.
o Emulsion Remover. Dilute the emulsion remover as instructed on the label and
pour it into a spray bottle. Place the screen in a washout sink and spray both sides
of the stencil so that the product evenly covers the stencil. Using a soft brush,
scrub the stencil until it is broken up in all areas. Apply more emulsion remover if
necessary. Wash away the stencil with a pressure washer (a 1000 psi pressure
washer was used at SPTF).
o Haze Remover. Thoroughly mix the haze remover paste. Wet the screen before
applying the haze remover. Scoop out the paste from the container and apply the it
to a brush. Brush the haze remover into the stained areas on both sides mesh.
Allow the haze remover to stand for a maximum of 8 minutes. Rinse the screen
with a gentle water spray, followed by a high pressure wash.
Alternative System Performance at SPTF
Alternative System Alpha was tested at SPTF on two screens (one with a solvent-based
ink, and one with a UV-curable ink). This product system is not recommended for use with
water-based inks. On the screen with the solvent-based ink, the ink dissolved well with
moderate scrubbing. On the screen with the UV ink, the ink dissolved more easily and minimal
scrubbing was needed. Four wipes were used to clean each screen.
On both screens, the emulsion remover dissolved the stencil with moderate scrubbing
effort, leaving no emulsion stain. There was a moderate ink stain remaining on the solvent-
based ink screen after emulsion removal, but the application of the haze remover removed the
stain completely. On the screen with UV ink, a light stain remained after emulsion remover
use, but the haze remover lightened the stain considerably.
Products were applied according to the manufacturer's recommended application
procedure. The technician noted that the ink remover did have an unpleasant odor.
Alternative System Performance Details
Performance Details from Facility 8
Over the four week demonstration period, this facility reclaimed 48 screens with the
Product System Alpha. The screen printing manager reclaimed the screens himself during the
DRAFT-September 1994 V-97
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
demonstration period. He was willing to experiment with different application techniques to
improve the performance of the alternative system.
The printer thought the ink remover performance was satisfactory, but results were
inconsistent and the product required extra scrubbing effort to achieve acceptable results. He
noted that the ink remover performance was unacceptable on epoxy inks, even with the extra
effort. One specific observation was that the ink remover did not stay wet on the screen which
made wiping more difficult. Performance improved, however, when he sprayed the product
both on the rag and on the screen. After using the ink remover, the printer evaluated each
screen and reported that the ink was removed effectively on 62% of the screens.
Typically, this facility uses hot water to start the breakdown of their emulsion. When
following the manufacturer's application instructions for the Alpha emulsion remover, which
does not require hot water, the printer found the emulsion came off in "strings," instead of
dissolving. The stringy, solid mass clogged the drain. To solve this problem, the printer rinsed
the screen with hot water before applying the emulsion remover. This additional step took an
extra 3 - 5 minutes, but the emulsion remover performance improved.
The haze remover did not sufficiently remove the haze on approximately 20% of the
screens. The printer wiped these screens with lacquer thinner (which easily removed the haze)
before reusing the screen. The observer confirmed that this supplementary wipe down was
necessary and noted that the white rag with lacquer thinner on it turned black as the dark haze
was removed from the screen. Overall, the printer felt the alternative haze remover
performance was not acceptable.
Data from the printer's product evaluation forms was analyzed to determine if there were
any correlations between variations in the product performance and changes in the
demonstration conditions (e.g., ink type, emulsion type, screen condition). The printer was
asked to evaluate the screen after using each product (ink remover, emulsion remover, and
haze remover). In addition, the printer recorded the amount of ink remaining on the screen at
the start of reclamation. In reviewing this data, it was found that for screens where the initial
ink remaining on the screen was high (i.e., it was not carded off well), there was an ink stain
remaining on the screen after emulsion removal (for 100% of the screens in the demonstration).
When the initial ink remaining on the screen was recorded as "low", an ink stain remained after
emulsion removal for only 33% of the screens. This could indicate that if the screen is
effectively carded before ink removal (as the manufacturer recommends), the product
performance may improve significantly. Overall, 76% of the screens had an ink stain or stencil
stain after using the emulsion remover. After applying the haze remover, 20% of the screens
could not be reused because of the remaining haze.
During the four week demonstration, this facility did not notice any change in screen
failure rate or any deterioration of the screen mesh. The printer had no problems with print
image quality while using Product System Alpha, however, he felt he avoided potential print
quality problems by cleaning the screens again with his own ink remover before reusing them.
Performance Details from Facility 13
Overall, this facility was not satisfied with the performance of System Alpha. The
alternative system required more time and effort than their standard products and were not as
effective in cleaning the screens as their standard products. Because of the extra time required,
the facility could not reclaim screens fast enough to keep up with their need to reuse the
screens. The screen reclaimer also did not like the strong smells associated with the alternative
DRAFT-September 1994 V-98
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
system. For these reasons, the printing manager made the decision to discontinue participation
in the demonstrations after two weeks. More experimenting with application methods could
have lead to improved performance, but this facility did not seem willing to try. The facility
contact also mentioned that the reclamation employee was not reliable and that he did not feel
confident in the screen reclamation results that were provided. In analyzing the limited data
from this facility, the performance of the alternative system did not seem to be affected by ink
type, ink color, mesh type, or other demonstration conditions.
The ink remover did not perform as well as their usual product. It removed ink less
effectively than was expected and involved more applications and rinsing (which meant more
time) to get the ink out of the mesh. The only application changes attempted were to use more
product and effort. The added scrubbing was considered a very negative characteristic of the
ink remover.
Even at full strength the emulsion remover required more scrubbing and time to remove
the emulsion from the screens than their usual product. The alternative emulsion remover did
remove the stencil, however, because of the extra time required, the facility discontinued use of
the emulsion remover after the first week of demonstrations.
The haze remover did not reduce stains in the mesh as effectively as the facility's usual
haze remover. Almost every time the haze remover was used, the facility had to follow with
their usual haze remover to get the screen clean enough for reuse. When using their standard
product system, this facility needed to use a haze remover for only about 30 percent of their
screens. Facility 13 did not experiment with application methods other than extra scrubbing
and they stopped using the haze remover after the first week of demonstrations.
No changes were noted in the screens used with the alternative system. Longer-term use
of the alternative system may have damaged the screens or reduced screen life because of the
excessive scrubbing that was needed with Product System Alpha.
Performance Details from Facility 14
Performance of System Alpha was average at Facility 14. The results are complicated by
the fact that three different people were involved in the demonstrations and the two original
screen reclamation employees were terminated after about three weeks into the demonstration
period. The initial data quality seemed good, but a lot of information was missing from the
forms that were submitted from the last week(s) of employment of the terminated employees.
The new screen reclaimer may not have followed the same procedures when using the
alternative system.
The ink remover worked fairly well, but sometimes had to be reapplied for the screens to
be thoroughly cleaned. The product worked particularly well with vinyl inks. The ink
remover's performance was improved by applying the ink remover immediately after a print run
and letting it sit on the screen for up to a day before it was pressure rinsed off. The
manufacturer's directions do not give any recommendations of the soaking time for the ink
remover.
The emulsion remover was reported to have worked well at this facility and it worked
faster than their usual product. In one case, however, the emulsion remover left a slight green
tint in the screens, but this was removed by their usual haze remover.
DRAFT-September 1994 V-99
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
The initial screen reclaimers felt that the haze remover had average performance, but the
final reclaimer felt that it left more of a haze in the mesh than she expected. This later
reclaimer only used the product on a few screens and may not have applied the ink remover
immediately after the press run which the original employees were doing to improve the
performance of the ink remover. This may explain why the new employee thought that more
haze than usual was left on the screens. The alternative haze remover and the standard haze
remover used at this facility are almost identical chemically. Also, the print quality was very
rarely documented by this facility, although it may be safe to assume that problems with print
quality would have been reported, if obvious.
The analysis of the data from this facility did not show any correlation between the
performance of the alternative system and any variations in ink type, ink color, mesh type, or
other demonstration conditions. No side effects on the screens or changes in the screen failure
rates were noted during the demonstrations.
Alternative System Performance Table Compiled from Field Sites
The table below highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 8
Facility 8 prints labels, nameplates, and graphic overlays, primarily on plastics, but they
also do some printing on paper and metals. Their typical run length is 100 sheets, and
approximately 75% of their orders are repeat orders. Of the 40 - 50 employees at this facility,
approximately 3 are involved in screen reclamation. All printing is done with solvent-based
inks; both vinyl and epoxy inks are used. All screens used in the Performance Demonstrations
were made of a monoester mesh that was treated with a roughening paste and a degreaser when
each screen was initially stretched. Mesh count during the demonstration period ranged from
195 - 330 threads/inch and an indirect stencil was used for all screens. The average screen size
used at this facility is 24.5 inches x 31.75 inches (778 in2) and 10-15 screens are reclaimed
daily.
Screen Reclamation Area in Facility 8
The screen printing, ink removal, and screen reclamation activities are all done in the
same area of the facility. Ink removal is done at the press and screen reclamation is done in a
spray booth. The open plant area with high ceilings and overhead fans provide ventilation for
the general area. The spray booth has an integrated ventilation fan in the hood. The average
temperature during the observer's visit was 68°F (and 40% relative humidity). Rags used for
clean up and for ink removal are cleaned under contract by a laundry service. Waste water
from the high pressure wash of the emulsion remover and haze remover is filtered at this
facility.
DRAFT-September 1994 V-100
-------
•o_
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Table V-92
On-Site Performance Summary For System Alpha
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
8
Facility
13
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
10.8±17.6hrs
(n=50)
1.8±4.2mins
(n=50)
1.1 ±3.5mins
(n=50)
1.5±3.0hrs
(n=15)
5.7±5.8mins
(n=6)
5.7±4.0mins
(n=3)
1.7±0.8oz.
(n=50)
1.0±0.2oz.
(n=50)
1.0±0.0oz.
(n=39)
2.5±0.8oz.
(n=15)
3.9±20oz.
(n=7)
1.3±0.5oz.
(n=4)
5.9±2.5mins
(n=32)
9.0±3.9mins
(n=50)
7.6±2.5mins
(n=39)
15.5±8.0mins
(n=15)
11.7±4.5mins
(n=7)
9.5±2.4mins
(n=4)
Moderate
Moderate
Moderate
Moderate
Moderate
Moderate
Good on 40% of
screens; Fair on
22%; Poor on
38%
With hot water,
removed stencil.
Haze was not
removed from
20% of screens.
Removed the ink
but required extra
time and effort.
Removed stencil,
but required extra
time and effort.
Did not effectively
remove the haze.
• 20% of screens
required
additional
cleaning before
reusing them.
• Needed to use
hot water to get
the emulsion to
break down.
• Most screens
had to be re-
cleaned with the
standard haze
remover before
the could be
reused.
Solvent-
based
vinyl and
epoxy inks
UV-
curable
and
Solvent-
based inks
Indirect
photo
stencil
Direct photo
stencil
Monofilamen
t Polyester;
195-330
threads/inch
Abraded
polyester;
155-390
threads/inch
823 in2
1591 in2
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Table V-93
On-Site and Laboratory Performance Summary For System Alpha
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CD"
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System
Component
Performance
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
14
Ink Remover
Emulsion
Remover
Haze
Remover
6.6 ± 39.4 hrs
(n=37)
19.9 ±17.9 hrs
(n=37)
5.0 ± 19.6 mins
(n=37)
4.4 ±2.0
oz.
(n=37)
4.1 ±0.7
oz.
(n=37)
4.0 ±1.0
oz.
(n=15)
5.0 mins
(n=1)
5.0 ±0.0
mins
(n=36)
5.2 ±0.8
mins
(n=16)
Low/
Moderate
(n=37)
Low
(n=37)
Moderate
(n=14)
Worked very well
with vinyl ink;
acceptable on other
inks by increasing
the soaking time.
Removed stencil
easily.
Haze remaining on
some screens had to
be removed with their
standard product.
• Most screens could be
reused, however, some
had to be recleaned
with other products.
• Two reclaimers felt the
haze remover
performance was
acceptable, one did not.
Solvent-
based
inks
Direct
photo
stencil
305-390
threads/inch
1577 in2
Laboratory Testing at SPTF
SPTF
Solvent-
based Ink
SPTF
UV-
curable
Ink
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
15 mins
24 hours
Omins
15 mins
24 hours
Omins
1 .5 oz.
1 .0 oz.
1 .0 oz.
2.0 oz.
1 .0 oz.
1 .0 oz.
3.9 mins
3.7 mins
9.7 mins
3.5 mins
2.6 mins
10.0 mins
Moderate
Moderate
Low
Low
Moderate
Low
Ink dissolved with scrubb ng; has bad odor.
Stencil dissolved completely; medium ink stain.
Removed stain completely.
Ink dissolved well; has bad odor.
Stencil dissolved completely; medium ink stain
remaining.
Lightened ink stain.
Solvent-
based
UV-
curable
Dual cure
direct
Dual cure
direct
Polyester; 255
threads/inch
Polyester; 390
threads/inch
360 in2
360 in2
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
Current Screen Reclamation Products at Facility 8
Facility 8 uses an ink remover that is a solvent blend of 50% toluene and 50% methyl
ethyl ketone, as well as a proprietary blend of propylene glycol ethers (<30%), Stoddard Solvent
(a petroleum distillate) (<5%), and d-limonene (<20%). As an emulsion remover, they use a
formulation consisting primarily of sodium periodate. Information on their haze remover was
not currently available.
Current Screen Reclamation Practices in Facility 8
The screen reclamation process at Facility 8 is described below:
o Ink Remover: Card of excess ink. Pour lacquer thinner from a one-gallon can onto
the screen surface with the screen lying flat. Using reusable rags, wipe the ink off
the screen. After ink removal at the press, move the screen to the reclamation
area.
o Emulsion Remover: Wet the screen with hot water at low pressure. Spray an ink
remover on the emulsion side of the screen. Dip a brush into the container of
emulsion remover and brush it into both sides of the screen. Rinse both sides of
the screen with a high pressure (2500 psi) washer to remove the emulsion.
o Haze Remover: If an ink stain remains after emulsion removal, spray more lacquer
thinner onto the screen and rub it in with a scrubber pad. After allowing the
lacquer thinner to soak for 1 - 2 minutes, remove the excess ink with a high
pressure wash. Haze remover is only applied to approximately 25% of the screens.
When needed, apply the haze remover by pouring it from a quart container onto a
brush and then rubbing it into the screen. Rinse the screen with the high pressure
washer.
General Facility Background for Facility 13
Facility 13 prints store displays, decals, and outdoor signs. Their products are printed
on plastics, paper, and metal. A typical run length is 500 - 1000 sheets and approximately 25%
of their orders are repeat orders. There are about 70 employees at this facility and 1 - 3
employees are responsible for screen reclamation. The facility uses both UV ink and solvent-
based ink. During the Performance Demonstrations they used a direct photo stencil and the
screen mesh was an abraded polyester. Mesh counts ranged from 155 - 390 threads/inch. The
screen size typically used in this facility is 49 inches x 41 inches, and approximately 20 screens
are reclaimed daily.
Screen Reclamation Area in Facility 13
Ink removal and screen reclamation are both done within the screen printing area of the
facility where local ventilation is provided. The screen reclamation area is 20 - 50 ft2 in size.
During the observer's visit, the average temperature in the area was 76°F (and 44% relative
humidity). Rags used for screen reclamation activities are disposed of as hazardous waste.
Waste water from emulsion and haze removal washes is not filtered at this facility.
DRAFT-September 1994 V-103
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
Current Screen Reclamation Products at Facility 13
Facility 13 uses an ink remover that is a proprietary blend consisting primarily of
tripropylene glycol methyl ether. Their emulsion remover consists primarily of sodium
periodate. Information on their haze remover was not available.
Current Screen Reclamation Practices in Facility 13
Gloves, eye protection, aprons, and respiratory protection are available for employees
during screen reclamation. At Facility 13, screens are reclaimed as follows:
o Ink Remover: Card off the excess ink at press. Dip a soft bristle brush into a five-
gallon bucket of ink remover and brush it onto the screen. The dirty ink remover
brush is repeatedly dipped into this bucket so the ink remover becomes diluted
with ink residue. Pressure wash (1000 psi) the screen.
o Emulsion Remover: Dip a soft bristle brush into the bucket of emulsion remover
and rub the product into screen. Apply enough emulsion remover to both sides of
the screen to cover the stencil. Pressure wash both sides. Rinse the screen with
low pressure water, vacuum it dry, wipe it dry with a disposable rag, and set it in
front of an electric fan to dry.
o Haze Remover: Haze remover is used on approximately 50% of the screens,
primarily when black, red, and blue inks are used. If haze remover is not needed,
apply undiluted ink remover to the screen with a brush after emulsion removal.
Rub into both sides of the screen, then pressure wash. Rinse both sides of the
screen with low pressure water from a hose. If haze remover is used, do not apply
the ink remover after emulsion removal. To apply the haze remover, dip a soft
bristle brush into the paste. Rub it into both sides of the stain and wait for 5-15
minutes, depending on the severity of the haze. Pressure wash the screen. Vacuum
the screen dry, then wipe it with a disposable wipe. Place the screen in front of a
fan to dry.
General Facility Background for Facility 14
Facility 14 prints three-dimensional panels, pressure-sensitive labels, and specialty items
for advertising. Primarily, they print on plastics and metals, but they also do some printing on
paper. A typical run is 100 - 300 sheets and approximately 85% of their orders are repeat
orders. Of the approximately 12 employees at this facility, 3 are involved in screen reclamation
activities. Several different types of ink are commonly used at Facility 14, including thermal
setting, vinyls, and UV-curable, and small amounts of lacquers, enamels, and epoxies. All
screens used in the Performance Demonstrations were made of a monofilament polyester and a
direct photo stencil emulsion was applied. Mesh count during the demonstration period ranged
from 305 - 390 threads/inch. The average screen size used at this facility is 12 ft2 and
approximately 12 screens are reclaimed daily.
Screen Reclamation Area in Facility 14
This facility has two spray booths; one for ink removal and one for emulsion and haze
removal. At the ink removal area, the solvent is applied with a pressure sprayer and then
filtered and recycled through the system. For ventilation, there is a hood above each spray
booth. The average temperature during the observer's visit was 72°F (and 45% relative
DRAFT-September 1994 V-104
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
humidity). Rags used for screen reclamation are washed by an industrial laundry service.
Spent filters are disposed of as hazardous waste. Waste water from the high-pressure wash of
the emulsion remover and haze remover is not filtered.
Current Screen Reclamation Products at Facility 14
For ink removal, Facility 14 uses either a product consisting of 99% tripropylene glycol
methyl ether, or a proprietary solvent blend sold by a manufacturer not participating in the
performance demonstration. MSDS information on the latter product states it contains no
hazardous substances, is non-flammable, has no SARA reportable chemicals, and meets
California's South Coast Air Quality Management District requirements. Their emulsion
remover is a formulation consisting primarily of sodium periodate. For haze removal, they use
either an aqueous blend which consists of potassium hydroxide (27%) and tetrahydrofurfuryl
alcohol (11%), or an aqueous blend that contains sodium hydroxide (5%) and
tetrahydrofurfuryl alcohol (17%).
Current Screen Reclamation Practices in Facility 14
The screen reclamation process at Facility 14 is described below:
o Ink Remover: Card off the excess ink. At the press, spray on the ink remover and
wipe off about 95% of the ink with reusable rags. Approximately 2 - 4 rags are used
for each screen. Take the screen to the wash out sink and spray on the ink
remover solvent from the recirculating tank. With a brush, scrub the ink remover
into the screen, then squeegee off the excess solvent and ink. Wipe down with rags.
If ink clumps are remaining, spray on more ink remover and wipe the screen again.
o Emulsion Remover: Move the screen to the reclamation area. Spray emulsion
remover on the top of the screen and use a scrubber pad to spread it out and work
it into the screen. Rinse with a high pressure (2000 psi) wash to remove the
emulsion. With a brush, apply a degreaser then rinse with a low pressure (200 psi)
wash.
o Haze Remover: After emulsion removal, a haze remover is used only if needed (on
approximately 6% of the screens). Apply the haze remover by dipping a brush in
the product and rubbing it into the screen. Rinse with a high pressure water spray.
DRAFT-September 1994 V-105
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Alpha
Cost
Table V-94
Method 2: Summary of Cost Analysis for System Alpha
Cost Element Description
Baseline
(Traditional
Svstem 4^
Alternative System Alpha
Facility 8
Facility 13
Facility 14
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
823
12.5
1,591
20
1,577
12
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous
Waste Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost ($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
22.5
4.92
1.1
0.17
1.8
0.21
1.0
<0.01
1.0
0.30
31
0.02
36.7
8.02
4.1
0.61
2.5
0.31
3.9
0.01
1.3
0.37
60
0.04
15.3
3.34
0
0
4.4
0.53
4.1
0.01
4.0
1.18
59
0.04
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
5.62
6.79
17,574
10,183
9.36
9.37
46,800
14,062
5.10
5.92
15,313
8,886
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs, however,
are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-106
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Product System Chi
Formulation
Ink Remover:
Emulsion Remover:
Haze Remover:
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
Water
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Occupational Exposure
Table V-95
Occupational Exposure Estimates for Alternative System Chi
System
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol methyl ether
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Diethylene glycol series ethers
Tripropylene glycol methyl ether
N-methylpyrrolidone
Ethoxylated nonylphenol
Inhalation (mg/day)
I
0
0
3
0
0
0
0
0
3
0
II
0
0
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
0
IV
0
0
0.1
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
312
858
312
78
16
1540
312
858
312
78
Immersion
1456
4000
1460
364
73
7210
1456
4000
1460
364
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-107
-------
Table V-96
Occupational Risk Estimates for Method 2, Alternative System Chi
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Name
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Hazard Quotient
Inhalation
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
3,600
NA
NA
NA
NA
NA
37
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
1,800
NA
39
NA
NA
NA
1,800
NA
39
NA
LOAEL
46
NA
NA
NA
NA
NA
46
NA
NA
NA
Immersion
NOAEL
380
NA
8.4
NA
NA
NA
380
NA
8.4
NA
LOAEL
9.8
NA
NA
NA
NA
NA
9.8
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Clear concerns exist for chronic dermal exposures to diethylene glycol series ethers
used in ink removal based on the calculated margins-of-exposure.
o Concerns exist for developmental toxicity risks from dermal exposures to N-
methylpyrrolidone based on the calculated margin-of-exposure. Similar
calculations for inhalation exposures to N-methylpyrrolidone indicate very low
concern.
o Inhalation exposures to other ink remover components are very low.
o Dermal risks from other ink remover components could not be quantified because
of limitations in hazard data, but exposures can be high.
o The haze remover components are identical to the ink removers and present
essentially the same risk profile.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover (all systems except Beta) use
either a strong oxidizer such as hypochlorite or periodate or a strong base such as
sodium hydroxide. The haze removers in Alpha, Epsilon, Gamma, Mu, Omicron,
and Theta also contain these compounds. All of these materials present a high
concern for skin and eye irritation and tissue damage if workers are exposed in the
absence of proper protective clothing. None of the emulsion removers present
significant inhalation risks.
DRAFT-September 1994 V-109
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Environmental Releases
Table V-97
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Chi
System
Ink Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Diethylene glycol series ethers
Tripropylene glycol series ethers
N-methylpyrrolidone
Ethoxylated nonylphenol
Release Under Each Scenario
(g/day)
I
air
0.1
0.1
6.8
0
0
0
0.1
0.1
6.8
0
water
0
0
0
0
6
615
104
286
97
26
land
138
381
132
35
0
0
0
0
0
0
II
air
0
0
0.1
0
0
0
0
0
0.1
0
III
air
0
0
0
0
0
0
0
0
0
0
IV
air
0
0
0.2
0
0
0
0
0
0
0
water
270
742
270
67
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Chi
From Ink Removal Operations:
Diethylene glycol series ethers
0.1 g/day to air
270 g/day to water from rags at commercial laundry
138 g/day to landfill
Propylene glycol series ethers
0.1 g/day to air
742 g/day to water from rags at commercial laundry
381 g/day to landfill
DRAFT—September 1994
V-110
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
N-methyl pyrrolidone
7.1 g/day to air
270 g/day to water at commercial laundry
132 g/day to landfill
Ethoxylated nonylphenol
67 g/day to water from rags at commercial laundry
35 g/day to landfill
From Emulsion Remover:
Sodium periodate
6 g/day to water
From Haze Remover:
Diethylene glycol series ethers
0.1 g/day to air
104 g/day to water
Propylene glycol series ethers
0.1 g/day to air
286 g/day to water
N-methyl pyrrolidone
6.9 g/day to air
97 g/day to water
Ethoxylated nonylphenol
26 g/day to water
Table V-98
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Chi
Substance:
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
To Air:
0.2 g/day
0.2 g/day
1 4 g/day
To Water:
104 g/day
270 g/day at laundry
286 g/day
742 g/day at laundry
97 g/day
270 g/day at laundry
26 g/day
67 g/day at laundry
6 g/day
To Landfill:
138 g/day
381 g/day
132 g/day
35 g/day
DRAFT—September 1994
V-111
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Releases to Water from a Single Facility
Table V-99
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
Amount Released
to Water from
Facility
104g/day
270 g/day at
laundry
286 g/day
742 g/day at
laundry
97 g/day
270 g/day at
laundry
26 g/day
67 g/day at laundry
6 g/day
Waste water
Treatment
Removal
Efficiency
83%
83-97 %
97%
100 %
100 %
Amount to Water
After Waste water
Treatment
18 g/day
46 g/day
49 g/day
126 g/day
3 g/day
8.1 g/day
0 g/day
0 g/day
0 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
2x10'2
4x10'2
5x10'2
1 x 10'1
3x10'3
8x10'3
0
0
' ug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-112
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Releases to Air from Individual Screen Printing Facilities
Table V-100
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Amount of Releases
per day
0.2 g/day
0.2 g/day
1 4 g/day
Highest Average
Concentration 100 M away
3.5x10-4ug/m3
3.5x10-4ug/m3
2.9x10-2ug/m3
Annual Potential
Dose, mg/yeara
3x10'3
3x10'3
2x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Chi.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Alternative System Chi below.
Hazard Quotient values below one indicate very low risk. Margin-of-Exposure (MOE) values
above 100 for a NOAEL or above 1000 for a LOAEL indicate very low risk.
DRAFT—September 1994
V-113
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Table V-101
Risks from Potential Drinking Water Exposures
Screen Reclamation Method 2, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Sodium periodate
Daily Stream
Concentration, (ug/L)
5.8 xirj2
i.5xirj1
1.1X10'2
0
0
Daily Dose from
Drinking Water
(mg/kg)
2x1 0'6
4x1 0'6
3x1 0'7
0
0
NOAEL or
LOAEL (mg/kg)
51 LOAEL
not available
175 NOAEL
not available
not available
MOE-
NOAEL or
LOAEL/Dose
3x1 07
6x1 08
Table V-102
Risk Estimates for Ambient Air Releases from a Single Model Facility
Screen Reclamation Method 2, Alternative System Chi
Substance
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Highest Avg
Concentration 100 M
away
3.5x10-4ug/m3
3.5x10-4ug/m3
2.9x10-2ug/m3
Daily Potential
Dose, (mg/kg)
1x10'7
1x10'7
8x1 0'6
NOAEL or
LOAEL (mg/kg)
51 LOAEL
not available
175 NOAEL
MOE-
NOAEL or
LOAEL/
Dose
5x1 08
2x1 07
Ecological Risks From Water Releases Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Chi reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Chi Performance, and Related Variables
This product system consisted of an ink remover and an emulsion remover. In place of a
separate haze remover product, the ink remover was reapplied to remove haze. A degreaser
accompanied this product system and was used by the facilities, however, detailed information
on the performance of the degreaser is not included in the scope of this project. The
performance of the product system was demonstrated at Facilities 3 and 21. Facility 3 prints
decals and vacuum formed sheets; Facility 21 prints decals for glass and ceramics. During the
DRAFT—September 1994
V-114
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
four week demonstration period, Facility 3 reclaimed 47 screens and Facility 21 reclaimed 48
screens. Both facilities used only solvent-based inks during the demonstrations.
The ink remover performance was considered satisfactory by Facility 3 and was
considered good at Facility 21. At Facility 3, the alternative ink remover took longer to
solubilize the ink and required more physical effort than their usual product. Facility 21
reported that the Product System Chi ink remover worked very well on most of their inks, but
the alternative ink remover did not work as well with cover/flux ink or clear cover coats. They
have similar problems with their standard ink remover on the cover/flux and clear coats. They
also found additional scrubbing was needed when using the alternative ink remover on very
coarse (low mesh count) screens. Overall, they described the ink remover performance as
good, but not quite as good as their standard product.
The two facilities were both quite pleased with the performance of the emulsion remover.
Facility 3 reported the performance was as good as their standard product. Facility 21 thought
that the emulsion remover worked much better than their usual product. Although it worked
well on both direct and capillary film emulsions, Facility 21 found a little more effort was
required to remove the capillary film emulsions than the direct emulsions.
This system did not include a haze remover. Instead, the manufacturer recommended
that the ink remover be used a second time as a haze remover. After using the ink remover
following removal of the emulsion, Facility 3 reported that an image was still left on the screen
and that, when used for haze removal, the ink remover did not perform as well as their usual
haze remover. At Facility 21, a haze remover was needed on only one screen of the 48 screens
reclaimed.
Alternative System Chi Profile
The manufacturer recommends applying Product System Chi as follows:
o Ink Remover: Card up the excess ink to remove as much as possible from the
screen. Bring the screen to the reclaiming area and apply the ink remover as soon
as possible, even if the screen is not to be cleaned until later. Use a spray bottle
and apply the product to both sides of the screen, using ample product to coat the
inked areas completely. Thoroughly brush the ink remover into the screen, paying
close attention to print areas and heavy ink spots. Allow as much time as possible
for the product to dissolve the ink. If more product is needed to loosen the ink,
apply it in the needed areas and brush again. Pressure rinse the screen, beginning
with the well side, from the bottom of the screen to the top. Turn the screen
around and repeat the pressure rinse from bottom to top.
o Emulsion Remover: Dilute 1 part emulsion remover in 4 - 5 parts water. Spray the
emulsion remover onto the wet screen and allow enough time for the product to
completely dissolve the emulsion. Use a brush to loosen the emulsion on the entire
screen. Pressure wash the screen on both sides, rinsing from the top to the bottom.
At SPTF, a 1000 psi pressure washer was used.
o Additional Stain Removal Step: If stains remain in the screen, allow the screen to
dry and repeat the application procedure for the ink remover and pressure rinse.
DRAFT-September 1994 V-115
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
Alternative System Performance at SPTF
Product System Chi was tested at SPTF on three screens (one with a solvent-based ink,
one with a UV-curable ink, and one with a water-based ink). The ink remover performance
varied, depending on the type of ink used. Performance of the emulsion remover and the haze
remover was consistent for all three screens. All products were applied according to the
manufacturer's recommended application procedure.
On the screen with the solvent-based ink, there was considerable ink residue remaining
after spraying the screen with product, scrubbing with a brush, and rinsing with a high
pressure wash. The technician also noticed that the stencil was beginning to peel off. After
repeating the ink remover application process, the ink residue was still present and about half
of the stencil had been removed. The ink dissolved more easily on the screen with UV ink,
however, after using the ink remover, a gray haze remained on the screen, but there was no
noticeable ink residue and the stencil was intact. On the screen with the water-based ink, the
product dissolved the ink fairly well, however, a light ink residue remained on the screen and
the stencil began to peel off.
The emulsion remover easily dissolved the stencil with only light scrubbing on all three
screens, leaving no emulsion residue behind. On the screen with the solvent-based ink, the
heavy ink residue was still present after using the emulsion remover. When additional ink
remover was applied (used instead of a haze remover in this product system), it removed the
residue and lightened the stain. After using the emulsion remover on the screen with UV ink, a
moderate to heavy ink stain remained. The reapplication of the ink remover lightened this
stain considerably. On the screen with water-based ink, the ink residue persisted in some
areas and there was a heavy ink stain on the screen after using the emulsion remover. An
additional application of ink remover lightened the stain, but did not remove it.
Alternative System Performance Details
Performance Details from Facility 3
Throughout the performance demonstration period, the facility contact was asked about
the performance of the components of Product System Chi. He was generally pleased with the
performance of the ink remover and emulsion remover, although the ink remover took longer to
solubilize the inks than their standard product in some cases, when used as a haze remover,
the ink remover usually did not remove the ghost image from the screen. Overall, the facility
contact remarked that he did not think that System Chi would be a viable long-term alternative
reclaiming system for his plant.
The ink remover worked acceptably on all screens, although it was somewhat slower to
dissolve the inks than the facility's regular ink remover. The printer tried using the product to
clean the squeegee and flood bar on the press after printing runs, but found that it was slow to
break down the ink and left an oily film. After several cycles of printing and reclaiming with the
demonstration screens, a noticeable ink haze began to build up in the screens, indicating that
the ink remover was not removing all the ink from the mesh. The buildup was not enough to
prevent successful printing of regular jobs with the screens, but the facility contact felt that the
performance of the screens on a transparent ink image or a flood coat would be unacceptable.
There were some variations in the time it took to remove the ink, ranging from 2 to 12
minutes. However, the recorded data does not show any correlation between the ink remover
time and any of the variable screen conditions, such as ink color or number of impressions.
DRAFT-September 1994 V-116
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
The emulsion remover worked well, with no notable variations in performance among the
screens used for the demonstration period. The facility contact did not think the product was
chemically different from what he had been using previously.
This system did not include a haze remover; instead the manufacturer recommended
applying the ink remover again to remove any remaining haze. At Facility 3, the ink remover
did not satisfactorily remove the haze. Ghost images continued to build on the screens
throughout the demonstration period. The facility normally uses two haze remover products.
One haze remover is a milder chemical, which leaves a small amount of ink haze in the screens.
This product is used by itself on a regular basis until ghost images in the screen become
unacceptable. The other haze remover, which is a stronger chemical, is then used to de-haze
the screen to a baseline clean state, after which the screen reclaimer returns to the milder
chemical for as many reclaimings as possible. The facility contact remarked that the
performance of the alternative haze remover is similar to their "milder" regular haze remover,
except that the ink haze built up faster using the alternative product.
Product System Chi did not appear to cause screen failure, or have any noticeable
permanent effects on the screens or frames. The three squirt bottles shipped with the products
started leaking around the triggers during the first week of the demonstration, and had to be
replaced. It is not known if this is an effect of the products or not.
Performance Details from Facility 21
This facility was generally pleased with the performance of System Chi. Currently, the
facility uses an automatic screen washer, which cleans the screens in a closed system that
recycles the solvent. This was a very organized facility and the quality of the data received was
probably quite high. They thoroughly documented the demonstrations and only one screen
reclaimer was involved in the demonstrations. The production manager was responsible for
monitoring the future print quality on screens reclaimed with the alternative system. He paid
very careful attention to screen conditions and would have noticed any deleterious effects of the
alternative system. No changes in the screen mesh or print quality were noted during the
dem onstr ations.
The ink remover worked well, however it was not as efficient as their standard product.
The facility particularly liked the ink remover's performance with metallic inks. When used on
screens with cover (flux) coats or with other clear ink coats, the ink remover did not work well,
although the facility has similar problems with their current ink remover. Added scrubbing
was needed to remove ink from very coarse (low mesh count) screens. Ink color and number of
impressions did not seem to affect ink remover performance.
The emulsion remover worked much better ("excellent") than the product they had been
using. Although it worked very well on both emulsion types, the emulsion remover required a
little more effort to remove capillary film emulsion than direct emulsion.
For Product System Chi, a second application of the ink remover was used in place of a
haze remover as needed. At this facility, a haze remover was needed on only one screen. On
that screen, a ghost image remained in the mesh after using the ink remover one time. After
reapplying the ink remover two more times, the image was lightened enough to reuse the
screen. Normally, this facility does not use a haze remover.
DRAFT-September 1994 V-117
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 3
Facility 3 prints decals and vacuum formed sheets on plastics and paper. A typical run is
250 sheets, and 71% of their orders are repeat orders. Of the approximately 40 employees at
this facility, 1 - 3 are involved in screen reclamation. All printing is done with solvent-based
inks. Screens used in the Performance Demonstrations were polyester or monoester/polyester
with a mesh count of 180 - 370 threads/inch. The facility used a dual cure emulsion. The
average screen size at this facility is 15 ft2 and approximately 15 screens are reclaimed daily.
Screen Reclamation Area in Facility 3
Ink removal is done at the press where local ventilation is provided. The screen
reclamation room is approximately 150 ft2, with a large spray booth built into one wall, and is
also ventilated with a local system. The average temperature during the observer's visit was
64°F (and 39% relative humidity). Rags used for clean up and for ink removal are cleaned by a
laundry service. Waste water from the high-pressure wash of the emulsion remover and haze
remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 3
Facility 3 uses a proprietary solvent blend for ink removal, which consists of n-butyl
acetate (81%) and toluene (19%). For emulsion removal, they use a formulation consisting of
100% sodium periodate. They use two different haze removal products at this facility. One
product is a proprietary solvent blend which contains at least sodium hydroxide and
cyclohexanone. Their other haze removal product, sold by a manufacturer who is not
participating in the performance demonstration, contains no carcinogens, no ingredients with
TLV or PELs, and no petroleum derivatives, according to the MSDS.
Current Screen Reclamation Practices in Facility 3
Using their standard products, screens are reclaimed as follows:
o Ink Remover: Card off the excess ink. Pour the ink remover onto the screen and
wipe with rags until clean. Approximately 2 - 4 rags are used for each screen.
Gloves and eye protection are worn during ink removal.
o Emulsion Remover: Dip a scrubber pad into the container of emulsion remover.
Scrub both sides of the screen. Using a high pressure wash (1200 psi), rinse the
screen. Gloves, eye protection, respiratory protection, and ear protection are
available to employees for emulsion removal and haze removal.
DRAFT-September 1994 V-118
-------
Table V-103
On-Site Performance Summary For System Chi
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
3
Facility
21
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
7.2±3.6mins
(n=50)
15.1 ±21.7hrs
(n=50)
0.2±0.2mins
(n=47)
7.6 ± 12.6 hrs
(n=51)
4.7±8.6mins
(n=51)
15.0mins
(n=1)
1.1 ±0.4oz.
(n=50)
2.1 ±0.4oz.
(n=50)
2.1 ±0.3oz.
(n=47)
1.1 ±0.3oz.
(n=48)
1.5±1.4oz.
(n=48)
2.0 oz.
(n=1)
6.6±2.3mins
(n=50)
2.9±0.3mins
(n=50)
2.9±0.3mins
(n=47)
2.0±1.5mins
(n=47)
2.5±2.2mins
(n=48)
3.5±0.7mins
(n=2)
Moderate
Low
Low
Low
Low
Moderate
Dissolved ink with
extra effort.
Removed stencil
easily.
Ghost images built
up.
Dissolved ink with
extra effort.
Removed stencil
easily.
Several applications
needed to remove
haze.
• All screens could
be reused.
• Printer was
concerned with
effect of possible
haze build up over
time.
• All screens could
be reused for
future print jobs.
• Haze removal
step rarely
needed.
• Worked well on
metallic inks.
Solvent-
based
Solvent-
based
Dual Cure
Capillary film
and Direct
photo stencil
Polyester, no
treatment;
180-370
threads/inch
Polyester, half-
calendared or
low elongation
threads;
60-390
threads/inch
1977 in2
1088 in2
o
Q.
IS3
m
o.
o_
m
m
o'
<
CO
co_
?5^
C
CD"
ff
•o
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CO
CD
I
Q)
8-
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a
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f
5T
O
-------
Table V-104
Laboratory Testing Performance Summary For System Chi
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity Applied
Average
Cleaning Time
Average Effort
Required
Performance for
Each System
Component
Laboratory Testing at SPTF
SPTF
Solvent-
based
Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based
Ink
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
not recorded
1.0 oz.
2.5 oz.
1.0 oz.
1.0 oz.
1.0 oz.
2.0 oz.
1.5oz.
1.5oz.
7.5mins
3.3mins
4.7mins
4.0mins
4.0mins
4.0mins
4.5mins
4.1 mins
3.3mins
Moderate
Low
Low
Low
Low
Low
Moderate
Low
Low
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
Heavy ink residue. Started to remove
stencil.
Dissolved stencil easily. Heavy ink
residue remaining.
Lightened ink stain.
Dissolved the ink but left a grey haze
over entire screen.
Dissolved stencil easily.
Lightened the ink stain.
Light ink residue. Stencil started peeling.
Dissolved stencil easily. Heavy ink stain
and light residue.
Lightened ink stain.
Solvent-
based
UV-
curable
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester; 255
threads/inch
Polyester; 390
threads/inch
Polyester; 255
threads/inch
360 in2
360 in2
360 in2
o
Q.
IS3
m
o.
o_
m
m
o'
<
CO
co_
?5^
C
CD"
ff
•o
Q)
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CO
CD
I
Q)
8-
O
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o
Q.
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f
5T
O
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
o Haze Remover: The facility uses two haze remover products. Apply the first
product to every screen. Spray the product onto the screen, brush it into the
stained area on both sides and rinse with a high pressure wash. The second
product is a stronger chemical and is used only when the ghost images in the
screen become unacceptable (approximately 15% of the reclamations). To apply
this haze remover, dip a scrubber pad into the container of product and scrub both
sides of the screen. Rinse with a high pressure wash.
General Facility Background for Facility 21
Facility 21 prints decals for glass and ceramics. Their typical run length is 1000 sheets
and approximately 50% of their orders are repeat orders. There are approximately 15 -20
employees at this facility, and 1 - 3 people are responsible for screen reclamation. During the
Performance Demonstration, this facility used solvent-based inks, a capillary film emulsion,
and screens with mesh counts that ranged from 60 - 390 threads/inch. Their average screen
size is 3 feet x 3 feet and 20 - 25 screens are reclaimed daily.
Screen Reclamation Area in Facility 21
Ink removal and screen reclamation are both done in the screen reclamation room, which
is approximately 150 ft2 in size. A fan in the hood above the reclamation sink provides
ventilation for the area. During the observer's visit, the average temperature in the room was
68°F (and 56% relative humidity). Ink remover is recycled off-site, and the recycled product is
returned to the facility for in-house use. Reusable shop rags are cleaned by an industrial
laundry service. Waste water from the washes of the emulsion remover and haze remover is
not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 21
The standard ink remover at Facility 21 is a proprietary product, sold by a manufacturer
not participating in the performance demonstration, that contains no carcinogens, no
ingredients with TLV or PELs, and no petroleum derivatives, according to the MSDS. Their
emulsion remover contains primarily sodium periodate. Their standard haze remover is a
proprietary solvent blend which includes sodium hydroxide and cyclohexanone.
Current Screen Reclamation Practices in Facility 21
During the screen reclamation process at Facility 21, personal protective equipment
available to the employees includes gloves, eye protection, aprons, respiratory protection, ear
protection, and barrier cream. Screens are reclaimed as follows:
o Ink Remover: At the press, card off excess ink and wipe the screen with the in-
process ink remover. Bring the screen to the screen reclamation room. Spray on
the ink remover and rub it into the screen with a scrubber pad. Remove the ink by
running a squeegee over the screen. Wipe off both sides of the screen with a
reusable rag. One or two rags are used on each screen. Move the screen to the sink
and rinse both sides of the screen with a hose to remove the blockout.
o Emulsion Remover: Spray both sides of the screen with the emulsion remover. Let
sit until the emulsion starts to dissolve. Rub the stencil with a reusable rag. Rinse
the screen with a high pressure wash (1000 psi).
DRAFT-September 1994 V-121
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
o Haze Remover: A haze remover is rarely used (on approximately 1 % of the screens
reclaimed). Instead, the ink remover is reapplied to about 50% of the screens. For
the remaining screens, reclamation is considered complete after the emulsion
removal step. When haze remover is used, apply as follows: dip a brush in the
product container, rub the haze remover into the screen, and rinse with a pressure
wash.
DRAFT-September 1994 V-122
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Chi
Cost
Table V-105
Method 2: Summary of Cost Analysis for Alternative System Chi
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Chi
Facility 3
1,977
15
Facility 21
1,088
23
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
12.3
2.69
1.2
0.18
1.1
0.21
2.1
0.07
2.1
0.39
0
0
8.0
1.74
1.2
0.19
1.1
0.21
1.5
0.05
2.0
0.37
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
3.55
3.89
13,312
5,829
2.56
3.25
14,413
4,879
"Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-123
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Delta
Product System Delta
Formulation
Ink Remover:
Emulsion Remover:
Haze Remover:
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Sodium periodate
Water
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Occupational Exposure
Table V-106
Occupational Exposure Estimates for Alternative System Delta
System
Ink Remover
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:1)
Sodium periodate
Water
Haze Remover
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Inhalation (mg/day)
I
2
0
0
0
0
2
0
0
II
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
IV
0.1
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
702
780
78
39
1520
702
780
78
Immersion
3280
3640
364
182
7100
3280
3640
364
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-124
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
Occupational Risk Estimates
Quantitative risk estimates could not be determined for this system due to insufficient
data. See risk conclusions for areas of concern for this system.
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Although no risks could be quantified because of limitations in hazard data,
relatively high dermal exposures to ink remover and haze remover components
could occur.
o Inhalation exposures to all components are very low.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-125
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Delta
Environmental Releases
Table V-107
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Delta System
System
Ink Remover
Dibasic esters
Tripropylene glycol series ethers
Ethoxylated nonylphenol
Emulsion Remover (diluted 1:1)
Sodium periodate
Water
Haze Remover
Dibasic esters
Tripropylene glycol series ethers
Ethoxylated nonylphenol
Release Under Each Scenario
(g/day)
I
air
3.7
0.1
0
0
0
3.7
0.1
0
water
0
0
0
16
605
239
269
27
land
319
359
36
0
0
00
0
0
II
air
0
0
0
0
0
00
0
0
III
air
0
0
0
0
0
00
0
0
IV
air
0.2
0
0
0
0
00
0
0
water
608
675
67
0
0
00
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Delta
From Ink Removal Operations:
Dibasic esters
3.9 g/day to air
608 g/day to water from rags at commercial laundry
319 g/day to landfill
Propylene glycol series ethers
0.1 g/day to air
675 g/day to water from rags at commercial laundry
359 g/day to landfill
Ethoxylated nonylphenol
67 g/day to water from rags at commercial laundry
36 g/day to landfill
DRAFT—September 1994
V-126
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Delta
From Emulsion Remover:
Sodium periodate
16 g/day to water
From Haze Remover:
Dibasic esters
3.7 g/day to air
239 g/day to water
Propylene glycol series ethers
0.1 g/day to air
269 g/day to water
Ethoxylated nonylphenol
27 g/day to water
Table V-108
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Delta
Substance:
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Sodium periodate
To Air:
7.6 g/day
0.2 g/day
To Water:
239 g/day
608 g/day at laundry
269 g/day
675 g/day at laundry
27 g/day
67 g/day at laundry
16 g/day
To Landfill:
31 9 g/day
359 g/day
36 g/day
DRAFT—September 1994
V-127
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Delta
Releases to Water from a Single Facility
Table V-109
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Delta
Substance
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Sodium Periodate
Amount Released
to Water from
Facility
239 g/day
608 g/day at
laundry
269 g/day
675 g/day at
laundry
27 g/day
67 g/day at laundry
16 g/day
Waste water
Treatment
Removal
Efficiency
84-97 %
83-97 %
100 %
100 %
Amount to Water
After Waste water
Treatment
22 g/day
55.1 g/day
35 g/day
88 g/day
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
2x10'2
6x10'2
3x10'2
9x10'2
0
0
' ug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-110
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Delta
Substance
Dibasic esters
Propylene glycol series ethers
Amount of Releases
per day
7.6 g/day
0.2 g/day
Highest Aver age
Concentration 100 M away
1.6x10-2ug/m3
3.5x10-4ug/m3
Annual Potential Dose,
mg/yeara
1.1x10'1
3x10'3
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
DRAFT—September 1994
V-128
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Delta.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Delta reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Delta Performance, and Related Variables
The performance of the Alternative System Delta was demonstrated at Facilities 10 and
11, who both used UV-cured inks. This product system consisted of an ink remover and an
emulsion remover. In place of a separate haze remover product, the manufacturer
recommended that the ink remover be reapplied to remove haze. A degreaser accompanied this
product system and was used by the facilities, however, detailed information on the
performance of the degreaser is not included in the scope of this project. Facility 10 prints
store displays and Facility 11 prints vehicle markings and pressure sensitive decals. During
the demonstrations, Facility 10 reclaimed 17 screens over a 3 week period and Facility 11
reclaimed 31 screens over 4 weeks.
At Facility 10, the ink remover removed the ink efficiently on 67% of the screens. On the
other 33% of the screens, a slight ink residue remained on the screen after using the ink
remover. Overall, the performance of the ink remover was considered fair, however, it required
extra effort and it had a strong smell and the screen reclamation employees thought it gave
them headaches. Facility 11 had better results and they considered the performance of the ink
remover to be very good. It consistently and efficiently removed the ink from their screens
under most conditions.
The emulsion remover worked very well and both facilities expressed an interest in
continuing to use the product after the demonstrations were complete. Facility 10 found the
product worked best when diluted at one part emulsion remover to one part water. Facility 11
used a dilution of one part emulsion remover to three parts water.
Neither facility regularly documented the performance of the ink remover used in a
second application as a haze remover. Facility 10 used it a few times and found that it did not
remove the haze satisfactorily. On subsequent screens where a haze remover was needed, they
used their standard haze remover product. At Facility 11, the ink remover and emulsion
remover cleaned the screen well enough that a haze removal step was not needed.
DRAFT-September 1994 V-129
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
Alternative System Delta Profile
The manufacturer recommends applying Alternative System Delta as follows:
o Ink Remover Card up the excess ink to remove as much as possible from the
screen. Apply the ink remover as soon as possible after the press run, even if the
screen is not to be cleaned until later. Use a spray bottle and apply the product to
both sides of the screen, using ample product to coat the inked areas completely.
Thoroughly brush the ink remover into the screen, paying close attention to print
areas and heavy ink spots. Allow as much time as possible for the product to
dissolve the ink. If more product is needed to loosen the ink, apply it in the needed
areas and brush again. Pressure rinse the screen, beginning with the well side,
from the bottom of the screen to the top. Turn the screen around and repeat the
pressure rinse from bottom to top. At SPTF, a 1000 psi pressure washer was used.
o Emulsion Remover Dilute 1 part emulsion remover in 4 - 5 parts water. Spray the
emulsion remover onto the wet screen and allow enough time for the product to
completely dissolve the emulsion. Use a brush to loosen the emulsion on the entire
screen. Pressure wash the screen on both sides, rinsing from the top to the bottom.
o Additional Stain Removal Step If stains remain in the screen, allow the screen to
dry and repeat the application procedure for the ink remover and pressure rinse.
Alternative System Performance at SPTF
Product System Delta was tested at SPTF on three screens (one with a solvent-based ink,
one with a UV-curable ink, and one with a water-based ink). The ink remover performance
varied, depending on the type of ink used. Performance of the emulsion remover and the haze
remover was more consistent for the three screens. All products were applied according to the
manufacturer's recommended application procedure.
On the screen with the solvent-based ink, there was some ink residue remaining after
applying the ink remover. While scrubbing the screen to remove the ink, approximately half of
the emulsion was also removed. The results were similar on the screen with UV ink. Moderate
ink residue remained on the screen and some of the stencil in the half-tone area peeled off
while scrubbing. On the third screen (water-based ink), the ink residue was still heavy after
applying the ink remover. Again, some of the stencil was lost while brushing in the ink
remover. For this screen (water-based ink), the technician repeated the ink remover
application process, which removed most of the residue, but also removed most of the stencil.
Because two applications of ink remover were needed, the quantity of ink remover and the time
it took to clean the screen were about twice as much for the screen with water-based ink.
The emulsion remover easily dissolved the stencil on all three screens, leaving no
emulsion residue behind. On the screen with the solvent-based ink, a heavy ink residue was
still present after using the emulsion remover. The haze remover, which is an additional
application of the ink remover in this product system, was then applied. It removed the
residue, but an ink stain remained on the screen. Some ink residue remained on the screen
with UV ink after using the emulsion remover, but the haze remover (a second application of
ink remover) removed the residue, leaving a moderate ink stain. The emulsion remover worked
best on the screen with water-based ink. The stencil dissolved easily with only light scrubbing.
A small amount of ink residue remained, as well as moderate ink stain. A reapplication of the
ink remover removed the residue, but did not lighten the stain significantly.
DRAFT-September 1994 V-130
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
Alternative System Performance Details
Performance Details from Facility 10
System Delta had average success at this facility. The ink remover performance was
acceptable and the emulsion remover worked very well. A second application of the ink
remover as a haze remover did not remove the haze from the screens, therefore the facility used
their standard haze remover when needed. After three weeks, the print manager decided they
did not want to continue their participation in the performance demonstrations because their
standard ink remover and haze remover worked better than the alternative system.
The ink remover's effectiveness was considered average at this facility. Prior to the
performance demonstrations, the facility was using an ink remover that had a chemical
composition very similar to that of the ink remover supplied in Product System Delta. This
facility cards off excess ink and also wipes the screen with a rag so there is very little ink left on
the screen when the ink remover product is applied. The reclaimers did not like using this
product because of its strong smell and many of the employees felt that the ink remover gave
them headaches. Facility 10 did not use a pressure wash to remove the ink, as recommended
by the manufacturer. Instead, they wiped off the dissolved ink with reusable rags.
The emulsion remover was very effective when diluted one part emulsion remover to one
part water (the manufacturer recommends diluting with 4 - 5 parts water). At this dilution
level, the reclaimers were very pleased with its performance and wanted to continue using the
product. This facility also liked the emulsion remover's lack of odor. When they first started
using this emulsion remover, they diluted it in 4 parts water, as recommended. They found it
did not work as well as their usual emulsion remover, so they tried diluting it in two parts
water, and found it worked best when one part emulsion remover was diluted in one part
water.
The facility infrequently documented the performance of the ink remover as a haze
remover when applied a second time. After only a few screens, they felt that their usual haze
remover worked much more effectively. On most of the screens, no haze remover was needed,
however, when it was required, Facility 10 used their standard haze remover after using the
alternative ink remover and emulsion remover.
Facility 10 did not notice that the alternative system performed differently with screen
conditions. The data did not show any correlations between screen conditions (e.g., ink color,
ink drying time) and indicators of performance (e.g., time to clean, quantity of product used).
The printer felt that screens that sat around for days before reclamation were more difficult to
clean than screens cleaned immediately after the print run ended.
No changes were noticed in screen wear or in screen failure rates. Print image quality
was good, however, since they were using their own haze remover, it is difficult to determine if
there would have been any changes to the print image quality as a result of using only the
alternative system.
Performance Details from Facility 11
Overall this facility felt that System Delta worked well. The printing manager felt that if
the alternative system is actually safer for his workers or for the environment, then he would
like to use this product system at his facility. The application procedures for the alternative
DRAFT-September 1994 V-131
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
system closely resembled their usual reclamation procedures and this similarity may have
made Facility 11 more receptive to using System Delta.
The ink remover effectively removed the ink from the screens in all instances. A UV-
cured ink system was used with all screens in the demonstrations. The printer commented
that the ink remover was "less effective" when the ink dried on the screen for a long time. The
data from this facility shows that screens where the reclaimer took 5 minutes or less to remove
the ink had dried an average of 2.7 hours prior to ink removal. Screens where the ink removal
step took longer than 5 minutes had dried an average of 21.6 hours. By applying the ink
remover immediately after the press run, as recommended by the manufacturer, it appears
time spent on ink removal could possibly be reduced. Facility 11 followed the manufacturers
instructions and used a pressure wash to remove the ink from the screen. Before the ink
removal step, most of the ink was carded off the screen.
The emulsion remover worked very well for this facility at a variety of concentrations.
The initial reclamations were performed without diluting the emulsion remover and
performance was very good. After trying several different dilution ratios, they found a mix of
one part product to three parts water worked very well at this facility.
After applying the ink remover and emulsion remover, the screens were clean enough that
a haze removing step was unnecessary. Even without a haze remover step during the
reclamation process, the print quality was excellent. When using their usual products, this
facility attempts to minimize their use of haze remover; they only uses haze remover to clean a
screen when there is a haze that has built up over time or when much adhesive remains in the
screen.
The same screen reclaimer performed all of the demonstrations and evaluated the
printing performance of the reclaimed screens. However, the reclaimer was moved to the
position of printer during the demonstrations period. Undoubtedly, this change reduced the
number of screens that were reclaimed with the alternative system and the forms were also
lacking in details. Since he was pleased with the alternative system performance, he did not
take the time to record many specific details.
Overall the use of System Delta did not produce any deleterious effects of the screen mesh
or subsequent print image quality. The printing supervisor noted that the alternative system
may be reducing their screen failure rate.
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 10
Facility 10 prints store displays, primarily on paper, but they also print on plastics,
metal, ceramic, glass, and other materials. Their typical run length is 200 - 500 impressions
and less than 5% of their orders are repeat orders. Of the approximately 25 employees at this
DRAFT-September 1994 V-132
-------
Table V-111
On-Site Performance Summary For System Delta
•o_
CD"
CD
System
Component
Performance
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh
type;
Thread
count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
10
Facility
11
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
1 7.4 ± 40.9 hr
(n=18)
1 7.2 ± 32.7 hr
(n=18)
3.0mins
(n=1)
11.4±22.2hr
(n=30)
4.7 ± 14.4 min
(n=31)
not needed
9.9±4.2oz.
(n=18)
8.6±1.5oz.
(n=18)
1.0 oz.
(n=1)
7.7±3.5oz.
(n=29)
8.0±3.5oz.
(n=30)
not needed
9.2 ±2.1 mins
(n=16)
4.7 ±2.2 mins
(n=18)
17.0 mins
(n=1)
6.3 ±3.3 mins
(n=29)
6.0 ±3.2 mins
(n=31)
not needed
Moderate
Moderate
Moderate
Low/
Moderate
Low/
Moderate
not needed
Removed ink well
on 67% of screens;
Slight residue on
33%.
Easily removed
stencil.
Did not remove
haze.
Consistently
removed ink well.
Easily removed
stencil.
Not needed.
• This facility used
their own haze
remover on most
screens.
• Ink remover
performance was
considered
average.
• All screens were
reusable.
• Print image
quality was
excellent.
• No haze remover
needed.
UV-
curable
UV-
curable
Direct photo
stencil
Direct photo
stencil
Twill
weave;
305-390
threads/
inch
Monofilame
nt twill
weave;
390
threads/
inch
7767 in2
5291 in2
o
Q.
IS3
m
o.
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-------
Table V-112
Laboratory Performance Summary For System Delta
•o_
CD"
CD
System
Component
Performance
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink type(s)
Emulsion type
Mesh
type;
Thread
count
Average
Screen
Size
Laboratory Testing at SPTF
SPTF
UV-
curable
Ink
SPTF
Solven
t-based
Ink
SPTF
Water-
based
Ink
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
1.0 oz.
1.0 oz.
1.5oz.
1.0 oz.
1.5oz.
2.0 oz.
2.5 oz.
1.0 oz.
1.5oz.
3.5mins
4.8mins
2.5mins
4.5mins
3.7mins
3.5mins
7.1 mins
3.8mins
2.8 mins
Med
Med
Low
Med
Med
Low
Med
Low
Low
Moderate ink residue remaining. Half of
stencil peeled off.
Removed stencil. Ink residue remaining.
Removed residue. Dark ink stain left.
Moderate ink residue remaining; some
stencil deterioration.
Removed stencil completely. Ink residue
remaining.
Removed residue; moderate ink stain left.
Slight ink residue remaining. Dissolved
most of the stencil.
Removed stencil completely. Slight ink
residue and some ink stain remaining.
Removed residue. Slight ink stain left.
UV-curable
Solvent-
based
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
390
threads/in
ch
Polyester;
255
threads/in
ch
Polyester;
255
threads/in
ch
360 in2
360 in2
360 in2
o
Q.
IS3
m
o.
o_
m
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
facility, 1 - 3 are involved in screen reclamation activities. The screens used in the Performance
Demonstrations were twill mesh with mesh counts of 305 - 390 threads/inch and a direct photo
stencil was applied. The average screen size at this facility is 70 inches x 100 inches and 5-10
screens are reclaimed daily.
Screen Reclamation Area in Facility 10
Ink removal is done near the press where plant wide ventilation is provided. Screen
reclamation is done in a separate room which is ventilated to the main production area. Within
the reclamation room, there is a back-lit spray booth with a vented hood. During the observer's
visit, the ambient conditions in the ink removal area were 67°F and 45% relative humidity. In
the screen reclamation room, the temperature averaged 63°F and the relative humidity was
60%. Reusable rags used for ink removal are cleaned by a laundry service. Waste water from
the wash in emulsion removal and haze removal is filtered prior to disposal.
Current Screen Reclamation Products at Facility 10
Facility 10 uses a proprietary blend ink remover consisting of at least propylene glycol
ethers and dimethyl adipate. For emulsion removal, they use a proprietary aqueous mixture
which contains periodate salt (< 10%). Their haze remover is a proprietary aqueous mixture
which contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 10
Using their standard products, this facility reclaims their screens following the procedure
described below:
o Ink Remover: Immediately after the print run, card off excess ink at the press.
Saturate a reusable rag in ink remover and wipe remaining ink off the screen.
Approximately 2 - 4 rags are used for each screen. Gloves are worn during ink
removal.
o Emulsion Remover: Rinse the screen with a pressure washer (1500 psi). Spray
emulsion remover onto both sides of the screen and scrub with a scrubber pad.
Pressure rinse on both sides. Gloves, eye protection, respiratory protection, and
ear protection are available to employees during emulsion removal and haze
removal activities.
o Haze Remover: If there are any ink stains or stencil stains on the screen, reapply
the ink remover or the emulsion remover where needed. Pressure rinse again. If
the second application does not clean the screen sufficiently, then apply the haze
remover. Typically, haze remover is only required on 2 - 5% of the screens
reclaimed. To apply, dip a bristle brush into the pail of haze remover. Brush the
haze remover into both sides of the screen and let sit for one minute. Rinse the
screen with a high pressure water spray.
General Facility Background for Facility 11
Facility 11 prints fleet graphics and pressure sensitive decals. Typically, they print about
100 units per run and 50% of their orders are repeat orders. There are approximately 35
employees at this facility, and 1 - 3 people are involved in screen reclamation activities. During
the Performance Demonstrations, this facility used UV-cured inks and a direct photo stencil.
DRAFT-September 1994 V-135
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
Screens with a monofilament twill weave and a mesh count of 390 threads/inch were used. The
average screen frame size used in this facility is 68 inches x 88 inches and approximately 5
screens are reclaimed per day.
Screen Reclamation Area in Facility 11
Ink removal and screen reclamation are both done in the same area of the facility which is
50 - 100 ft2 in size. Natural ventilation and a shipping door next to the back-lit reclamation
spray booth provide air flow for the area. During the observer's visit, the average temperature
in the area was 59°F (and 42% relative humidity). Ink removal waste is sent to an off-site
recycler. Waste water from the washes of the emulsion remover and haze remover is not
recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 11
Facility 11 uses a standard ink remover that is a proprietary product, sold by a
manufacturer not participating in this project. According to the MSDS, this product contains
no carcinogens, no ingredients with TLVs or PELs, and no petroleum derivatives. Information
on the emulsion remover used at Facility 11 was not available. Their haze remover is a
proprietary aqueous mixture that contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 11
Screen reclamation at Facility 11 usually follows the procedure detailed below. One
exception is when there is a clear coat on the screen. In this case, lacquer thinner is applied to
remove the clear coat prior to the ink removal step. Haze remover is rarely used at this facility
(on approximately 1 - 3% of the screens reclaimed). It is usually only required when there is
excessive adhesive and block out on the screen. During the screen reclamation process at
Facility 11, gloves and eye protection are worn. Screens are reclaimed as follows:
o Ink Remover: At the press, card off the excess. Bring the screen to the screen
reclamation area and spray on the ink remover. Remove the ink by running a
squeegee across the screen. Wipe off both sides of the screen with a reusable rag (2
- 4 rags are used on each screen) and pressure rinse (1000 psi).
o Emulsion Remover: Dip a scrubber pad with a handle into the container of
emulsion remover and scrub the product on the stencil side of the screen. Repeat
dipping and scrubbing until stencil is covered (4 - 5 dips). Turn the screen over
and spray emulsion remover on the other side of the screen. Let the remover sit on
the screen for one or two minutes. Pressure rinse.
o Haze Remover: A haze remover is rarely used (on approximately 1 - 3% of the
screens reclaimed). When haze remover is used, apply as follows: dip a brush in
the product container, rub the haze remover into the screen, and rinse with a high
pressure wash. Lacquer thinner is used to remove any stains remaining on the
screen.
DRAFT-September 1994 V-136
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Delta
Cost
Table V-113
Method 2: Summary of Cost Analysis for Alternative System Delta
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Delta
Facility 11
5,292
5
Facility 10
7,767
8
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
12.3
2.69
0.0
0.0
7.7
0.99
8.0
0.28
not
used
0
0
30.9
6.76
6.5
0.97
9.9
1.27
8.6
0.30
1.0
0.13
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
3.96
3.28
4,953
4,917
9.43
7.66
17,675
11,489
"Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-137
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Product System Epsilon
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
Sodium periodate
Sulfate salt
Water
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Sodium hydroxide
Derivatized plant oil
Water
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
DRAFT—September 1994
V-138
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Occupational Exposure
Table V-114
Occupational Exposure Estimates for Epsilon System
System
Ink Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Emulsion Remover (diluted 1:4)
Sodium periodate
Sulfate salt
Water
Haze Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Alkali/Caustic
Water
Inhalation (mg/day)
I
39
17
0
0.1
0.1
1.6
4.6
0
0
0
12
5.2
0
0
0
0.5
1.4
0
0
0
0
0
II
0.3
0.4
0
0
0
0.1
0.1
0
0
0
0.3
0.4
0
0
0
0.1
0.1
0
0
0
0
0
III
0.2
0.2
0
0
0
0
0.1
0
0
0
0.2
0.2
0
0
0
0
0.1
0
0
0
0
0
IV
1.4
1.7
0
0
0.2
0.2
0.4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
468
234
312
101
55
156
234
23
23
1510
234
117
156
51
27
78
62
140
62
117
408
109
Immersion
2180
1090
1460
473
255
728
1090
109
109
7060
109
546
728
273
127
364
291
655
291
546
1890
510
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-139
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures to cyclohexanone and benzyl alcohol during both ink removal and haze
removal. Similar calculations for inhalation exposures to cyclohexanone and benzyl
alcohol indicate low concern.
o Margin-of-exposure calculations indicate a marginal concern for developmental
toxicity risk from inhalation exposures to cyclohexanone during ink removal.
Reproductive and developmental toxicity risks from dermal exposures to
cyclohexanone could not be quantified.
o Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures and low concern for chronic inhalation exposures to methoxypropanol
acetate.
o Risks from other ink remover and haze remover components could not be
quantified because of limitations in hazard data, although dermal exposures to all
components could be relatively high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-140
-------
Exhibit V-115
Occupational Risk Estimates for System Epsilon
o
Q.
IS3
CO
Name
Ink Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Emulsion Remover (diluted to 3%)
Sodium periodate
Sulfate salt
Water
Hazard Quotient
Inhalation
0.12
0.45
NA
0.004
NA
NA
NA
NA
NA
NA
Dermal
Routine
1.3
5.6
NA
4.8
NA
NA
NA
NA
NA
NA
Immersion
6.2
26
NA
23
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
120
0
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
m
Q.
c?
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
Q.
f
5T
CO
o"
-------
Exhibit V-116
Occupational Risk Estimates for System Epsilon
o
Q.
IS3
CO
Name
Haze Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Alkali/Caustic
Water
Hazard Quotient
Inhalation
0.03
0.14
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
0.8
2.8
NA
1.8
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
3.6
13
NA
8.7
NA
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
400
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
m
Q.
c?
o_
m
m
o'
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
Q.
f
5T
CO
o"
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Environmental Releases
Table V-117
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Epsilon
System
Ink Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Emulsion Remover (diluted to 3%)
Sodium periodate
Sodium salt
Water
Haze Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Alkali/Caustic
Water
Phncnhatp calt
Release Under Each Scenario
(g/day)
I
air
82
36
0
0.2
0.2
3.2
9.6
0
0
0
25
11
0
0.1
0.1
1
2.9
0
0
0
0
n
land
126
68
138
45
24
66
94
0
0
0
0
0
0
0
0
0
0
0
0
0
0
n
water
00
0
0
0
0
0
0
9
9
602
55
29
53
17
9.3
26
37
48
21
138
37
91
II
air
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0
0
n
III
air
0.4
0.5
0
0
0
0.1
0.1
0
0
0
0.7
0.8
0
0
0.1
0.1
0.2
0
0
0
0
n
IV
air
2.9
3.6
0
0
0.3
0.5
0.8
0
0
0
0.4
0.5
0
0
0
0.1
0.1
0
0
0
0
n
water
402
199
270
88
47
135
202
0
0
0
0
0
0
0
0
0
0
0
0
0
0
n
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-143
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Environmental Releases from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Epsilon
From Ink Removal Operations:
Cyclohexanone
86 g/day to air
402 g/day to water from rags at commercial laundry
126 g/day to landfill
Methoxypropanol acetate
40.9 g/day to air
199 g/day to water at commercial laundry
68 g/day to landfill
Diethylene glycol
270 g/day to water at commercial laundry
138 g/day to landfill
Benzyl alcohol
0.2 g/day to air
88 g/day to water at commercial laundry
45 g/day to landfill
Derivatized plant oil
0.6 g/day to air
47 g/day to water from rags at commercial laundry
24 g/day to landfill
Aromatic solvent naphtha
4 g/day to air
135 g/day to water from rags at commercial laundry
66 g/day to landfill
Diacetone alcohol
10.7 g/day to air
202 g/day to water from rags at commercial laundry
94 g/day to landfill
From Emulsion Remover:
Sodium periodate
9 g/day to water
Sulfate salt
9 g/day to water
From Haze Remover:
Cyclohexanone
26.8 g/day to air
55 g/day to water
DRAFT-September 1994 V-144
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Environmental Releases from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Epsilon (cont.)
Methoxypropanol acetate
13.1 g/day to air
29 g/day to water
Diethylene glycol
53 g/day to water
Benzyl alcohol
0.1 g/day to air
17 g/day to water
Derivatized plant oil
0.3 g/day to air
9.3 g/day to water
Aromatic solvent naphtha
1.3 g/day to air
26 g/day to water
Diacetone alcohol
3.4 g/day to air
37 g/day to water
Alkyl benzene sulfonates
48 g/day to water
Ethoxylated nonylphenol
21 g/day to water
Phosphate salt
21 g/day to water
Sodium hydroxide
138 g/day to water
DRAFT-September 1994 V-145
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Table V-118
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Epsilon
Substance:
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Alkali/Caustic
Sodium periodate
Sulfate salt
To Air:
113g/day
54 g/day
0.3 g/day
0.9 g/day
5.3 g/day
14.1 g/day
To Water:
55 g/day
402 g/day at laundry
29 g/day
199 g/day at laundry
53 g/day
270 g/day at laundry
17 g/day
88 g/day at laundry
9.3 g/day
47 g/day at laundry
26 g/day
135 g/day at laundry
37 g/day
202 g/day at laundry
48 g/day
21 g/day
21 g/day
138 g/day
9 g/day
9 g/day
To Landfill:
126 g/day
68 g/day
138 g/day
45 g/day
24 g/day
66 g/day
94 g/day
DRAFT—September 1994
V-146
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Releases to Water from a Single Facility
Table V-119
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Epsilon
Substance
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Derivatized plant oil
Aromatic solvent naphtha
Diacetone alcohol
Alkyl benzene sulfonates
Ethoxylated nonylphenol
Phosphate salt
Sodium hydroxide
Sodium periodate
Sulfate salt
Amount Released
to Water from
Facility
55 g/day
402 g/day at
laundry
29 g/day
199 g/day at
laundry
53 g/day
270 g/day at
laundry
17 g/day
88 g/day at laundry
9.3 g/day
47 g/day at laundry
26 g/day
135 g/day at
laundry
37 g/day
202 g/day at
laundry
48 g/day
21 g/day
21 g/day
138 g/day
9 g/day
9 g/day
Waste water
Treatment
Removal
Efficiency
83%
97%
84%
97%
100 %
92-96 %
83%
97%
100 %
100 %
100 %
100 %
100 %
Amount to Water
After Waste water
Treatment
9.4 g/day
68.3 g/day
9x10'1g/day
6 g/day
8.5 g/day
43.2 g/day
5 x 10 "1 g/day
3 g/day
0 g/day
2 g/day
10.8 g/day
6.3 g/day
34 g/day
1.4 g/day
0 g/day
0 g/day
0 g/day
0 g/day
0 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
9x10'3
7x10'2
9x10'4
6x10'3
9x10'3
4x10'2
5x10'4
3x10'3
0
2x10'3
1 x 10'2
6x10'3
3x10'2
1 x 10'3
0
0
0
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-147
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Releases to Air from Individual Screen Printing Facilities
Table V-120
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Epsilon
Substance
Cyclohexanone
Methoxypropanol acetate
Derivatized plant oil
Aromatic solvent naphtha
Benzyl alcohol
Diacetone alcohol
Amount of Releases per
day
113g/day
54 g/day
0.9 g/day
5.3 g/day
0.3 g/day
14.1 g/day
Highest Average
Concentration 100 M away
2.3x10-1ug/m3
1.1x10-1ug/m3
1.8x10'3ug/m3
1.1x10-2ug/m3
6x10'4ug/m3
3x10'2ug/m3
Annual Potential
Dose, mg/yeara
2
8x10'1
1 x 10'2
8x10'2
4x10'3
2x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Epsilon.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Epsilon reach an
ecotoxicity concern concentration.
DRAFT—September 1994
V-148
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Performance
General Summary of Product System Epsilon. Performance, and Related Variables
This product system consisted of an ink remover, emulsion remover and haze remover.
It's performance was demonstrated at Facility 20 and Facility 24. Facility 20 employs
approximately 10 people and prints mainly banners and displays. Facility 24 employs 15-20
people in their production area with 4 employees involved in the screen printing operations of
their business. They print pressure sensitive labels and Lexan face plates. Over a thirty-day
period, Facility 20 reclaimed 48 screens and Facility 24 reclaimed 16 screens using Product
System Epsilon. Both facilities used solvent-based inks, and Facility 24 also used UV-curable
inks. Facility 20 used a dual-cured emulsion and Facility 24 used a direct photo stencil.
There were some differences between the two facilities in their evaluations of the
performance of Product System Epsilon. Facility 20 found the ink remover was effective, but it
took longer to breakdown the ink than their standard product. Facility 24 had very good
results with the ink remover. They felt it worked as well as the products they had used
previously and they were using less product per screen. The ink remover worked well on both
UV and solvent-based inks, but the UV ink was easier to clean than the solvent-based ink.
The alternative emulsion remover performance was very good at both facilities. The two
facilities reported that the performance was even better than their standard products; it
dissolved the stencil quickly and easily.
Both facilities thought that the haze remover performance was acceptable, and in most
cases, it worked as well as their other products.
Alternative System Epsilon Profile
The manufacturer recommends applying Product System Epsilon as follows:
o Ink Remover After carding off as much excess ink as possible, spray both sides of
the screen with the ink remover. Also spray a rag and rub both sides of the screen
until all ink residue is completely dissolved or emulsified and the emulsion
becomes clearly visible. Rinse well with water.
o Emulsion Remover Dilute the powdered emulsion remover in water as follows: 1%
for photoemulsions, 2% for fast exposing solvent resistant emulsion, 3% for dual-
cured and water resistant photo emulsions. Stir thoroughly until the product is
dissolved. Pour the diluted mixture into a spray bottle. Spray the solution on both
sides of the screen. Rub the screen gently with a brush for approximately two
minutes. Rinse thoroughly with a high pressure water spray. A 1000 psi pressure
wash was used at SPTF. If any ink residue remains, apply additional ink remover
to the screen, brush it in for a few minutes until emulsified, and pressure rinse.
o Haze Remover Create a mixture of haze remover and ink remover in a ratio of 1:4
to 1:1. Scoop out the mixture and apply it to a brush. Brush the paste into both
sides of the screen. Wait for a minimum of 10 minutes up to a maximum of 30
minutes. Rinse the mixture off with running water and then spray out the dissolved
and softened residue with a high pressure washer.
DRAFT-September 1994 V-149
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Alternative System Performance at SPTF
Product System Epsilon was used at SPTF on three screens (one with a solvent-based
ink, one with a UV-curable ink, and the third with water-based ink). The ink remover dissolved
the solvent-based ink well and was easy to use. A light grey haze was left on the screen. On the
screen with UV ink, the ink dissolved quickly, wiped off easily, rinsed clean of residue, but left
a moderate ink stain. When used on the screen with water-based ink, more time and effort
were needed to remove the ink which seemed to dry in the screen. With the extra effort, the ink
was removed except for a light ink stain. For each of the three screens, one rag was used to
remove the ink.
On all three screens, the emulsion remover dissolved the stencil with some scrubbing.
The remainder of the stencil came off easily with the pressure wash. There was no emulsion
stain or residue on any of the screens. On the screen with the solvent-based ink, a moderate
ink stain remained after using the emulsion remover. The UV ink screen and the water-based
ink screen had light stains. On all the screens, the haze remover lightened the ink stain, but
did not remove it completely; a light ink stain was still visible.
Manufacturer's instructions were followed in applying the products to the screen. The
technician noted that the ink remover had an unpleasant odor, but that it was not very strong.
Alternative System Performance Details
Performance Details from Facility 20
Users of the reclaiming products were asked to evaluate the performance of the
components of System Epsilon relative to the facility's regular system. The screen reclaimer
thought that the products were generally better than their previously used ones. The
operations manager, however, felt that the ink remover did not perform quite as well in cutting
some inks as their previously used products. No evaluation sheets were received from Facility
20, although the facility reported that they sent them. Unfortunately, they did not make copies
of the sheets before they were mailed. Therefore, all performance information from Facility 20
was received through the observer's on-site documentation and through weekly telephone
conversations with the facility. The observer interviewed both the reclamation employee and
the operations manager, who was also one of the printers who used the ink remover.
The ink remover worked acceptably in the facility, although some of the printers who
used it complained that it acted slowly. Performance was not as good on catalyzed inks as on
other solvent-based inks. The catalyzed inks also require more effort to remove with the
facility's regular ink remover, but the alternative ink remover did not perform as well as the
regular product in this case. The alternative product did eventually remove all the ink from the
screens. The operations manager, who also used the product, commented that it was more of
an respiratory irritant than their previously used product; he said that the alternative ink
remover smelled bad and made him dizzy.
The emulsion remover worked well at this facility. One screen, with an 83 mesh screen
that had been used with an aggressive ink system, required at least two applications of
emulsion remover to clean. Two applications of emulsion remover are also required when
using the facility's standard emulsion remover with this type of screen. The reclaimer felt that
either the coarse mesh or the ink system could have made the screen more difficult to clean.
DRAFT-September 1994 V-150
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
Haze remover performance was acceptable. Again, when reclaiming screens with a mesh
count of 83 threads per inch, the haze remover also had to be applied 2 or 3 times.
Overall, the use of Product System Epsilon had no deleterious effects on the screen mesh
or on the subsequent print quality image and the printer did not notice any change in screen
failure rate over the time period that the alternative system was in use.
Performance Details from Facility 24
This facility felt the ink remover and the emulsion remover worked better than their
standard system, and the haze remover performed as well as their own product. Screen
printing is a relatively small part of the operations at this facility, and although they used
Product System Epsilon on all the screens they reclaimed, the total number of screens over four
weeks was 14.
The ink remover consistently removed the both the solvent-based and the UV-curable
inks. Although the product performance was good for both ink types, this printer found the UV
inks easier to clean than the solvent-based inks. In addition, the facility found the quantity of
alternative ink remover used per screen was significantly less than the quantity used of
standard product.
The printer felt the emulsion remover was as effective as their standard product, and it
dissolved the stencil quickly.
Product System Epsilon haze remover performance was evaluated as the same as the
facility's standard haze remover. Although the data from this facility indicates that there were
several cases where the screen could not be reused for reverse printing or for use with
transparent inks, the printer felt that these restrictions were not entirely due to the alternative
system. Some of the remaining ink stains may have been on the screen prior to the start of the
dem onstr ations.
During the four weeks the products were used in this facility, no change in the screen
failure, mesh deterioration, or print quality were noted. The observer felt the facility evaluated
the alternative system's performance objectively and conscientiously. At the conclusion of the
demonstrations, the printer mentioned that he was interested in continuing to use the
alternative ink remover and emulsion remover.
Alternative System Performance Table Compiled from Field Sites
The table below highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 20
Facility 20 prints banners and point-of-purchase displays on paper, plastic, metals,
ceramics, and glass. Their typical run is 20 parts and about 20% of their orders are repeat
orders. Of the approximately 10 employees at this facility, 1 - 3 are involved in screen
DRAFT-September 1994 V-151
-------
Table V-121
On-Site Performance Summary For System Epsilon
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average Quantity
Applied
Average
Cleaning Time
Average Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
20
Facility
24
Ink remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
no data
no data
no data
10.3 ±26.1 hrs
(n=14)
13.8 ±12.2 hrs
(n=14)
2.9 ±2.1 mins
(n=14)
3.0 oz. (n=1)
3.3±0.6oz.
(n=3)
4.0±1.7oz.
(n=3)
4.2±1.7oz.
(n=14)
4.2±1.9oz.
(n=13)
1.5±0.5oz.
(n=14)
no data
no data
no data
3.7 ± 1.5 mins
(n=13)
3.7 ± 1.1 mins
(n=14)
10.9 ±4.7 mins
(n=14)
Moderate
Moderate
Moderate
Moderate
Low
Low
Removed ink well,
but took some extra
time.
Easily removed
stencil.
Lightened ink stain.
Removed ink well,
especially UV ink.
Easily removed
stencil.
Usually removed
haze.
• Data forms were
not received from
this facility.
• All information is
based on weekly
phone calls.
• All screens could
be reused after
reclamation.
• Some screens
could not be used
for reverse printing.
• Light ink stain
remained.
Solvent-
based
vinyl,
enamels
Solvent-
based
and UV-
curable
Dual cure
Direct
photo
stencil
Polyester;
83-280
threads/inch
Monofilamen
t Polyester,
no
treatment;
355
threads/inch
2538 in2
1296 in2
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Table V-122
Laboratory Performance Summary For System Epsilon
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using Product
Average
Quantity Applied
Average
Cleaning Time
Average Effort
Required
Performance for
Each System
Component
Laboratory Testing at SPTF
SPTF
Solvent-
based
Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based
Ink
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
1 .5 oz.
1 .0 oz.
1 .0 oz.
1 .5 oz.
1 .5 oz.
1 .0 oz.
1 .5 oz.
1 .0 oz.
1 .0 oz.
3.9mins
3.4mins
31.8 mins
3.3mins
3.8 mins
2.2 mins
5.6 mins
3.2 mins
32.8 mins
Low
Moderate
Low
Low
Moderate
Low
Moderate
Moderate
Low
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
Dissolved ink well; gray haze left on screen.
Dissolved stencil; medium ink stain
remaining.
Lightened ink stain.
Dissolved ink well; has unpleasant odor.
Dissolved stencil; light ink stain remaining.
Lightened ink stain.
Dissolved ink with scrubbing.
Dissolved stencil; light nk stain remaining.
Lightened ink stain.
Solvent-
based
UV-
curable
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
260
threads/inc
h
Polyester;
390
threads/inc
h
Polyester;
260
threads/inc
h
360 in2
360 in2
360 in2
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
reclamation activities. The facility uses a variety of solvent-based inks including vinyl, enamel,
and a multipurpose ink. They use a dual cure emulsion. Screens used in the Performance
Demonstrations were polyester (untreated) with a mesh count of 83 -280 threads/inch. The
average screen size at this facility is 4 feet x 5 feet and approximately 5-10 screens are
reclaimed daily.
Screen Reclamation Area in Facility 20
The ink removal and screen reclamation activities are done in the press room in a back-lit
spray booth. A plant-wide system provides the ventilation for the screen reclamation area. The
average temperature during the observer's visit was 68°F (and 36% relative humidity). Ink
waste is disposed of as hazardous waste. Waste water from the high-pressure wash of the
emulsion remover and haze remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 20
The standard ink remover product at Facility 20 is an acetone blend. For emulsion
removal, they use a proprietary aqueous mixture which includes periodate salt (< 10%). Their
standard haze remover is a proprietary aqueous mixture with sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 20
This facility uses a custom blended ink remover. The application procedure listed below
is used for most screens. One exception is the 83 mesh, where two applications of the
emulsion remover are required. Occasionally, a dried ink requires an initial rinse with
cyclohexanone. The screen reclamation process is described below:
o Ink Remover: Card off excess ink from the screen. Apply ink remover to a reusable
rag from a safety can. Gloves and eye protection are usually worn during this step.
Brush the product into the screen. Wipe the screen with a reusable rag. Continue
wiping with clean rags until ink no longer comes off on the rag. Typically, 2 - 4 rags
are used on each screen.
o Emulsion Remover: After ink removal, rinse the screen with the hose. Apply the
emulsion remover with a spray bottle. Scrub in the product with a pad brush.
Rinse the screen with a pressure wash (100 psi).
o Haze Remover: To apply haze remover, dip a bristle brush into the pail of product.
Brush the haze remover into both sides of the screen and let sit for one minute.
Rinse the screen with a high pressure water spray. If the stain is dark, reapply the
haze remover and let sit for 1 - 2 minutes and rinse again with the high pressure
spray.
General Facility Background for Facility 24
The majority of the products printed by Facility 24 are pressure sensitive mylar labels
and polycarbonate Lexan face plates. Run lengths are typically 500 - 1000 impressions, and
approximately 50% of their business is for repeat orders. There are 15-20 employees involved
in production operations at this facility and 2 - 3 are involved in screen reclamation operations.
The facility uses both solvent-based inks and UV inks; sometimes on the same screen. They
use a direct photo stencil and a monofilament (untreated) polyester mesh. All screens used in
DRAFT-September 1994 V-154
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
the Performance Demonstrations had a mesh count of 355 threads/inch. The average screen
size at this facility is 36" x 36" and 3 - 5 screens are reclaimed each week.
Screen Reclamation Area in Facility 24
Ink removal is done at press side and screen reclamation takes place nearby in a spray
booth. The high ceilings and facility-wide ventilation cover both work areas. During the
observer's visit, the average temperature in the area was 68°F (and 40% relative humidity).
Rags used for ink removal are cleaned under a contract with a laundry service. Waste water
from screen reclamation is not recycled or filtered.
Current Screen Reclamation Products at Facility 24
Facility 24 uses a proprietary solvent blend ink remover consisting primarily of
cyclohexanone, diacetone alcohol and dipropylene glycol methyl ether. Their emulsion remover
is a proprietary aqueous mixture with at least sodium periodate. Their standard haze remover
is an aqueous blend consisting of sodium hydroxide (5%) and tetrahydrofurfuryl alcohol
%).
Current Screen Reclamation Practices in Facility 24
At Facility 24, all screens are reclaimed following the application procedure below:
o Ink Remover: At the press, scrape the excess ink off the screen. Wearing gloves,
eye protection, and an apron, pour the ink remover onto the screen from a one-
gallon can. Scrub with an abrasive brush. Wipe the screen with reusable rags until
ink no longer comes off on the rag. Rinse the screen with a pressure wash (500
psi).
o Emulsion Remover: Spray emulsion remover onto both sides of the screen. Work
the product into the screen using a scrubber pad. Rinse both sides of the screen
with a high pressure wash. After washing off the emulsion, spray the screen with
an ink degradent. Wait for one minute. Scrub the screen with a brush and pressure
rinse both sides.
o Haze Remover: Wearing gloves and eye protection, dip a brush into the bucket of
haze remover. Brush the product into the screen on the effected area on both sides.
Wait for 15 minutes. Rinse both sides of the screen with a high-pressure wash.
DRAFT-September 1994 V-155
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Cost
Table V-123
Method 2: Summary of Cost Analysis for Alternative System Epsilon
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Epsilon
Facility 20
2,538
8
Facility 24
1,296
1
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
9.7
2.12
7.0
1.05
3.0
0.18
3.3
0.09
4.0
0.27
112
0.08
18.3
4.00
3.8
0.57
4.2
0.26
4.2
0.11
1.5
0.10
57
0.04
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
3.79
3.08
7,097
4,624
5.08
5.29
1,269
7,930
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-156
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
Product System Gamma
Formulation
Ink Remover Propylene glycol series ethers
Diethylene glycol series ethers
Dibasic esters
Fatty alcohol ethers
Derivatized plant oil
Emulsion Remover Sodium periodate
Sulfate salt
Phosphate salt
Water
Haze Remover Sodium hypochlorite
Alkali/Caustic
Sodium alkyl sulfonate
Water
DRAFT-September 1994 V-157
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Occupational Exposure
Table V-124
Occupational Exposure Estimates for Alternative System Gamma
System
Ink Remover
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Emulsion Remover
Sodium periodate
Sulfate salt
Phosphate salt
Water
Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium alkyl sulfate
Inhalation (mg/day)
I
0
0
0.2
0.4
1.3
0
0
0
0
0
0
0
0
II
0
0
0
0
0
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
0
0
0
0
IV
0
0
0.2
0.1
0.2
0
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
62
780
62
187
468
39
16
117
1270
585
39
827
109
Immersion
291
3640
291
873
2184
182
73
546
5930
2730
182
3860
510
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
DRAFT—September 1994
V-158
-------
Exhibit V-125
Occupational Risk Estimates for System Gamma
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Q.
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CO
Name
Ink Remover
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Emulsion Remover
Sodium periodate
Sulfate salt
Phosphate salt
Water
Hazard Quotient
Inhalation
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NA
NA
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
2258
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
57
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
481
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
12
NA
NA
NA
NA
NA
NA
NA
NA
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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Exhibit V-126
Occupational Risk Estimates for Alternative System Gamma
o
Q.
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Name
Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium alkyl sulfate
Hazard Quotient
Inhalation
NA
NA
NA
NA
Dermal
Routine
NA
NA
NA
NA
Immersion
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
192
LOAEL
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
41
LOAEL
NA
NA
NA
NA
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Clear concerns exist for chronic dermal exposures to diethylene glycol butyl ether
acetate used in ink removal based on the calculated margin-of-exposure.
o Developmental toxicity risks from dermal exposures to diethylene glycol butyl ether
acetate are very low based on the calculated margin-of-exposure.
o Risks from other ink remover and haze remover components could not be
quantified because of limitations in hazard data, although dermal exposures to all
components could be relatively high.
o Developmental and chronic toxicity risks from dermal exposures to sodium alkyl
sulfate in haze remover are very low based on the calculated margin of exposure.
o Inhalation exposures to all components are very low.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-161
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Environmental Releases
Table V-127
Environmental Release Estimate for Screen Cleaning Operations
Method 2, Gamma System
System
Ink Remover
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Emulsion Remover
Sodium periodate
Sulfate salt
Phosphate salt
Water
Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium alkyl sulfate
Release Under Each Scenario
(g/day)
I
air
0
0.1
0.3
0.8
3.0
0
0
0
0
0
0
0
0
water
0
0
0
0
0
16
6
47
506
200
13
282
37
land
28
355
28
84
210
0
0
0
0
0
0
0
0
II
air
0
0
0.1
0
0
0
0
0
0
0
0
0
0
III
air
0
0
0
0
0
0
0
0
0
0
0
0
0
IV
air
0
0
0.3
0.1
0.3
0
0
0
0
0
0
0
0
water
54
675
54
162
405
0
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-162
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Table V-128
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Gamma
Substance:
Diethylene glycol butyl ether acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Sodium periodate
Sulfate salt
Phosphate salt
Other
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
To Air:
0.1 g/day
0.7 g/day
0.9 g/day
3.0 g/day
To Water:
54 g/day from laundry
675 g/day from laundry
54 g/day at laundry
162 g/day at laundry
405 g/day at laundry
16 g/day
6 g/day
47 g/day
47 g/day
200 g/day
13 g/day
37 g/day
To Landfill:
28 g/day
355 g/day
28 g/day
86 g/day
210 g/day
DRAFT—September 1994
V-163
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Releases to Water from a Single Facility
Table V-129
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Gamma
Substance
Diethylene glycol butyl ether
acetate
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Sodium Periodate
Sulfate salt
Phosphate salt
Other
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Amount Released
to Water from
Facility
54 g/day at laundry
675 g/day at
laundry
54 g/day at laundry
162 g/day at
laundry
405 g/day at
laundry
16 g/day
6 g/day
47 g/day
47 g/day
200 g/day
13 g/day
37 g/day
Waste water
Treatment
Removal
Efficiency
83%
83%
100 %
100 %
84-97 %
100 %
100 %
100 %
100 %
100 %
100 %
100 %
Amount to Water
After Waste water
Treatment
9.2 g/day
115 g/day
0
0
28.3 g/day
0
0
0
0
0
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
9x10'3
1 x 10'1
0
0
3x10'2
0
0
0
0
0
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-164
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Releases to Air from Individual Screen Printing Facilities
Table V-130
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Gamma
Substance
Tripropylene glycol methyl ether
Derivatized plant oil
Fatty alcohol ethers
Dibasic esters
Amount of Releases
per day
0.1 g/day
0.7 g/day
0.9 g/day
3.0 g/day
Highest Average
Concentration 100 M
away
2x10'4ug/m3
1.4x10-3ug/m3
2x10'3ug/m3
5x10'3ug/m3
Annual Potential Dose,
mg/yeara
1 x 10'3
1 x 10'2
1 x 10'2
5x10'2
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Gamma.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Gamma reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Gamma Performance, and Related Variables
Product System Gamma, demonstrated at Facilities 16 and 25, consisted of an ink
remover, an emulsion remover, and a haze remover. Facility 16 prints vehicle markings;
Facility 25 prints appliance panel overlays, back-lit automotive panels, and store displays.
During the four week demonstration period, Facility 16 reclaimed 55 screens although ink
DRAFT—September 1994
V-165
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
remover was only used on seven screens and haze remover was only used on three screens;
Facility 25 reclaimed 54 screens but the ink remover and haze remover were only used on
about half of these. During the demonstrations, both Facility 16 and 25 used solvent-based
inks.
Facility 16 reported that the ink remover left an unacceptable amount of ink on the screen
and required a lot of physical effort. Facility 25 also reported that the ink remover was not
acceptable, leaving ink residue on the screen, especially in the open areas of the screen mesh.
The ink remover required much more time to apply (up to more than twice as long in some
cases) with much greater physical effort than the products normally used at these facilities.
Leaving the ink remover to sit for 3 - 5 minutes on the screen helped improve performance on
the screen areas covered with emulsion, but did not help to remove the ink on the open screen
areas.
Both facilities reported that the emulsion remover worked very well. Facility 16 was able
to shorten the time between application and rinse from the recommended one or two minutes
to less than one minute without compromising the product performance. Facility 25 improved
the emulsion remover performance by wetting the screen before applying the emulsion remover.
Neither facility found the performance of the haze remover to be acceptable. They found
the haze remover did not remove the ink haze left in the screen, which resulted in ghost images
in future print jobs. Both facilities had to use their standard haze remover on their screens
before they could be reused.
Alternative System Gamma Profile
The manufacturer recommends applying Product System Gamma as follows:
o Ink Remover Card up the excess ink. Spray both sides of the screen with the ink
remover. Also spray a rag or brush with the product and rub both sides of the
screen until all of the ink residue is completely dissolved or emulsified and the
emulsion becomes clearly visible. Rinse well with water. For tests done at SPTF, a
1000 psi spray was used for rinsing the ink remover, emulsion remover, and haze
remover.
o Emulsion Remover Scoop the emulsion remover out of the container and apply it
to a brush. Use the brush to distribute the product evenly on both sides of the
screen. After approximately two minutes spray out with a pressure washer. If no
pressure water is available, brush until the photo emulsion is completely
dissolved,and rinse out with a strong water spray. Should any ink residue remain,
apply additional ink remover to the screen, brush it in for a few minutes until
emulsified,then pressure rinse.
o Haze Remover Spray haze remover evenly on both sides of the screen. Distribute
the product evenly using a nylon brush. Let sit for at least one hour. If the ink is
dried, let it sit for up to 24 hours. Rinse off with water.
Alternative System Performance at SPTF
Product System Gamma was tested at SPTF on three screens (one with a solvent-based
ink, one with a UV-curable ink, and one with a water-based ink). The ink remover performance
DRAFT-September 1994 V-166
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
varied depending on the type of ink used. The emulsion remover and haze remover
performance was consistent for all three screens. All products were applied according to the
manufacturer's instructions.
On the screen with the solvent-based ink and the screen with UV ink, the ink remover
dissolved the ink well with no effect on the stencil. On the water-based ink screen, however,
heavy scrubbing and more product were needed to remove the ink. While scrubbing, the stencil
started to break down in the half-tone area. For all the screens, only one rag was used for ink
removal.
The emulsion remover easily dissolved the stencil with only light scrubbing on all three
screens, leaving no ink or emulsion residue behind. The technician noted that most of the
stencil dissolved while she was brushing, and the pressure wash took off the remainder. The
screens did have a moderate ink stain remaining. Subsequent application of the haze remover
lightened the ink stains so that a light to very light ink stain remained.
Alternative System Performance Details
Performance Details from Facility 16
Product System Gamma ink remover and haze remover did not work well and Facility 16
decided not to use these products during the demonstration period. The emulsion remover
seemed to work very well; it was evaluated for the entire four-week demonstration period.
During the demonstrations, there did not appear to be any change in the screen failure rate, or
any noticeable effects on the screen mesh or frames.
The ink remover was only used to clean four screens. The printer sprayed the product
on and let it sit for 30 second before wiping. In all cases it took a lot of effort to clean the
screens. The ink remover left an oily film and an ink residue in the mesh. The facility decided
to discontinue using the alternative ink remover based on these results.
The emulsion remover worked well, with no notable variations in performance among the
screens used during the demonstration period. Although the product instructions require
waiting 1 - 2 minutes after applying the product before pressure washing, the reclaimer found
that the emulsion began to fall off the screen within 30 - 45 seconds after application. Screens
were therefore pressure washed sooner than specified, with no noticeable effect on product
performance. Facility 16 uses screens encompassing a large range of sizes, including some very
large screens used for producing fleet markings for semi-trailers. The amount of emulsion
remover used to clean the screens varied accordingly, although the results were consistent.
At this facility, the haze remover did not remove ghost images from the screens. After
initial printing using the prescribed procedure, the screen reclaimer left the haze remover on a
screen for 48 hours in an attempt to remove the ghost image, with no success. The facility had
to use their regular haze remover on the screens in order to be able to reuse them in
production. Use of the alternative haze remover was discontinued and the product was not
included in the performance demonstration. For both the haze remover and the ink remover,
an insufficient number of screens were reclaimed with these products to determine any
correlations between demonstration conditions (e.g., number of impressions, ink color) and the
product performance.
At Facility 16, one employee applied the ink remover, and a second reclaimed the screens
and evaluated the printing quality on subsequent runs. Neither of these employees had direct
DRAFT-September 1994 V-167
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
contact with the observer during the performance demonstration. Three different people served
as the facility contact during the course of the study. The confusion of so many different
contacts probably prevented the performance demonstration from being managed as closely as
it was in other facilities.
Performance Details from Facility 25
Although all three components of System Gamma were used during part of the
performance demonstrations, the ink remover and haze remover did not work well enough to
be used for the complete four week period. The emulsion remover worked well and was used
for the entire demonstration period. During the demonstrations, the printer did not notice any
changes in the screen failure rate or any detrimental effects on the screen mesh, or frame.
The ink remover did not work well at Facility 25. It should be noted that the standard
ink remover used at this facility is chemically very different from the alternative ink remover
supplied as part of Product System Gamma. Adverse chemical interactions may have occurred
on some of the older screens due to the differences in the chemicals, and may have affected all
phases of the alternative system performance. The employee who used the alternative ink
remover tried several different procedures in order to improve the performance such as using
presoaked rags to get more ink remover on the screen, waiting 3 - 5 minutes after application
before wiping the ink, and laying rags soaked in ink remover over the screen as soon as it came
off the press. Although these procedures helped remove the ink from the stencil surface, there
was still a large amount of ink left in the screen; enough to completely block the mesh in some
cases. The residual ink was not removed by the emulsion and haze removal steps. The facility
used the alternative ink remover for a week and a half before they had to stop because of the
poor performance. None of the screens cleaned with this alternative product worked well in
production, so they all had to be reprocessed with the facility's regular products before
acceptable printing quality was achieved. The facility used several different solvent ink systems
and, in reviewing the data from the printer's observations, the ink system and the length of the
ink drying time seemed to be the most influential variable in determining the level of
performance of the alternative system. However, the ink remover performance was not
acceptable for any of the ink systems used.
The emulsion remover performed consistently well on all screens and stencils. The
reclaimer found that the product acted faster on the stencil if the screen was wetted before
applying the emulsion remover.
The haze remover did not work well. The haze remover was allowed to react on the
screens as long as 24 hours, without successfully removing the ink haze. The reclaimer
continued to use the haze remover after use of the ink remover was suspended, to see if it
would perform better if the haze was less severe. She found that the haze remover worked
better if the screens were dried before the product was applied. Even so, too much ink haze
was left in the screens to be able to successfully reuse them. Ink residue left in the mesh
caused ghost images in subsequent jobs, and eventually solubilized in similar ink systems,
which caused the inks to become discolored during the printing runs. Facility 25, therefore,
discontinued the use of the alternative haze remover after the second week of demonstrations.
At Facility 25, printing quality judgements were made by the printer, along with the other
employees involved in the study. The personnel involved seemed to work hard to try to get
acceptable results from the products.
DRAFT-September 1994 V-168
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
Alternative System Performance Table Compiled from Field Sites
The following table highlights the performance of the product system as recorded by the
printers using the products at the demonstration facilities. In addition to the field
demonstration performance data, results of the product tests performed at SPTF are also
summarized in this table. More descriptive information on the demonstration facilities is
included in Section 6.
Facility Profiles
General Facility Background for Facility 16
Facility 16 prints fleet vehicle markings on vinyl film. Their typical run length is 200
sheets, and approximately 60% of their orders are repeat orders. There are over 50 employees
at this location, and 7-10 are involved in ink removal and 1 - 3 are involved in screen
reclamation. For the performance demonstrations, all inks used were solvent-based on
polyester or monoflex screens with capillary film emulsions. Screens mesh counts of 200 - 390
threads/inch were used for the demonstrations. Average screen size at this facility is 12 ft2 and
approximately 20 screens are reclaimed daily.
Screen Reclamation Area in Facility 16
After initial ink removal at the press, the remainder of the ink is removed in the same
washout booth as is used for emulsion and haze removal. The reclamation area is 50 - 100 ft2
and is ventilated via the facility-wide system. The average temperature during the observer's
visit was 68°F (and 62% relative humidity). Spent solvent and ink waste are sent off-site to a
recycler.
Current Screen Reclamation Products at Facility 16
Information on the chemical composition of the standard ink remover at this facility was
not available for this document. For emulsion removal, they use a proprietary aqueous mixture
with at least sodium periodate. Their haze remover is a formulation which contains 100%
sodium periodate.
Current Screen Reclamation Practices in Facility 16
Using their standard products, this facility reclaims their screens following the procedure
described below. Gloves are worn during ink removal, and during emulsion and haze removal
gloves, eye protection, aprons, and respiratory protection are available as personal protective
equipment for the operators.
o Ink Remover: Card off the excess ink. At the press, apply press wash to a
disposable wipe from a safety can and wipe down the screen. Bring the screen to
the washout booth. Apply ink remover to both sides of the screen from a bucket
with a brush. Wait for one minute, then rinse with a high pressure (2000 psi)
spray. Remove the tape from the screen edges and rinse again with the high
pressure washer.
o Emulsion Remover: Dip a brush in the container of emulsion remover and brush it
into both sides of the screen. Rinse with the high pressure wash and let the screen
dry before applying the haze remover.
DRAFT-September 1994 V-169
-------
Table V-131
On-Site Performance Summary For Alternative System Gamma
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning
Time
Avg Effort
Req'd
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Inklype(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
16
Facility
25
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
3.0±2.4mins
(n=7)
52.4 ± 272.0 mins
(n=55)
0.0 ±0.0 mins
(n=55)
19.2 ±15.0 mins
(n=23)
13.2 ±31.1 hrs
(n=54)
4.6 ±11.8 hrs
(n=54)
5.0±2.0oz.
(n=7)
2.3±1.3oz.
(n=51)
3.3±1.5oz.
(n=3)
10.8±4.6oz.
(n=22)
1.2±0.4oz.
(n=50)
5.3±7.2oz.
(n=23)
11.1 ±6.6
mins (n=7)
1.8± 1.8mins
(n=50)
3.0 ±0.0 mins
(n=1)
11.7±5.2
mins
(n=22)
3.0 ±0.3 mins
(n=50)
2.2 ±0.4 mins
(n=12)
Med
Low
Med
High
Low
Low
Ink and oily
residue left in
mesh.
Easily removed
stencil on all
screens.
Did not remove
ghost images.
Excessive ink
residue left in
screen.
Quickly, easily
removed stencil.
Ink haze remained
in screen.
• Did not use the
ink remover or
haze remover due
to poor
performance.
• Stopped using ink
remover and haze
remover after 2
weeks due to poor
results.
Solvent-
based
Solvent-
based
Capillary film
Direct photo
stencil
Polyester,
untreated or
abraded;
200-390
threads/
inch
Polyester, no
treatment or
abraded;
175-420
threads/
inch
2294 in2
1848 in2
o
Q.
IS3
m
o.
o_
m
m
o'
<
CO
co_
?5^
C
CD"
ff
•o
Q)
I
CD
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CO
CD
I
Q)
8-
O
a
o
Q.
CO
O
Q.
f
5T
CD
m
3
m
-------
Table V-132
Laboratory Performance Summary For Alternative System Gamma
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average Quantity
Applied
Average
Cleaning Time
Avg Effort
Req'd
Performance for Each
System Component
Overall System
Performance
Demonstration Conditions
Ink type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
Laboratory Testing at SPTF
SPTF
Solvent-
based
Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based
Ink
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
1.5oz.
1.0 oz.
1.0 oz.
1.5oz.
1.5oz.
0.5 oz.
2.0 oz.
1.0 oz.
1.0 oz.
3.8mins
3.9mins
1.8mins
3.5mins
4.8mins
1.8mins
5.8mins
4.8mins
2.0mins
Low
Low
Low
Low
Low
Low
Med
Low
Low
Ink dissolved well. No effect on stencil.
Removed stencil easily. Moderate ink stain
remaining.
Lightened stain.
Ink dissolved well. No effect on stencil.
Removed stencil easily. Moderate ink stain
remaining.
Lightened stain.
Heavy scrubbing required to dissolve ink.
Parts of stencil deteriorated.
Removed stencil easily. Moderate ink stain
remaining.
Lightened stain.
Solvent-
based
UV-curable
Water-based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
260 threads/
inch
Polyester;
390 threads/
inch
Polyester;
260 threads/
inch
360 in2
360 in2
360 in2
o
Q.
IS3
m
o.
o_
m
m
o'
<
CO
co_
?5^
C
CD"
ff
•o
Q)
I
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CD
I
Q)
8-
O
a
o
Q.
CO
O
Q.
f
5T
CD
m
3
m
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
o Haze Remover: Dip a brush into the haze remover and apply the product to both
sides of the screen. Allow the screen to air dry. Rinse the screen with the high
pressure sprayer.
General Facility Background for Facility 25
Facility 25 prints point-of-purchase displays and overlays for appliances and automotive
applications. Print runs at this facility average 16 hours and approximately 80% of their orders
are repeat orders. During the Performance Demonstration, this facility used solvent-based inks
and a direct photo stencil on polyester screens with mesh counts of 175 - 420 threads per inch.
The most common screen sizes at Facility 25 are 42 inches x 42 inches and 42 inches x 50
inches. Approximately 25 screens are reclaimed daily.
Screen Reclamation Area in Facility 25
Ink removal is done at the press and screen reclamation is done in a separate reclaim
room. At the press, the facility-wide system provides ventilation for the area. A local,
mechanical system over the spray booth ventilates the screen reclamation area. During the
observer's visit, the average temperature in the facility was 68°F (and 34% relative humidity).
Spent solvent waste is recycled both on-site and off-site, and recycled product is reused in the
facility. Ink waste is disposed of as hazardous waste. Waste water from the washes of the
emulsion remover and haze remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 25
This facility's standard ink remover is a solvent blend which includes the following
chemicals: cyclohexanone (<60%), xylenes (<5%), ethyltoluene (< 15%), trimethylbenzenes
(<35%), C-10 aromatics (<5%), and cumene (<5%). They also use another solvent blend which
contains methyl ethyl ketone (<35%), toluene (<55%), n-butyl acetate (<20%), and heptane
(< 15%). Their emulsion remover is either a proprietary aqueous mixture with at least periodate
salt (< 10%), or a proprietary aqueous mixture with at least an acid salt. For haze removal, this
facility uses a proprietary aqueous mixture with at least sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 25
During the screen reclamation process at Facility 25, personal protective equipment
available to the employees includes gloves, eye protection, aprons, and ear protection. Screens
are reclaimed as follows:
o Ink Remover: At the press, card off excess ink. To remove the ink, rub the screen
with wipes that are saturated in ink remover. Approximately 6 - 8 wipes are used
for each screen.
o Emulsion Remover: Wet the screen with the hose to soften the blockout. Spray
emulsion remover onto both sides of the screen and let sit for 30 seconds. Rinse
from the bottom to the top of the screen with a high pressure wash (2500
psi)followed by a low pressure wash.
o Haze Remover: Allow the screen to air dry before applying the haze remover. Dip a
brush in the haze remover and rub into screen. Wait for one minute. Rinse with a
high pressure spray. Vacuum dry the screen.
DRAFT-September 1994 V-172
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
Cost
Table V-133
Method 2: Summary of Cost Analysis for Alternative System Gamma
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Gamma
Facility 16
2,294
20
Facility 25
1,848
25
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
15.9
3.48
5.0
0.75
5.0
0.43
2.3
0.24
3.3
0.24
0
0
16.9
3.70
7.0
1.04
10.8
0.92
1.2
0.12
5.3
0.39
0.0
0.0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
5.14
5.06
25,708
7,590
6.17
5.61
38,547
8,417
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
Product System Mu
DRAFT—September 1994
V-173
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Periodic acid
Water
Sodium hypochlorite
Alkali/Caustic
Sodium alkyl sulfate
Water
DRAFT—September 1994
V-174
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Occupational Exposure
Table V-134
Occupational Exposure Estimates for Alternative System Mu System
System
Ink Remover
Dibasic esters
Methoxypropanol acetate
Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Emulsion Remover
Periodic acid
Water
Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium alkyl sulfate
Inhalation (mg/day)
I
3
31
21
0
0
0
0
0
0
0
0
II
0
0.4
0.6
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
0
0
IV
0.2
1.7
2.4
0
0.2
0
0
0
0
0
0
Dermal (mg/day)
Routine
1014
312
156
94
62
156
1400
585
39
827
109
Immersion
4728
1460
728
437
291
728
6550
2730
182
3860
510
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-175
-------
Table V-135
Occupational Risk Estimates for Alternative System Mu
o
Q.
IS3
CO
Name
Mu - Ink Remover
Dibasic esters
Methoxypropanol acetate
Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Mu - Emulsion Remover
Periodic acid
Water
Mu - Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium lauryl sulfate
Hazard Quotient
Inhalation
NA
0.8
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
7.4
NA
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NA
35
NA
NA
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
300
LOAELd
NA
600
432
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
190
LOAEL
NA
NA
67
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
41
LOAEL
NA
NA
14
NA
NA
NA
NA
NA
NA
NA
NA
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Concerns exist for chronic risks from both inhalation and dermal exposures to d-
limonene during ink removal based on the calculated margins-of-exposure.
o Hazard quotient calculations for methoxypropanol acetate used in ink removal
indicate a marginal concern for chronic dermal exposures and low concern for
chronic inhalation exposures.
o Margin-of-exposure calculations show possible concerns for developmental toxicity
risks from inhalation exposures to methoxypropanol acetate.
o Developmental and chronic toxicity risks from dermal exposures to sodium alkyl
sulfate in haze remover are very low based on the calculated margin of exposure.
o Risks from other ink remover and haze remover components could not be
quantified because of limitations in hazard data, although dermal exposures to all
components could be relatively high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-177
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Environmental Releases
Table V-136
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Mu
System
Ink Remover
Dibasic esters
Methoxypropanol acetate
Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Emulsion Remover
Periodic acid
Water
Haze Remover
Sodium hypochlorite
Alkali/Caustic
Water
Sodium alkyl sulfate
Release Under Each Scenario
(g/day)
I
air
5.1
64
43
0
0.3
0
0
0
0
0
0
water
0
0
0
0
0
62
559
200
13
282
37
land
446
75
27
42
27
0
0
0
0
0
0
II
air
0
0.8
1.2
0
0.1
0
0
0
0
0
0
III
air
0
0.5
0.7
0
0
0
0
0
0
0
0
IV
air
0.3
3.6
5.1
0
0.3
0
0
0
0
0
0
water
877
266
130
81
54
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-178
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Table V-137
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Mu
Substance:
Dibasic esters
Methoxypropanol acetate
Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Periodic acid
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
To Air:
5.4 g/day
68.9 g/day
50 g/day
0.7 g/day
To Water:
877 g/day at laundry
266 g/day at laundry
130 g/day at laundry
81 g/day at laundry
54 g/day at laundry
62 g/day
200 g/day
13 g/day
37 g/day
To Landfill:
446 g/day
75 g/day
27 g/day
42 g/day
27 g/day
DRAFT—September 1994
V-179
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Releases to Water from a Single Facility
Table V-138
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Mu
Substance
Dibasic esters
Methoxypropanol acetate
Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Periodic acid
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Amount Released
to Water from
Facility
877 g/day at
laundry
266 g/day at
laundry
130 g/day at
laundry
81 g/day at laundry
54 g/day at laundry
62 g/day
200 g/day
13 g/day
37 g/day
Waste water
Treatment
Removal
Efficiency
84-97 %
97%
> 99 %
100 %
100 %
100 %
100 %
100 %
100 %
Amount to Water
After Waste water
Treatment
42.5 g/day
8 g/day
< 1.3 g/day
0
0
0
0
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
5x10'2
8x10'3
<1 x 10'3
0
0
0
0
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-180
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Releases to Air from Individual Screen Printing Facilities
Table V-139
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Mu
Substance
Dibasic esters
Methoxypropanol acetate
Limonene
Derivatized plant oil
Amount of Releases per
day
5.4 g/day
68.9 g/day
50 g/day
0.7 g/day
Highest Average
Concentration 100 M away
1.1x10'2ug/m3
1.4x10-1ug/m3
1 x 10'1 ug/m3
1.4x10-3ug/m3
Annual Potential Dose,
mg/yeara
8x10'2
1
7x10'1
1 x 10'2
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Mu.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, product System Mu reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Mu Performance, and Related Variables
This product system consisted of an ink remover, an emulsion remover, and a haze
remover. The performance of the product system was demonstrated at Facilities 17 and 22.
Facility 17 prints decals; Facility 22 prints back-lit automotive overlays. During the four week
demonstration period, Facility 17 reclaimed 18 screens and Facility 22 reclaimed 44 screens.
DRAFT—September 1994
V-181
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
For the performance demonstrations, Facility 17 used primarily UV-cured inks, and Facility 22
used solvent-based inks.
Facility 17 reported that the ink remover worked well, although black (UV-cured) inks
were more difficult to remove than the other UV-cured inks. Facility 22 reported that the ink
remover performance was unacceptable for their solvent-based ink system. Extra physical
effort and time were needed, and a lot of product was applied, but an ink residue still remained
on the screen. The standard ink remover used at Facility 22 is chemically very different from
the alternative ink remover supplied as part of Product System Mu. These differences may
have caused adverse chemicals interactions on older screens.
The emulsion remover performance was very good at both facilities. It removed the
emulsion quickly, easily, and completely. Facility 22 commented that the emulsion remover
performance was "excellent."
Facility 17 reported that the haze remover worked better and faster than one of their
usual products, but not as well as the haze remover that they use for difficult stains. The haze
remover's performance was also affected by the number of impressions in the previous test
run: it did not work as well after runs with many impressions. Facility 22 reported that the
haze remover did not work at all and they had to use their standard product before they could
reuse the screen. There was no visible change in the haze when the haze remover was applied.
Alternative System Mu Profile
The manufacturer recommends applying Product System Mu as follows:
o Ink Remover Card up the excess ink. Spray both sides of the screen with the ink
remover. Also spray a rag or brush with the product and rub both sides of the
screen until all of the ink residue is completely dissolved or emulsified and the
emulsion becomes clearly visible. Rinse well with water. For tests done at SPTF, a
1000 psi spray was used for rinsing the ink remover, emulsion remover, and haze
remover.
o Emulsion Remover Using a spray bottle, apply the emulsion remover to both sides
of the screen. Distribute the product evenly with a brush and scrub the screen
gently for approximately two minutes. Rinse thoroughly with a high pressure water
spray.
o Haze Remover Spray haze remover evenly on both sides of the screen. Distribute
the product using a nylon brush. Let sit for at least one hour. If the ink is dried,
let it sit for up to 24 hours. Rinse off with water. If stains remain in the screen,
allow the screen to dry and repeat the application procedure for the ink remover
and pressure rinse.
Alternative System Performance at SPTF
Product System Mu was tested at SPTF on three screens (one with a solvent-based ink,
one with a UV-curable ink, and one with a water-based ink). The ink remover and the haze
remover performance varied depending on the type of ink used. The emulsion remover and the
haze remover performance was consistent on all three screens.
DRAFT-September 1994 V-182
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
On the screen with the solvent-based ink and the screen with UV ink, the ink remover
dissolved the ink easily with little scrubbing and no effect on the emulsion. On the water-based
ink screen, however, the ink dried in the screen and heavy scrubbing and more product were
needed to remove the ink. While scrubbing, the stencil started to break down in the half tone
area. For all three screens, one wipe was used to remove the ink.
The emulsion remover easily dissolved the stencil with only light scrubbing on all three
screens, leaving no ink or emulsion residue behind. The screens did have a light-to-moderate
ink stain was remaining. Subsequent application of the haze remover lightened the ink stains
of the UV ink and the water-based ink screen, so that a very light ink stain remained. The haze
remover did not lighten the moderate ink stain on the screen with the solvent-based ink.
Alternative System Performance Details
Performance Details from Facility 17
Facility 17 thought that Product System Mu cleaned the screens well and the screen
reclaimer noted that the odors associated with the alternative system were not as bad as those
produced by the facility's usual products.
The ink remover performed well. Compared to their standard product, the reclaimer
noted that when using the alternative ink remover, he did not have to scrub the screens as
much and did not have to use as much product to get the screens clean. The printer
commented that it was more difficult to remove all of the ink from the screen when the previous
print run was a long one. However, the data, although limited, do not show a change in the ink
remover quantity or time corresponding to a change in the length of the previous run. Black
UV-cured inks were not removed as effectively as other UV-cured ink colors.
The emulsion remover performance was very good on all screens. The haze remover
worked well in most cases, except when the haze was unusually dark. This facility normally
uses two haze removers: one is a weaker chemical that is used more frequently and the other,
stronger chemical, is only used for stubborn stains. The Product System Mu haze remover
worked better than the weaker of their two usual haze removal products, but not as well as the
stronger chemical. On the one screen they reclaimed that had solvent-based ink on it, the
alternative haze remover did not remove the haze and the printer had to use their stronger haze
remover to clean the screen. All other screens reclaimed had been used with UV ink, and on
these screens, the facility felt that the alternative haze remover performed as well as and more
quickly than the weaker of their two haze removers.
Using the alternative system did not substantially change the screen cleaning routine at
this facility. The printer did not notice any changes in the screen condition during the time the
alternative system was in use. If less scrubbing is associated with the use of the alternative
system, then screen abrasion and possibly the screen failure rate could decrease with
continued use of the alternative system.
Performance Details from Facility 22
This facility found the performance of Product System Mu ink remover and haze remover
was not acceptable. The printer thought the emulsion remover performance was very good.
The ink remover was applied to the screens immediately after completion of the press
runs. Cleaning the screens still took a high level of effort and a long time to accomplish. All
DRAFT-September 1994 V-183
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
screens took at least 20 minutes to clean, and two screens took 60 minutes. Screen cleaning
required 10-16 ounces of product; because of the large quantity required, the facility ran out
of ink remover after cleaning the twentieth screen. Even with this extra effort, and extra
product, an ink residue remained on the screens. The ink remover was especially ineffective on
ink which built up partially dried on the edge of the screen during long runs. Overall, the
facility contact commented that the product did not seem to cut the ink at all. It should be
noted that the standard ink remover used by this facility contains strong hydrocarbon solvents
and is chemically very different from the alternative ink remover. These chemical differences
may have led to an adverse chemical interaction.
The emulsion remover worked well, with no notable variations in performance among the
screens used. It required a low level of effort, and consistently removed all the emulsion from
the screens. The performance of the haze remover proved to be unacceptable at Facility 22.
Ghost images were not removed from the screens and the facility was not able to reuse the
screens until they were treated with their standard haze remover. For this reason, use of the
alternative haze remover was suspended during the first week of the demonstration.
At Facility 22 the facility contact, who was the product development manager, removed
the ink, reclaimed the screens and evaluated the printing quality on subsequent runs. Although
these were not tasks he usually performs, it should have ensured consistency of judgement on
the product performance evaluations. Product System Mu did not appear to cause screen
failure, or have any noticeable effects on the screens or frames.
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 17
Facility 17 prints decals on paper, plastics, metals, ceramics, and glass. Their typical
run length is 400 impressions, and approximately 5% of their orders are repeat orders. There
are about 5 employees at this location, and 1 - 3 are involved in screen reclamation. Both
solvent-based and UV-curable ink systems are used at this facility; primarily UV inks were used
during the performance demonstrations. Screens with mesh counts of 280 - 390 threads/inch
and direct photo stencils were used for the demonstrations. The average screen size at this
facility is 16 ft2 and approximately 25 screens are reclaimed daily.
Screen Reclamation Area in Facility 1 7
Ink removal is done at the press where local ventilation is provided. Emulsion and haze
removal are done in a sink in the screen reclamation area, which is approximately 150 ft2 and
is ventilated via a hood above the sink. The average temperature during the observer's visit was
70°F (and 41% relative humidity). Spent solvent and ink waste are disposed of as hazardous
waste. Waste water from the high-pressure wash of the emulsion remover and haze remover is
not recycled or filtered at this facility.
DRAFT-September 1994 V-184
-------
Table V-140
On-Site Performance Summary For System Mu
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall
System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
17
Facility
22
Ink remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
13.9±16.9hrs
(n=19)
4.9±1.7hrs
(n=19)
21.3 ±1 0.5 mins
(n=19)
15.6 ±12.6 mins
(n=20)
22.5 ± 72.5 hrs
(n=47)
2.2 ±1.2 mins
(n=47)
2.7±0.7oz.
(n=18)
2.6±0.6oz.
(n=18)
2.9±0.7oz.
(n=18)
11.6±1.4oz.
(n=20)
1.1 ±0.3oz.
(n=47)
1.3±0.5oz.
(n=6)
7.0 ±3.9
mins (n=19)
5.7 ±2.0
mins
(n=19)
data not
recorded
30.5 ±12.0
mins (n=20)
2.8 ±0.5
mins
(n=47)
1.3 ±0.6
mins
(n=3)
Moderate
Low
Moderate
High
Low
Moderate
Removed ink well.
Removed stencil
easily.
Worked well on
moderate haze.
Left ink residue in
the screen.
Removed stencil
easily.
Left ghost image
in screens.
•Haze
remover
required at
least one hour
of wait time.
• All screens
with UV ink
were reusable.
• Used their
standard haze
remover
before reusing
screens.
• Emulsion
remover
worked
better than any
other they
tried.
UVink
(one
screen
with
solvent-
based
ink)
Solvent-
based
Direct
photo
stencil
Direct
photo
stencil
Mesh type
not recorded;
280-390
threads/inch
Mono-
filament
polyester;
230-305
threads/inch
2270 in2
1520 in2
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Table V-141
Laboratory Performance Summary For System Mu
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System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Laboratory Testing at SPTF
SPTF
Solvent-
based Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based Ink
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
1.0 oz.
0.5 oz.
1.0 oz.
1.5oz.
1.0 oz.
0.5 oz.
2.0 oz.
1.5oz.
0.5 oz.
3.5mins
3.6mins
2.0mins
2.9mins
3.3mins
2.0mins
6.1 mins
3.1 mins
2.0 mins
Low
Med
Low
Low
Med
Low
High
Med
Low
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
Dissolved ink easily.
Dissolved stencil well.
stain remaining.
Moderate ink
Haze remover did not lighten ink stain.
Dissolved ink very eas ly.
Dissolved stencil well.
remaining.
Light ink stain
Lightened ink stain.
Excessive scrubbing and product
required to remove dried ink.
Dissolved stencil well.
remaining.
Light ink stain
Lightened ink stain.
Solvent-
based
UV-
curable
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
260
threads/inch
Polyester;
390
threads/inch
Polyester;
260
threads/inch
360 in2
360 in2
360 in2
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
Current Screen Reclamation Products at Facility 1 7
The standard ink remover used at Facility 17 is a proprietary blend consisting of at least
propylene glycol ethers (<50%). Their emulsion remover is a proprietary aqueous mixture
which contains periodate salt (< 10%). For haze removal, they use a proprietary aqueous
mixture with sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 1 7
Using their standard products, this facility reclaims their screens following the procedure
described below. Gloves, eye protection, aprons, respiratory protection, and barrier cream are
available as personal protective equipment for the operators during screen reclamation
activities.
o Ink Remover: Card off the excess ink. At the press, spray press wash onto the
screen and wipe with reusable rags. Repeat if necessary. One or two rags are used
for each screen. Bring the screen to the reclamation sink and spray the ink
remover onto both sides of the screen from a low pressure (60 psi) sprayer. Rub
the product into the screen with a brush, then pressure rinse (1200 psi) the screen.
o Emulsion Remover: Spray the emulsion remover onto both sides of the screen
from a low pressure sprayer. Brush the emulsion remover into the screen.
Pressure rinse and allow to air dry.
o Haze Remover: This facility uses two haze remover products. The weaker chemical
is used for light to moderate stains. The stronger product is used only when the
haze is dark. For light to moderate haze, spray the screen with the haze remover
and let it sit for about 30 minutes. Scrub both sides of the screen for about one
minute each and rinse with the pressure washer. Give the screen a final rinse at
low pressure from a hose. For dark haze, coat both sides of the screen with the
haze remover using the scoop coater (this is the same kind of coater that is used
when applying emulsion to the screen and it applies a thin, even coat). Let sit for 3
- 4 minutes. Pressure wash both sides of the screen.
General Facility Background for Facility 22
Facility 22 prints back-lit automotive graphic overlays on plastics. Typically, they print
about 500 sheets per run and approximately 90% of their orders are repeat orders. There are
approximately 40 employees at this facility, and two people are involved in screen reclamation.
During the Performance Demonstration, this facility used solvent-based inks and a direct photo
stencil. Polyester screens with mesh counts of 230 - 305 threads per inch were used. The
average screen size in this facility is 40 inches x 40 inches and approximately 12 screens are
reclaimed daily.
Screen Reclamation Area in Facility 22
Ink removal is done both at the press and in the screen reclamation room. At the press,
the plant system (facility-wide) provides ventilation. In the screen reclamation area, there is a
back-lit spray booth and the area is ventilated by a fan in the hood of the booth. During the
observer's visit, the average temperature in the facility was 68°F (and 44% relative humidity).
Ink waste is disposed of as hazardous waste and rags are disposed of as non-hazardous waste.
DRAFT-September 1994 V-187
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
Waste water from the washes of the emulsion remover and haze remover is not recycled or
filtered at this facility.
Current Screen Reclamation Products at Facility 22
For ink removal, Facility 22 uses a custom solvent blend which consists of ethyl acetate
(20% - 27%), methyl ethyl ketone (20%), and xylene (20%). As an emulsion remover, they use a
proprietary aqueous mixture with at least sodium periodate. Their standard haze remover is a
proprietary blend which consists primarily of tripropylene glycol methyl ether.
Current Screen Reclamation Practices in Facility 22
During the screen reclamation process at Facility 22, personal protective equipment
available to the employees includes gloves, eye protection, and ear protection. Screens are
reclaimed as follows:
o Ink Remover: At the press, card off excess ink and wipe the screen with rags that
are saturated in ink remover. Bring the screen to the screen reclamation room.
Saturate disposable wipes in the ink remover and wipe both sides of the screen.
Four to six wipes are used on each screen. Rinse the screen with a high pressure
washer (2000 psi).
o Emulsion Remover: Spray both sides of the screen with the emulsion remover.
Wipe the screen with a scrubber pad. Rinse with a high pressure wash. If needed,
spray on more product, brush and rinse again.
o Haze Remover: Dip a disposable wipe in the haze remover container and wipe both
sides of the screen. Rub the product into the stained areas with a brush. Rinse
with a high pressure wash on both sides, followed by a final, low pressure rinse
with the hose. Vacuum dry the screen.
DRAFT-September 1994 V-188
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Mu
Cost
Table V-142
Method 2: Summary of Cost Analysis for Alternative System Mu
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Mu
Facility 17
2,270
25
Facility 22
1,520
12
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
17.2
3.75
1.0
0.15
2.7
0.16
2.6
0.21
2.9
0.17
110
0.08
34.6
7.58
10.8
1.61
11.6
0.70
1.1
0.09
1.3
0.08
73
0.05
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
4.53
4.79
28,295
7,185
10.11
9.33
30,338
13,997
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-189
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
Product System Phi
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Dibasic esters
Sodium periodate
Water
Ethoxylated nonylphenol
Other
N-methyl pyrrolidone
Dibasic esters
Occupational Exposure
Table V-143
Occupational Exposure Estimates for Alternative System Phi
System
Ink Remover
Dibasic esters
Emulsion Remover
Sodium periodate
Water
Ethoxylated nonylphenol
Other
Haze Remover
N-methylpyrrolidone
Dibasic esters
Inhalation (mg/day)
I
4
0
0
0
0
6
1
II
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
IV
0.2
0
0
0
0
0
0
Dermal (mg/day)
Routine
1561
47
1210
123
181
780
780
Immersion
7270
218
5640
575
844
3640
3639
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-190
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
DRAFT-September 1994 V-191
-------
Table V-144
Occupational Risk Estimates for Alternative System Phi
o
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Name
Ink Remover
Dibasic esters
Emulsion Remover
Sodium periodate
Water
Ethoxylated nonylphenol
Haze Remover
N-methylpyrrolidone
Dibasic esters
Hazard Quotient
Inhalation
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
NA
NA
NA
NA
NA
Immersion
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
2076
NA
LOAELd
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
16
NA
LOAEL
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
3.3
NA
LOAEL
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Dermal exposures to N-methylpyrrolidone during haze removal present a concern
for developmental toxicity risk based on the calculated margins-of-exposure.
Similar estimates for inhalation exposures to N-methylpyrrolidone indicate very low
concern.
o Risks from other ink remover and haze remover components could not be
quantified because of limitations in hazard data, although dermal exposures to all
components could be relatively high.
o Inhalation exposures to all other components are very low.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-193
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
Environmental Releases
Table V-145
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Phi
System
Ink Remover
Dibasic esters
Emulsion Remover
Sodium periodate
Water
Ethoxylated nonylphenol
Other
Haze Remover
N-methylpyrrolidone
Dibasic esters
Release Under Each Scenario
(g/day)
I
air
8.1
0
0
0
0
12
3.1
water
0
19
481
49
72
270
279
land
766
0
0
0
0
0
0
II
air
0
0
0
0
0
0.1
0
III
air
0
0
0
0
0
0
0
IV
air
0.3
0
0
0
0
0
0
water
1349
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Environmental Releases from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Phi
From Ink Removal Operations:
Dibasic esters
8.4 g/day to air
1349 g/day to water from rags at commercial laundry
766 g/day to landfill
From Emulsion Remover:
Sodium periodate
19 g/day to water
Ethoxylated nonylphenol
49 g/day to water
Other
72 g/day to water
DRAFT—September 1994
V-194
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
From Haze Remover:
N-methyl pyrrolidone
12.1 g/day to air
270 g/day to water
Dibasic esters
3.1 g/day to air
279 g/day to water
Table V-146
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Phi
Substance:
Dibasic esters
Sodium periodate
Ethoxylated nonylphenol
Other
N-methyl pyrrolidone
To Air:
11. 5 g/day
12.1 g/day
To Water:
279 g/day
1349 g/day at laundry
19 g/day
49 g/day
72 g/day
270 g/day
To Landfill:
766 g/day
Releases to Water from a Single Facility
Table V-147
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Phi
Substance
Dibasic esters
Sodium periodate
Ethoxylated nonylphenol
Other
N-methyl pyrrolidone
Amount Released
to Water from
Facility
279 g/day
1349 g/day at
laundry
19 g/day
49 g/day
72 g/day
270 g/day
Waste water
Treatment
Removal
Efficiency
84-97 %
100 %
100 %
100 %
97%
Amount to Water
After Waste water
Treatment
13.8 g/day
66.4 g/day
0
0
0
8.1 g/day
Daily Stream
Concentration,
ug/La for 1000
MLD Receiving
Water
1 x 10'2
6x10'2
0
0
0
8x10'3
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-195
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
Releases to Air from Individual Screen Printing Facilities
Table V-148
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Phi
Substance
Dibasic esters
N-methyl pyrrolidone
Amount of Releases per
day
11.5g/day
12.1 g/day
Highest Average
Concentration 100 M away
2.3x10-2ug/m3
2.5x10-2ug/m3
Annual Potential
Dose, mg/yeara
2x10'1
2x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Phi.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Phi reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Phi. Performance, and Related Variables
This product system consisted of an ink remover, an emulsion remover, and a haze
remover. It's performance was demonstrated at Facility 5 and Facility 23. Facility 5 employs
approximately 15 people with 3 employees involved in the screen printing area of the business.
They print interior signs, markings on parts, and identification badges. Facility 23 employs five
people and prints mainly on plastics. Their products include front panels, overlays, and labels.
Over a four week period, Facility 5 reclaimed 40 screens. Facility 23 used Product System Phi
for two weeks and reclaimed 8 screens. During the demonstrations, both facilities primarily
used solvent-based vinyl inks, but they also tried System Phi on acrylic vinyl, epoxy, and
DRAFT-September 1994 V-196
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
metallic inks. Facility 5 used a capillary film emulsion on a polyester screen and Facility 23
used a dual-cure emulsion on a multifilament polyester screen.
Both facilities reported similar results with Product System Phi. At Facility 5, the ink
remover broke down the ink effectively but required more effort than their own ink remover.
Facility 23 found that the ink remover performance was inconsistent; it worked well on metallic
inks, but did not remove ink from around the edges of the stencil when using vinyl ink. Both
facilities noticed that the ink remover tended to deteriorate the stencil if it was not wiped off
immediately after application. For this reason, the facilities felt that this product should not be
used for in-process ink removal.
The emulsion remover was very effective and it easily removed the stencil with very little
scrubbing. Both facilities reported the System Phi emulsion remover performed better than the
product they were using before the demonstrations.
Facility 5 reported that a haze remained on the screen after using the haze remover, but it
did not affect future print image quality. Over time, the printer felt this haze could potentially
deteriorate the screen mesh. Facility 23 reported that the haze remover left a ghost image and
some screens could not be reused for reverse printing or for printing with transparent inks.
Alternative System Phi Profile
The manufacturer recommends applying Product System Phi as follows:
o Ink Remover After carding off as much excess ink as possible, apply ink remover
to the screen using a spray bottle. With a soft brush or sponge, work the ink
remover into the screen. Rinse or wipe both sides of the screen with a lint-free
cloth.
o Emulsion Remover Shake the bottle well and spray emulsion remover on both
sides of the screens. Work the product into the screen using a nylon mesh pad or
brush. If the product is too thick to spray, pour it from the spray bottle onto the
brush or screen. Wait for 2 - 3 minutes, but do not allow the emulsion remover to
dry. Rinse the screen with a pressure washer (a 1000 psi washer was used at
SPTF).
o Haze Remover Allow the screen to dry before applying the haze remover. Place the
screen flat side down on a non-porous surface. Spray the haze remover on the
ghost image and/or emulsion residue to be removed. Using a nylon brush or pad,
work the product into the screen. Wait for 2 - 3 minutes and rinse. For dried
solvent inks, lacquers, enamels, vinyls, cured plastisol, or fixed emulsions, let sit
for 30 minutes and wipe clean with lint free towel.
Alternative System Performance at SPTF
Product System Phi was tested at SPTF on two screens (one with a solvent-based ink, and
one with a UV-curable ink). This product is not recommended for use on water-based inks. On
both screens, the ink dissolved quickly with minimal effort. There was a slight blue color on
the wipe (the color of the stencil), but upon inspection the stencil did not look like it was
damaged or deteriorated. On the screen with solvent-based ink, six rags were needed to remove
the ink, and on the UV ink screen, five rags were used. The technician noticed a slight odor.
DRAFT-September 1994 V-197
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
The emulsion remover also worked well; it completely dissolved the stencil with only light
scrubbing on both screens. After using the emulsion remover, the screen with solvent-based
ink had a very light stain and slight ink residue in small areas. The haze remover lightened the
stain only slightly, but it removed the ink residue. The screen with UV-curable ink had a dark
ink stain and the haze remover lightened it somewhat, but did not remove it completely. The
technician noted that the haze remover was very easy to use and required minimal effort. There
was a slight odor to the product, but it was not unpleasant.
The recommended application procedure was followed with a few slight variations. The
ink remover was allowed to sit on the screen for 30 seconds before it was rubbed in with a
sponge. The haze remover was removed with a pressure wash.
Alternative System Performance Details
Performance Details from Facility 5
At the conclusion of the Performance Demonstrations, the printer was asked to compare
the performance of each component of Product System Phi to the system they previously used
at this facility. Overall, the printer felt the emulsion remover worked better, and the ink
remover and the haze remover did not work as well as their previous reclamation products.
On most screens the printer reported that the ink was removed effectively, however, there
was an light to moderate ink haze remaining on 35% of the screens after using the ink remover.
This facility found the ink remover performance was the same whether used on vinyl inks or on
epoxies. Although not included in the Performance Demonstration protocol, the printer used
this product as an in-process ink remover, not just as a reclamation ink remover. He found it
would start to deteriorate the stencil if left on the screen for more than a few seconds. By
spraying on the ink remover, wiping it off very quickly, and allowing the screen to dry before
printing, he was able to use it in-process without affecting the print quality.
The printer was very enthusiastic about the emulsion remover, commenting that it
consistently dissolved the stencil very quickly with minimal effort. After the conclusion of the
Performance Demonstrations, he requested more information on the product so he could
continue to use it in his facility.
The haze remover performance was not up to the standards of this printing facility.
When following the manufacturer's application instructions, the haze remover did not remove
the haze satisfactorily. The printer commented that he thought the haze remaining on the
screen would deteriorate the screen over time. To improve the performance, the printer let the
haze remover sit on the screen overnight (instead of the recommended 3 - 5 minutes), he wiped
the product off with rags before pressure washing, and he tried using more ink remover hoping
that there would be less ink stain later. None of these techniques improved the performance of
the product. The printer did note that he preferred the very mild odor of this product to the
strong, unpleasant odor of his own haze remover.
In reviewing the data from the printer's evaluation forms, there does not seem to be a
correlation between any specific screen condition (e.g., ink type, ink color, number of
impressions) and variations in the product performance. Overall, the use of Product System
Phi had no deleterious effects on the screen mesh or on the subsequent print quality image and
the printer did not notice any change in screen failure rate over the time period that the
alternative system was in use.
DRAFT-September 1994 V-198
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
Performance Details from Facility 23
Generally, this facility felt the emulsion remover worked well, but they were not satisfied
with the ink remover and the haze remover of Product System Phi. While the actual
performance of the alternative system was often adequate, the procedures involved with using
the products disrupted the facility's routine. After two weeks of demonstrations, this facility
discontinued their participation in the project and only submitted data on 8 screens. In
addition to problems with the product application procedures, this facility experienced
personnel problems that contributed to their decision to discontinue their participation after
two weeks. The main screen printer/screen reclaimer involved with the demonstrations was
absent for two weeks in the middle of the project. No screen reclamation with the alternative
system continued during her absence. When she returned, so much work had accumulated
that the facility decided they could not spare the time for the demonstrations.
The printer found the performance of the ink remover to be inconsistent. When using
metallic inks, the alternative ink remover worked better than their standard product. With
other ink types, the ink remover did not effectively remove the ink from the edges of the stencil
and it did not remove as much ink from the screen as their standard product. Their standard
ink remover is a solvent blend whose chemical composition is very different from that of the
alternative ink remover. On older screens that have been reclaimed many times, adverse
chemical interactions between the standard products and the alternative system could occur
due to these differences.
The printer felt the emulsion remover was as effective as their standard product, and it
dissolved the stencil faster than their standard emulsion remover.
Product System Phi haze remover required more contact time with the screen than this
facility's usual haze remover. This additional waiting time impeded the facility's ability to reuse
screens at the needed rate. In addition to the inconvenient wait time, the haze remover often
did not reduce the haze sufficiently and the facility had to follow up with their usual product
before the screen could be reused. The printer noted that the haze remover was less irritating
to the respiratory system than their usual haze remover.
During the two weeks the products were used in this facility there was no noticeable mesh
deterioration, no change in the screen failure rate, and no change in print quality.
Alternative System Performance Table Compiled from Field Sites
The table below highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 5
Facility 5 makes interior signs, marks parts, and prints identification badges. Primarily,
they print on plastics and on metals. A typical run is 100 pieces, and approximately 80% of
their orders are repeat orders. Of the 15 employees at this facility, approximately 3 are
DRAFT-September 1994 V-199
-------
Table V-149
On-Site Performance Summary For Alternative System Phi
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System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Inktypefs)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility 5
Facility
23
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
2.5±9.6mins
(n=40)
1.3±0.6mins
(n=40)
8.2 ± 37.6mins
(n=40)
50.6 ± 40.6 hrs
(n=9)
48.0 ± 40.8 hrs
(n=10)
1.6±0.8mins
(n=10)
1.3±0.5oz.
(n=40)
1.7±0.5oz.
(n=40)
1.1 ±0.5oz.
(n=40)
2.0±1.9oz.
(n=9)
1.0±0.0oz.
(n=10)
1.2±0.4oz.
(n=10)
3.7±4.2mins
(n=40)
2.6±0.5mins
(n=40)
1.6±0.5mins
(n=40)
6.9±10.6mins
(n=9)
2.9±1.4mins
(n=10)
12.2 ±14.1 mins
(n=10)
Moderate
Moderate
Moderate
Low
Low/
Moderate
Moderate
Light/Moderate ink
haze on 35% of
screens.
Quickly, easily
removed stencil.
Did not consistently
remove haze.
Inconsistent
performance. Worked
well on metallic inks;
did not work well on
other inks used.
Quickly, easily
removed stencil.
30 min. wait time
required caused
scheduling problems
at this facility.
• Ink remover
deteriorated the
stencil.
• Light ink stain
remained after
reclamation.
• Facility stopped
using the product
after 2 weeks
because of the
additional time
required for the
haze remover and
personnel
problems.
• Ink remover
deteriorated the
stencil and could
not be used in
process.
Solvent-
based
(primarily
vinyl, some
epoxy)
Solvent-
based vinyl
Capillary film
Dual-cure
Polyester, no
treatment;
305
threads/inch
Multi-
filament
polyester; 1 95 -
305
threads/inch
281 5 in2
883 in2
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Table V-150
Laboratory Performance Summary For Alternative System Phi
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Laboratory Testing at SPTF
SPTF
Solvent-
based Ink
SPTF
UV-curable
Ink
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
2.5 oz.
0.5 oz.
1.0 oz.
2.0 oz.
0.5 oz.
0.5 oz.
6.7mins
6.4mins
5.6mins
5.5mins
5.5mins
6.2mins
Low
Low
Low
Low
Low
Low
Overall System
Performance
Demonstration Conditions
Ink type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
Ink dissolved easily.
Stencil dissolved easily; slight ink residue
and light stain remaining.
Lightened stain slightly; removed residue.
Ink dissolved very easily.
Stencil dissolved easily; dark ink stain
remaining.
Lightened ink stain, but did not remove it.
Solvent-
based
UV-curable
Dual cure
direct
Dual cure
direct
Polyester; 255
threads/inch
Polyester; 390
threads/inch
360 in2
360 in2
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
involved in screen printing operations and 1 employee is responsible for screen reclamation
activities. The facility uses a variety of solvent-based inks including vinyl-based inks, epoxy
inks and a multipurpose ink. They use capillary film for their emulsion. All screens used in
the Performance Demonstrations were polyester (no treatment) with a typical mesh count of
305 threads/inch. The average screen size at this facility is 20" x 20" and approximately 2 - 3
screens are reclaimed daily.
Screen Reclamation Area in Facility 5
The screen printing, ink removal, and screen reclamation activities are all done in the
same room which is approximately 100 ft2 in size. A fan and the door to outside provide
ventilation for the room. The average temperature during the observer's visit was 68°F (and
40% relative humidity), but when an oven located in the same room is in operation, the
temperature can increase significantly. Rags used for ink removal are disposed of as non-
hazardous waste. Waste water from the high pressure wash of the emulsion remover and haze
remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 5
The standard ink remover used at Facility 5 is a blend which contains 55% - 56%
propylene glycol ether. For emulsion removal, they use a product which contains sodium
metaperiodate (5%) and their standard haze remover contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 5
This facility primarily uses a multipurpose ink remover, however, when using specialized
inks (20% of their jobs), they use the ink remover recommended by the ink manufacturer.
Emulsion remover and haze remover are used on all screens. For their standard inks, the
screen reclamation process is described below:
o Ink Remover: Immediately after the printing job is completed, card off excess ink
from the screen with cardboard. Apply ink remover to a reusable rag from a safety
can. Gloves are usually worn during this step. Wipe both sides of the screen with
the rag. Continue wiping with clean rags until ink no longer comes off on the rag.
Typically, 2 - 4 rags are used on each screen. Wipe both sides of the screen with a
dry rag to remove oily film.
o Emulsion Remover: Screen reclamation is usually done at the end of the work day
for several reasons: screens that are used throughout the day can all be reclaimed
at the same time for more efficient operation, the haze remover can dry overnight,
and fewer employees are subject to the strong, unpleasant odor of the haze
remover. To apply the emulsion remover, dip a brush into the product container,
wearing gloves, and brush the emulsion remover into both sides of the screen. Wait
for 1 - 5 minutes. Rinse both sides of the screen with a high pressure (1000 psi)
wash. Wipe both sides of the screen with a dry rag.
o Haze Remover: Typically, haze remover is used immediately after emulsion
removal, at the end of the day. The haze remover is a two-part system. To apply,
dip a nylon brush into the pail containing the first haze remover component,
wearing gloves, eye protection, and a respirator (if desired). Rub the haze remover
into the dry screen on both sides. Allow to dry overnight. Rinse with a high
DRAFT-September 1994 V-202
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
pressure wash. Apply the second part of the haze remover product with a brush.
Wait for one minute. Rinse with a high pressure wash.
General Facility Background for Facility 23
The majority of the products printed by Facility 23 are front panels, overlays, and labels
on plastics. They also do some printing on paper, metals, and glass. Run lengths are typically
150 impressions, and approximately 82% of their business is for repeat orders. There are less
than 5 employees at this facility and two are involved in screen reclamation operations. The
facility uses several types of solvent-based inks including vinyls, acrylic vinyls, and epoxy inks.
They use a dual-cure emulsion and a multifilament (untreated) polyester mesh. Mesh counts
used in the Performance Demonstrations ranged from 195 - 305 threads/inch. The average
screen size at this facility is 1,305 in2 and approximately 3 - 5 screens are reclaimed daily.
Screen Reclamation Area in Facility 23
Ink removal is done at press side and screen reclamation takes place nearby in a back-lit
spray booth. The facility-wide ventilation covers both work areas. During the observer's visit,
the average temperature in the ink removal area was 70°F (and 35% relative humidity), and the
screen reclamation area temperature was 62°F (and 55% relative humidity). Rags used for ink
removal are cleaned under a contract with an industrial laundry service. Spent solvent from
ink removal operations and ink waste are disposed of as hazardous waste. Waste water from
the washes of the emulsion remover and haze remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 23
For ink removal, Facility 23 uses a proprietary blend which contains at least xylene,
propylene glycol methyl ether, and diacetone alcohol. Their standard emulsion remover
product is 100% sodium periodate, and their standard haze remover is a proprietary aqueous
mixture which contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 23
At Facility 23, the application procedure described below is used for most screens.
Usually, four screens are reclaimed at the same time. The reclamation procedure is as follows:
o Ink Remover: At the press, scrape the excess ink off the screen. Wearing gloves,
wipe the edges of the screen with disposable lint-free wipes. Dampen a reusable rag
with ink remover from a pump can and wipe both sides of the screen. Continue
dampening the rag and wiping until the ink is no longer coming off on the rag.
Usually, one or two rags are used on each screen. Once the rag stops picking up
the ink, use a blow dryer to evaporate the solvent from the screen.
o Emulsion Remover: Put the screen in the sink and wet the screen. Wearing gloves
and eye protection, spray emulsion remover onto both sides of the screen and let it
sit for approximately two minutes. Rinse with a high pressure (1000 psi) water
spray.
o Haze Remover: Dip a brush into the bucket of haze remover, wearing gloves, eye
protection, and, if desired, an apron and respirator. Rub the haze remover into the
screen on the effected area on both sides. Wait for 3 - 5 minutes for screens on
retensionable frames and 5-10 minutes for screens on fixed frames. Rinse with a
low pressure water spray, followed by a high pressure wash.
DRAFT-September 1994 V-203
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
Cost
Table V-151
Method 2: Summary of Cost Analysis for Alternative System Phi
Cost Element Description
Baseline
(Traditional
Svstem 4^
Alternative System Phi
Facility 5
Facility 23
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
2,815
3
883
4
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost ($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
8.0
1.74
2.9
0.43
1.3
0.25
1.7
0.33
1.1
0.35
0
0
22.0
4.81
1.3
0.19
2.0
0.39
1.0
0.19
1.2
0.37
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
3.11
6.10
1,991
9,233
5.96
7.82
5,957
11,728
"Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-204
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AE
Product System Omicron-AE
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Diethylene glycol butyl ether
Propylene glycol
Sodium periodate
Ethoxylated nonylphenol
Water
Ethoxylated nonylphenol
Phosphate surfactant
Water
Other
Occupational Exposure
Table V-152
Occupational Exposure Estimates for Alternative System Omicron-AE
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover
Sodium Periodate
Ethoxylated nonylphenol
Water
Haze Remover
Other
Ethoxylated nonphenol
Phosphate surfactant
Water
Inhalation (mg/day)
I
0
17
0
0
0
0
0
0
0
II
0
0.1
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
IV
0
0.4
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
984
576
47
31
1480
109
16
78
1360
Immersion
4590
2690
218
146
6920
510
73
364
6330
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-205
-------
Table V-153
Occupational Risk Estimates for Alternative System Omicron AE
Name
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover
Ethoxylated nonylphenol
Phosphate surfactant
Water
Hazard Quotient
Inhalation
NA
0.01
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
0.4
NA
NA
NA
NA
NA
NA
NA
Immersion
NA
1.9
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
142
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
3.6
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
30
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
0.8
NA
NA
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Margin-of-exposure calculations indicate clear concerns for chronic dermal
exposures to workers using diethylene glycol butyl ether in ink removal.
o Margin-of-exposure calculations also show possible concerns for developmental
toxicity risks from dermal "immersion" exposures to diethylene glycol butyl ether.
Routine dermal exposures, however, represent a very low concern for
developmental toxicity risks.
o Hazard quotient calculations for inhalation and dermal exposures to propylene
glycol during ink removal indicate very low concern.
o Inhalation exposures to other components are very low.
o Risks from other components could not be quantified because of limitations in
hazard data, although dermal exposures to all components could be relatively high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-207
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AE
Environmental Releases
Table V-154
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Omicron-AE
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover
Other
Ethoxylated nonphenol
Phosphate surfactant
Water
Release Under Each Scenario
(g/day)
I
air
0
35
0
0
0
0
0
0
0
water
0
0
19
13
603
43
6.2
31
540
land
440
222
0
0
0
0
0
0
0
II
air
0
0.2
0
0
0
0
0
0
0
III
air
0
0.1
0
0
0
0
0
0
0
IV
air
0
0.7
0
0
0
0
0
0
0
water
852
497
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Omicron-AE
From Ink Removal Operations:
Diethylene glycol butyl ether
852 g/day to water from rags at commercial laundry
440 g/day to landfill
Propylene glycol
36 g/day to air
497 g/day to water from rags at commercial laundry
222 g/day to landfill
DRAFT—September 1994
V-208
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AE
From Emulsion Remover:
Sodium periodate
19 g/day to water
Ethoxylated nonylphenol
13 g/day to water
From Haze Remover:
Other
43 g/day to water
Ethoxylated nonylphenol
6.2 g/day to water
Phosphate surfactant
31 g/day to water
Table V-155
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AE
Substance:
Diethylene glycol butyl ether
Propylene glycol
Sodium periodate
Ethoxylated nonylphenol
Other
Phosphate surfactant
To Air:
36 g/day
To Water:
852 g/day at laundry
497 g/day at laundry
19 g/day
19.2 g/day
43 g/day
31 g/day
To Landfill:
440 g/day
222 g/day
DRAFT—September 1994
V-209
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AE
Releases to Water from a Single Facility
Table V-156
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AE
Substance
Diethylene glycol butyl ether
Propylene glycol
Sodium periodate
Ethoxylated nonylphenol
Other
Phosphate surfactant
Amount
Released to
Water from
Facility
852 g/day at
laundry
497 g/day at
laundry
19 g/day
19.2 g/day
43 g/day
31 g/day
Waste water
Treatment
Removal
Efficiency
83%
97%
100 %
100 %
100 %
100 %
Amount to Water
After Waste water
Treatment
1 45 g/day
14.9 g/day
0
0
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
1 x 10'1
1 x 10'2
0
0
0
0
' ug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-157
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AE
Substance
Propylene glycol
Amount of Releases per
day
36 g/day
Highest Aver age
Concentration 100 M away
7.3x10-2ug/m3
Annual Potential
Dose, mg/yeara
5x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Omicron-AE.
DRAFT—September 1994
V-210
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Omicron-AE reach
an ecotoxicity concern concentration.
Performance
General Summary of System Omicron-AE Performance, and Related Variables
Product System Omicron-AE and Product System Omicron-AF were submitted for
demonstration by the same manufacturer. They have the same ink remover and the same
emulsion remover, but each one has a different haze remover to complete the system. Although
these systems do share a common ink remover and emulsion remover, Omicron-AE and
Omicron-AF are each evaluated as a separate Product System in this documentation. It was the
intention of the Performance Demonstrations to evaluate reclamation systems as a whole, not
individual products, whenever possible.
The performance of Omicron-AE was demonstrated at Facilities 2 and 19. This product
system consisted of an ink remover, an emulsion remover, and a haze remover. A degreaser
also accompanied this product system and was used by one of the facilities, however, detailed
information on the performance of the degreaser is not included in the scope of this project.
Facility 2 prints signs, and displays; Facility 19 prints overlays, and membrane switches.
During the demonstration, Facility 2 reclaimed 30 screens using solvent-based inks over a 4
week period. Facility 19 did not participate in the demonstrations after the observer's one day
visit. During the visit, they reclaimed four screens, but based on the poor results of those first
reclamations, they decided not to participate in the project. Neither facility tried alternative
application techniques to improve product performance.
Facility 2 reported that the ink remover performed poorly and required a lot more
scrubbing than their usual product. The chemical composition of the alternative ink remover
was extremely different than the constituents of the facility's standard product. Adverse
interactions may have occurred because of these chemical differences. The ink remover seemed
to work better when used immediately after printing, but the performance was still not
acceptable. At Facility 19, the ink remover had to be re-applied and scrubbed into the screen
repeatedly, and all residual ink was still not removed.
In general, Facility 2 liked the emulsion remover better than their usual product, although
it took extra time to use the hand sprayer and the emulsion remover was not as effective when
thick ink residue was present. Facility 19 was not satisfied with the emulsion remover
performance. They reported that the emulsion remover had to be re-applied and scrubbed into
the screen repeatedly; even then residual emulsion was left on the screen.
DRAFT-September 1994 V-211
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
Both facilities found the haze remover performance to be unacceptable. Facility 2 saw no
reduction in haze after applying the product. At Facility 19, the haze remover did not
completely remove the haze. This facility, however, had very high standards in terms of haze
removal; other facilities would have been satisfied with this level of haze removal. It should be
noted that both facilities used standard haze removers that were very different chemically than
the alternative haze remover. On screens that were reclaimed many times, there is potential for
adverse effects due to interaction of the standard and alternative systems.
Alternative System Omicron-AE Profile
The manufacturer recommends applying Product System Omicron-AE as follows:
o Ink Remover Card off the extra ink left in the screen. Apply the ink remover with a
spray bottle to both sides of the screen. Brush the product into the screen to
loosen the ink on both sides. Wipe the screen clean. Repeat spraying and wiping
until the screen is clean.
o Emulsion Remover Place the screen in a washout sink and spray both sides of the
stencil with the emulsion remover so that it evenly covers the stencil. Wait one
minute. Use a soft brush to loosen the stencil and scrub the screen until the stencil
is broken up in all areas. Apply more emulsion remover if necessary. Rinse the
screen with a pressure washer (a 1000 psi pressure wash was used at SPTF).
o Haze Remover Spray the haze remover on the stained areas on both sides of the
screen. Brush the product in and let stand for 3 - 4 minutes. Pressure rinse from
the bottom of the screen to the top on both sides.
Alternative System Performance at SPTF
Product System Omicron-AE was tested at SPTF on three screens (one with a solvent-
based ink, one with a UV-curable ink, and one with a water-based ink). Products were applied
according to the manufacturer's recommended application procedure. On the screens with the
solvent-based ink and with UV ink, the ink dissolved well with little effort. On the solvent-
based ink screen, the stencil was affected in the half-tone area, but there was no effect on the
stencil on the UV ink screen. Six wipes were used to remove the ink from each screen. On the
screen with water-based ink, the ink dissolved well, however, extra scrubbing was needed. The
stencil was affected in the half-tone area. Again, six wipes were used.
On all three screens, the emulsion remover dissolved the stencil effectively. On the screen
with solvent-based ink and the UV ink screen, moderate scrubbing was required to break up
the stencil and the pressure wash remove the stencil completely. A light to moderate ink stain
remained on each screen. On the screen with water-based ink, the stencil dissolved easily with
only light scrubbing, but there was a small amount of ink residue remaining in the half-tone
areas, in addition to a moderate ink stain.
The haze remover lightened the stains on all three screens and removed the ink residue
on the water-based ink screen. However, all screens did have some ink stain remaining after
the application of the haze remover.
DRAFT-September 1994 V-212
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
Alternative System Performance Details
Performance Details from Facility 2
Except for the emulsion remover, Product System Omicron-AE performed poorly at this
facility. Unfortunately, this facility became very busy during the demonstration period. The
excessive workload reduced the amount of time available for using the alternative system and
for experimenting with the application procedures. A total of 30 screens were reclaimed with
Product System Omicron-AE over a 4 week period, but the Omicron-AE ink remover and haze
remover were only used on 7 of the screens, due to poor performance. The Omicron-AE
emulsion remover was used on 26 screens and worked very well.
The ink remover did not work well at this facility, which used solvent-based ink during
the demonstrations. The screen reclaimer scrubbed one screen for 40 minutes trying to get the
ink out of the mesh, whereas no scrubbing is needed with their usual ink remover. The
alternative ink remover was chemically very different than this facility's standard product and
chemical interactions could have occurred. Their usual ink removing method involved spraying
solvent onto a screen in a small, closed room. This was a particularly unpleasant room in that
there was a high concentration of solvents in the air, and there was also a lot of build-up of ink
solids on the floor and walls. No respirators were seen when the observer was on-site,
although the facility reported that respirators are usually worn in the "solvent room." Use of the
alternative ink remover did not require the reclaimer to be in the ink reclamation room.
Facility 2 liked the performance of the emulsion remover very much and they thought it
performed better than their usual product, even when diluted at one part emulsion remover to
two parts water. The manufacturers application procedure did not instruct the printer to
dilute the emulsion remover. When there was a thick ink residue left in the screen, the
emulsion was more difficult to remove.
The haze remover did not reduce the haze in the screen mesh at all. The standard haze
remover at this facility contains some very strong chemicals such as dichloromethane and has a
very different chemical composition from the alternative haze remover. These differences could
result in adverse chemical interactions on the screen, to improve performance, this facility
used the alternative haze remover concurrently with Comet cleanser to remove the haze. Comet
is typically used at this facility as a degreaser.
No changes in screen failure rate were noted during the demonstrations, but it could be
speculated that a reduced screen failure rate would result from longer term use of the
alternative system at this facility because of the abrasiveness of their usual products (such as
Comet). Unfortunately, the lower abrasiveness of the alternative system may be offset by the
amount of scrubbing required to get the screens clean. The reclaimer noted that his scrubbing
was producing visible wear in the screen mesh.
Performance Details from Facility 19
This facility did not continue using System Omicron-AE after the initial demonstration
during the observer's visit. The alternative system did not clean the screens to a level at all
acceptable to this facility and they were not willing to experiment with different application
procedures that may have improved performance. Also, the alternative system seemed to
require more time and effort than the facility's usual procedures.
DRAFT-September 1994 V-213
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
This facility has one screen reclaimer per shift and neither speak English. Forms were
going to be translated into Spanish and the printing manager was present for much of the
demonstrations and served as an interpreter. This facility tends to wash about 24 screens at a
time in groups of eight. Using the alternative system severely interrupted the reclamation
process established at this facility. This facility reclaims about 60 to 80 screens per shift.
Currently, they only use one product for ink removal, emulsion removal, and haze removal. It
is a very effective product, but the observer noticed it is also corrosive and emits strong vapors.
Other facilities that use this product try to limit its use. This facility uses no other reclamation
products and expects all screens to be completely without haze when reclamation is finished.
Other facilities have less stringent haze removal requirements or expectations. The alternative
system performance would probably have been considered acceptable at many other facilities.
Also note that there may have been adverse chemical interactions between this facility's
standard haze remover and the alternative haze remover, because the two haze removers are
chemically very different.
During the observer's visit, the alternative system was used with different ink systems
and several application techniques were evaluated. The type of ink did not seem to affect the
alternative system performance levels. No changes in the rate of screen wear or failure were
noted during the product demonstration. It is likely that the alternative system would be less
corrosive than their standard product in the long term.
The ink remover did not work effectively enough for this facility. Average ink removal was
observed, but the ink remover often had to be applied and scrubbed into the screen multiple
times. Ink often remained in the screen at the edges of the print image and stencil. This level
of removal did not compare to the results this facility has using their standard product as an
ink remover, where usually no scrubbing is needed.
The emulsion remover often did not remove all of the emulsion from the screen. The
emulsion remover required more scrubbing than with their standard product. Often, multiple
applications were required to remove all of the emulsion. Still, emulsion tended to remain in
the screen around the edges of the stencil.
The haze remover worked fairly well leaving only a light haze. This haze, which would
have been acceptable at many of the other facilities participating in the project, was
unacceptable for this facility. Even when the haze remover was allowed to stay on the screen
for longer than the directions suggested, no appreciable improvement in performance was
noted. When Facility 19 uses their usual haze remover, the haze disappears from the screen.
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 2
Facility 2 prints signs, banners, and store displays on plastics and paper. A typical run
is 150 pieces and approximately 40% of their orders are repeat orders. Of the approximately
DRAFT-September 1994 V-214
-------
Table V-158
On-Site Performance Summary For Alternative System Omicron AE
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using
Product
Average
Quantity Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
2
Facility
19
Ink remover
Emulsion
remover
Haze remover
Ink remover
Emulsion
Remover
Haze Remover
7.1 ±9.3hrs
(n=14)
1.3±3.7hrs
(n=30)
2.2±6.7hrs
(n=30)
3.7±1.5hrs
(n=3)
not recorded
(n=0)
3.0mins
(n=1)
12.6 ±13.1 oz.
(n=7)
7.5±3.7oz.
(n=26)
14.6 ±5.1 oz.
(n=7)
2.3±1.2oz.
(n=3)
1.3±0.6oz.
(n=3)
2.3±2.5oz.
(n=4)
18.6±15.5mins
(n=7)
6.6±3.4mins
(n=26)
15.0 ±4.1 mins
(n=7)
7.3 ±4.5 mins
(n=3)
3.3 ±0.6 mins
(n=3)
10.0 ±9.3 mins
(n=4)
Moderate
Low
Low
High
Moderate
High/
Moderate
Ink residue not
removed from mesh.
Easily, completely
removed stencil.
Seemed to have no
effect on the haze.
Ink remained in
screen after several
applications.
Reapplication needed
to remove emulsion.
Lightened the ink
stain.
• Only 7 screens
reclamined
w/system, due to
poor
performance.
• Did not
participate after
observer's visit,
due to
poor product
performance.
Solvent-
based inks
Solvent-
based
Direct photo
stencil
Direct photo
stencil
Mesh type not
specified;
230 threads/in.
PeKap;
156-390
threads/in.
5663 in2
957 in2
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Table V-159
Laboratory Performance Summary For Alternative System Omicron AE
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
Before Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for Each
System Component
Laboratory Testing at SPTF
SPTF
Solvent-
based
Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based
Ink
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
3.0 oz.
0.5 oz.
0.5 oz.
2.0 oz.
0.5 oz.
0.5 oz.
3.0 oz.
1.0 oz.
1 .0 oz.
8.3mins
3.8mins
5.0mins
7.3mins
4.2mins
5.1 mins
7.2mins
3.5 mins
5.5 mins
Low
Moderate
Low
Low
Moderate
Low
Moderate
Low
Low
Overall System
Performance
Demonstration Conditions
Inktype(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
Dissolved ink well. Stencil affected in
areas.
Dissolved stencil. Light ink stain
remaining.
Lightened, but did not remove, ink stain.
Dissolved ink well.
Dissolved stencil. Medium ink stain
remaining.
Lightened, but did not remove, ink stain.
Dissolved ink with wiping
in areas.
Stencil affected
Dissolved stencil. Medium ink stain and
residue.
Lightened, but did not remove, ink stain.
Solvent-
based
UV-curable
Water-
based
Dual cure
direct
Dual cure
direct
Dual cure
direct
Polyester;
260 threads/
inch
Polyester;
390 threads/
inch
Polyester;
260 threads/
inch
360 in2
360 in2
360 in2
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
12 employees at this facility, 5 are involved in screen reclamation. All printing is done with
solvent-based inks and the screens used in the Performance Demonstrations all had a mesh
count of 230 threads/inch with a direct photo stencil. The typical screen size at this facility is
50 ft2 and about 6 screens are reclaimed daily.
Screen Reclamation Area in Facility 2
Ink removal is done in a spray booth in the "solvent room" which is approximately 30 ft2
in size and is not ventilated. Screen reclamation is done in a spray booth in the general plant
area and is ventilated by the facility-wide system. The average temperature during the
observer's visit was 65°F (and 49% relative humidity). Ink remover solvent is filtered, recycled
and reused in-house. Waste water from the emulsion and haze remover booth is not recycled
or filtered.
Current Screen Reclamation Products at Facility 2
Facility 2 uses a proprietary ink remover that includes at least toluene (31%), xylene
(24%), methyl isobutyl ketone (19%), ethylbenzene (6%) and diacetone alcohol. Their standard
emulsion remover contains at least sodium periodate. For haze removal, they use a proprietary
solvent blend that contains either at least dichloromethane (90%) and isopropanol (1 %), or a
blend that includes sodium hydroxide and cyclohexanone.
Current Screen Reclamation Practices in Facility 2
All screen printing at this facility is done using solvent-based inks. Screen reclamation
employees wear gloves and eye protection for all steps of the process; respiratory protection is
also used for ink removal. The screen reclamation process is:
o Ink Remover: Card off excess ink at the press. Bring screen to ink removal room
and soak screen with solvent spray (from the low pressure spray in the recycling
tank). Wipe off the solvent and ink with a squeegee. Wipe the screen and frame
with disposable rags. Repeat the application of solvent (spray, wipe and squeegee)
if necessary.
o Emulsion Remover: In the reclamation sink, pressure wash both sides of the
screen. Dip a rag in the emulsion remover and wipe down the screen with the rag.
Pressure wash.
o Haze Remover: Haze remover is used only about once per week. To apply, scrape
paste onto the screen with a card and work it into the screen. Pressure wash. On
all screens, a degreaser is applied after emulsion removal. Comet cleanser is used
as the degreaser. Sprinkle the Comet on the screen surface. Using the emulsion
remover-soaked rag, rub the Comet into the screen. Dip the rag in the emulsion
remover again and scrub areas with remaining ink. Pressure wash.
General Facility Background for Facility 19
Facility 19 prints graphic overlays, front panels, and membrane switches. They print on
plastics, metals, and paper. Their jobs usually run for 5 - 1500 impressions and
approximately 70% of their orders are repeat orders. This facility uses solvent-based inks and
a direct photo stencil. The alternative system was used on screens with mesh counts ranging
DRAFT-September 1994 V-217
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
from 156 - 390 threads/inch. Typical screen size in this facility is 30 inches x 33 inches, and
approximately 60 - 80 screens are reclaimed daily.
Screen Reclamation Area in Facility 19
Ink removal is done at the presses and screen reclamation is done in a separate area,
approximately 35 ft2 in size, where ventilation is provided through a hood over the back-lit
spray booth. During the observer's visit, the average temperature in the facility was 70°F (and
44% relative humidity). Rags used for ink removal are cleaned weekly by a laundry service.
Waste water from screen reclamation is filtered prior to disposal.
Current Screen Reclamation Products at Facility 19
At Facility 19, their standard ink remover is a proprietary solvent blend consisting of at
least 20% propylene glycol ethers, and petroleum hydrocarbons (< 10%). Information on the
chemical constituents of their emulsion remover was not available. Their standard haze
remover is a proprietary solvent blend which contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 19
At Facility 19, 10 - 15 screens are cleaned at the same time. The same product is used
for ink removal, emulsion removal and haze removal. Screens are reclaimed as follows:
o Ink Remover. Emulsion Remover, and Haze Remover: Card off excess ink at the
press. Bring screen to the reclamation area. Rinse screen with pressure washer
(2000 - 2500 psi) to remove block out. Spread the reclamation product with a
brush onto both sides of the screen. Let sit for approximately 3 - 4 minutes.
Pressure rinse. Reapply the product, let sit for about 10 minutes, then pressure
rinse. Gloves, eye protection, ear protection and aprons are worn while using this
product.
DRAFT-September 1994 V-218
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AE
Cost
Table V-160
Method 2: Summary of Cost Analysis for Alternative System Omicron-AE
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Omicron-AE
Facility 2
5,663
6
Facility 19
957
70
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous Waste
Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
40.2
8.80
16
2.43
12.6
0.96
7.5
0.56
12.6
0.89
0
0
20.7
4.52
0
0
2.3
0.18
1.3
0.10
2.3
0.16
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
13.65
10.85
20,470
16,278
4.96
5.49
86,787
8,240
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs, however,
are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-219
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AF
Product System Omicron-AF
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Diethylene glycol butyl ether
Propylene glycol
Sodium periodate
Ethoxylated nonylphenol
Water
Ethoxylated nonylphenol
Phosphate surfactant
Alkali/Caustic
Water
Occupational Exposure
Table V-161
Occupational Exposure Estimates for Alternative System Omicron-AF
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Omicron (Emulsion Remover)
Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover
Ethoxylated nonphenol
Alkali/Caustic
Phosphate surfactant
Other
Water
Inhalation (mg/day)
I
0
17
0
0
0
0
0
0
0
0
II
0
0.1
0
0
0
0
0
0
0
0
III
0
0
0
0
0
0
0
0
0
0
IV
0
0.4
0
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
984
576
47
31
1480
16
156
78
109
1200
Immersion
4590
2690
218
146
6920
73
728
364
510
5610
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-220
-------
Table V-162
Occupational Risk Estimates for Alternative System Omicron AF
Name
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover
ethoxylated nonylphenol
Alkali/Caustic
Phosphate surfactant
Water
Hazard Quotient
Inhalation
NA
0.01
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
0.4
NA
NA
NA
NA
NA
NA
NA
Immersion
NA
1.9
NA
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
142
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
3.6
NA
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
30
NA
NA
NA
NA
NA
NA
NA
NA
LOAEL
0.8
NA
NA
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Margin-of-exposure calculations indicate clear concerns for chronic dermal
exposures to workers using diethylene glycol butyl ether in ink removal.
o Margin-of-exposure calculations also show possible concerns for developmental
toxicity risks from dermal "immersion" exposures to diethylene glycol butyl ether.
Routine dermal exposures, however, represent a very low concern for
developmental toxicity risks.
o Hazard quotient calculations for inhalation and dermal exposures to propylene
glycol during ink removal indicate very low concern.
o Inhalation exposures to other components are very low.
o Risks from other components could not be quantified because of limitations in
hazard data, although dermal exposures to all components could be relatively high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-222
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AF
Environmental Releases
Table V-163
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Omicron-AF
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover
Ethoxylated nonphenol
Alkali/Caustic
Phosphate surfactant
Other
Water
Release Under Each Scenario
(g/day)
I
air
0
35
0
0
0
0
0
0
0
0
water
0
0
19
13
603
5.6
56
28
43
428
land
440
222
0
0
0
0
0
0
0
0
II
air
0
0.2
0
0
0
0
0
0
0
0
III
air
0
0.1
0
0
0
0
0
0
0
0
IV
air
0
0.7
0
0
0
0
0
0
0
0
water
852
497
0
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Omicron-AF
From Ink Removal Operations:
Diethylene glycol butyl ether
852 g/day to water from rags at commercial laundry
440 g/day to landfill
Propylene glycol
36 g/day to air
497 g/day to water from rags at commercial laundry
222 g/day to landfill
DRAFT—September 1994
V-223
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AF
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Omicron AF (cont.)
From Emulsion Remover:
Sodium periodate
19 g/day to water
Ethoxylated nonylphenol
13 g/day to water
From Haze Remover:
Other
39 g/day to water
Ethoxylated nonylphenol
5.6 g/day to water
Alkali/caustic
56 g/day to water
Phosphate surfactant
28 g/day to water
Table V-164
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AF
Substance:
Diethylene glycol butyl ether
Propylene glycol
Sodium periodate
Ethoxylated nonylphenol
Alkali/caustic
Other
Phosphate surfactant
To Air:
36 g/day
To Water:
852 g/day at laundry
497 g/day at laundry
19 g/day
18.6 g/day
56 g/day
39 g/day
28 g/day
To Landfill:
440 g/day
222 g/day
DRAFT—September 1994
V-224
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AF
Releases to Water from a Single Facility
Table V-165
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AF
Substance
Diethylene glycol butyl
ether
Propylene glycol
Ethoxylated nonylphenol
Sodium Periodate
Other
Phosphate surfactant
Alkali/caustic
Amount Released
to Water from
Facility
852 g/day at
laundry
497 g/day at
laundry
18.6 g/day
19 g/day
39 g/day
28 g/day
56 g/day
Waste water
Treatment
Removal
Efficiency
83%
97%
100 %
100 %
100 %
100 %
100 %
Amount to Water
After Waste water
Treatment
1 45 g/day
14.9 g/day
0
0
0
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
1 x 10'1
1 x 10'2
0
0
0
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-166
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Omicron-AF
Substance
Propylene glycol
Amount of Releases per
day
36 g/day
Highest Average Concentration
100 M away
7.3x10-2ug/m3
Annual Potential
Dose, mg/yeara
5x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
DRAFT—September 1994
V-225
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Omicron-AF.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Omicron-AF reach
an ecotoxicity concern concentration.
Performance
General Summary of System Omicron-AF Performance, and Related Variables
Product System Omicron-AE and Product System Omicron-AF were submitted for
demonstration by the same manufacturer. They have the same ink remover and the same
emulsion remover, but each one has a different haze remover to complete the system. Although
these systems do share a common ink remover and emulsion remover, Omicron-AE and
Omicron-AF are each evaluated as a separate Product System in this documentation. It was the
intention of the Performance Demonstrations to evaluate reclamation systems as a whole, not
individual products, whenever possible.
Product System Omicron-AF is a water-based system and it consisted of an ink remover,
an emulsion remover, and a haze remover. A degreaser accompanied this product system,
however, detailed information on the performance of the degreaser is not included in the scope
of this project. The performance of the product was demonstrated at Facilities 4 and 18.
Facility 4 prints decals using UV-curable inks; Facility 18 prints nameplates, panels, and
graphic overlays using solvent-based inks. During the demonstration periods, Facility 4 used
the alternative system to reclaim 19 screens over a 2 week period and Facility 18 reclaimed 32
screens over 4 weeks. Facility 4 discontinued use of the alternative product system after two
weeks, due to the poor performance of the ink remover and the haze remover.
At Facility 4, the ink remover removed the ink from the mesh satisfactorily, however,
residue remained in the stencil area on most of the screens. The printer felt the ink residue
was minimal, and if he were using his standard haze remover, this residue would not have been
a problem. Facility 18 reported that the ink remover worked as well as their standard
products.
The emulsion remover worked very well at both facilities. It removed the stencil
completely and easily. The haze remover performance was not acceptable at either facility.
Facility 4 reported that the haze remover was not effective in removing any of the ink haze, even
with vigorous scrubbing and procedural modifications. A ghost image appeared on subsequent
print jobs, which required that the printer clean the screens again with his standard product.
DRAFT-September 1994 V-226
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
At Facility 18, the haze remover left too much haze under all conditions and their standard
haze remover had to be used after the alternative system before the screen could be reused.
Because of this poor performance, the facility stopped using the haze remover during the first
week of demonstrations.
Alternative System Omicron-AF Profile
The manufacturer recommends applying Product System Omicron-AF as follows:
o Ink Remover After carding off as much excess ink as possible, use a spray bottle to
apply ink remover to both sides of the screen. Brush the product on the screen
surface to loosen the ink on both sides. With a clean cloth, wipe the screen clean.
Repeat spraying on the ink remover and wiping it off until the screen is clean.
o Emulsion Remover Place the screen in a washout sink and spray both sides of the
stencil with the emulsion remover so that it evenly covers the stencil. Wait one
minute. Use a soft brush to loosen the stencil and scrub the screen until the stencil
is broken up in all areas. Apply more emulsion remover if necessary. Rinse the
screen with a pressure washer (a 1000 psi pressure wash was used at SPTF).
o Haze Remover Pour the haze remover into a bucket. Dip a brush into the bucket
and scrub the product into both sides of the screen in the effected areas. Let stand
for 1 - 2 minutes. Pressure rinse from the bottom of the screen to the top. Turn
the screen around and repeat the pressure rinse from bottom to top on the other
side of the screen.
Alternative System Performance at SPTF
Product System Omicron-AF was tested at SPTF on three screens (one with a solvent-
based ink, one with a UV-curable ink, and one with a water-based ink). On the screen with the
solvent-based ink, the ink dissolved well with moderate effort (5 wipes were used). On the last
rag there was a slight blue color (the color of the stencil) which may indicate that the ink
remover could deteriorate the stencil. Ink remover performance on the screen with UV-curable
ink was similar expect there was some red coloring on the rag as well as blue. The red tint
could indicate an effect on the adhesive (which is red) that holds the screen to the frame. The
UV-curable ink screen also required moderate effort to remove the ink and 6 rags were used.
Compared to the other two screens, the screen with water-based ink required additional time,
effort (7 rags), and product to loosen the ink. Also on the water-based ink screen, the
technician noted that the ink remover started to deteriorate the stencil.
On all three screens, the emulsion remover dissolved the stencil quickly and with
moderate scrubbing effort and the pressure rinse removed it completely. On the screen with
solvent-based ink, a moderate ink stain remained on the screen after using the emulsion
remover. The UV screen had a lighter stain. The water-based ink screen had a moderate stain
with some ink residue remaining in the half-tone area. The haze remover lightened the stains
on all three screens and removed the ink residue on the water-based ink screen.
Products were applied according to the manufacturer's recommended application
procedure. After using the haze remover, the technician noted that there was a small hole in
the screen with solvent-based ink that was not there before using the haze remover.
DRAFT-September 1994 V-227
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
Alternative System Performance Details
Performance Details from Facility 4
After using Product System Omicron-AF for two weeks, Facility 4 decided they did not
want to continue participation in the performance demonstrations. When using the screens
reclaimed with Omicron-AF in subsequent print jobs, the printer noticed a ghost image. He
cleaned the screens again using his own product to remove the haze and was then able to reuse
the screens. Faced with a tight production schedule, the printer was unable to continue using
Product System Omicron-AF since additional time would be required to reclean the screens
with his standard product.
After using the ink remover, the printer evaluated the screen and reported that the ink
was removed effectively on 80% of the screens. However, after using the emulsion remover, the
printer noted that on every screen an ink residue remained in the stencil area. He felt that this
ink residue normally would not have been a problem, because his haze remover could remove
it. The alternative haze remover could not.
The printer was pleased with the performance of the emulsion remover. He reported that
it removed the stencil completely and easily.
The performance of the haze remover was unacceptable at this facility. When following
the manufacturers application instructions, the haze remover reduced the residue, but did not
remove it or significantly lighten the ink stain on the mesh, even after vigorous scrubbing and a
long high pressure water wash. A ghost image was clearly visible on subsequent print jobs
which required the printer to clean the screen again with his standard haze remover.
To improve the product performance, the printer varied several conditions: he increased
the soaking time on the screen for the ink remover and the haze remover, he increased the
quantity of ink remover and haze remover, he sprayed the haze remover on a scrubber pad
instead of directly onto the screen, and he tried drying the screen before using the haze
remover. These techniques did not improve the performance of the product system. During
the two weeks of demonstrations, product performance was quite consistent as were the
demonstration conditions (e.g., ink type, emulsion type, screen condition). The printer did not
think further use of the product would provide any different data.
Overall, the printer did not notice any change in screen failure rate over the time period
that the alternative system was in use, however, he did need to clean each screen a second time
with his own haze remover in order to be able to reuse it. The printer thought this haze would
build up on the screen and would eventually prevent the emulsion from adhering to the screen.
Performance Details from Facility 18
Facility 18 used Product System Omicron-AF for four weeks. The press area supervisor
was asked to comment on the performance of the system several times during the performance
demonstration period. He felt that, in general, the ink remover and emulsion remover products
worked as well as the products they were previously using. The haze remover, however, did not
give acceptable results, and they stopped using it during the first week of the demonstrations.
The ink remover worked well in most cases. Two of their solvent-based inks which were
difficult to clean with their regular products also required more effort with the alternative
system. The facility's standard procedure for these inks is to apply haze remover twice after
DRAFT-September 1994 V-228
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
reclaiming. Ink residue left by the alternative chemicals required this practice to be continued
during the performance demonstration.
The emulsion remover performed well on all screens and stencils. The reclaimer noted
that the stencil dissolved easily with this product. The haze remover did not work well. After
reclaiming several screens, it was determined that the screens could not be reused until the
facility's regular haze remover was applied to them. Facility 18 therefore discontinued the use
of the alternative haze remover.
Screen size at this facility was relatively uniform, and careful controls were placed on
screen condition and tension. Retensionable frames were used exclusively. The screens were
brought to the reclaiming area with most of the ink removed from them already, having been
carded off at the press. Facility 18 had tried other products which were advertised as "safer",
and they had one bad experience where one of the products damaged their plumbing system.
The same person reclaimed the screens and evaluated the print image quality. This employee
was knowledgeable about the entire screen printing process.
The products in System Omicron-AF were not observed to be detrimental to the screen
mesh, the printing equipment during the performance demonstration. Print image quality was
not affected.
Alternative System Performance Table Compiled from Field Sites
The table below highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 4
Facility 4 prints decals on plastic sheets. A typical run is 3,000 sheets, and
approximately 50% of their orders are repeat orders. Of the 30 - 40 employees at this facility,
approximately 4 are involved in screen reclamation. All printing is done with UV-curable inks.
All screens used in the Performance Demonstrations were polyester (calendared) with a typical
mesh count of 390 threads/inch with a direct photo stencil. The average screen size at this
facility is 35 inches x 38 inches and approximately 6 screens are reclaimed daily.
Screen Reclamation Area in Facility 4
The screen printing, ink removal, and screen reclamation activities are all done in the
same area of the facility. The ink removal area consists of a work table about 20 feet from the
press, and screen reclamation is done in a spray booth nearby. The open plant area with high
ceilings and overhead fans provide ventilation for the area. The average temperature during the
observer's visit was 73°F (and 35% relative humidity). Rags used for clean up and for ink
removal are cleaned by a laundry service. Waste water from the high-pressure wash of the
emulsion remover and haze remover is not recycled or filtered at this facility.
DRAFT-September 1994 V-229
-------
Table V-167
On-Site Performance Summary for Alternative System Omicron-AF
•o_
CD"
CD
System
Component
Performance
Avg Drying Time
BeforeUsing Product
Average
Quantity Applied
Average
Cleaning Time
Average Effort
Required
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
Facility
4
Facility
18
Ink remover
Emulsion
Remover
Haze
Remover
Ink Remover
Emulsion
Remover
Haze
Remover
46.1 ± 49.3 hrs (n=22)
5.5±10.2hrs(n=22)
4.1 ±2.0mins(n=22)
28.5 ± 28.0 hrs (n=47)
1.2 ±1.1 mins(n=47)
0.8±2.7mins(n=47)
1.6 ±0.7
oz.(n=22)
1.4±0.5oz.
(n=22)
2.1 ±0.7oz.
(n=12)
2.2±0.5oz.
(n=46)
3.6±1.2oz.
(n=47)
1.9±0.7oz.
(n=11)
5.1 ±0.6mins
(n=12)
4.9±0.3mins
(n=12)
5.0±0.2mins
(n=12)
2.7±0.9mins
(n=46)
4.0 ± 1.1 mins
(n=47)
4.1 ± 1.4 mins
(n=11)
Moderate
Low
High
Low
Low
Low
Ink residue in stencil
area.
Easily removed
stencil.
Did not remove ghost
image from most
screens.
Removed ink well.
Easily removed
stencil.
Did not reduce haze.
• Most screens could
not be reused due to
a haze.
• A ghost image
appeared when the
screens were
reused.
• The facility
discontinued use
after 2 weeks.
• Facility was
pleased with the ink
and emulsion
removers.
• They switched back
to their own haze
remover after one
week.
uv-
curable
Solvent-
based
Direct
photo
stencil
Direct
photo
stencil and
capillary
film
Monofilament
Polyester,
calendered;
390
threads/inch
Mono-
filament
polyester; 110-
460
threads/inch
1577 in2
11 50 in2
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Table V-168
Laboratory Performance Summary for Alternative System Omicron-AF
•o_
CD"
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SPTF
Solvent-
based Ink
SPTF
UV-curable
Ink
SPTF
Water-
based Ink
System
Component
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Performance
Avg Drying Time
Before Using
Product
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
Average
Quantity
Applied
1.5oz.
1.0 oz.
1.0 oz.
1.5oz.
1.0 oz.
0.5 oz.
2.5 oz.
1.0 oz.
1.0 oz.
Average
Cleaning
Time
5.7mins
4.1 mins
4.0mins
6.5 mins
4.1 mins
4.5 mins
7.8 mins
4.4 mins
4.2 mins
Average
Effort
Required
Moderate
Moderate
Low
Low
Low
Low
Moderate
Moderate
Low
Performance for
Each System
Component
Ink dissolved well.
Stencil dissolved easily.
remaining.
Overall System
Performance
Moderate ink stain
Lightened the ink stain.
Ink dissolved well.
Stencil dissolved easily.
remaining.
Light ink stain
Lightened the ink stain.
Ink dissolved with extra effort and product.
Stencil dissolved easily.
remaining.
Some ink residue
Removed residue; lightened stain.
Demonstration Conditions
Ink type(s)
Solvent-
based
UV-curable
Water-
based
Emulsion
type
Dual cure
direct
Dual cure
direct
Dual cure
direct
Mesh type;
Thread count
Polyester; 260
threads/inch
Polyester; 390
threads/inch
Polyester; 260
threads/inch
Average
Screen
Size
360 in2
360 in2
360 in2
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
Current Screen Reclamation Products at Facility 4
As their standard screen reclamation products, Facility 4 uses two proprietary products
for ink removal, and also uses proprietary products for emulsion and haze removal. These
products are sold by a manufacturer not participating in the performance demonstration. The
MSDSs for all of these products state that they contain no carcinogens, no ingredients with
TLVs or PELs, and no petroleum derivatives.
Current Screen Reclamation Practices in Facility 4
Screen reclamation employees wear eye protection for all steps of the process; gloves and
barrier cream are also available. The reclamation process is described below:
o Ink Remover: Card off excess ink at the press. Spray on the in-process ink
remover and wipe the screen with a reusable rag. Bring the screen over to the ink
removal area and place the screen flat on the table. Wipe with a sponge, then, using
a squeegee on both sides, pull the residue down to the bottom of the screen. Use a
rag to wipe off the residue. One rag is used for every two or three screens. Bring
the screen over to the pressure wash booth. From a five-gallon container, spray
both sides of the screen with the ink degradent. Use a scrubber pad to rub the
product into the screen. Pressure wash (1000 psi) both sides of the screen to rinse
out the ink and blockout, and also to loosen the masking tape around the edges of
the frame.
o Emulsion Remover: Spray both sides of the screen with emulsion remover from a
five-gallon container. Brush the stencil area on both sides with a scrubber pad.
Rinse the both sides of the screen with a high pressure wash.
o Haze Remover: Haze remover is used on all screens being reclaimed. Spray on
haze remover from a 24 ounce spray bottle. Scrub the effected area with a scrubber
pad. Wait for one minute and rinse with a pressure wash.
General Facility Background for Facility 18
Facility 18 prints graphic overlays for the electronics industry and nameplates and
panels. All of their printing is done on plastics. Their typical run length is 16 hours and
approximately 80% of their orders are repeat orders. There are approximately 40 employees at
this facility, three of which are involved in screen reclamation activities. During the
Performance Demonstration, this facility used solvent-based inks and they used both a direct
photo stencil and a capillary film stencil. High tension monofilament polyester mesh
(untreated) screens with mesh counts ranging from 110 - 460 threads/inch were used. Typical
screen sizes in this facility are 1,596 in2 or 952 in2, and approximately 10 - 15 screens are
reclaimed daily.
Screen Reclamation Area in Facility 18
Ink removal and screen reclamation operations are both done within the screen printing
area of the facility where local ventilation is provided. The ink removal area consists of a work
table and a spray booth. A second spray booth is used for reclamation; this booth is back-lit
and is separated from the ink removal booth by a stainless steel sink. During the observer's
visit, the average temperature in both areas was 65°F (and 49% relative humidity). In the ink
removal area, a filtration system is used to filter and recirculate the ink remover solvent. These
DRAFT-September 1994 V-232
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AF
filters are disposed of as hazardous waste along with the used shop rags. Waste water from the
washes of the emulsion remover and haze remover is not recycled or filtered at this facility.
Current Screen Reclamation Products at Facility 18
As their standard ink remover, Facility 18 uses a proprietary solvent blend that contains
at least pentanedioic acid and dimethyl ester (<20%). Their standard emulsion remover is a
proprietary aqueous mixture with at least sodium periodate. For haze removal, this facility
uses a proprietary aqueous mixture that contains sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 18
At Facility 18, screens are reclaimed as follows:
o Ink Remover: Spray on the ink remover from the recirculation tank through a
manual pressurized brush system. Rub the screen with a scrubber pad on both
sides of the screen. Spray both sides of the screen with low pressure water.
Gloves, eye protection, and aprons are worn during ink removal.
o Emulsion Remover: Spray on the emulsion remover and let it sit for approximately
30 seconds. Rinse with a high pressure (1500 psi) wash. Blow dry the screen with
compressed air, then vacuum dry the screen, and blow with compressed air again
until the screen is completely dry. Gloves, eye protection, aprons, respiratory
protection, and ear protection are used during emulsion removal.
o Haze Remover: Dip a scrubber pad into the container of haze remover. Rub the
product into the screen. Allow the screen to drain then bring it to another tub and
let sit to dry for 30 minutes. Apply ink remover from the recirculation tank and let
sit for 5 minutes. Allow the screen to drain into recirculation tank. Bring the
screen over to the spray booth and spray with a low pressure spray followed by a
high pressure wash.
DRAFT-September 1994 V-233
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Omicron-AF
Cost
Table V-169
Method 2: Summary of Cost Analysis for Alternative System Omicron-AF
Cost Element Description
Baseline
(Traditional
Svstem 4^
Alternative System Omicron-AF
Facility 4
Facility 18
Facility Characteristics
Average screen size (in2)
Average # screens/day
Cost Elements
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous
Waste
Disposal
2,127
6
1,210
6
1,150
13
per Screen
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost ($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
15.0
3.28
1.3
0.20
1.6
0.12
1.4
0.10
2.1
0.15
0
0
10.8
2.37
1.3
0.20
2.2
0.17
3.6
0.27
1.9
0.14
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
3.86
4.45
5,784
6,675
3.14
3.89
9,823
5,836
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at
demonstration facilities to reflect the screen size and number of screens cleaned per day under the baseline
scenario. Labor costs, however, are not normalized. Normalization allows a comparison between the baseline and
facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-234
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Zeta
Product System Zeta
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Propylene glycol series ethers
Sodium periodate
Water
Alkali/Caustic
Propylene glycol
Water
Occupational Exposure
Table V-170
Occupational Exposure Estimates for Alternative System Zeta
System
Ink Remover
Propylene glycol series ethers
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Propylene glycol
Water
Inhalation (mg/day)
I
139
0
0
0
0
0
II
0.6
0
0
0
0.1
0
III
0
0
0
0
0
0
IV
2.8
0
0
0
0
0
Dermal (mg/day)
Routine
1560
16
1540
234
62
1260
Immersion
7280
73
7210
1090
291
5900
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Occupational Risk Conclusions and Observations
Ink Remover and Haze Remover
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using propylene glycol series ethers in ink removal. Possible
concerns also exist for chronic dermal exposure to propylene glycol series ethers
based on the calculated hazard quotients, which assume 100% dermal absorption.
If the actual dermal absorption rate of propylene glycol series ethers is significantly
lower, this concern would be significantly reduced or eliminated.
DRAFT—September 1994
V-235
-------
Table V-171
Occupational Risk Estimates for Alternative System Zeta
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Name
Ink Remover
Propylene glycol series ethers
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Propylene glycol
Water
Hazard Quotient
Inhalation
3.2
NA
NA
NA
0.1
NA
Dermal
Routine
18
NA
NA
NA
0.04
NA
Immersion
87
NA
NA
NA
0.2
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
LOAELd
100
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Zeta
o Inhalation exposures to propylene glycol series ethers also present possible
concerns for developmental toxicity risks, based on margin-of-exposure
calculations.
o Hazard quotient calculations for chronic inhalation and dermal exposures to
propylene glycol during haze removal indicate very low concern.
o Inhalation exposures to other components are very low.
o Risks from other ink remover and haze remover components could not be
quantified because of limitations in hazard data, although dermal exposures to all
components could be relatively high.
Emulsion Removers (All Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
Environmental Releases
Table V-172
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Zeta
System
Ink Remover
Propylene glycol series ethers
Emulsion Remover (diluted 1:4)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Propylene glycol
Water
Release Under Each Scenario
(g/day)
I
air
290
0
0
0
0.7
n
water
0
6
615
80
21
431
land
375
0
0
0
0
n
II
air
1.4
0
0
0
0.2
n
III
air
0.8
0
0
0
0.1
n
IV
air
5.8
0
0
0
0
n
water
1345
0
0
0
0
n
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
V-237
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Zeta
Table V-173
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Zeta
Substance:
Propylene glycol series ethers
Sodium periodate
Alkali/caustic
Propylene glycol
To Air:
297.6 g/day
1 g/day
To Water:
1345 g/day at laundry
6 g/day
80 g/day
21 g/day
To Landfill:
375 g/day
Releases to Water from a Single Facility
Table V-174
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 2, Alternative System Zeta
Substance
Propylene glycol series
ethers
Sodium periodate
Alkali/caustic
Propylene glycol
Amount Released
to Water from
Facility
1375 g/day
6 g/day
80 g/day
21 g/day
Waste water
Treatment
Removal
Efficiency
83-97 %
100 %
100 %
97%
Amount to Water
After Waste water
Treatment
222 g/day
0
0
0.6 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
2x10'1
0
0
6x10'4
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-238
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
Releases to Air from Individual Screen Printing Facilities
Table V-175
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 2, Alternative System Zeta
Substance
Propylene glycol series ethers
Propylene glycol
Amount of Releases
per day
297.6 g/day
21 g/day
Highest Average
Concentration 100 M away
6.1 x 10-1 ug/M3
4.3x10-2ug/m3
Annual Potential
Dose, mg/yeara
4
3x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions and Observations
o Health risks to the general population from both air and water exposures are very
low for Method 2, Product System Zeta.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 2, Product System Zeta reach an
ecotoxicity concern concentration.
Performance
General Summary of Product System Zeta Performance, and Related Variables
This product system consisted of an ink remover, emulsion remover, and a haze remover.
The performance of the products was demonstrated at Facilities 6, 7, and 15. Facility 6 prints
store displays, traffic markings, and movie posters; Facility 7 prints decals, labels, vehicle
markings, and store displays; Facility 15 prints plexiglass displays, store displays, and
banners. During the demonstration period, Facility 6 reclaimed seven screens, Facility 7
reclaimed four screens, and Facility 15 reclaimed eight screens. Facility 6 used solvent,
ultraviolet (UV)-cured, and water-based inks; Facility 7 and Facility 15 used solvent-based and
UV-cured inks.
DRAFT-September 1994 V-239
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
Facility 6 reported that the performance of the alternative ink remover was poor, and they
had to reclean their screens using their standard ink remover after the alternative product.
Although the ink remover performed poorly with solvent and UV-cured inks in general,
Facility 6 reported that the alternative ink remover worked well on one screen with water-based
inks and on one with UV-cured ink. Facility 7 reported that for solvent-based inks, the ink
remover seemed to dry on the screen and did not take the ink out; the alternative ink remover
did work well with UV-cured inks. To improve performance of the ink remover, the screen
reclamation employee needed to begin wiping the ink remover off the screen immediately after
spraying instead of waiting, as recommended. If the ink remover was not wiped off
immediately, it dried on the screen and then they needed to use their regular ink remover.
Facility 15 reported that the ink remover did not work at all for this facility; it had to be applied
a number of times and, even with more scrubbing than usual, it had to be followed with their
standard product.
Both Facility 6 and Facility 7 found the emulsion remover did not work well when diluted
with five parts water. When the facilities increased the emulsion remover concentration by
diluting with only three parts water, the emulsion remover dissolved the stencil. At Facility 6,
the performance of the emulsion remover was not consistent, even at the stronger
concentration. Facility 7 was generally pleased with the performance of the emulsion remover
at the stronger concentration, however, they still had problems if the emulsion remover was
permitted to dry in the mesh. Facility 15 reported that the emulsion remover was passable, but
the facility still preferred their own product. The alternative emulsion remover required extra
scrubbing effort (even at full strength) at Facility 15.
All three facilities reported that the haze remover did not have any effect on the haze.
They all had to use their own haze remover in many cases. These facilities did not reclaim
many screens using the Product System Zeta for several reasons: they were disappointed and
discouraged by the early results, the products arrived later then expected and the observer was
not present to assist the printers with the application procedure or to offer suggestions for
improving performance, and the production schedules of the shops was unusually busy.
Because of these factors, none of the facilities put extensive effort into attempting to alter
application techniques to make the products work at their shop.
Alternative System Zeta Profile
The manufacturer recommends applying Product System Zeta as follows:
o Ink Remover Card off the extra ink left in the screen. Using a spray bottle, apply
the ink remover to both sides of the screen. Allow up to 2 minutes for penetration.
Squeegee or wipe soaked ink into waste bin. Rinse with high pressure water (a
pressure spray of 1000 psi was used at SPTF).
o Emulsion Remover Depending on conditions, dilute one part emulsion remover
with up to 5 parts of water. Using a spray bottle, apply the emulsion remover to
both sides of the screen and work it in with a nylon mesh pad or brush. Wait one
minute and do not allow the mixture to dry on the screen. Rinse both sides of the
screen with high pressure water.
o Haze Remover Spray the haze remover thoroughly and evenly onto both sides of
screen. Allow at least 15 minutes for normal penetration. Overnight soaking will
not damage the screen. Scrub with a synthetic brush or pad. Rinse both sides of
screen with high pressure wash.
DRAFT-September 1994 V-240
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
Alternative System Performance at SPTF
Product System Zeta was tested at SPTF on three screens (one with a solvent-based ink,
one with a UV-curable ink, and one with a water-based ink). The ink remover performance
varied depending on the type of ink used. The emulsion remover and haze remover
performance was consistent for all three screens.
On all three screens, the modifications were made to the manufacturer's instructions for
applying ink remover. First, the technician applied the ink remover following the
recommended method (spray on both sides of the screen, wait two minutes, squeegee off ink,
and rinse with pressure washer). This application method did not satisfactorily remove the ink
from any of the three screens. To improve the ink remover performance, the technician
reapplied the product using a different method. For the second ink remover application, the
technician wiped the screen with a dry rag to remove excess water, sprayed more ink remover
over the entire screen, and wiped with rags until the rag was no longer picking up the ink. On
the screen with solvent-based ink, the screen had some spots of ink residue and a medium gray
haze after the first ink remover application. The stencil was affected in the half-tone area and it
turned a light blue color in some areas. A second application of ink remover on the solvent-
based ink screen removed the ink residue, but the stencil color came up on the rag. Four rags
were used. On the screen with the UV ink, after the first ink remover application procedure,
there was a heavy gray stain over the entire screen, ink residue remained in some areas, and
the stencil had a dull finish. After the second application of the ink remover, the screen still
had some ink stains remaining, but the gray haze was removed. Three rags were used. On the
water-based ink screen, after the first application of ink remover was squeegeed off, ink residue
remained, mainly on the emulsion. The ink wiped off easily when the ink remover was applied
again. The rag was blue with the emulsion from the half-tone areas. Two rags were used.
On all three screens, the stencil dissolved easily with moderate scrubbing. A moderate
ink stain remained on all of the screens, but there was no stencil stain or ink residue. The
haze remover did not appear to lighten the ink stain on any of the screens. The technician also
noted that the odor of the haze remover was so strong, she felt an exhaust fan or a respirator
was required. Overall, although an ink stain remained on the screens, SPTF did not think the
stain would affect future print quality and therefore, evaluated the product system as
acceptable.
Alternative System Performance Details
Performance Details from Facility 6
This facility had mixed success with System Zeta. The demonstrations were complicated
by the fact that the screen reclaimers spoke almost no English and the forms had to be
translated into Spanish. Two different reclaimers participated in the demonstrations, but
another person was involved to either translate the reclaimer's forms or to write down results.
Because of this situation, the observer was not confidant that all the information received was
accurate. Another confounding factor was that the product arrived late at the facility and the
observer was not present to assist the printer with the application instructions and with
trouble-shooting, as was done at most other facilities. It is possible that better results could
have been achieved had the observer been present.
At Facility 6, the ink remover did not work as well as their usual product. During the
demonstrations, this facility used the alternative system on screens with solvent-based, UV-
curable, and water-based inks. The alternative ink remover performed poorly with solvent-
DRAFT-September 1994 V-241
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
based inks, it worked well on one screen with water-based inks, and performance was mixed
on screens with UV-inks. Facility 6 needed to use their regular remover to get the ink out of
several of the screens after using the alternative ink remover.
This facility had mixed results with the emulsion remover. In general, when the emulsion
remover was used at a strength of three parts of product to one part water, or stronger, the
stencil dissolved quickly. At weaker concentrations, the emulsion remover worked much more
slowly than their usual product and the printer needed to use their usual emulsion remover to
get the screens clean. However, these results were not consistent, and on some screens where
the stronger formulation was used, the stencil did not dissolve completely.
The haze remover worked very poorly for this facility. It did not seem to reduce haze
produced by UV-cured or solvent-based inks and it was not used with water-based inks.
Performance Details from Facility 7
The alternative system arrived at Facility 7 during a very busy period. The facility's initial
response to the alternative system's performance was negative. The poor initial performance
combined with increased activity at the facility led to a situation where little information was
collected on alternative system performance. This facility also received the alternative system
shipment late and the observer did not have the opportunity to assist the printer with the
application technique or to suggest procedures to improve performance. This assistance was
given through telephone conversations between the observer and the facility contact, however,
this may not have been as effective as in-person support.
The ink remover performance at Facility 7 was poor. The facility was particularly
unhappy with the directions which said to let the ink remover sit on the screen. The ink
remover dried quickly into the screens, stuck into the mesh and it was then completely
ineffective at removing ink. This facility was only able to use the ink remover if they applied
additional ink remover and began wiping it out of the mesh immediately. These changes
improved the performance of the ink remover slightly, but often the facility used their usual ink
remover to remove all ink from the screens. Facility 7 did use the ink remover on one screen
with UV ink and found it worked much better. As their standard ink remover, this facility uses
a lacquer thinner in some cases. Adverse interactions could occur when using the alternative
ink remover because its chemical composition is very different from lacquer.
Initially, the facility diluted one part emulsion remover to five parts water. At this
concentration, the emulsion remover did not dissolve the stencil unless the product was
reapplied. When they changed the dilution to one part emulsion remover to three parts water,
the stencil dissolved easily with little scrubbing effort. The facility did have problems with the
emulsion remover drying quickly into the mesh. Wiping the emulsion remover immediately off
of the screen aided the product's performance.
The haze remover was not effective at this facility; they did not think that the haze
remover worked at all. Facility 7 only filled in the haze remover information on the data sheets
for one screen, although they tried it on several screens and the performance was consistently
disappointing.
Performance Details from Facility 15
Facility 15 did not like System Zeta compared to their usual products. Under most
conditions, they were unhappy with the performance of the alternative system. Because the
alternative system did not work well, the facility recleaned their screens with their usual
DRAFT-September 1994 V-242
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
products after each demonstration. This double cleaning greatly increased the time required
for screen reclamation. Each time the facility tried the alternative system, their confidence in
the product's abilities to clean the screen decreased making it even harder to convince the
facility to continue with the demonstrations. They submitted data on only eight screens.
The ink remover did not effectively remove the ink from the screens unless it was applied
several times. Compared to their standard product, more scrubbing was required and the
facility often had to follow up with their usual ink remover to get the ink out of the screens.
The standard ink remover is very different chemically than the alternative product. This
difference may cause adverse chemical interactions.
At Facility 15, the emulsion remover had to be applied multiple times to effectively clean
the screens. Using the emulsion remover undiluted did not eliminate the need for a second
application to remove all emulsion from the screen. Even with multiple applications of the
undiluted emulsion remover, Facility 15 often had to use their usual emulsion remover to get
the screens to the level of cleanliness that they wanted.
The haze remover required harder scrubbing than their usual product and did not seem
to reduce the haze. Once again, Facility 15 had to resort to using their usual haze remover to
reduce the haze to an acceptable level.
The performance of the alternative system did not seem to be affected by the types of ink
or by ink color, although there was a possibility that the alternative system worked slightly
better with UV-cured inks than with solvent-based inks. Since the data available was so
limited, it is not possible to draw any conclusions on correlations between product
performance variations and screen conditions. No screen side effects were noticed during the
performance demonstrations, although increased scrubbing will produce a greater level of mesh
abrasion, which may in turn lead to higher screen failure rates.
Alternative System Performance Table Compiled from Field Sites
The following table highlights the observed performance of the product system and the
relevant conditions of the demonstration, as recorded by the printers using the products at the
demonstration facilities. In addition to the field demonstration performance data, results of the
product tests performed at SPTF are also summarized in this table. More descriptive
information on the demonstration facilities is included in the section following the table.
Facility Profiles
General Facility Background for Facility 6
Facility 6 prints store displays, transit markings, and movie posters on plastics and
paper. Their typical run length is 250 - 300 sheets, and approximately 5% of their orders are
repeat orders. Of the approximately 25 employees at this facility, 1 - 3 are involved in screen
reclamation. Currently, they used solvent-based, water-based, and UV inks, but they are in the
process of discontinuing their use of solvent-based ink systems. All screens used in the
Performance Demonstrations were made of a polyester mesh with thread counts ranging from
280 - 420 threads/inch. The average screen size used at this facility is 35 ft2 and 10-15
screens are reclaimed daily.
DRAFT-September 1994 V-243
-------
Table V-176
On-Site Performance Summary For Alternative System Zeta
•o_
CD"
CD
Facility 6
Facility 7
Facility 15
System
Component
Ink remover
Emulsion
remover
Haze remover
Ink remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Performance
Avg Drying Time
Before Using
Product
24.0 ±1 5.2 hrs
(n=6)
12.0 ±13.8 hrs
(n=4)
11.5±2.5mins
(n=4)
3.6±1.0mins
(n=4)
3.8 ±7.5 hrs
(n=4)
0.0±0.0mins
(n=4)
10.2 ±21.1 hrs
(n=5)
13.3 ±21. 5 hrs
(n=8)
1.5±2.0mins
(n=6)
Average
Quantity
Applied
8.3 ±8.2
oz.
(n=6)
6.5 ±2.5
oz.
(n=4)
2.8 ±1.0
oz.
(n=4)
8.5 ±4.5
oz.
(n=4)
1.3 ±0.5
oz.
(n=4)
2.0 oz.
(n=1)
3.0 ±0.9
oz.
(n=6)
4.1 ±2.7
oz.
(n=8)
2.3 ±0.5
oz.
(n=6)
Average
Cleaning
Time
2.8 ±1.3
mins (n=6)
4.8 ±3.8
mins (n=4)
2.2 ±0.5
mins (n=4)
4.8 ±1.3
mins (n=4)
1.2 ±0.5
mins
(n=4)
15.0 mins
(n=1)
6.2 ±5.3
mins
(n=6)
6.5 ±4.0
mins
(n=8)
20.2 ±14.9
mins
(n=6)
Average
Effort
Required
Moderate
Moderate/
High
Moderate
Moderate
Low
High
Low
High
Moderate
Performance for Each
System Component
Ink residue in screen.
Worked well sometimes,
but inconsistent results.
Seemed to have no effect
on haze.
Dried into the screen mesh
and did not remove ink
effectively.
Reapplication of product
needed to remove stencil.
Seemed to have no effect
on haze.
A lot of product was
required to remove the ink.
Stencil dissolved slowly
with extra scrubbing effort.
Seemed to have no effect
on haze.
Overall System
Performance
• Only 7 screens were
reclaimed at this facility.
• They did not use the
products because of poor
performance.
• Only 4 screens were
reclaimed at this facility.
• They did not use the
products because of poor
performance.
• This facility had to use
their standard products
before the screens could be
reused.
• They reclaimed 8 screens
before dropping out of the
performance
demonstrations
Demonstration Conditions
Ink type(s)
Solvent-
based, UV
ink, and
water-
based inks
Solvent-
based and
UV inks
Solvent-
based and
UV inks
Emulsion
type
Direct photo
stencil
Capillary film
Direct photo
stencil
Mesh type;
Thread count
Polyester, no
treatment;
280-420
threads/inch
Polyester,
abraded;
230-390
threads/inch
Polyester; 1 56
-305
threads/inch
Average
Screen
Size
3926 in2
3060 in2
2084 in2
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-------
Table V-177
Laboratory Performance Summary For Alternative System Zeta
•o_
CD"
CD
SPTF
Solvent-
based
Ink
SPTF
UV-
curable
Ink
SPTF
Water-
based
Ink
System
Component
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Ink Remover
Emulsion
Remover
Haze Remover
Performance
Avg Drying Time
Before Using
Product
15mins
24 hours
Omins
15mins
24 hours
Omins
15mins
24 hours
Omins
Average
Quantity
Applied
2.5 oz.
1.0 oz.
1.0 oz.
1.0 oz.
1.5oz.
1.0 oz.
1.5oz.
1.5oz.
1.0 oz.
Average
Cleaning
Time
6.0 mins
4.3mins
16.6mins
4.6mins
4.5mins
17.3mins
5.7 mins
4.5mins
16.9 mins
Average
Effort
Required
High
Moderate
Low
High
Moderate
Low
High
Moderate
Low
Performance for Each
System Component
Overall System
Performance
2 applications required to remove ink; stencil
deteriorated in areas.
Stencil dissolved easily; some ink stain left.
Did not appear to lighten haze at all; strong
odor.
2 applications required to remove ink; stains in
some spots.
Stencil dissolved easily; some ink stain left.
Did not appear to lighten haze at all; strong
odor.
2 applications required to remove ink; stencil
deteriorated in areas.
Stencil dissolved easily; some ink stain left.
Did not appear to lighten haze at all; strong
odor.
Demonstration Conditions
Ink
type(s)
Solvent-
based
UV-
curable
Water-
based
Emulsion
type
Dual cure
direct
Dual cure
direct
Dual cure
direct
Mesh type;
Thread count
Polyester; 260
threads/inch
Polyester; 390
threads/inch
Polyester; 260
threads/inch
Average
Screen
Size
360 in2
360 in2
360 in2
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
Screen Reclamation Area in Facility 6
Screen reclamation is done in a reclamation room near the main production area. The
open area provides ventilation for screen reclamation activities and hoods are being added over
the reclamation spray booth. The average temperature during the observer's visit was 71°F
(and 45% relative humidity). Waste water from ink removal activities is filtered and the filters
are disposed of as hazardous waste. Waste water from the high-pressure wash of the emulsion
remover and haze remover is not filtered.
Current Screen Reclamation Products at Facility 6
Facility 6 uses a proprietary blend which contains propylene glycol ethers (<50%) as their
standard ink remover. Their emulsion remover is a proprietary aqueous mixture with
periodate salt (< 10%). For haze removal, they use a proprietary blend consisting of at least
sodium hydroxide, potassium hydroxide and propylene glycol ether.
Current Screen Reclamation Practices in Facility 6
The screen reclamation process at Facility 6 is described below. Gloves, eye protection,
aprons, respiratory protection, barrier cream, and ear protection are available to all employees
involved in screen reclamation.
o Ink Remover: Card off the excess ink at the press. Bring the screen to the
reclamation room and spray the ink remover onto the screen at 80 psi from a 55
gallon drum with a nozzle. Squeegee off the ink. Spray the screen and squeegee it
again. Pressure wash (2500 psi) both sides of the screen.
o Emulsion Remover: Spray both sides of the screen with the emulsion remover and
let sit for a few seconds. Pressure wash the screen. Spray more ink remover onto
both sides of the screen and let sit for one minute. Rinse with a high pressure
washer, followed by a low pressure water rinse. Allow the screen to air dry.
o Haze Remover: Dip a brush into the container of haze remover and work it into
both sides of the screen with the brush or with a scrubber pad. Let sit for three to
five minutes then rinse with a high pressure wash, followed by a low pressure
rinse.
General Facility Background for Facility 7
Facility 7 prints roll labels, fleet markings, point of purchase displays, and decals. A
typical run length is 275 sheets. There are less than 5 screen printing employees at this facility.
The facility uses both UV ink and solvent-based ink. During the Performance Demonstrations
they used a capillary film emulsion and the screen mesh was an abraded polyester. Mesh
counts ranged from 230 - 390 threads/inch. The screen size typically used in this facility is 60"
x 52", and 10 - 12 screens are reclaimed daily.
Screen Reclamation Area in Facility 7
Ink removal and screen reclamation are done in separate spray booths located next to
each other in the plant. Ventilation for both areas is provided by local overhead fans and
ventilated hoods. During the observer's visit, the average temperature in the area was 71°F
(and 41 % relative humidity). Rags used for screen reclamation activities are cleaned by a
DRAFT-September 1994 V-246
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
laundry service. Used ink removal solvents are recycled on-site and the recycled product is
used in-house. Filtered waste from ink removal is disposed of as a hazardous water. Waste
water from emulsion removal and haze removal activity is not filtered at this facility.
Current Screen Reclamation Products at Facility 7
For ink removal, Facility 7 uses lacquer thinner, as well as a proprietary product sold by
a manufacturer not participating in the performance demonstration. The MSDS states that this
product contains no carcinogens, no ingredients with TLVs or PELs, and no petroleum
derivatives. Their standard emulsion remover is a proprietary aqueous mixture which contains
periodate salt (< 10%). As a haze remover, they use a proprietary aqueous mixture with sodium
hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 7
Employees wear gloves and eye protection during ink removal and screen reclamation.
Respiratory protection is also available for haze removal. Facility 7 screens are reclaimed as
follows:
o Ink Remover: Card off the excess ink at the press. On screens that have been
printed with clear inks, spray lacquer thinner on both sides of the screen and wipe
with reusable rags (two or three rags are used on each screen). The lacquer thinner
is recycled. Bring the screen to the ink removal station and spray with ink remover
on the squeegee side. Wipe off ink residue with a reusable rags. Repeat application
of the ink remover and wipe the screen. Bring the screen to the pressure wash
station and rinse both sides of the screen.
o Emulsion Remover: Spray on emulsion remover and work it into the screen with a
scouring pad. Pressure rinse the screen and allow to dry in front of the fan.
o Haze Remover: Haze remover is only used on approximately 1 screen per month.
To apply, dip a rag or brush into the haze remover, work it into the screen, then
rinse with the pressure washer.
General Facility Background for Facility 15
Facility 15 prints store fixtures, banners and point-of-purchase displays. They primarily
print on plastics, but they also do some jobs on paper, metal, and wood. A typical run is 800
sheets and 70% of their orders are repeat orders. Of the approximately 5 employees involved in
screen printing at this facility, 2 are involved in screen reclamation activities. Several different
types of ink are commonly used at Facility 15, including vinyls, epoxies and UV-curable inks.
All screens used in the Performance Demonstrations were polyester and a direct photo stencil
emulsion was applied. Mesh counts during the demonstration period ranged from 156 - 305
threads/inch. The average screen size used at this facility is 35 inches x 45 inches and 4 - 5
screens are reclaimed daily.
Screen Reclamation Area in Facility 15
Ink removal is primarily done at the press and screen reclamation is done in a back-lit
spray booth. The temperature during the observer's visit was 58°F (and 50% relative
humidity). Rags used for ink removal and screen reclamation are washed by an industrial
DRAFT-September 1994 V-247
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
laundry service. Waste water from the high-pressure wash of the emulsion remover and haze
remover is not filtered at this facility.
Current Screen Reclamation Products at Facility 15
For ink removal, Facility 15 uses acetone, as well as a proprietary product sold by a
manufacturer not participating in the performance demonstration. The MSDS states that this
product contains no carcinogens, no ingredients with TLVs or PELs, and no petroleum
derivatives. For emulsion removal, they use a proprietary aqueous mixture with at least
sodium periodate. Their standard haze remover is an aqueous blend consisting of potassium
hydroxide (27%) and tetrahydrofurfuryl alcohol (11%).
Current Screen Reclamation Practices in Facility 15
Gloves, eye protection, and aprons are worn during screen reclamation. The screen
reclamation process at Facility 15 is described below:
o Ink Remover: Card off the excess ink at the press. Pour lacquer thinner onto a
reusable rag and wipe the screen. Bring the screen to the sink, wet it down, and let
it sit for 30 seconds to five minutes. Pressure wash (1500 psi) to remove the
blockout.
o Emulsion Remover: Spray product onto the screen and rub it in with a scrubber
pad. Let the screen sit for 10 seconds to 5 minutes. Pressure rinse. Spray on
more product where needed, rub in with the scrubber pad, pressure rinse and
allow the screen to air dry. When the screen is dry, pour acetone onto a rag and
wipe the screen and the frame to remove any remaining ink. Wipe again with a
clean, lint-free disposable rag. Pressure wash.
o Haze Remover: After emulsion removal, a haze remover is used only if needed (on
approximately 5% of the screens). When haze remover is used, the acetone wash
step is eliminated. Haze remover is applied using a scraper, followed by a high
pressure water spray.
DRAFT-September 1994 V-248
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Zeta
Cost
Table V-178
Method 2: Summary of Cost Analysis for Alternative System Zeta
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Cost Elements f
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous
Waste
Disposal
Baseline
(Traditional
Svstem 4^
2,127
6
Alternative System Zeta
Facility 6
3,926
13
Facility?
3,060
11
Facility 15
2,084
5
3er Screen
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
17.6
3.85
0.0
0.00
8.3
1.50
6.5
0.23
2.8
0.64
115
0.08
21.0
4.59
3.8
0.56
8.5
1.53
1.3
0.04
2.0
0.47
90
0.07
32.8
7.18
0.0
0.00
3.0
0.54
4.1
0.15
2.3
0.55
61
0.04
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Normalized3
6.27
6.27
9,399
9,399
6.31
5.39
19,704
8,080
7.26
6.51
19,973
9,772
8.46
8.99
9,521
13,479
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs, however,
are not normalized. Normalization allows a comparison between the baseline and facility results.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-249
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process Method 3 Process
Method 3: SPAI Workshop Process
Method 3 (illustrated in Figure V-4) is taught as an alternative method of screen
reclamation by the technical staff at the Screen Printing Association International (SPAI) in
screen printing workshops. Information provided by SPAI staff was used to document this
alternative method. The process for Method 3 is detailed below:
Method 3 Process
o Clean the screen with the ink remover product to remove the majority of the ink
residue from the screen.
o Prior to the screen coming in contact with water, spray the screen on both sides of
the stencil with an ink degradant or ink solubilizer.
o Scrub the stencil with a soft brush on both sides to break down the components of
the ink. Water wash the emulsion off the screen.
o To remove the oily film that covers the screen, spray screen degreaser on both sides
of the stencil and wipe off with rags.
o Apply (spray) emulsion remover and rinse screen with water.
SPAI staff state that the main advantage of this method is that it eliminates the use of a
haze remover; caustic haze removers can damage the screen mesh, limiting the future use of the
screen. Screen printers can also avoid exposure to the harsh chemicals that can be used in
haze removal.
Because the manufacturer of Alternative System Omicron supplied a screen degreaser
formulation along with other product formulation information, System Omicron, minus the
haze remover product, was used as the one alternative system in Method 3. In order to evaluate
Method 3 as an alternative screen reclamation method, several assumptions were used in the
risk and cost assessment. It was not possible to make these assumptions based on an actual
performance demonstration of Method 3. Although the demonstration of the effectiveness of
this method was one of the original intentions of the performance demonstration, logistical
problems prevented a performance evaluation. The assumptions used in the assessment of
Method 3 are as listed below:
o In total, this process takes approximately the same amount of time as Screen
Reclamation Method 2
o For the ink degradant and the screen degreaser products, about 3 oz. of each
product is used per screen size of approximately 2100 in2.
o The ink remover and the ink degradant have the same chemical composition (no
ink degradant was supplied for the performance demonstration)
o Some of the parameters from the Method 2 evaluation of System Omicron were
used in the cost estimation, including labor costs and quantities of ink and
emulsion removers used (reference Chapter 3 methodology).
DRAFT-September 1994 V-250
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Method 3 Process
Figure V - 4
Process Steps Included in Method 3
Ink Removal
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Ink Degradant/l
Water Rinse
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Screen
Degreaser
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPINEOLS
• ALCOHOLS
Emulsion
Removal/Water
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
DRAFT—September 1994
V-251
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process System Omicron
In this assessment of Method 3 using System Omicron (minus haze remover), there is no
comparable assessment of a traditional system of screen reclamation products. Reference
Methods 1 and 2 for a determination of the occupational and population risks, as well as
performance, of a traditional screen reclamation product system.
System Omicron Formulation
Ink Remover: Diethylene glycol butyl ether
Propylene glycol
Ink Degradant: Diethylene glycol butyl ether
Propylene glycol
Screen Degreaser: Isopropanol
Ethoxylated nonylphenol
Water
Emulsion Remover: Sodium periodate
Ethoxylated nonylphenol
Water
DRAFT-September 1994 V-252
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Occupational Risk Conclusions and Observations
Occupational Exposure
Table V-179
Occupational Exposure Estimates for Method 3, Alternative System Omicron
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Ink Dearadant
Diethylene glycol butyl ether
Propylene glycol
Deareaser
Isopropanol
Ethoxylated nonylphenol
Water
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Inhalation (mg/day)
I
0
17
0
17
2
0
0
0
0
0
II
0
0.1
0
0.1
2
0
0
0
0
0
III
0
0
0
0
1
0
0
0
0
0
IV
0
0.4
0
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
984
576
984
576
16
47
1500
47
31
1480
Immersion
4590
2690
4590
2690
73
218
6990
218
146
6920
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Occupational Risk Conclusions and Observations
Ink Remover/Ink Degradant/Screen Degreaser
Margin-of-exposure calculations indicate clear concerns for chronic dermal
exposures to workers using diethylene glycol butyl ether in ink removal.
Margin-of-exposure calculations also show possible concerns for developmental
toxicity risks from dermal "immersion" exposures to diethylene glycol butyl ether.
Routine dermal exposures, however, represent a very low concern for
developmental toxicity risks.
DRAFT—September 1994
V-253
-------
Table V-180
Occupational Risk Estimates for Method 3, Alternative System
Name
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Ink Dearadant
Diethylene glycol butyl ether
Propylene glycol
Deareaser
Isopropanol
Ethoxylated nonylphenol
Water
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Hazard Quotient
Inhalation
NA
0.01
NA
0.01
NA
NA
NA
NA
NA
NA
Dermal
Routine
NA
0.4
NA
0.4
NA
NA
NA
NA
NA
NA
Immersion
NA
1.9
NA
1.9
NA
NA
NA
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
140
NA
140
NA
NA
NA
NA
NA
NA
NA
LOAEL
3.6
NA
3.6
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
30
NA
30
NA
NA
NA
NA
NA
NA
NA
LOAEL
0.8
NA
0.8
NA
NA
NA
NA
NA
NA
NA
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CO
CO
CD
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CO
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
CO
m
3
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3
CO
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process Occupational Risk Conclusions and Observations
o Hazard quotient calculations for inhalation and dermal exposures to propylene
glycol during ink removal indicate very low concern.
o Inhalation exposures to other components are very low.
o Risks from other components could not be quantified because of limitations in
hazard data, although dermal exposures to all components could be relatively high.
Emulsion Removers (All systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or periodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain
these compounds. All of these materials present a high concern for skin and eye
irritation and tissue damage if workers are exposed in the absence of proper
protective clothing. None of the emulsion removers present significant inhalation
risks.
DRAFT-September 1994 V-255
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Environmental Releases
Environmental Releases
Table V-181
Environmental Release Estimates in Screen Cleaning Operations
Method 3, Alternative System Omicron
System
Ink Remover
Diethylene glycol butyl ether
Propylene glycol
Ink Dearadant
Diethylene glycol butyl ether
Propylene glycol
Screen Deareaser
Isopropanol
Ethoxylated nonylphenol
Water
Emulsion Remover
Sodium periodate
Ethoxylated nonylphenol
Water
Release Under Each Scenario
(g/day)
I
air
0
35
0
35
4.2
0
0
0
0
0
water
0
0
330
158
1
16
510
19
13
603
land
440
222
0
0
0
0
0
0
0
0
II
air
0
0.2
0
0.2
4.1
0
0
0
0
0
III
air
0
0.1
0
0.1
2
0
0
0
0
0
IV
air
0
0.7
0
0
0
0
0
0
0
0
water
852
497
0
0
0
0
0
0
0
0
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 3, Alternative System Omicron
From Ink Removal Operations:
Diethylene glycol butyl ether
852 g/day to water from rags at commercial laundry
440 g/day to landfill
DRAFT—September 1994
V-256
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Environmental Releases
Propylene glycol
36 g/day to air
497 g/day to water from rags at commercial laundry
222 g/day to landfill
From Screen Degreaser Operations:
Isopropanol
10.3 g/day to air
1 g/day to water
Ethoxylated nonylphenol
16 g/day to water
From Ink Degradant Operations
Diethylene glycol butyl ether
330 g/day to water
Propylene glycol
35.3 g/day to air
158 g/day to water
From Emulsion Removal Operations
Sodium periodate
19 g/day to water
Ethoxylated nonylphenol
13 g/day to water
Table V-182
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 3, Alternative System Omicron
Substance:
Diethylene glycol butyl ether
Propylene glycol
Isopropanol
Ethoxylated nonylphenol
Sodium periodate
To Air:
7 1.3 g/day
10.3 g/day
To Water:
330 g/day
852 g/day at laundry
158 g/day
497 g/day at laundry
1 g/day
29 g/day
19 g/day
To Landfill:
440 g/day
222 g/day
DRAFT—September 1994
V-257
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Environmental Releases
Table V-183
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 3, Alternative System Omicron
Substance
Diethylene glycol butyl
ether
Propylene glycol
Isopropanol
Ethoxylated nonylphenol
Sodium periodate
Amount Released
to Water from
Facility
330 g/day
852 g/day at
laundry
158 g/day
497 g/day at
laundry
1 g/day
29 g/day
19 g/day
Waste water
Treatment
Removal
Efficiency
83%
97%
83%
100 %
100 %
Amount to Water
After Waste water
Treatment
56.1 g/day
1 45 g/day
4.7 g/day
14.9 g/day
0.2 g/day
0
0
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
6x10'2
1 x 10'1
5x10'3
1 x 10'2
2x10'4
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
DRAFT—September 1994
V-258
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
Releases to Air from Individual Screen Printing Facilities
Table V-184
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 3, Alternative System Omicron
Substance
Propylene glycol
Isopropanol
Amount of Releases per
day
71.3g/day
10.3g/day
Highest Average
Concentration 100 M away
1.5x10-1ug/m3
2x10'2ug/m3
Annual Potential
Dose, mg/yeara
1
1 x 10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions And Observations
o Health risks to the general population from both air and water exposures are very
low for Method 3, SPAI Workshop Process.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 3, SPAI Workshop Process reach an
ecotoxicity concern concentration.
Performance
Due to resource constraints in this project, it was not possible to demonstrate the
effectiveness of Method 3. However, the Screen Printing Association International can be
contacted for information on how this method performs.
DRAFT—September 1994
V-259
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process
Cost
Cost
Table V-185
Summary of Cost Analysis for Method 3, Alternative System Omicron
Description
Baseline
(Traditional
System 4)
Alternative System
Omicrona
Facility Characteristics
Average screen size (in2)
Average # screens/day
2,127
6
2,127
6
Cost Elements per Screen
Labor
Materials and Equipment
Reclamation
Product
Use
Hazardous Waste Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost ($)
Degreaser
Average Volume (oz.)
Cost ($)
Degradant
Average Volume (oz.)
Cost ($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
—
—
34
0.02
17.9
3.92
2.25
0.34
4.87
0.37
4.33
0.33
—
3.0
0.21
3.0
0.23
0
0.00
Totals
Total Cost ($/screen)
Total Cost ($/year)
6.27
9,399
5.57
8,358
Alternative reclamation system costs were estimated using a combination of performance demonstration results
from facilities testing product system Omicron and from SPAI on the SPAI Workshop Process.
DRAFT—September 1994
V-260
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Technology using High-Pressure Water Blaster Method 4 Process
Method 4: Alternative Screen Reclamation Technology using High-Pressure
Water Blaster
Method 4 is currently in use at some screen printing facilities as an alternative to
traditional screen reclamation. Method 4 utilizes the action of a high-pressure water blaster
(3000 psi) so that the need for ink removal chemicals is eliminated (see Figure V-5). Emulsion
and haze remover chemicals are still applied to the screen, and the water blaster also aids in
removal of stencil and haze. Because an ink remover is not used in screen reclamation in
Method 4, source reduction, the highest priority in the pollution prevention hierarchy, is
achieved. However, simply because the ink remover is not used does not mean that
occupational and population risk is low. The intrinsic hazard of the particular chemicals used
in emulsion and haze remover products must be combined with worker and general exposure
to the chemicals to generate a risk assessment. In the following discussion of Method 4, data
detailing occupational and population exposure are presented to support overall risk
conclusions for a system designated Alternative System Theta. One manufacturer supplied the
actual technology and chemicals, as well as chemical formulations, for use in Method 4. The
process for Method 4 is detailed below:
Method 4 Process
o Remove excess ink from the screen surface; do not apply ink remover.
o Spray emulsion remover on the print side of the screen. Allow to work for 10-30
seconds. Wash both sides of the screen from top to bottom with a 3000 psi
pressure wash to remove ink and stencil residue.
o Apply haze remover to screen with a rag soaked in product. Allow screen to set for
3 minutes. Rinse screen with 3000 psi water blaster from the bottom to the top on
the print side of the screen. Reverse screen and rinse on the ink side.
The manufacturer suggests that the following equipment is necessary for the use of this
technology: washout booth with backlight capability, high-pressure washing system, spray
wand with pattern control nozzle, dual low pressure chemical applicator system. As in all
screen reclamation methods, printers should consider the composition of the reclamation
effluent and whether it meets federal, state and local regulations for discharges to sewer or
septic tanks. Because this method involves the use of large quantities of water, energy and
natural resource issues should also be considered. Reference Chapter 7 for a discussion of this
topic.
In this assessment of Method 4 using Alternative Technology Theta, there is no
comparable assessment of a traditional system of screen reclamation products. Reference
Methods 1 and 2 for a determination of the occupational and population risks, as well as
performance, of a traditional screen reclamation product system.
DRAFT-September 1994 V-261
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Technology using High-Pressure Water Blaster
Method 4 Process
Figure V - 5
Process Steps Included in Method 4
Ink Removal
No Chemicals
Emulsion
Removal
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
High Pressure
Water Blast
(3000 psi)
Haze Removal/
High Pressure
Rinse
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
DRAFT—September 1994
V-262
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster
Alternative Technology Theta Chemical Formulations
Alternative Technology Theta Chemical Formulations
Ink Remover:
Emulsion Remover:
Haze remover:
None
Sodium periodate
Water
Cyclohexanone
Furfuryl alcohol
Alkali/caustic
Occupational Exposure
Table V-186
Occupational Exposure Estimates for Method 4, Alternative System Theta
System
Emulsion Remover3
Sodium periodate
Water
Emulsion Remover (diluted 1:3)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Cyclohexanone
Fufural alcohol
Inhalation (mg/day)
I
0
0
0
0
0
25
0
II
0
0
0
0
0
0.3
0
III
0
0
0
0
0
0
0
IV
0
0
0
0
0
0
0
Dermal (mg/day)
Routine
1250
312
312
1250
515
515
530
Immersion
5820
1460
1460
5820
2400
2400
2480
aThis system can be used with or without diluted emulsion remover, depending on the needs of the facility.
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry
Occupational Risk Conclusions and Observations
Haze remover
o Hazard quotient calculations indicate marginal concerns for chronic dermal
exposures and very low concern for chronic inhalation exposures to Cyclohexanone
during haze removal.
DRAFT—September 1994
V-263
-------
Table V-187
Occupational Risk Estimates for Method 4, Alternative System Theta
22 CD"
5f
3: Q"
CQ' *.
Name
Emulsion Remover
Sodium periodate
Water
Emulsion Remover (diluted 1:3)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Cyclohexanone
Furfuryl alcohol
Hazard Quotient
Inhalation
NA
NA
NA
NA
NA
0.07
NA
Dermal
Routine
NA
NA
NA
NA
NA
1.5
NA
Immersion
NA
NA
NA
NA
NA
6.8
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
196
NA
LOAELd
NA
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
NA
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aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient values less
than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster
Alternative Technology Theta Chemical Formulations
o Margin-of-exposure calculations show low concern for developmental and
reproductive toxicity risks from inhalation exposures to cyclohexanone.
Reproductive and developmental toxicity risks from dermal exposures to
cyclohexanone could not be quantified.
o Inhalation exposures to other components are very low.
o Risks from other haze remover components could not be quantified because of
limitations in hazard data, although dermal exposures to all components could be
relatively high.
Emulsion Removers (All systems)
All of the systems that employ an emulsion remover use either a strong oxidizer such as
hypochlorite or periodate or a strong base such as sodium hydroxide. The haze removers in
Alpha, Epsilon, Gamma, Mu, Omicron, and Theta also contain these compounds. All of these
materials present a high concern for skin and eye irritation and tissue damage if workers are
exposed in the absence of proper protective clothing. None of the emulsion removers present
significant inhalation risks.
Environmental Releases
Table V-188
Environmental Release Estimates in Screen Cleaning Operations
Method 4, Alternative System Theta
System
Emulsion Remover
Sodium periodate
Water
Emulsion Remover (diluted 1:3)
Sodium periodate
Water
Haze Remover
Alkali/Caustic
Cyclohexanone
Fufural alcohol
Release Under Each Scenario
(g/day)
I
air
0
0
0
0
0
53
0
water
177
44
44
177
291
239
300
land
0
0
0
0
0
0
0
II
air
0
0
0
0
0
0.7
0
III
air
0
0
0
0
0
0.4
0
IV
air
0
0
0
0
0
0
0
water
0
0
0
0
0
0
0
DRAFT—September 1994
V-265
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster
Environmental Releases
Table V-188
Environmental Release Estimates in Screen Cleaning Operations
Method 4, Alternative System Theta
System
Release Under Each Scenario
(g/day)
I
air
water
land
II
air
III
air
IV
air water
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario 11 = pouring 1 ounce of fluid for sampling; Scenario III = transferring
chemicals from a 55 gallon drum to a 5 gallon pail; Scenario IV = storing waste rags in a drum and transferring them to a laundry.
Table V-189
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 4, Alternative System Theta
Substance:
Sodium periodate
Alkali/caustic
Cyclohexanone
Furfural alcohol
To Air:
54.1 g/day
To Water:
44 g/day
291 g/day
239 g/day
300 g/day
To Landfill:
DRAFT—September 1994
V-266
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster
General Population Risk Conclusions And Observations
Releases to Water from a Single Facility
Table V-190
Estimated Releases to Water from Traditional Formulations from
Screen Reclamation at a Single Facility
Using Screen Reclamation Method 4, Alternative System Theta
Substance
Sodium periodate
Alkali/caustic
Cyclohexanone
Furfural alcohol
Amount Released
to Water from
Facility
44 g/day
291 g/day
239 g/day
300 g/day
Waste water
Treatment
Removal
Efficiency
100 %
100 %
83%
97%
Amount to Water
After Waste water
Treatment
0
0
41 g/day
9 g/day
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
0
0
4x10'2
9x10'3
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
Releases to Air from Individual Screen Printing Facilities
Table V-191
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 4, Alternative System Theta
Substance
Cyclohexanone
Amount of Releases per
day
54.1 g/day
Highest Aver age
Concentration 100 M
away
1.1x10'1
Annual Potential Dose,
mg/yeara
8x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions And Observations
o Health risks to the general population from both air and water exposures are very
low for Method 4, Alternative Screen Reclamation Technology using High Pressure
Water Blaster.
DRAFT—September 1994
V-267
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster General Population Risk Conclusions And Observations
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the single facility releases of Method 4, Alternative Screen Reclamation
Technology using High Pressure Water Blaster.
Performance
General Summary of Alternative Reclamation Technology Theta Performance
The performance of the Alternative Technology Theta was demonstrated at Facility 1
under conditions similar to those used at SPTF for alternative system testing. This facility,
however, demonstrated the performance of an alternative screen reclamation technology,
instead of an alternative chemical system. The alternative technology demonstrated was a high
pressure wash system with a 3000 psi spray applicator. When reclaiming screens with System
Theta, an emulsion remover and a haze remover are used, but no ink remover is needed.
Several different types of emulsion and haze removers are sold with this technology. The
performance demonstration was conducted using the chemical products that are normally used
by this volunteer facility which are supplied by the Theta equipment manufacturer. Therefore,
this performance evaluation of this technology is based only on those chemicals used in the
testing.
The SPTF staff felt the performance of the system was very good. During the
demonstration, the ink was carded off on both sides of the screen which caused some
complications during testing. Since the screen was not actually used for printing, the ink on
the stencil side transferred through to the print side when the screen was carded. To remove
this excess ink, the print side was also scraped. The ink on the print side of the screen was
more difficult to remove and this ink also made it harder to remove the emulsion. Under
normal printing operations, ink does not reach the print side of the screen, therefore SPTF staff
thought this difficulty would not occur at a printing facility. The observer felt System Theta
could efficiently and effectively clean the screen, while reducing the labor, effort, and quantity of
chemicals required for reclamation.
Alternative Screen Reclamation Technology Theta Profile
Reclaim screens with Alternative Screen Reclamation Technology Theta as follows:
o Ink Removal and Emulsion Removal. Card up excess ink from the screen. Dilute
the emulsion remover as instructed. Spray the emulsion remover on the print side
of the screen. Allow to sit for 10 to 30 seconds. Wash both sides of the screen
DRAFT-September 1994 V-268
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster Performance
from the bottom to the top with the 3000 psi spray applicator to remove the ink and
stencil residue.
o Haze Removal. With a rag soaked in haze remover, rub the screen on the ink side
and allow to set for 3 minutes. Rinse from the bottom to the top on the print side
of the screen with the 3000 psi applicator. Turn the screen and rinse with System
Theta equipment on the ink side. For tough stains, allow the haze remover to set
for up to 10 minutes.
Alternative System Performance Evaluated by SPTF
Alternative Screen Reclamation Technology Theta was tested by SPTF on three screens
(one with a solvent-based ink, one with a UV-curable ink, and one with a water-based ink).
Since SPTF does not have the System Theta equipment on-site, the test was performed at a
volunteer printing facility that regularly uses the Theta equipment. SPTF prepared the test
screens using the same parameters as were used for the testing of alternative chemical systems
(these parameters are listed in the appendix). At the printing facility, the inks were applied to
the stencil side of the screen, and excess ink was carded off. However, the ink was applied for
testing purposes only (screens were not used for printing) and when excess ink was carded off,
it transferred to the print side of the screen. When the ink on the print side was scraped off, it
spread to cover the stencil. Inks were allowed to dry for 18 hours before reclamation. The ink
residue on both sides of the screen does not accurately represent the conditions in typical
printing operations, however, it does represent a worst case condition. SPTF thought that the
presence of ink on the print side of the screen lengthened the wash time required to remove the
ink and the emulsion.
On the screen with the solvent-based ink and the screen with water-based ink, the stencil
dissolved easily with the application of the high pressure water; no scrubbing was needed.
There was no emulsion or ink residue left in the screen, but there was a medium ink stain
remaining on the screen with solvent-based ink and a very light stain on the water-based ink
screen. On both screens, all of the ink and stencil did dissolve after less than four minutes of
washing with the high pressure sprayer, however, the areas of the emulsion where the ink was
on the print side of the screen did not dissolve as quickly as the areas where there was no ink
on the print side. SPTF staff noted that these conditions did not represent an actual printing
situation well and that they did not feel that the extra time was a fault of the high pressure
spray system. The haze remover completely eliminated the stains. When the haze remover was
applied, the product immediately dissolved the ink stain, even before the waiting period or the
pressure wash.
Results were similar for the screen with UV ink. In most areas the stencil dissolved very
easily without any scrubbing. After 4 minutes of water blasting, emulsion was still present in
blocks where the ink was scraped on the print side of the screen. Again, SPTF staff felt that the
residual emulsion was caused by the test conditions and that it did not indicate poor
performance on the part of the Theta system. Some ink stain was remaining especially in areas
where the emulsion was left. The haze remover removed all of the ink, leaving only a very light
stain, but the emulsion was still remaining in approximately one-third of the blocks. To remove
the emulsion, the emulsion remover was reapplied and allowed to sit for 20 seconds. After
water blasting the screen again, the emulsion was completely removed.
Overall, the SPTF staff present at the demonstration thought System Theta was a very
efficient and effective technique for screen cleaning. Use of the system could minimize the
DRAFT-September 1994 V-269
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster Cost
quantity of chemicals needed for screen reclamation by eliminating the ink remover and by
using the high water pressure to reduce the quantity of emulsion and haze remover required.
System Theta also reduces the labor time and effort needed to reclaim a screen.
Alternative Technology Performance Table
The following table highlights the observed performance of the Alternative Screen
Reclamation Technology Theta during the product tests performed by SPTF.
Cost
Data collected by SPTF staff during a facility visit and equipment specifications provided
by the manufacturer were used to develop the cost for this method. The capital cost of this
equipment was annualized by the method described in Chapter 3, added to the recurring
operating and maintenance costs and divided by the number of screens reclaimed per year to
arrive at the per screen equipment costs. Water, wastewater and electrical usage costs were
included in the cost estimate for this method only. As in all other cost estimations, the cost of a
filtration system was not included as the analysis was focused on quantifying cost differences
between reclamation systems, without accounting for filtration costs that may occur in all cases.
DRAFT-September 1994 V-270
-------
•o_
CD"
CD
Table V-192
Alternative Screen Reclamation Technology Theta
System
Component
Performance
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Overall System Performance
Demonstration Conditions
Ink type
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
SPTF Testing at Volunteer Facility 1
Solvent-
based Ink
UV-
curable
Ink
Water-
based Ink
Ink and
Emulsion
Removal
Haze
Remover
Ink and
Emulsion
Remover
Haze
Remover
Ink and
Emulsion
Remover
Haze
Remover
18 hours
Omins
18 hours
Omins
18 hours
Omins
0.5 oz.
1.5oz.
1.0 oz.
1.5oz.
1.0 oz.
1.5oz.
2.7mins
1.7mins
5.5mins
1.5mins
3.3mins
1.5mins
Low
Low
Low
Low
Low
Low
Removed stencil completely without
scrubbing; where ink was put on print
side of stencil, emulsion was more
difficult to remove.
Screen very clean; virtually no stain
remaining.
Removed most of the stencil easily
without scrubbing; where ink was
scraped onto print side of screen, stencil
residue remained.
No ink residue, and very light stain.
Parts of emulsion remained; a second
application of emulsion remover was
needed.
Removed stencil completely without
scrubbing; where ink was put on print
side of stencil, ink was more difficult to
remove.
Screen very clean; virtually no stain
remaining.
Solvent-
based
UV-cured
Water-
based
Dual-cure
direct
Dual-cure
direct
Dual-cure
direct
Polyester;
245
threads/inc
h
Polyester;
390
threads/inc
h
Polyester;
245
threads/inc
h
360 in2
360 in2
360 in2
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-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster
Cost
Table V-193
Method 4: Summary of Cost Analysis for Alternative Technology Theta
Cost Element Description
Facility Characteristics
Average screen size (in2)
Average # screens/day
Baseline
(Traditional
System 4)
Cost Element Description
2,127 Average screen size (in2)
6 || Average # screens/day
Alternative
System Theta
Facility 1
360
13
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Hazardous
Waste Disposal
Time spent applying,
scrubbing, and removing
reclamation products (min)
Cost ($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
Time spent pressure washing,
applying and removing removing
reclamation products (min)
Cost ($)
Pressure Wash Equipment
Cost($)
Water Use (gal.)
Electricity Use (kWhr)
Utility Cost($)
Emulsion Prep Product
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount (g)
Cost($)
5.4
1.18
0.25
10.7
0.65
0.11
0.8
0.11
1.5
0.36
0
0
Totals
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Nnrmali7fiHa
6.27
6.27
9,399
9,399
Total Cost ($/screen)
Normalized3
Total Cost ($/year)
Nnrmali7fiHa
2.02
4.53
6,315
6,797
3Normalized values adjust product usage, number of screens cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
l:No filtration system costs were included in this calculation.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-272
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Feasibility
Method 5: Automatic Screen Reclamation Technology
Automatic screen washers are commercially available technologies that remove ink, or in
some cases, ink, emulsion and haze, by focusing appropriate reclamation products on a screen
mesh surface within a fully enclosed unit. Limited information was available on this technology
because those manufacturers who manufacture this type of equipment chose not to participate
in the performance demonstration or other facets of the project. The system can be selective, in
that it can be used to remove ink only, or to completely reclaim screens. These units employ a
washout booth, pressurized sprayer/applicator, and filtration system to effectively remove ink;
refer to Chapter 6 for a discussion of these equipment costs. Because these systems have a
fully enclosed cleaning area, the amount of occupational exposure to the chemical reclamation
system in use can potentially be minimized.
Features
Although the automatic screen washing technology can consist of any number of options,
automatic screen washers have several basic components. The general shape for the entire unit
is a large, fully enclosed, metal cube that can house a variety of screen sizes (see Figure V-6).
The screen to be cleaned is placed inside the chamber and secured with clamps. When the
screen is in place and the enclosure door closed, the cleaning process can begin.
First, a mobile mechanical arm sprays solvent through one or more pressurized
applicator nozzles onto the screen for any number of preset cleaning cycles. These applicator
systems can operate in various ways depending on the system, but most apply the cleaner at
pressures ranging from 30 psi to 150 psi (see Chapter 6 for further information on pressurized
applicator systems). The used solvent then drains off the screen and usually drops directly
into the filtration system. The effluent travels through the filtration system to remove the
contaminants from the waste stream, and the recycled solvent can often be recirculated for
subsequent use. These filtration and recirculation systems are available with various
specifications and options and are discussed in more detail in Chapter 6.
While this is the generic washing system for ink removal, many other variations are
currently available. One available option is multi-stage ink removal. Some automatic screen
washers are equipped to remove the ink in several stages or cycles such as washing, rinsing, or
blowing, and equipment employing any or all of these cycles are available. In such a system, the
ink would be completely washed out in the first cycle, rinsed again to remove stubborn residue,
and blown dry using air pressure. Automatic screen washers are also available to remove
emulsion and haze, as well as ink, from screens. The general process for this is to apply an
emulsion remover to the screen (usually with hot water and a spray applicator) after ink
removal is complete; the screen is then pressure-washed and rinsed with water. A haze remover
can then be applied with a spray applicator. For more specific information on automatic screen
washing units, printers should consult manufacturers, product literature, and other printers.
Feasibility
The automatic screen washing systems may not be a feasible option for a large segment
of the screen printing industry because they are predominantly manufactured for larger
reclaiming operations. The size and speed of these systems allow a printer to remove the ink
from large quantities of screens in a very short period of time; most systems can clean a screen
DRAFT-September 1994 V-273
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology
Feasibility
Figure V-6
The Typical Exterior of an Automatic Screen Washing System Used for Ink Removal
Wash unit with interior spray nozzles
Filters
Solution Holding
Tank & Sludge Collector
Pump
in under five minutes. In addition, the cost of an automatic screen washing system can
discourage most small printers from purchasing one. Some automatic systems that remove
only ink can be purchased for approximately $5,000 to 7,000; the majority of these units cost
between $15,000 and 30,000. The more expensive units may include emulsion and haze
removal. Such a high cost for reclamation equipment may make automated screen systems an
implausible method of screen reclamation for smaller printers. On the other hand, those
printers willing to pay the cost for such a technology can largely dictate the exact specifications
needed; an automatic system can be created to suit the need of virtually any facility. The size of
an automated system may vary to allow screens as large as 60"x 70" to be cleaned. These units
may also have multiple interior cleaning areas.
Evaluation
Due to the lack of manufacturer participation, the demonstration of the performance of
an automatic screen washer was not undertaken. However, a risk assessment was developed
for an automatic screen washing system used by a facility that participated in the performance
demonstration; this particular screen washer only removed ink. Experimental parameters
DRAFT—September 1994
V-274
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Evaluation
used in the occupational exposure and population exposure calculations were drawn from the
data available from this single site. Because the manufacturer of the ink remover product used
in the screen washer did not participate in the project, the formulation for the ink remover was
not available (considered proprietary). The risk assessment could not be undertaken for the
actual solvents used in the screen washer because the composition of the ink remover was
unknown. The experimental parameters for the screen washer were instead used with two
other ink removers, mineral spirits and lacquer thinner, to develop a risk assessment. These
two ink removers were also assessed in screen reclamation in Methods 1 and 2 as components
of Traditional Systems 1 and 3.
Process Description
This automatic screen washer is an enclosed system used for ink removal only. It
consists of two tanks, a wash tank and a rinse tank, each with 35 gallons of the same solvent.
The screens are held stationary in the washer machine while an arm with spray nozzles moves
up and down the stationary screens, spraying ink remover solvent. The solvent runs off the
screen back into the tank from which it came. The machine is programmed to activate the
pump for the appropriate tank (wash or rinse) at specific intervals for different spray cycles.
The wash tank gets dirtier at a quicker rate than the rinse tank because the rinse tank
cleans off the screen for the last time. When the wash cycle solvent is eventually replaced, the
spent solvent is pumped out of the tank into a drum and allowed to settle. The pumping is
performed by opening and closing valves in the machine. The solvent on top of the sediment is
pumped back into the wash tank after the sediment settles. The spent rinse solvent is pumped
into the wash tank and fresh solvent is pumped into the rinse tank. According to one facility
that uses an automatic screen washer, approximately 7-10 gallons of solvent are lost during 55
operating days and the bath is changed every 8-9 months. The settled sediment from the spent
wash solvent is disposed of as hazardous waste.
Any solvent drippage from screens during screen removal is collected and returned to the
tank. The trap in the reclamation sink generates a solids waste. According to the facility, about
0.5 pounds of waste is generated per year and disposed of as municipal waste.
Occupational Exposure and Environmental Releases
Assumptions
o The amount of occupation exposure and risk depends upon the amount of cleaner
released from the automatic screen washer.
o 35 screens are cleaned per day
o Automatic cleaning for 6 minutes per screen
o Total machine operating time is 210 minutes per day
o 20 oz. per day of solvent losses occur due to volatilization
DRAFT-September 1994 V-275
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Exposure and Environmental Releases
o 3 employees work with the screen washer
o 15 minutes per employee for screen removal
The exposure/release scenario includes air releases due to volatilization of the ink
remover solvent during machine operation. Dermal contact of the ink remover solvent would
occur during screen removal. Spent baths and solids waste from the machine trap are
periodically disposed of.
EPA has evaluated occupational exposure and risk of automatic screen washers using
chemical systems based on Traditional System 1 and Traditional System 3.
Table V-194
Environmental Release Estimates from Automatic Screen Washer
Solvent System
Ink remover solvent
Releases to Air (g/day)
555
Table V-195
Occupational Exposure from Automatic Screen Washer
Solvent System
Ink remover solvent
Inhalation (mg/day)
266
Dermal (mg/day)
3,900
Estimation Methodology
In operation, the automatic screen cleaner sprays the screen with solvent and then allows
the screen to drip dry. This process is repeated for the rinse cycle. Releases of the solvent to
the air consist of the following:
1) Volatilization from drops of the solvent as they are being sprayed toward the screen.
2) Volatilization from the screen as it drips.
3) Volatilization from the liquid solvent pool.
The first part consists of forced-convection mass transfer past a set of spheres. The
second involves free convection from a vertical plate. These processes are not described by the
estimation methods in the CEB manual. If the unit were open to atmosphere, equations would
be needed for all of these processes. However, the unit is closed during operation, so that the
three evaporation sources merely serve to saturate the vapor space in the machine. When the
machine is opened, this vapor is released to the atmosphere and the workers are exposed to it.
The mass of solvent in this released vapor is (assuming complete saturation of the vapor
space):
DRAFT-September 1994 V-276
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Exposure and Environmental Releases
V P
(——)(—)M
24.45 760
where
V is the volume of the headspace (1)
P is the vapor pressure of the solvent (mmHg)
M is the molecular weight of the solvent (g/mol)
Now, we know that 8.5 gallons of solvent is lost in this way over 55 working days. At a
solvent density of 0.95 g/cc, this corresponds to 555 g/day. The vapor pressure of the solvent is
3.6 mmHg. The molecular weight is probably close to 150 g/mol. Isobutyl isobutyrate, a known
component of the mixture, has a molecular weight of 144 g/mol. Other compounds with the
correct volatility (and we know that the solvent consists entirely of VOCs) have molecular
weights in the same range. Thus, the volatilization rate of any other solvent will be:
555 x (—)(—)
3.6 150
As noted in our earlier reports, the worker exposure in mg/day equals the air release in
g/day times 0.48. Thus, the worker exposure in mg/day is:
0.48 x 555 x (—)(—)
3.6 150
Thus, if the total vapor pressure of any other solvent and the average molecular weight of its
vapors can be computed, the airborne releases and worker exposure can be estimated.
These are worst-case estimates which assume that all of the leakage occurs during
removal of the screens, and none occurs overnight or on weekends when workers are absent.
Example 1. Estimate the air releases and environmental exposure for ink removal from 6
screens using the automatic screen washer.
For ink remover solvent, 555 g of ink are released to air per day during the cleaning of 20
screens. For 6 screens, the amount released to air per day will be:
555 x (6/35) = 95 g/day
For 6 screens, the worker exposure is:
0.48 x 95 = 46 mg/day
Example 2. Estimate the air releases and environmental exposure for ink removal from 6
screens using the automatic screen washer with mineral spirits as the ink remover.
Mineral spirits (light hydrotreated) has the following physical properties:
Molecular weight: 86
Vapor pressure: 1 mm Hg
Density: 0.78 g/L
DRAFT-September 1994 V-277
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Occupational Risk Conclusions
For mineral spirits, the volatilization will be:
95 x (1/3.6) x (86/150) = 15.1 g/day
The worker exposure will be:
0.48 x 95 x (1/3.6) x (86/150) = 7.3 gm/day
Example 3: Estimate the Air Releases and Environmental Exposure for Ink Removal from 6
Screens Using the Automatic Screen Washer with Lacquer Thinner as the Ink Remover.
Occupational Risk Estimates
Quantitative risk estimates could not be determined for this system due to insufficient
data. See risk conclusions for areas of concern for this system.
Occupational Risk Conclusions
Automatic Screen Washer - Mineral spirits (ink remover only)
o Inhalation exposures were significantly lower (reduced by about 70%) than the
exposures during manual use of this system. Risks could not be quantified because
of limitations in hazard data.
o Dermal exposures can still be relatively high.
Automatic Screen Washer - Lacquer Thinner (ink remover only)
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposures to toluene, methyl ethyl ketone, and methanol.
DRAFT-September 1994 V-278
-------
Table V-196
Occupational Risk Estimates for Auto Screen Washers Using Lacquer Thinner as the Ink Remover
o
Q.
Ol
CO
Name
Ink Remover
Methyl ethyl ketone (2-butanone)
Butyl acetate normal
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Hazard Quotient
Inhalation
7.7
NA
1.2
NA
5.6
NA
Dermal
Routine
56
NA
5.6
NA
111
NA
Immersion
NA
NA
NA
Margin Of Exposures
Inhalation
NOAEL
NA
NA
NA
NA
NA
NA
LOAELd
NA
NA
NA
NA
NA
NA
Dermal
Routine
NOAEL
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
Immersion
NOAEL
NA
NA
NA
NA
NA
NA
LOAEL
NA
NA
NA
NA
NA
NA
aMargin of Exposure (MOE) values above 100 for a NOAEL and 1000 for a LOAEL indicate low risk.
bHazard Quotient is the ratio of the estimated chronic dose/exposure level to the Reference Dose (RfD) or the Reference Concentration (RfC). Hazard Quotient
values less than 1 imply that adverse effects are very unlikely to occur.
CNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
o
3
8?
I
B-
o
CD
O
O_
O
CD
ff
•o
Q)
I
CD
CO
CO
CD
s
I
Q)
8-
O
a
o
Q.
CO
O
a.
tn
;*-
ff
en
o'
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology
Occupational Risk Conclusions
Table V-197
Estimated Air Releases and Environmental Exposure for Ink Removal Screens Using the
Automatic Screen Washer with Lacquer Thinner as the Ink Remover
Lacquer Thinner
Methyl ethyl
ketone
Butyl acetate
Methanol
Naphtha, light
aliphatic
Toluene
Isobutyl
isobutyrate
wt%
30
15
5
20
20
10
Molecular
Weight
72.11
116.2
32.04
86
92.14
144.21
Mole
fraction
0.34
0.11
0.13
0.19
0.18
0.06
Vapor
pressure
(mm Hg)
77.50
12.80
126.88
20.00
28.00
3.20
Partial
pressure
(mm Hg)
26.43
1.35
16.23
3.81
4.98
0.18
Emission
335.23
27.68
91.47
57.67
80.74
4.61
Inhalation
160.91
13.29
43.91
27.68
38.76
2.21
Dermal
1,170
585
195
780
780
390
o Hazard quotient calculations indicate clear concerns for chronic dermal exposures
to toluene and methyl ethyl ketone and marginal concerns for dermal exposures to
methanol.
o The risks described above are slightly lower than the corresponding risks during
manual use of this system.
o Risks from other components could not be quantified because of limitations in
hazard data, although dermal exposures to all components could be relatively high.
Table V-198
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Automatic Screen Washer, Mineral Spirits
Substance:
Mineral Spirits
To Air:
15.1 g/day
To Water:
To Landfill:
DRAFT—September 1994
V-280
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology
Occupational Risk Conclusions
Estimated Releases to Air from Individual Screen Printing Facilities
Table V-199
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Automatic Screen Washer, Mineral Spirits
Substance
Mineral Spirits
Amount of Releases per
day
15.1 g/day
Highest Aver age
Concentration 100 M
away
3x10'2
Annual Potential Dose,
mg/yeara
2x10'1
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
Table V-200
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Automatic Screen Washer, Lacquer Thinner
Substance:
Methyl ethyl ketone
n-butyl Acetate
Methanol
Aromatic solvent naphtha
Toluene
Isobutyl isobutyrate
To Air:
335 g/day
27.7 g/day
9 1.5 g/day
57.7 g/day
80.7 g/day
4.6 g/day
To Water:
To Landfill:
DRAFT—September 1994
V-281
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology
Cost
Table V-201
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Automatic Screen Washer, Lacquer Thinner
Substance
Methyl Ethyl Ketone
n-butyl acetate
Methanol
Naphtha, light aliphatic
Toluene
Isobutyl isobutyrate
Amount of Releases per
day
335 g/day
27.7 g/day
9 1.5 g/day
57.7 g/day
80.7 g/day
4.6
Highest Average
Concentration 100 M away
7x10'1ug/m3
5x10'2ug/m3
2x10'1ug/m3
1 x 10'1 ug/m3
2x10'1ug/m3
9x10'3ug/m3
Annual Potential
Dose, mg/yeara
5
4x10'1
1
8x10'1
1
7x10'2
aThis estimates doses for people living 100 Meters from the hypothetical facility. The actual number of people who would fall
into this range can be determined from census data, if the facility location is known. The model used to calculate
concentrations is more completely explained in the Overview by Media-Air Section in Chapter III. To calculate the annual
potential dose, the concentration is multiplied by the amount a person will breathe (20 m3/day) and the number of days per
year (365), and the units are converted to mg/year by dividing by 1000.
General Population Risk Conclusions And Observations
o Health risks to the general population from both air and water exposures are very
low for Method 5, Automatic Screen Reclamation Technology.
Although air releases were evaluated for only a single facility, it is very unlikely that an
analysis of cumulative air releases would lead to different risk conclusions. Examples of
general population exposure and risk estimates are shown for Method 2, Traditional System 1
in Methods 1 and 2 and Alternative System Chi in Method 2; please reference these sections as
illustrative examples. Hazard Quotient values below one indicate very low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above 1000 for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o Cumulative releases of mineral spirits present a concern for risk to aquatic species.
The largest contributor to these releases is the hypothetical commercial laundry
that launders the shop rags used by the area's screen printers.
o None of the other components of any of the two traditional ink removers reached an
ecotoxicity concern concentration, even when considering the cumulative releases
from all shops in the area.
o None of the single facility releases of the traditional ink removers reach an
ecotoxicity concern concentration.
DRAFT—September 1994
V-282
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Cost
Cost
Two cost estimates were developed which reflect both the baseline facility's operations
and size and the range of equipment available. Typically, automatic screen washers substitute
for the ink removal step; emulsion removal and haze removal may still be required.
Automatic Screen Washer # 1 is the unit used by the facility that also participated in the
performance demonstration. It was a large capacity (in terms of the maximum size of screen)
enclosed washer with a fully automated feed system to move the screens through separate wash
and rinse areas. It was assumed that mineral spirits was present in both reservoirs. As
mineral spirits are used in the ink removal step, the cost analysis of automatic screen washer
# 1 assumes the same emulsion and haze removal costs as in the baseline. Its original
manufacturer's purchase price of $95,000 was used as a basis for the cost analysis, although in
actuality, the facility purchased the equipment second-hand at auction. The only operating costs
were related to solvent make-up (daily) and replacement of the reservoirs' contents 70 gallons
(every eight to nine months). Time spent loading and unloading the washers was taken from
manufacturer's documentation of the equipment. As the equipment's electrical rating was not
available from information provided by the distributor, electrical costs were not included. The
price of mineral spirits ($4.00/gallon) was taken from the Workplace Practices Questionnaire.
Emulsion removal and haze removal costs were assumed to be similar to those of the baseline
system.
Automatic Screen Washer #2 is a smaller unit on which some minimal information was
gathered. Screens must be loaded and unloaded by hand. Because it uses a solvent with lower
volatile fraction than # 1, more solvent remains on the screen and must be washed off following
ink removal. Time spent loading and unloading the washers was taken from manufacturer's
documentation of the equipment. Two pumps operate using compressed air which is
reportedly available from other sources at the facility; the cost of a generator was not included
in the cost analysis. The price of the ink remover was provided by the equipment supplier.
Emulsion removal costs were assumed to be similar to those of the baseline system. The
manufacturer indicated that a haze remover was not required given the formulation of the ink
remover.
DRAFT-September 1994 V-283
-------
Chapter VI
Overall Pollution Prevention Opportunities for Screen Reclamation
Screen Disposal as a Method of Pollution Prevention
Screen reclamation is typically a chemical and labor-intensive process. During the course
of the assessment of various screen reclamation methods, it was proposed that disposal of
imaged screens, rather than reclamation, might be a feasible alternative. It was known that
some screen printers with long production runs and extremely small screens, such as those
used to print on pill bottles, simply cut the screen mesh out of the frame after completion of the
production run. The question arises as to whether printers who use larger screens in shorter
production runs could also feasibly dispose of their screens. By simply disposing of the screen,
printers could eliminate the high cost of reclamation chemicals, labor time associated with
screen reclamation, and occupational and population exposure to the chemicals used in screen
reclamation, thus reducing risk. Conversely, printers would have to dispose of more screens,
which could be expensive if the ink and emulsion components were required to be disposed of
as hazardous waste. The time involved in preparing screens for printing, especially stretching
and tensioning, would also be increased.
It would be difficult to directly compare the two options in terms of pollution prevention
potential due to the different types of source reduction achieved by the two methods. While
screen disposal may reduce chemical usage, screen reclamation might involve less hazardous
waste disposal, particularly if filtration systems are used in the reclamation process. Other
areas, such as screen performance, are also not easily defined. Some screen printers claim that
screen performance improves with screen use because the tension throughout the screen mesh
becomes evenly distributed. Because it is experimentally difficult to assess such claims, only a
cost analysis of screen reclamation versus screen disposal was undertaken. Information on
screen disposal was not collected as part of the performance demonstrations.
The cost estimate of screen disposal was developed for comparison to other reclamation
methods. One cost estimate was developed to reflect the baseline facility's operations and size;
it is profiled in Table VI-1. It should be noted that screen disposal is most cost effective under
two circumstances not assumed for the model facility's operations: where production runs
approach the useful life of a screen and where the size of the screen is relatively small. A
number of assumptions were used to estimate the cost of this substitute method, including:
• No other changes in operations or equipment were required.
• Waste screens do not need to be handled as hazardous waste under RCRA, which
would greatly increase the estimated cost.
• The replacement of screens (after reaching the end of the useful life of the mesh)
was not considered in the baseline nor in any of the other reclamation methods; it
is estimated to be approximately $0.60/screen reclamation. Consequently, this
value was deducted from the total cost of this method.
• The average wage rate of screen stretchers ($6.87), which is slightly higher than for
screen reclaimers, was used to calculate labor costs for this method.
DRAFT-September 1994 VI-1
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Screen Disposal as a Method of Pollution Prevention
Table VI-1
Summary of Cost Analysis for Screen Disposal Alternative
Description
Baseline
(Traditional
System 4)
Description
Screen
Disposal
Alternative
Facility Characteristics
Average screen size (in2) 2,127
Average # screens/day || 6
Average screen size (in2) 2,127
Average # screens/day || 6
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Waste Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost($)
# of rags used
Cost($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost($)
Haze Remover
Average Volume (oz.)
Cost ($)
Amount, Hazardous (g)
Cost ($)
24.4
5.33
3
0.45
8.0
0.22
3.5
0.13
3.0
0.12
34
0.02
Time spent stretching, degreasing,
and removing screen (min)
Cost($)
Screen Mesh (in2)
Cost($)
Prep Degreasing
Volume (oz.)
Cost ($)
Amount, Nonhazardous (g)
Cost ($)
50
11.50
2,345
38.5
1.0
0.02
NAa
NA
NA
NA
0.64
< 0.01
Totals
Total Cost ($)/screen
Total Cost ($)/year
6.27
9,399
Total Cost/Screen"
Total Cost/year"
49,43
74,141
Note: Screen disposal is cost effective only with smaller screen sizes and/or long production runs, where the number of impressions nears
the expected life of the screen.
aNot applicable. Screen disposal does not require this cost element.
bThe replacement of screens (after the end of the useful life of the mesh) was not considered in the baseline or other alternative reclamation
methods evaluated. A value of $0.60 per screen was therefore deducted from the total cost of this method.
DRAFT—September 1994
VI-2
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention
through Improved Workpractices Responses to the Workplace Practices Questionnaire
Printers should not view this cost estimate as a final analysis, because the operations of any
one facility can be different from the assumptions used in generating this cost analysis.
However, it is clear that screen disposal may not be a cost-effective option for a majority of
screen printing facilities.
Pollution Prevention through Improved Workpractices
Pollution prevention is the use of materials, processes, practices or products that avoid,
reduce or eliminate wastes or toxic chemical releases. Pollution prevention can be
accomplished through activities such as material substitution, source reduction and closed
loop recycling. This section of the CTSA focuses on ways that printers can achieve pollution
prevention through improved workplace practices.
Responses to the Workplace Practices Questionnaire
Many screen printers are finding that they can save time and cut costs by improving their
workplace practices to prevent pollution. This was one of the key findings of a section on
pollution prevention opportunities included in the Workplace Practices Questionnaire for
Screen Printers (see Appendix B). Almost 36 percent of the respondents reported that they had
implemented changes in workplace practices to reduce their use of ink removal or screen
cleaning/reclamation products. Almost 24 percent had made equipment changes, 26 percent
had made product changes, and another 26 percent had made process changes . The majority
of the respondents reported that pollution prevention, whether through improved workplace
practices, or changes in equipment, products or processes, either decreased or caused no
change in materials cost, the time required to clean/reclaim the screen, and disposal costs.
Almost 30 percent of the respondents to the questionnaire reported having a pollution
prevention, waste minimization, or source reduction program at their facility. The concepts of
pollution prevention and waste minimization are almost synonymous, except pollution
prevention places more emphasis on preventing environmental releases to any media at the
source. Source reduction is the highest level in the pollution prevention hierarchy, since it
involves going to the source of pollution to identify prevention opportunities.
More than 75 percent of the respondents had tried an alternative ink removal or screen
cleaning/reclamation product for environmental or worker safety reasons. Of these
respondents, more than 50 percent reported the performance of the alternative chemical
product was satisfactory, while only 19 percent found the product unsatisfactory. Others
indicated they had mixed results from different products, that they were concerned about cost
or that their operators were resisting any changes to alternative chemical products.
It is apparent from these results that screen printers have an excellent opportunity to
prevent pollution simply by reevaluating their workplace practices with the environment in
mind. Furthermore, pollution prevention through improved workplace practices results in cost
savings through the reduced use of materials, reduced waste disposal costs, and other benefits.
Many printers who responded to the survey reported that pollution prevention through
improved workplace practices is simply a common-sense approach.
DRAFT-September 1994 VI-3
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention
through Improved Workpractices Responses to the Workplace Practices Questionnaire
To learn more about how printers are using improved workplace practices to prevent
pollution, the University of Tennessee Center for Clean Products and Clean Technologies
contacted the printers responding to the survey who indicated they have a pollution prevention,
source reduction, or waste minimization program that they would be willing to share with the
DfE Printing Project. Using the actual experiences of screen printers and data from other
sources, the following framework for pollution prevention through improved workplace
practices was developed. To ensure the anonymity of printers who responded to the Workplace
Practices Questionnaire for Screen Printers, no personal references are provided with this
material.
Framework for Pollution Prevention
The basic framework for pollution prevention through improved workplace practices
involves
o raising employee awareness
o materials management and inventory control
o process improvement
o periodic, in-house audits.
Raising employee awareness is the best way to get employees to actively participate in a
pollution prevention program. Materials management and inventory control means
understanding how chemicals and materials flow through a facility to identify the best
opportunities for pollution prevention. Implementing these steps will help to prevent pollution
through good management practices in the workplace. Process improvement through
workplace practices means reevaluating the day-to-day operations that make up the printing
and screen cleaning and reclamation processes. Implementing this step helps prevent pollution
through good operator practices in the workplace. Finally, in-house audits are used to collect
real-time data on the effectiveness of a pollution prevention program. This step gives both
operators and managers the incentive to strive for continuous improvement.
Raising Employee Awareness
When asked why they do not use alternative, less polluting chemical products or methods
to clean and reclaim the screen, many printers respond that press operators are reluctant to
change from traditional chemicals and methods; they simply do not believe the alternatives will
work. This implies that a large barrier to pollution prevention in the printing industry may be
an unwillingness to try new products and new techniques due to a lack of awareness of the
potential benefits. Printers need to understand that pollution prevention can result in
improved worker health and safety, an improved working environment, cost savings, and
reduced or less toxic waste streams leaving the plant, which means less overall impact on
human health and the environment. Many printers are beginning to design and implement
programs to teach employees about the benefits of pollution prevention. Table VI-2 lists some
of the steps to and benefits of raising employee awareness.
Although most of the printers contacted during the follow-up survey did not have a
written environmental or pollution prevention policy, several did have written operating
procedures that could be used to guide pollution prevention activities. One printer in Ohio said
he had recently written procedures on chemical handling and disposal to ensure that there was
DRAFT-September 1994 VI4
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices
Framework for Pollution Prevention
no misunderstanding about proper chemical handling, and to minimize the potential for an
accidental discharge of potentially hazardous materials. Having procedures available also
makes his job easier, since employees can first go to the procedure if they have questions about
chemical handling and disposal. Another printer had begun to write operating and
maintenance procedures for each process (e.g., printing process, screen cleaning/reclamation
process, etc.) to control quality and materials use at his facility, and to establish environment
quality goals for the facility.
Table VI-2
Benefits of Workplace Practices to Raise Employee Awareness
Workplace Practices
Prepare a written environmental policy
Prepare written procedures on equipment operation and
maintenance, materials handling and disposal
Provide employee training on health and safety issues,
materials handling and disposal
Seek employee input on pollution prevention activities
Make employees accountable for waste generation and
provide incentives for reduction
Provide feedback to employees on materials handling and
disposal and pollution prevention performance
Benefits
Establishes environmental management goals; illustrates
management commitment to pollution prevention and
environmental goals
Better informs employees of the proper procedures for using
and disposing of materials
Ensures that employees have proper training to understand
benefits of proper materials handling and disposal, and
potential consequences of improper workplace practices to
their health and safety, the environment, and company
profitability
Encourages the persons closest to the process, the
operators, to develop the best, most creative approach to
pollution prevention; employee involvement and ownership
of the program is essential to a successful program
Encourages employees to be aware of ways they can
prevent pollution; rewards active involvement in pollution
prevention activities
Re-emphasizes management commitment to pollution
prevention; encourages employees to continue to improve
Materials Management and Inventory Control
Proper materials management and inventory control is a simple, cost-effective approach
to prevent pollution. Several printers described materials management and inventory control
as the common-sense approach to good business and pollution prevention. Keeping track of
chemical usage and limiting the amount of chemicals on the process floor gives operators an
incentive to use the minimum amount of chemical required to do the job. Ensuring that all
chemical containers are kept closed when not in use minimizes the amount of chemical lost
through evaporation to the atmosphere. Not only do these simple practices result in less
overall chemical usage, and thus a cost savings, they also result in reduced worker exposure to
toxic chemicals and an improved working environment. Table VI-3 lists some of the steps to
and benefits of materials management and inventory control.
DRAFT—September 1994
VI-5
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices
Framework for Pollution Prevention
Process Improvements
Once the flow of materials within a facility has been documented, the next step is to
analyze the process, materials logs and waste generation logs to identify workplace practices
Table VI-3
Benefits of Workplace Practices for Materials Management and Inventory Control
Workplace Practices
Manage inventories on a first-in, first-out basis
Maintain accurate logs of chemical and materials stock,
chemicals and materials use, and waste generation rates
Minimize the amount of chemicals kept on the floor at any
time
Centralize responsibility for storing and distributing
chemicals
Segregate waste by waste stream and keep in marked,
easily accessible, closed containers
Keep spent solvents in marked, easily accessible, closed
containers
Benefits
Reduces materials and disposal costs of expired materials
Understanding materials flow and how it relates to waste
generation rates provides insights into pollution prevention
opportunities
Gives employees an incentive to use less materials
Gives employees an incentive to use less materials
Allows for more effective reuse or recycling of waste materials;
prevents nonhazardous waste from becoming contaminated
with hazardous waste; minimizes evaporation of VOCs;
reduces worker exposure
Promotes waste segregation, recovery and reuse; minimizes
evaporation of VOCs; reduces worker exposure
that can be adopted to prevent pollution at the source. Table VI-4 lists some workplace
practices that prevent pollution and their benefits.
A printer in Tennessee wrings excess solvent from used rags into a covered container.
After allowing the heavier contaminants to settle to the bottom, he simply decants the solvent off
the top for reuse and disposes of the sludge. Another printer uses a safe, explosion-proof
centrifuge to recover excess solvent. Before investing in a centrifuge, however, printers should
make sure that the equipment meets all health and safety requirements (e.g., protection from
flammability and explosion hazards) specified by the state or local government.
A printer in Minnesota reported that he had identified chemical overspray not directed at
the screen during emulsion and haze removal as one of the biggest sources of chemical loss.
Employees built a simple "catching frame" to place around the screen during the chemical
application steps. The catching frame is used to capture the overspray, which is then recycled
or reused.
Another printer in New York said his facility keeps chemicals in safety cans or other
sealed containers to minimize solvent loss from evaporation. They used to use a pump and
spray unit to apply ink degradant and emulsion remover, followed by a high-pressure water
wash. They only use haze remover if it is absolutely necessary. This facility has now gone to
manual, spot-application of the ink degradant and manual application of the emulsion remover,
DRAFT—September 1994
VI-6
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices
Framework for Pollution Prevention
followed by a low-pressure rinse. A final high-pressure water blast follows this rinse step.
Results of industrial hygiene monitoring at the facility indicate that this new method of applying
chemical results in no overspray of chemicals and reduced worker exposure, since the high-
pressure water blaster no longer disperses the chemicals as a mist in the air. They have also
reduced the accidental discharges from crimped or cracked discharge lines in the pump
system. This printer estimates that the new methods for applying chemicals to the screen have
resulted in a 15 percent reduction in material use.
Table VI-4
Benefits of Process Improvements to Prevent Pollution
Workplace Practices
Keep chemicals in safety cans or covered containers
between uses
Use plunger cans, squeeze bottles or specialized spraying
equipment to apply chemicals to the screen
Consider manual, spot-application of chemicals, where
applicable
Use a pump to transfer cleaning solutions from large
containers to the smaller containers used at the work station
Reduce the size of the towel or wipe used during clean-up
Reuse shop towels on the first pass with ink remover
Evaluate alternative chemical: water dilution ratios (increase
the amount of water)
Only apply chemicals where necessary
Avoid delays in cleaning and reclaiming the screen
Gravity-drain, wring, or centrifuge excess solvent from rags
Place catch basins around the screen during the screen
cleaning/reclamation process
Use appropriate personal protective equipment (gloves,
barrier cream, respirator, etc.)
Benefits
Reduces materials loss; increases worker safety; reduces
worker exposure
Reduces potential for accidental spills; reduces materials
use; reduces worker exposure
Reduces materials use; reduces worker exposure if aerosol
mists are avoided
Reduces potential for accidental spills; reduces worker
exposure
More efficient use of the towel; reduces solvent use; reduces
worker exposure
Reduces material (shop towel and ink remover) use; reduces
worker exposure
Reduces chemical usage with no loss of efficiency; reduced
worker exposure
Reduces chemical usage; reduces worker exposure
Simplify ink and emulsion removal; less potential for haze on
the screen
Recovers solvent for reuse
Captures chemical overspray for recovery and reuse
Reduces worker exposure
DRAFT—September 1994
VI-7
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices Framework for Pollution Prevention
Periodic, In-house Audits
Periodic, in-house audits are conducted for a number of reasons, including the following:
o to ensure that each step of the pollution prevention program is being implemented
o to collect data on the benefits and costs of the pollution prevention program
o to identify additional pollution prevention opportunities.
Pollution prevention programs have the same goal as total quality management programs:
continuous improvement. Periodic, in-house audits provide the information necessary to
ensure that goal is met. The results of the audit should be shared with all employees to raise
employee awareness about the benefits of the pollution prevention program, and to provide
them feedback on pollution prevention progress.
Realizing Pollution Prevention Benefits
The results of the Workplace Practices Questionnaire for Screen Printers showed that
there are tremendous opportunities for screen printers to reduce pollution through improved
workplace practices. Below, chemical application methods, equipment and materials use,
product storage and retrieval, and waste storage and disposal are four areas drawn from the
questionnaire to illustrate these pollution prevention opportunities.
Printers were asked to check the method (or methods) that best describes how they apply
ink removal, emulsion removal, and haze removal chemicals to the screen. Table VI-5
summarizes their responses. The majority of the respondents indicated they typically use some
type of spray or specialized equipment to apply ink or emulsion remover to the screen.
However, a significant percentage either poured chemical product directly from the container
onto the screen or dipped a rag or brush into a container and wiped the screen. If these results
are indicative of the industry as a whole, substantial pollution prevention benefits could be
achieved by (1) raising employee awareness about the health, safety and environmental issues
associated with excess chemicals being released to the air or washed down the drain, (2)
controlling materials and inventory to reduce the unnecessary use of chemicals, (3) applying
chemicals more carefully, and (4) using catchments or collection basins to capture chemical
overspray for recovery and reuse.
Table VI-6 shows the types of equipment (brush, spray gun, squeegee) and materials
(disposable or reusable rags) that respondents to the survey use during the three main screen
cleaning and reclamation steps. The variability of these results also indicates printers have
opportunities to prevent pollution by (1) identifying the optimal equipment to use during the
screen cleaning/reclamation step and (2) using reusable shop towels.
Printers were also asked (1) how they retrieve ink removal and screen reclamation
products from chemical storage and (2) if they keep both large and small containers in the ink
removal and screen cleaning/reclamation area, how they transfer products from large
containers to small containers for use. Most of the respondents either move an entire container
into the press room (14 percent) or pump the contents into a smaller container (41 percent),
but 26 percent pour the contents into a smaller container and 3 percent ladle the contents into
a smaller container. Clearly, the latter respondents have a greater potential for accidental spills
during the chemical transfer operation.
DRAFT-September 1994 VI-8
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices
Framework for Pollution Prevention
Printers who keep both large and small containers in the ink removal and screen/cleaning
reclamation area were slightly more likely to pour (34 percent) or ladle (1 percent) the contents
into a smaller container. Forty percent of these respondents use a pump to transfer the
contents into a small container at the work station. Again, a simple change in workplace
practices to using a pump, which is easier to control, instead of pouring the chemicals or using
a ladle, could prevent an accidental spill.
Finally, printers were asked if they store their waste materials in a closed container, an
open container, or in no specified container. Table VI-7 is a summary of their responses.
Although most of the respondents indicated they store their waste materials in a closed
container, there is still room for improvement, especially with waste rags and screen
reclamation wastes. Printers were also asked if they pretreat their rags prior to sending them
to a laundry or to a disposal facility. Almost 4 percent indicated they centrifuge their rags,
while 27 percent indicated they allow the excess solvent to drain out prior to recycling or
disposal. Almost 8 percent indicated they used some other form of pretreatment. Almost 50
percent of the respondents, however, indicated they do not pretreat their rags prior to recycling
or disposal. Again, a successful pollution prevention program could be used to (1) raise
employee awareness about the health and safety benefits of keeping waste materials in closed
containers and (2) develop a simple method to recover excess solvents from rags.
Table VI-5
Prevalence of Usage of Chemical Application Methods
Method of Chemical Application
pour from container onto screen
dip rag or brush into container and wipe screen
spray on w/ nozzle from tank
spray on w/ spray bottle
use specialized spraying equipment
Cleaning/Reclamation Step
Ink
9.3%
31.8
31.8
29.9
12.1
Emulsion
4.7%
28.0
24.3
31.8
12.1
Haze
5.6%
65.4
0.9
12.1
0.9
Note: Values represent percentage of printers responding to the particular check-off category. Some printers checked more
than one box; others did not respond to these sections. Therefore, numbers may not add up to 100 percent.
DRAFT—September 1994
VI-9
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Improved Workpractices
Framework for Pollution Prevention
Table VI-6
Prevalence of Use of Reclamation Equipment and Materials
Equipment and Materials Used
brush
low-pressure water spray
high-pressure water spray
water blaster
squeegee
disposable rags
reusable rags
Cleaning/Reclamation Step
Ink
40.2%
NA
NA
NA
1.9
16.8
28.0
Emulsion
41.1%
11.2
73.8
13.1
NA
5.6
7.5
Haze
3.7%
10.3
65.4
8.4
NA
0.9
4.7
Note: Values represent percentage of printers responding to the particular check-off category. Some printers checked more
than one box; others did not respond to these sections. Therefore, numbers may not add up to 100 percent.
NA = not applicable
Table VI-7
Prevalence of Waste Management Practices
Waste Management Practices
in closed container
in open container
no specified container
Waste
Ink Removal
71.0%
4.7
2.8
Screen
Reclamation
31.8%
3.7
15.9
Rags
77.6%
11.2
5.6
Note: Values represent percentage of printers responding to the particular check-off category. Some printers checked more
than one box; others did not respond to these sections. Therefore, numbers may not add up to 100 percent.
Conclusions
As can be seen by the above descriptions, a wide variety of pollution prevention
opportunities exist for screen printers. The basic framework for pollution prevention through
improved workplace practices is intended to be a guide or starting-point for individual printers
to develop pollution prevention practices within their own facility. The specific examples given
DRAFT—September 1994
VI-10
-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Sprayer/Application Systems
in the discussions above may not be applicable for every printer; the goals of pollution
prevention are facility specific and will evolve as a program develops. Nonetheless, substantial
opportunities exist for screen printers to prevent pollution through improved workplace
practices, although these opportunities will vary depending on the characteristics of each
facility.
Pollution Prevention through Equipment Modifications
Sprayer/Application Systems
The various systems for applying chemicals to a mesh surface offer some of the most
basic methods of pollution prevention. By allowing the screen reclaimer to control the amount
and direction of ink remover, emulsion remover, and/or haze remover, sprayer/application
systems effectively minimize the amount of solution used and reduce chemical waste at the
source. To further minimize chemical throughput, the more complex systems frequently
combine solvent recirculation systems with the spray applicator systems. The use of such
recirculation systems will be discussed at length in a subsequent section.
Features
This general category encompasses a large spectrum of products ranging in cost and
complexity. However, it is important to note that spray systems may not be applicable if the
emulsion remover or haze remover product is a paste. Printers should consult their suppliers.
Nevertheless, an applicator system at the most basic level may consist of a simple spray bottle
(e.g., plant mister) that can be purchased at virtually any hardware store for several dollars.
This spray bottle would substitute for simply pouring or wiping chemicals onto the screen
surface.
In addition to the spray bottle, a spray applicator system consisting of a spray applicator
device and a pump is an option available to screen printers (Figure VI-1). Such technologies
employ a low pressure air compressor to pump solvent onto the screen at various rates. The
rate of chemical flow to the screen is largely controlled by a variety of applicator attachments
made for such systems. These attachments can range from a scrubber-brush head (Figure VI-
1) to trigger-controlled spray guns (Figures VI-2 and VI-3). Cost for the spray applicators with
pumping systems can range from several hundred to several thousand dollars. Various
attachments to regulate flow are often included with such systems. Printers may purchase
items separately in order to modify or update an existing system. Another type of sprayer
system consists of a pressurized spray applicator and a solvent recirculation system. In
addition to regulating solvent flow, the solvent recirculation system regulates the drainage and
filtration of the spent solvent. Consequently, these combination systems are the most expensive
of the various application methods and often cost thousands of dollars.
Issues to Consider
Although these products can allow for significant source reduction, several issues must
be addressed in order to properly evaluate the method which provides the "best fit" for a
particular screen shop. While the use of a spray bottle may potentially reduce solvent use
compared to application with a solvent-soaked rag, the spray bottle may not provide significant
advantages with respect to time or effort for a particular facility. Printers should compare their
DRAFT-September 1994 VI-11
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Sprayer/Application Systems
Figure VI-1
Simple Spray Applicator System
(Note the trigger-controlled brush head used to regulate chemical flow)
Air-Operated
Pump
Chemical
Resistant
Hose
Brush
Head
current system of applying screen reclamation chemicals with an alternative application
method, such as a spray application system, keeping in mind cost, time, and effort.
Low pressure pumping systems can also reduce chemical throughput. This group
represents a significant improvement in pollution prevention compared to either rags or spray
bottles because they provide a greater opportunity to reduce solvent use. In addition, use of the
spray applicator/pumping system can reduce the time and effort required to clean a screen.
However, this group of devices does not allow for reuse of the solvents, thus, misses a pollution
prevention opportunity that is present with pressurized spray application systems and solvent
recirculation systems.
Conversely, while the pressurized spray applicator and recirculation system products
may decrease the time, effort, and waste associated with reclaiming screens, cost can be a
prohibitive factor. Since the cost for many of these technologies stretches into the thousands of
dollars, one should weigh the benefits obtained by such products against the total amount of
time and labor spent reclaiming screens. Additionally, there have been concerns about the
DRAFT—September 1994
VI-12
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Sprayer/Application Systems
Figure VI-2
Trigger Spray Gun for Applying Solvents
Pump
Hook-up for
Water or Solvents
Chemical
Resistant Hose
Adjustable
Nozzle
effects on a screen's mesh fiber when using a high-pressure sprayer to apply chemicals to the
screen. However, since the majority of products that use pressurized sprays to apply solvent
do so with a relatively low pressure (50 to 300 psi), mesh damage seems unlikely.
Summary
In conclusion, sprayer/application systems offer an excellent opportunity for source
reduction within screen reclamation. For the smaller printer who spends minimal time in
reclamation, the relatively inexpensive spray bottle might be the most cost-effective. However,
companies that spend a substantial amount of time and effort in reclamation might find the
more extensive spray systems a viable option. While the initial costs may be substantially
higher, some or all of the cost may be recovered through decreased solvent use. Further, these
systems may decrease labor costs because they tend to be quicker and easier methods for
cleaning screens. In addition to surveying product literature, a printer may wish to check with
several suppliers as well as other printers to determine which system would work best in
his/her shop.
Washout Booths
The use of the washout bin/booth presents another basic opportunity for pollution
prevention. The premise of the washout booth is that concentrating the ink and/or emulsion
DRAFT-September 1994 VI-13
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Washout Booths
FfcureVkJ
A Variation of the Sprayer/Applicator with Trigger Control
Spray
Applicator
Compressed
Air Pump
Screen
Wash Chemicals
remover within a specific area will minimize the quantity of solvent necessary for reclamation,
while maximizing the cleaning potential of the quantity used. Consequently, these booths are
built to focus the cleaning solution in a small semi-contained area (usually box shaped).
Although some booths consist of multiple cleaning areas to separate the ink and emulsion
removal functions (Figure VI-4), the single unit booths are equipped to remove both ink and
emulsion. The waste solution is usually funneled into a drain where it may be disposed of in
several ways.
Features
Although the conventional washout booth can be made to virtually any specification, the
basic design is relatively uniform. This design includes a rectangular base with a high back and
sides (Figure VI-5). The base is often slanted slightly to facilitate drainage, which allows the
effluent to funnel into a drain pipe.
Working from such a base unit, one can choose from a broad spectrum of options to
enhance the unit design. The most common option is that of booth lighting. Lighting is critical
to successful screen reclamation because it allows the reclaimer to better assess the
performance of the cleaning product as well as the efforts of the reclaimer. However, since
adequate shop lighting may or may not be present, washout booths are available in either
lighted or unlighted models. Unlit washout booths, as the name suggests, contain no internal
lighting fixtures. Depending on the size, these booths range in price from $1,000 to $3,000 or
$4,000. Conversely, the lit booths are equipped with an internal lighting system through
backlighting or overhead lighting. Backlighting provides a light source that emanates from
directly behind the screen and would highlight any ink or emulsion residue. Overhead lighting
DRAFT—September 1994
VI-14
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Washout Booths
Figure VM
Washout Booth Equipped with Separate Ink
and Emulsion Cleaning Areas
Ventilation into Plant or
Exhaust System
Screen
Effluent
can accomplish the same goal through lighting the area from above. Generally, either type of
lighting system will increase the overall cost of the booth by at least several hundred dollars.
In addition to the conventional washout booth, various other options exist that would
further upgrade its screen reclamation capability. These will be explored further in other
sections, but they merit mention here as well. A high pressure spray washer is a common
technology that can be used in conjunction with a washout booth for screen reclamation. These
washers physically blast ink and emulsion particles from the screen. High pressure washers
that dispense both water and solvent at variable pressures (50 to 5000 psi) are commercially
available. Depending on the pressure of the applicator, a system can cost anywhere from
$1,000 to $10,000.
A washout booth can also be modified to include a filtration system. A wide variety of
filtration systems are commercially available, and while some are equipped to filter solvents
other than water, many cannot. However, all filtration systems generally attempt to separate
out the particulates and other contaminants from the waste water. These devices connect the
washout booth to the sewer system or septic tank, and they play a prominent role in the waste
DRAFT—September 1994
VI-15
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Washout Booths
Figure VI-5
A Typical Washout Booth Shown with Optional Sprayer System
Screen
Pump
Wash-Out
Booth
Pressurized Spray
Applicator
treatment process. Filtration of waste can either facilitate compliance with federal, state, or
local water regulations or provide the basis for a recirculation system. The addition of a
filtration system could also increase the price of the screen reclamation system by at least a
thousand dollars.
The recirculation system is another major option that can be used in conjunction with
the washout booth. Most recirculation units employ a filtration apparatus, holding tanks for
new and used solvent, and a sprayer system. Figure VI-6 is an example of a fully equipped
washout booth. In addition to the various options previously discussed, this particular booth is
also equipped with a fume hood to minimize employee inhalation of volatile chemicals. This
type of system costs approximately $7,000 to $10,000.
Issues to Consider
The use of a washout booth in screen reclamation increases the opportunity for pollution
prevention. However, when considering the purchase of a booth, the determining factors
DRAFT—September 1994
VI-16
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Washout Booths
Figure VI-6
A More Advanced Washout Booth
(It is equipped with a sprayer system, drainage system, & fume hood)
Fume Hood &
Lighting
Pump
Spent Reclamation
Chemicals/Water
Spray
Applicator
Reclamation
Chemicals
remain cost, performance, and environmental and human risk reduction. Washout booths
would reduce solvent usage relative to application with a soaked rag. Thus, a printer must
examine his/her individual situation in conjunction with applicable federal, state, and local
environmental regulations to determine whether such a capital expenditure is prudent. In
addition, the printer should consider the time and effort spent in screen reclamation as well as
the potential cost savings from reduced solvent use and excess hazardous waste disposal when
considering the purchase of a washout booth.
Assuming that a printer has decided to purchase a washout booth, he/she needs to consider
the lighting requirements. A non-lit booth is less expensive than a lighted booth. If substantial
lighting is already available, a lighted booth may not be necessary. However, the models with
lights may make cleaning easier because ink and emulsion can clearly be seen, and the
potential need for re-cleaning a screen is minimized.
Finally, printers should consider the wide range of other options available for a washout
booth. For a simple operation, a booth by itself may be adequate. However, if reclamation is a
significant process within the shop, additions may be justifiable. Upgrading a washout booth
may vastly increase one's pollution prevention potential, but this increase coincides with an
DRAFT—September 1994
VI-17
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Filtration Systems
equivalent rise in the cost of the system. Printers should carefully consider the size of the
screen printing operation, the number of screens reclaimed, the cost associated with
reclamation, and the environmental regulations with which they must comply when considering
the purchase of a washout booth.
Summary
In short, a washout booth would provide another opportunity to minimize chemical
throughput. The booth provides a specific area in which to reclaim screens and can minimize
the potential solvent loss associated with open-area reclaiming. The booth can be made to
specifications; however, the price increases according to size and level of complexity. For the
small printer that reclaims very few screens, such an apparatus may not be a prudent or
feasible investment. However, for printers with a sizeable reclamation operation, a washout
booth may be a positive addition. Printers should consider their individual situations as well
as other sources of product information to make a choice that remains consistent with good
business practices.
Filtration Systems
Although they work by several different processes, filtration systems all perform
essentially the same function of eliminating specific substances from the waste stream. Used
independently, these products may not provide unique pollution prevention opportunities;
however, when used in conjunction with a recirculator/recycler, the filtration of solvent may
allow for substantial decreases in the quantity of solvent used. A filtration system's function
within the solvent recirculation process is to filter out particulates, heavy metals, hydrocarbons,
and other waste products. This process of treating the effluent makes it possible for
conditioned solution to recirculate back for reuse in subsequent reclamation.
Features
Effluent resulting from the screen reclamation process is a mixture of liquid and
particulates and can be filtered using two distinct processes: physical separation and
adsorption separation. Physical separation is accomplished through the use of mechanical
forces to separate the solid particles from the solution. The effluent is passed through porous
materials so that the particulates are collected and separated from the liquid. However, it is
only the solid particulate matter that is filtered out, and consequently, physical separation does
not address other potentially hazardous substances found in solution.
Adsorption separation is another type of filtration process. Adsorption removes
pollutants from an exhaust stream by the adherence of the pollutants to the surface of porous
solids.1 Given adequate time and the appropriate porous material, known as the adsorbent,
removal can be highly effective.2 Therefore, by passing waste water through a chosen material,
other pollutants in solution will bond with the adsorbent and can effectively be separated from
the effluent.
'Geankoplis, Christie J., Transport Processes and Unit Operations. (New York:Allyn and Bacon Inc.), 1983.
2Geankoplis, Christie J., Transport Processes and Unit Operations. (New York:Allyn and Bacon Inc.), 1983.
DRAFT-September 1994 VI-18
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Filtration Systems
The more basic filtration systems that deal only with physical separation provide a
method to remove particulate matter such as ink or emulsion particles from the reclamation
effluent. A typical physical separation filtration system consists of a number of filters that can
vary in shape, form, and size. As the effluent travels through the filters, particulates that are
too large to pass through the filter are retained on the filter media in a porous cake. As the
pore space from one filter to the next decreases, particles of various size are gradually
separated from the effluent. Mesh screens to trap tape, ink, and even large emulsion particles
are often the coarse filters at the beginning of the process, but eventually the series of filters are
able to remove even the most minuscule of particles (Figures VI-7 and VI-8). For example, it is
common for many systems to filter effluent to a particle size of 1-5 microns (approximately the
size of an adult human red-blood cell). Consequently, the treated effluent should ideally
contain only particles of insignificant size.
Filtration systems aimed at minimizing particulate matter can have a wide range of prices
depending on the system's complexity. A system that is equipped to handle less than ten
gallons per minute (gpm) can be purchased for under $ 1,000. At the opposite end of the
spectrum, systems that can handle much larger quantities of effluent can cost from $5,000 to
$7,000. Additionally, a physical filtration system can increase in price depending on the
desired level of filtration. The smaller the pore size within the filter media, the greater the
price. Finally, a printer with this type of filtration system should also expect an added annual
cost of $200 to $300 to replace the filter media.
Due to the wide variety of workpractices, inks, emulsions, and cleaning solutions, a
printer may often require more extensive filtration of the reclamation effluent. For this
purpose, the more advanced adsorption separation systems can be used; these systems
generally begin where the physical separation stops. The effluent, instead of being disposed of
or recirculated, enters an adsorption separation unit in order for any hydrocarbons, metals, or
other trace impurities to be removed. A porous substance, usually activated carbon or
diatomaceous earth, provides bonding sites for the impurities targeted for removal. "Activated"
carbon, when used in this sense, refers simply to a carbon compound with increased pore
space.3 This media usually has a non-polar configuration in order to eliminate the potential
problems that could result from attempting to filter water-based effluents.4 Thus, as the
effluent proceeds through the non-polar "activated" media, the contaminants such as
hydrocarbons and metals are retained while the remaining effluent passes through (Figure VI-
9).
After completion of this adsorption process, the effluent can either be circulated back to a
reservoir for subsequent use in screen reclamation or sent to disposal (see Figure Vi-10).
Depending on a particular operation, this filtrate may or may not represent a viable substance
for reuse. Printers should realize that only the aforementioned substances have been removed
(particulates, hydrocarbons, metals, and some trace contaminants), and the resulting solution
may or may not be adequately treated for either recirculation or disposal.
Although these advanced filtration systems do represent a significant improvement in the
quality of the resulting waste water, they are also substantially more expensive. These
adsorption filtration systems start at approximately $4,000 and can cost as much as $12,000
3Geankoplis, Christie J., Transport Processes and Unit Operations. (New York:Allyn and Bacon Inc.), 1983.
4If the media had a polar configuration, then the filter would exhibit a propensity towards the water molecules which are
also polar. The result would be retention of the entire effluent as the filter media would act as a giant sponge.
DRAFT-September 1994 VI-19
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Filtration Systems
Figure VI-7
Basic Filtration System
(Includes Both Screen & Bag Filters)
Effluent
Screen
Classifiers
to Separate Particulates
Filtered
Water
Bag Filter Media
Bag Filter Holder
Power Drain to
Remove Filtered Water
or $13,000. In addition, these systems require an annual upkeep cost of approximately $500
to $1,000 to purchase replacement filter media (diatomaceous earth or activated carbon).
Issues to Consider
One of the first major issues that a printer should consider is whether or not a filtration
system would be beneficial for a given screen operation. Adding a physical separation filtering
system to a reclamation process may provide a method to facilitate compliance with effluent
guidelines by reducing the particulate content of the solution for discharge. Further, when used
in combination with a solvent recycler or water re-circulator, a filtration device can possibly
decrease the quantity of new solvent required. Thus, in addition to aiding in compliance with
DRAFT—September 1994
VI-20
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Filtration Systems
Figure VI-8
Variation of Filtration System
(Effluent Passes Through Screen and Reaches Setting Tank Below)
Effluent Waste
Filter Media Stretches
Across Flow Tray
Settling
Tank
environmental regulations, it may provide the benefits of lower overhead costs and chemical
source reduction. However, the cost of such an addition may be prohibitive. For the small
printer who devotes little attention to reclaiming screens, spending hundreds or thousands of
dollars may not be a practical way to simply remain in compliance. In these cases, it may be
prudent to simply pay a disposal service to remove the effluent.
If a printer has decided to purchase a filtration system, he/she should consider the cost of
the option and evaluate the reclamation chemicals/printing chemicals that are currently used in
the print shop to determine which filtration system would perform best. By knowing the
specific contaminants which can be filtered by these two types of systems and by considering
the components of printing and reclaiming chemicals, the printer can better determine whether
an adsorption separation system is warranted. A printer may find that, after examination of
the chemicals used in the system, only physical separation is necessary.
DRAFT—September 1994
VI-21
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Filtration Systems
Figure VI-9
Advanced Filtration System
(These systems include an "activated" filter media to further clean the effluent)
Wash Water
Collection Tank
Activated Carbon
Filter
Connections to
Filtration Unit
Carbon-Filtered
Water to Sewer
Clean Water for Reuse
in Reclaiming
Pump
Pressurized Water
Supply Tank
For many aqueous-based chemical reclamation systems, the use of a physical separation
system may be sufficient. After undergoing filtration to remove the particulate matter, the
effluent in an aqueous-based chemical reclamation system may or may not have components
that require advanced filtration. Unless these solutions have hydrocarbon compounds or
metals in solution, filtering through an "activated" media probably would not provide additional
benefits. For example, chemical systems that are predominantly composed of surfactants or
ionic salts would probably best be served through physical separation and then recirculation.
However, printers should know that some commercially available aqueous chemical systems
may benefit from the use of adsorption separation, and advanced filtration may be essential for
recirculating solvent or simply maintaining compliance with applicable environmental
regulations.
For printers that use strictly non-aqueous chemical systems, physical separation is often
the only necessary method of filtration. After passing through the physical filtration unit, what
remains of a non-aqueous system would usually be a predominantly hydrocarbon solution. To
process this solution by adsorption separation would result in virtually all of the solution
becoming trapped within the advanced filter media. This would be costly and usually
DRAFT—September 1994
VI-22
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Filtration Systems
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-------
VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Filtration Systems
counterproductive. Generally, such non-aqueous systems can be recirculated for reuse in
screen reclamation after physical filtration until the solution becomes sufficiently contaminated
so that disposal is required as either hazardous or non-hazardous waste (consult appropriate
regulations in your area).
Summary
Filtration devices, when used in conjunction with a recirculation system, offer another
opportunity for pollution prevention through recycling. By screening the effluent resulting from
the screen reclamation process, filtering systems also facilitate compliance with effluent
guidelines. The cost of these systems should be carefully considered by a printing facility.
Printers should also consider potential savings generated by reducing the use of chemicals and
by avoiding fines that could result from noncompliance with federal, state, and local
environmental regulations.
Recirculation Systems
A recirculation system, though a combination of several technologies, allows a printer to
minimize solvent usage, and consequently, minimizes pollution at the source. Its purpose is to
filter contaminants from the cleaning solution so that the filtered solution can be reapplied to
future screens. Generally, a recirculation system consists of an applicator/sprayer system, a
filtration unit, and a recirculating mechanism. Information on some of these products appears
in previous sections.
Features
In many respects, a recirculation system represents a full commitment to pollution
prevention because of its concurrent use of several different technologies. A typical
recirculation system incorporates an applicator/sprayer, a filtration device, and a pump for
recirculating the solvent; it is almost always used in conjunction with a washout booth/bin.
Independently, each of these products may prove useful in efficiently reclaiming a screen, but
together, they provide far greater pollution prevention opportunities.
At the most basic level, recirculation systems are available for ink removal only (Figure
VI-11). After placing the screen in a washout booth to concentrate solvent application, the
printer uses the sprayer system to apply the cleaning solvent to the mesh surface. After
application, the used solvent, along with the ink sediment, drains to the filtration unit. When
the effluent passes through the filtration system, the ink particulates are filtered out. The
filtrate can then be recirculated by a pump to be reused in subsequent screen washing.
Printers who are interested in this type of system should expect to pay anywhere from
$1,500 to $3,000 for the complete system. This would usually include the applicator, filtration
unit, and recirculating pump with solvent reservoir. The price of such systems largely depends
on the solvent capacity of the system (generally from 10 to 50 gallons). Lastly, printers should
keep in mind that these systems only remove ink, and the emulsion/stencil must be removed
separately.
In order to provide recirculating capability when removing both ink and emulsion, a
printer may have to use an advanced hybrid system. This system includes several individual
DRAFT-September 1994 VI-24
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Recirculation Systems
Figure VI-11
Solvent Recirculating System
Recycled, Filtered
Solvent
Filtration Unit
components that are linked together and may provide satisfactory screen reclamation at an
economically competitive price. These individual components are essential when attempting to
recirculate both ink remover and emulsion remover because of the distinct chemical function of
each. The ink remover and emulsion remover must be filtered separately if successful
recirculation for reuse is desired; moreover, certain options available with some equipment
may provide a better match given a printer's unique operation. Printers should consider the
formulation of the chemical system currently used (aqueous or non-aqueous) in addition to any
other unique aspects of their operation when purchasing components for a recirculation
system. The easiest and most common method for accomplishing recirculation is by using a
water-based system of screen reclamation products.
Such a water-based system might include a washout booth, a pressure sprayer, a
filtration unit, a recirculating pump, and an aqueous-based chemical reclaiming system, as
shown in Figure VI-12. The chemical reclamation system in combination with the pressure
sprayer will be responsible for removing the ink and emulsion from the screen. Depending on
the chemical formulations of the cleaning products, a combined solution of water, cleaning
solution, ink, and emulsion particles is then carried to the filtration system where the
contaminants are removed through physical separation and possibly adsorption by an
"activated" media. As noted earlier, this process must be carried out separately for both ink
systems and emulsion systems; however, the end product of each filtration is a solution that
could be pumped by the recirculation pump back through the pressure sprayer to clean
subsequent screens.
This example is only one of many variations within the hybrid recirculation category. An
assortment of other options are commercially available using both aqueous and non-aqueous
based chemical reclamation systems. Interested printers should consult manufacturer's
product literature, other printers, and relevant environmental regulations to obtain more
information.
DRAFT-September 1994 VI-25
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Recirculation Systems
Figure VI-12
Advanced Reclamation System
(While this does depict may options. It could also Incorporate a reclrculatlon system)
Wash-Out
Booth
Pump
Activated
Carbon
Unit
Depending on the printer's requirements, the hybrid system could cost as little as $3,000
or as much as $ 15,000. The cost varies greatly because of the various kinds of equipment that
could be included in the hybrid system. Printers should carefully consider which equipment
best applies to their specific situation.
Issues to Consider
A printer should first and foremost determine whether a recirculation system is a
necessary and useful technology in which to invest; cost of the system would be an important
consideration. A small number of screens reclaimed daily or a small quantity of solvent used
annually are good indicators that a recirculation system may not be the most cost-effective
method for minimizing pollution.
However, for slightly larger operations, the ink remover recirculators may be an option.
Such products may reduce solvent use while effectively removing ink. The cost of these systems
is more moderate than the hybrid systems, but printers should keep in mind that
emulsion/stencil removal is not provided for with these ink systems.
For facilities that spend significant time and resources on screen reclamation, a hybrid
system may offer an excellent economic and environmental opportunity. Such systems are
generally expensive ($3,000 to $15,000), but, for those printers that use large quantities of
chemicals and reclaim a substantial number of screens, these systems offer several benefits.
First, these recirculation systems provide ample opportunity for source reduction of reclaiming
solvents. Since filtering and cleaning the used solvent for re-use can drastically reduce new
solvent consumption at a facility, a printer may be able to considerably decrease the cost of
doing business. Finally, these systems may, through the use of a filtration system, help
maintain compliance with applicable environmental regulations.
DRAFT—September 1994
VI-26
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Distillation Equipment
For those printers that do choose to adopt a recirculation system, one key issue
concerning pollution must be addressed. Printers should realize that although solvent use may
be reduced through a recirculation device, these systems are not designed to eliminate pollution
from a printing operation. Such systems merely change the form of the pollution from a bulk
liquid that requires disposal to a concentrated liquid, solid, or semi-solid waste (from the
filtration system) that must be dealt with as well. A printer should remember to consult
applicable federal, state, and local environmental regulations concerning water and waste
disposal.
Summary
A recirculation system can take on a variety of different forms. From a simple ink
remover recirculator to a system that involves complete reclamation, these systems can be
made to fit almost any operation. If a printer decides that this an appropriate method of
pollution prevention, he/she should carefully consider the vast array of options in order to
properly match the system to their facility. Further, printers should keep in mind that
recirculation systems are not closed systems and that they are not designed to eliminate
pollution from a printer's operation. Printers should consult applicable water and waste water
disposal regulations to ensure compliance.
Distillation Equipment
Distillation devices that can be used to reclaim used solvent represent another alternative
for addressing screen reclamation waste issues. These devices separate the contaminants from
screen reclamation effluent and provide an effective way to recycle and reuse spent solvent.
Thus, like a filtration and recirculation system, these solvent distillers provide an opportunity
to reduce solvent use and operating costs.
Features
After a solvent has been used in screen reclamation, it usually contains various
contaminants (resins, colorings/pigments, grease, etc.), which can either be disposed of as
waste, filtered, or distilled. The distillation process involves the separation of the original
solvent from the effluent's contaminants by boiling the solution. The vaporized portion of the
liquid, usually the desired solvent, is withdrawn to be condensed and reused. The basic
requirement for the separation of components by distillation is that at the boiling point of the
liquid, the composition of the vapor must be different from the composition of the liquid with
which it is in equilibrium.
The most frequently used distillation units that are commercially available operate using
a specific process known as differential distillation. In differential distillation, the effluent is
first placed in an enclosed heating container (Figures VI-13 and VI-14). The effluent is heated in
the container to approximately 20 to 30 degrees above the desired solvent's boiling point; at this
time, the solution begins to vaporize. The vapors rise and are then transported immediately to
a condenser, where the condensed vapor (distilled solvent) is collected.5 This can be
accomplished by circulating cool water or air within the condenser to lower the temperature of
5Geankoplis, Christie J., Transport Processes and Unit Operations. (New York:Allyn and Bacon Inc.), 1983.
DRAFT-September 1994 VI-27
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Distillation Equipment
Figure VI-13
A Typical Differential Distiller Capable of Distilling Up to 110 Gallons of Used Solvent per Cycle
(Note the distillation unit (far left) and the drum for recovered solvent (far right))
Used
Solvent
\
Temperature/
Pressure Controls
Distillation
Tank
Recovered
Solvent Drum
the entering vapor. As the temperature of the vapor drops, it condenses into the desired liquid.
This distillate can then be reused, while the contaminants remain in the original kettle to be
disposed of as solid waste (hazardous or non-hazardous). The amount of solvent recovered
largely depends on the type and concentration of the contaminants, but most distillation units
can recover up to 90 percent of the remaining solvent.
Although the process generally remains the same, solvent distillers are available in a wide
range of forms and sizes. A variety of distillation units that employ other methods of
distillation could potentially be used for screen reclamation, but at this time, differential
distillers represent well above 90 percent of the market. Most differential distillers are
equipped with a heating container and a condenser with a pipe connecting the two. The heating
containers can vary in size from a two gallon capacity to 250 gallon capacity, but despite this
size differential, the containers are all virtually the same in function and composition. The
main container is filled with a heat-transfer liquid (usually water, or polyethylene glycol), and
the drum containing the used solvent is placed into this media. An air tight lid covers the
apparatus, and a hose/pipe connecting the unit to the condenser is often inserted at this
location. The condenser, usually less than or equal to the heating unit in size, provides the
location for the vaporized solvent to recondense into liquid form. This part of the unit usually
incorporates a collection chamber for the recycled solvent and an internal recirculating cooling
system.
DRAFT—September 1994
VI-28
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications
Distillation Equipment
Figure VI-14
Variation of a Solvent Distillation Unit
Venting
Valve
Water Cooler
Condenser
Distillation
Distilled
Solvent
Solvent
Input
Power
Supply
Distillation units can vary as much in cost as they do in size. A small distiller (2 to 5
gallons) is available for several thousand dollars. As the capacity of the distiller increases, the
price also begins to increase. For a distillation unit with a 15 gallon capacity, a printer should
expect to pay approximately $ 10,000, and for the larger units (more than 100 gallons), prices
can rise into the $20,000 to $ 100,000 range.
Issues to Consider
The main issue for printers to address is the question of need. Given a printer's
individual operation, is a distillation unit the best method for reducing solvent use while
maintaining compliance with relevant environmental regulations? Distillation units can
provide an effective method for reclaiming used solvent for future use (these units frequently
yield 90 percent recovery of available solvent). Given this effective recovery potential and the
resultant decrease in new solvent use, these units may provide an extremely practical method of
pollution prevention for those printers that spend significant time, money, and effort in screen
DRAFT—September 1994
VI-29
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VI. OVERALL POLLUTION PREVENTION OPPORTUNITIES FOR SCREEN RECLAMATION
Pollution Prevention through Equipment Modifications Distillation Equipment
reclamation. However, the costs, which range in the thousands, may prove to be too high for a
smaller operation. Those printers that can not afford such an investment may wish to examine
other alternatives, such as filtration and/or recirculation to maximize the pollution prevention
opportunities.
Safety considerations may play a role in the decision of a printer to purchase a distillation
unit. In the past year, issues concerning the explosive nature of such products have been
raised. The International Fire Code Institute, an organization consisting of state fire marshals,
has been investigating whether these on-site distillation units constitute an explosion hazard
given the flammable nature of the solvents that are reclaimed. Consideration of changes in the
Uniform Fire Code are underway (these began in Washington State and are now being
considered in twelve western states), and the results of this inquiry may affect the availability of
such products on the American market. Printers should consult amendments to this code as
well as applicable environmental regulations when assessing distillation as a screen
reclamation option.
Summary
Distillation units can provide a cost-effective method to reclaim solvent used in screen
reclamation, and this may result in other benefits as well (lower cost, compliance benefits).
These differential distillers can vary in size (two or three gallon capacity up to 250 gallons) as
well as in cost. The relatively high cost may prohibit many small printers from utilizing this
technology. When purchasing these units, printers should consider cost, relevant
environmental regulations, and changes in the Uniform Fire Code affecting the availability and
use of distillers.
DRAFT-September 1994 VI-30
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Chapter VII
Cost/Benefit, Energy & Trade Issues
International Trade Issues
According to Marci Kinter of SPTF, screen reclamation in other parts of the world does
not vary greatly from screen reclamation in the United States. There is some evidence that the
size of screen printing shops in Europe may be larger; there are expensive automatic screen
washers produced and sold there which were apparently unable to find a market in the US.
Otherwise, screen reclamation products are basically the same as those used here. In addition,
there is much growth occurring in the Asia-Pacific market.1
Many of the screen reclamation products used in the US are produced in Europe,
including both traditional and alternative products.
Energy and Natural Resource Issues
Thus far, this CTSA has focused primarily on the trade-offs between risk, performance
and cost of alternative screen reclamation chemicals and methods. When designing products or
processes with the environment in mind, however, conservation of energy and natural
resources (e.g., materials) should also be a goal. This section identifies the areas where energy
and materials are consumed as a result of the screen reclamation process.
Screen Reclamation Processes
Table VII-1 presents the process steps performed in the four manual screen reclamation
methods described in Figure 1-2. Each time a process step is performed, whether it involves
the application of a chemical or a water wash, it results in the use of energy or natural
resources (e.g., chemicals derived from natural resources, water, disposable shop towels, etc.).
Energy is consumed when mechanized equipment is used, including hot water heaters
and pressurized water-spray units. Any use of materials results in the consumption of natural
resources, whether the material is water, chemicals, or shop towels. Although it is true that
materials can frequently be reclaimed once used, the reclamation process results again in the
use of energy and natural resources.
'SPAI. 1993. Screen Print '93 International Convention and Exposition. Screen Printing Association International,
Fairfax, VA. p!04.
DRAFT-September 1994 VII-1
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VII. MACROECONOMIC ISSUES
Energy and Natural Resource Issues
Collecting Data on Energy and Natural Resources Consumption
Table VIM
Steps Performed in Manual Screen Reclamation Methods
Screen Reclamation Step
Ink Removal Chemical
Degreaser/Degradant Chemical
Water Wash
Emulsion Removal Chemical
Water Wash
Haze Removal Chemical
Water Wash
Screen Reclamation Method
1
/
X
Optional
/
/
X
X
2
/
X
Optional
/
/
/
/
3
/
/
Optional
/
/
X
X
4
X
X
/
/
/
/
/
Key: / - Step performed
x - Step not performed
Collecting Data on Energy and Natural Resources Consumption
The first step in an analysis of energy and natural resources consumption is to select the
life cycle stages on which to focus. The life cycle of a typical product system begins with the
acquisition of the raw materials used to make the product and continues on through
manufacture, transportation, use, recycling, and disposal of the product. Energy and natural
resources consumption can occur during each of these life cycle stages, but may be much more
significant in one life cycle stage as compared to another. For example, studies of the life cycle
of the automobile have shown that the vast majority of the energy consumption of a typical auto
comes from the product use stage.
For screen cleaning and reclamation chemicals, the DfE Screen Printing Project elected to
focus on energy and natural resource consumption during the use stage, when printers are
actually cleaning and reclaiming their screens. We focused on this life cycle stage, and not the
other life cycle stages, for the following reasons:
o The amount of energy and natural resources consumed during the use of the
chemical products will vary depending on the relative amounts of chemical
products used, the types of equipment used to apply the products and reclaim the
screens, the temperatures at which the cleaning steps are conducted, and the
duration of the various cleaning steps. Since this life cycle stage could be
significant, it was decided to collect data on energy and natural resources
consumption during the performance evaluation.
o Manufacturers of screen reclamation products indicated that the same basic
process is used to formulate screen cleaning and reclamation products, regardless
DRAFT—September 1994
VII-2
-------
VII. MACROECONOMIC ISSUES
Energy and Natural Resource Issues Collecting Data on Energy and Natural Resources Consumption
of the types of ingredients. Therefore, no significant differences between products
were expected in energy and natural resources consumption during the product
formulation process.
o Significant differences could exist in the amounts of energy and natural resources
consumed when the chemical ingredients are manufactured. For example, chemical
ingredients manufactured from petroleum not only use energy during the chemical
manufacturing process, they also have an equivalent energy value. The amounts of
each individual chemical ingredient used in screen cleaning and reclamation
products is small, however, relative to the total consumption of these chemicals in
other industries or products. For this reason, and because of the limited resources
available to this project, no data were collected on the amounts of energy and
natural resources consumed during chemical ingredient manufacturing.
o Significant differences could also exist in the amounts of energy and natural
resources consumed when the raw materials used to make chemical ingredients are
acquired. For example, petroleum-based chemicals require the pumping of
petroleum from deep wells and transportation, usually by pipeline, to a petroleum
refinery. Citrus-based products are made from fruit harvested from trees and
transported, usually by truck or rail to a chemical manufacturer. For the same
reasons mentioned above, however, no data were collected on the amounts of energy
and natural resources consumed during the acquisition of raw materials.
o Differences may exist in the amounts of energy and natural resources required to
dispose of spent screen cleaning and reclamation chemicals or water contaminated
with screen cleaning chemicals. Due to limited resources, however, no data were
collected on energy and natural resources use during the treatment and disposal
stage of the product life cycle.
To assess energy and natural resources consumption during the performance
evaluations, the following data were initially requested from the observers and the volunteer
screen printing facilities:
o Equipment nameplate capacity or specifications (e.g., voltage, pressure, etc.);
o Equipment operating parameters, including operating pressure and flow rates for
spray or water-blast equipment, and water temperature (if heated water is
required);
o The amount (volume) of chemical product consumed during each
cleaning/reclamation step, and the amount of dilution with water, if any;
o The amount (volume) of water consumed during each water wash step, calculated
from the flow rate and the duration of the water wash step;
o The number of shop wipes required with the ink removal chemical; and
o The size and condition of the screen so that data could be normalized to a single
screen size.
Due to the large amount of data required for the performance evaluation, however, some
of the energy and natural resources data were not collected; the data requirements were taking
DRAFT-September 1994 VII-3
-------
VII. MACROECONOMIC ISSUES
Energy and Natural Resource Issues Energy Impacts
too much of the printer's time or the extent of the data requirements were not clear. As a
result, quantitative analysis of the energy and natural resources consumed with traditional and
alternative products during the screen cleaning/reclamation process was not possible. Listed
below, however, is a summary of the areas where energy and natural resources may be
consumed as a result of the screen reclamation process.
Energy Impacts of Screen Reclamation
o The use of chemicals products and water has an energy impact. As discussed
above, chemical manufacturing, distribution, recycling and disposal all require
energy inputs. Chemical use requires an energy input if mechanized equipment is
used. By the same token, the cycle of water treatment, distribution, and use
followed by wastewater treatment also requires energy inputs.
o During a water wash, the rate of energy use is dependent on the type of equipment
used to apply the water and the temperature of the water. Obviously, high-pressure
spray washes require more energy and equipment than a non-pressurized water
wash, however they may consume less water. Hot or warm water washes are much
more energy intensive than those conducted at ambient water temperatures. In fact,
it is likely that products requiring the use of heated water would have the greatest
energy impact, even if a quantitative analysis was done of all stages of the product
life cycle. A life cycle assessment of laundry detergents, for example, found that the
greatest environmental impact from using laundry detergents came from producing
the energy required to heat the water in hot-water washes.
o If a pressurized water wash is required, spray units can be used that optimize the
wetting potential and minimize water flow by using a combined stream of water and
air. In some cases, chemicals applied using a rag or brush can supply the abrasive
action that would be provided by a pressurized water wash. If the screen is
scrubbed manually, less chemical product may be required and a non-pressurized
wash can be used to rinse the screen.
Materials Acquisition and Natural Resource Impacts of Screen Reclamation
o Some screen reclamation methods may require the use of greater amounts of
chemical products than others, depending on the number of steps requiring
chemicals and the volume of chemical used in each step. The former depends on
the screen reclamation method selected; the latter depends on a number of factors,
including the chemical product used, the extent of ink and stencil on the screen,
employee preference, and time allowed for ink to dry before cleaning. The amount
of chemicals required to reclaim a screen should be optimized to the extent possible
to avoid unnecessary use of resources.
o The amount of water used during screen reclamation also depends on the screen
reclamation method and chemical products used. For example, several of the
alternative chemicals products evaluated during the performance testing did not
require a water wash after use. If a water wash is required, the amount should be
optimized to avoid unnecessary use of resources.
DRAFT-September 1994 VII4
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VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes
o If a water wash is performed, the resulting wastewater should be collected
separately from any chemical overspray or chemical run-off collected while the
chemical is being applied. This will allow for more efficient chemical recovery and
recycling, reduce the concentrations of contaminants in the wastewater, and thus,
improve the treatability of the wastewater.
o If the entire screen does not require cleaning or reclamation, reusable rags and
brushes can be used to apply chemical products to selected areas of the screen,
thus reducing the volume of chemical product used. Reusable rags and brushes
save resources compared to disposable products and contribute less to the solid
waste stream. The cleaning of reusable products, however, does result in a waste
stream and requires inputs of energy and natural resources.
o Disposable shop towels result not only in the consumption of resources, they also
generate solid, potentially hazardous, waste and increased disposal cost.
Cost/Benefit Analysis of Alternative Screen Reclamation Processes
The risk assessment conducted as a part of the CTSA analyzed the risk of each
alternative screen reclamation system used in each of the alternative methods as well as the
screen disposal work practice and the automatic screen washer technology. A cost analysis was
also performed to estimate the cost of each alternative screen reclamation method, technology,
and work practice evaluated in the CTSA. This section compares the costs and benefits (in
terms of reduced human health risks) of switching to alternative screen reclamation products,
technologies, and work practices. In addition, this analysis looks beyond just the costs
(material, labor, etc.) and benefits (reduced worker health risks) to printing operations of
switching to alternative systems and considers the potential for societal benefits. Specifically, it
considers the possibility that the use of screen reclamation substitutes could result in reduced
health risks to the general population, lower health insurance and liability costs for the printing
industry and society, and decreased adverse impacts to the environment. The costs and risk
trade-offs associated with the baseline and each method are summarized in Table VII-2.
Exposed Population
Due to resource limitations, it was not possible to quantify changes in individual or
population risks, i.e., changes in the incidence of associated health effects. As a result, this
analysis does not provide an estimate of risk reductions nor a dollar estimate of the benefits
associated with reduced health risks but makes qualitative comparisons of the estimated costs
and potential benefits of switching from traditional to alternative screen reclamation methods.
Estimates of the worker population potentially exposed to traditional and alternative screen
reclamation chemicals, however, are provided based on data collected in the risk assessment
and on estimates of numbers of printing facilities from SPAI (see Table VII-3). It has been
estimated that for small to medium sized facilities one to three employees are involved in screen
reclamation. Combining this information with the total number of print shops in the graphics
industry (20,000, SPAI, 1994) yields an estimated exposed worker population of between
20,000 and 60,000.2 For ink removers it is possible to further refine exposed worker
population estimates based on market share data for traditional and alternative ink removers.
2 Estimates of the exposed general population are not available.
DRAFT-September 1994 VII-5
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VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes
Exposed Population
Table VII-2
Costs and Risk Trade-offs of Screen Reclamation Substitutes
System Evaluated
Baseline for Method 1 (Traditional System 4 - Haze
Remover)
Method 1: Chemical substitutes
for ink removal and emulsion
removal. No haze removal
required.
Chi (no haze
remover)
Beta
Baseline for All Other Methods (Traditional System 4)
Method 2: Chemical substitutes
for ink removal, emulsion
removal and haze removal.
Method 3: Chemical substitutes
for ink removal, degreasing and
emulsion removal. No haze
removal required.
Method 4: Technology substitute
of screen disposal in lieu of
reclamation.
Technology Substitute
Work Practice Substitute
Alpha
Chi
Delta
Epsilon
Gamma
Mu
Phi
Omicron-AE
Omicron-AF
Zeta
Omicron
Theta
Automatic Screen
Washer
Screen Disposal
Cost/Screen
$3.63
$1.95-2.83
$7.97
$6.27
$5.92-9.37
$3.25-3.89
$3.28-7.66
$3.08-5.29
$5.06-5.61
$4.79-9.33
$6.10-7.82
$5.49-10.85
$3.89-4.45
$5.39-8.99
$5.57
$4.53
$4.13-10.14
$49.43
Cost/Facility
$5,446
$2,918-4,245
$11,958
$9,399
$8,886-
14,062
$4,879-5,829
$4,917-
11,489
$4,624-7,930
$7,590-8,417
$7,185-
13,997
$9,233-
11,728
$8,240-
16,278
$5,836-6,675
$8,080-
13,479
$8,358
$6,797
6,198-15,213
$74,141
Risk Trade-offs
Clear concern for worker dermal
risks and worker inhalation risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
Clear concern for worker dermal
risks and worker inhalation risks
Moderate concern for worker
dermal risks and low concern for
inhalation risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
Marginal concerns for worker
dermal risks and very low
concerns for worker inhalation
risks
Moderate concern for worker
dermal risks and very low concern
for inhalation risks
No risks associated with screen
reclamation products
Note: Costs presented are normalized costs. Ranges are presented when there was more than one facility using the method
and system in the performance demonstration.
DRAFT—September 1994
VII-6
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VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Exposed Population
Allocating between use of traditional and alternative products suggests that between 13,120 and
39,360 workers are exposed to traditional ink removers and 6,880 and 20,640 are exposed to
alternative ink removers.3 As there are few differences among emulsion removers it is
assumed that the total population of screen reclaimers are exposed to similar formulations of
emulsion removers. Finally, the market share of haze removers used by printing operations
that is considered to be traditional and the market share that is considered to be alternative is
not known. Consequently, for this cost exercise, it was assumed that all haze removers
currently used are traditional products. Not all printers, however, use haze removers.
Industry figures indicate that haze removal is performed on between 27 and 80 percent of
reclamations. The number of workers exposed to traditional haze removers is, therefore,
estimated to be between 5,400 and 48,000.
Table VII-3 also indicates the number of workers that could potentially experience a
reduction in risk (column 1) if alternative products were substituted for traditional products in
their shop. It should be noted, however, that benefits may be minimized if printers switch to
alternatives for some but not all screen reclamation products. A discussion of the potential
benefits that might result from reductions in the incidence of an illness (hypertension) linked to
exposure to chemicals typically used in screen reclamation (solvents), is presented later in this
section as an example of the type and magnitude of benefits that are associated with reductions
in health risks.
Table VII-3
Estimates of Exposed Worker Population
Ink Remover
Emulsion Remover
Haze Remover
Total Exposed Worker Population
Worker Population Exposed to
Traditional Products
13,120-39,360
Worker Population Exposed to
alternative products
6,880 - 20,640
20,000 - 60,000
5,400 - 48,000
0
20,000 - 60,000
The following discussion is limited to ink removers and haze removers used in each
method since EPA's risk assessment concluded that risks associated with traditional and
alternative emulsion removers were virtually the same. Emulsion remover risks include a
significant risk of skin irritation and tissue damage from the components of emulsion removers
(i.e., either strong oxidizers or strong bases) if screen reclaimers are exposed in the absence of
proper protective clothing. None of the traditional or alternative emulsion removers, however,
presents significant inhalation risks.
3 Market share equals 65.6 percent for traditional ink removers and 34.4 percent for alternative ink removers.
DRAFT-September 1994 VII-7
-------
VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Human Health Benefits
Human Health Benefits
The benefits associated with switching to less toxic ink removers and haze removers can
be described in terms of reduced risks to both printers and the general public. The results of
the EPA risk assessment suggest that, in general, the alternative products are much less volatile
than traditional products. While all of the traditional product systems present clear concerns
for worker inhalation exposures, only one of the alternative systems (Mu) presents a concern
for inhalation exposures to workers. Almost half of the alternative products, however, present
clear concerns for unprotected dermal exposures to workers, as do all of the traditional
products. Worker dermal exposures to all products, however, can easily be minimized by using
proper protective clothing during screen reclamation.
The most significant health risk to the general population from screen reclamation
products is associated with the release of volatile organic compounds that contribute to the
formation of photochemical smog in the ambient air. Traditional products, due to their greater
volatile fraction, are likely to have a much greater impact on ambient air quality, if released,
than the alternative products. In addition, the use of an automatic screen washer technology
for ink removal may significantly reduce air emissions of certain volatile ink remover
components, although the amount of reduction depends on the specific components of the
formulation and the type of technology employed. EPA's risk assessment indicates, however,
that health impacts to the general population from screen reclamation products are very low for
all traditional and alternative products, technologies and work practices evaluated.
Consequently, the reduction in risks associated with switching to alternative products,
technologies, or work practices are minor.
Associated Costs
Per screen costs depend on variations in labor costs, product usage, materials and
equipment, and hazardous waste disposal costs (screen size and number of screens cleaned
have been normalized to the baseline) at each facility in the performance demonstrations.4 As
shown in Table VII-2, the cost associated with using the baseline traditional screen reclamation
system equals $3.63/screen for method 1 and $6.27/screen for all other methods (assuming
reclamation of 6 screens per day and a screen size of 2,127 in2) and total facility costs of
$5,446/year and $9,399/year respectively.5 Under the alternative systems, costs range from
$1.95/screen ($2,918 per year) for Method 1 to $49.43/screen ($74,141 per year) for the Screen
Disposal option. Excluding Screen Disposal, the cost of alternative methods range from
$1.95/screen (Method 1) to $10.85/screen (Omicron-AE, Method 2). As such, cost savings
might be realized by printers switching to any of the methods except screen disposal, depending
on the operating conditions of their shop. Based on the performance demonstrations, two out
of three facilities in method 1, 14 out of 22 facilities in method 2, one out of two facilities in
method 3, the one facility in method 4, and one out of two facilities using the automatic screen
washer would experience cost savings from switching to alternative products, technologies, and
work practices. Cost savings indicated in the performance demonstrations range from as little
4 Normalized values adjust product usage, number of screen cleaned, and number of rags laundered at demonstration
facilities to reflect the screen size and number of screens cleaned per day under the baseline scenario. Labor costs,
however, are not normalized. Normalization allows a comparison between the baseline and facility results.
5 The baseline system for method 1 does not include a haze remover.
DRAFT-September 1994 VII-8
-------
VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Costs and Benefits by Method
as $0.17/screen to $3.19/screen and are frequently due to differences in labor costs.
Alternatively, printers could experience cost increases of between $1.39/screen and
$43.16/screen ($4.58/screen excluding screen disposal). It should be noted that these cost
estimates do not fully reflect the performance of product systems demonstrated. For example,
while performance characteristics such as volume of product and time to clean were
considered, other important characteristics such as whether the facility continued using the
alternative product and whether the product shortened the life of or destroyed the screen were
not considered.
Costs and Benefits by Method
The costs and benefits associated with each method are discussed separately below. For
each comparison, traditional system 4 is used as the baseline system. Briefly, human health
concerns for the baseline system are related to toluene, methyl ethyl ketone, and methanol for
ink removers and acetone, cyclohexanone, and mineral spirits for haze removers. Risks are
linked to chronic dermal and inhalation exposures to workers during both ink removal and
haze removal. Dermal exposures to workers using mineral spirits in haze removal can be quite
high but were not quantified in the risk assessment due to limitations in the data and the fact
that these risks are easily mitigated through the use of gloves.
Method 1: Chemical Substitutes for Ink Removal and Emulsion Removal. No Haze
Remover Required
The use of Chi and Beta in method 1 significantly reduced worker inhalation risks and
moderate worker dermal risks. Clear concern exists, however, for chronic dermal exposures to
diethylene glycol series ethers used in ink removal. Moderate concern exists for developmental
toxicity risks from dermal exposures to N-methylpyrrolidone. Concern for inhalation
exposures to other ink removal chemicals used in this system, however, is very low. Haze
remover is not used in this method. Dermal and inhalation risks associated with haze
removers are, therefore, completely avoided under this method. In terms of costs, two printers
switching to method 1 incurred cost savings of $0.80/screen ($1,20 I/year) and $1.68/screen
($2,528/year), however, one facility experienced a cost increase of $4.34/screen ($6,512/year).
Method 2: Chemicals Substitutes for Ink Removal, Emulsion Removal and Haze
Removal
Ten product systems are included in Method 2. Overall, this method, except for Mu, has
significantly reduced worker inhalation risks and moderate worker dermal risks as compared
to the baseline system. Concern does exist, however, for chronic dermal exposures to
diethylene glycol series ethers, cyclohexanone, benzyl alcohol, d-limonene, and propylene glycol
methyl ether used in ink removal. Marginal concerns exist for chronic inhalation exposure to
workers using propylene glycol series ethers and d-limonene in ink removal. Moderate concern
also exists for developmental toxicity risks from dermal exposures to N-methylpyrrolidone and
inhalation exposures to methoxypropanol acetate, propylene glycol series ethers, and
cyclohexanone.
Risks associated with other chemicals in product systems Alpha, Beta, Delta, Epsilon,
Gamma, Mu, Phi, Zeta, and Omicron could not be quantified due to limitations in the hazard
data. It is possible, however, that inhalation and dermal exposures to these chemicals could be
high.
DRAFT-September 1994 VII-9
-------
VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Costs and Benefits by Method
Fourteen of the 22 printing facilities using method 2 experienced cost savings of as much
as $3.19/screen ($4,775 per year). The remaining eight printing facilities experienced cost
increases from $0.24/screen ($373/year) to $4.58/screen ($6,879/year).
Method 3: SPAI Workshop Process - Chemical Substitutes for Ink Removal, Ink
Degradent, Degreasing, and Emulsion Removal. No Haze Removal Required
Similar to methods 1 and 2 above, method 3 has significantly reduced worker inhalation
risks and moderate worker dermal risks. Clear concern does exist, however, for chronic
dermal exposures to workers using diethylene glycol series ethers in ink removal. In addition,
there are possible concerns for developmental toxicity risks from dermal "immersion"
exposures to diethylene glycol series ethers. Switching from the baseline system to Method 3
resulted in a cost savings of $0.70/screen ($1,041/year).
Method 4: Technology Substitute of High Pressure Wash for Ink Removal, Technology
Substitute and Reclamation Products used for Emulsion and Haze Removal
Using a high pressure wash results in only marginal concerns for worker dermal risks
and very low concerns for worker inhalation risks. Specifically, there is a marginal concern for
chronic dermal exposures and a very low concern for chronic inhalation exposures to
cyclohexanone during haze removal. In addition, there is minimal concern for developmental
and reproductive toxicity risks from inhalation exposures to cyclohexanone. In terms of costs,
the printing facility in the performance demonstration switching to method 4 incurred a cost
savings of $1.74/screen ($2,602/year).
Technology Substitute of Automatic Screen Washer for Ink Removal.
Risks from the automatic screen washer were evaluated assuming use of the ink
removers from traditional system 1 and traditional system 3. Using traditional system 1 ink
remover, inhalation exposures were significantly lower (approximately 70% reduction) than the
exposures during the manual use of this ink remover. Using traditional system 3, marginal
concerns are for chronic inhalation exposures to toluene, methyl ethyl ketone and methanol are
indicated. Additionally, clear concerns for chronic dermal exposures to toluene and methyl
ethyl ketone and marginal concerns for dermal exposures to methanol are indicated. While the
automatic screen washer was not used by printing facilities in the performance demonstrations
estimates of the cost to printers of using the automatic screen washer technology were
generated. Based on these estimates, it is expected that printers switching from the baseline
product to a low cost ($5,000) automatic screen washer for ink removal would experience a
cost savings of $2.14/screen ($3,20I/year). Printing operations similar to the model facility
switching to a high cost ($95,000) automatic screen washer (more automated than the $5,000
washer) would experience a cost increase of $3.87/screen ($5,814/year).
Work Practice Substitute of Screen Disposal in Lieu of Reclamation.
Under this approach, reclamation does not occur. Rather, the screen is cut out of the
frame and disposed. As such, it is considered to be a pollution prevention activity and is
discussed more fully in Chapter Six: Overall Pollution Prevention Opportunities for Screen
Reclamation. It should be noted, however, that the costs associated with this approach are
quite high at $49.43/screen and represent a very significant cost increase to printers. Based on
DRAFT-September 1994 VII-10
-------
VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Additional and Societal Benefits
discussions with the Screen Printing Technical Foundation, it is suggested that screen disposal
is probably only cost effective with smaller screen sizes and/or long production runs, where the
number of impressions nears the expected life of the screen.
Additional and Societal Benefits
Potential Benefit of Reducing Hazardous Waste Disposal
In addition to reducing human health risks to screen reclamation workers, switching to
alternative products will create social benefits in the form of reducing the amount and toxicity
of hazardous wastes which are transported and disposed of in landfills and reducing releases
of volatile organic compounds (VOCs) that contribute to the formation of photochemical smog
in the ambient air. These benefits include the benefit to society of 1) reduced risk from
exposure to hazardous wastes during transport to landfills and in the event of migration of
contaminants from the landfill into groundwater and 2) reduced human health risk from
exposure to VOCs released into the atmosphere. Because the risk assessment did not link
exposures of concern to adverse health outcomes, however, it was not possible to estimate the
dollar value of these social benefits. It should also be noted that a reduction in the quantity of
hazardous waste generated could reduce the likelihood that a landfill or the generator's facility
will require a hazardous waste clean-up in the future, a cost that could ultimately be borne by
society.
Printing companies may also receive benefits in the form of reduced hazardous waste
disposal costs since, for most of these product systems, there would be no hazardous waste
associated with disposal of the product, although hazardous constituents in contaminated ink
may affect disposal of spent ink remover. Comparing the current cost of disposing of
hazardous waste estimated for the baseline facility and for facilities using alternative products
in the cost analysis, an estimate of the potential hazardous waste disposal benefit can be
estimated. Assuming 20,000 screen printing facilities involved in the graphics industry in the
U.S. (SPAI, 1994), the total annual current cost of disposing of hazardous waste is
approximately $600,000/year ($0.02/screen x 6 screens/day x 250 work days x 20,000 printing
facilities). Because the performance demonstrations were meant to be representative of small
and medium size facilities, this hazardous waste disposal cost does not account for any unit
cost differences attributed to disposal of hazardous wastes by large printing operations.
For 19 of the 28 printing facilities in the performance demonstrations, the cost of
disposing of hazardous waste would fall to $0/screen under an alternative method. It should be
noted that determination of hazardous wastes was based on ignitability of chemical
constituents and did not include toxicity testing. Where toxicity testing results in classification
of the wastes as hazardous, disposal costs would be incurred. In addition, there may be costs
associated with State and local regulations. The remaining nine facilities would incur
hazardous waste disposal costs of as much as $0.08/screen. The variation in per screen
disposal costs ($0.02 versus $0.08) is due to differences in the amount of hazardous waste
generated per screen under different options.
Total hazardous waste disposal costs for the entire industry, based on the results of this
cost analysis, range from $0/year to $2.4 million/year if printing facilities switch to alternative
systems ($0 - 0.08/screen x 6 screens/day x 250 work days x 20,000 printing facilities). Within
this range, the resulting cost savings or benefit could amount to as much as $600,000/year.
Alternatively, if all printers faced higher waste disposal costs, a total cost of $ 1.8 million/year
DRAFT-September 1994 VII-11
-------
VII. MACROECONOMIC ISSUES
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Additional and Societal Benefits
would result. As mentioned above, however, more than two thirds of the facilities in the
performance demonstrations would experience disposal costs of $0 and only one tenth of
facilities would experience disposal costs as high as $0.08/screen if they switched to an
alternative system. As such, it is unlikely that total costs would be as high as $ 1.8 million/year.
Potential Benefit of Avoiding Illnesses Linked to Exposure to Chemicals Commonly
Used in Screen Reclamation
As mentioned above, the risk assessment did not link exposures of concern to adverse
health outcomes. Data do exist, however, on the cost of avoiding or mitigating certain illnesses
that are linked to exposures to screen reclamation chemicals. Such cost estimates indicate
potential benefits associated with switching from traditional screen reclamation products to
less toxic products. For example, one disease associated with exposures to solvents typically
used in screen reclamation is hypertension. Hypertension (persistent high blood pressure)
increases the risk of heart attacks and stroke, particularly when coupled with high blood
cholesterol levels and enlargement of the heart's left ventricle. Hypertension has also been
linked to early mortality and short or long-term damage to the heart, kidneys, brain, eyes, and
circulatory system. Treatment for hypertension is largely focused on decreasing blood pressure
and controlling other risk factors in an attempt to avoid these more serious health effects. Per-
patient lifetime estimates of the direct medical costs of treating hypertension were developed in
a previous analysis titled The Medical Costs of Five Illnesses Related to Exposure to
Pollutants (Abt Associates, 1993). The results of this analysis suggest that avoiding one case of
hypertension would result in the avoidance of an average lifetime cost of treating hypertension
of between $3,654 to $11,551 (1993 dollars, updated from 1978 dollars using the Consumer
Price Index for medical care costs) for men and between $3,094 to $10,186 (1993 dollars,
updated from 1978 dollars using the CPI for medical care costs) for women. It should be noted
that this estimate is not inclusive of the non-medical direct costs or indirect costs of illness.
For example, child care and housekeeping expenses required due to illness considered to be
non-medical direct costs are not included. Similarly, indirect costs that reflect both the
decreased productivity of patients suffering a disability or death and the value of pain and
suffering borne by the afflicted individual and/or family and friends are not included. This
estimate does suggest, however, the minimum benefit per affected person that would accrue to
society if switching to an alternative screen reclamation product system reduced hypertension
cases among workers and other individuals exposed to screen reclamation chemicals. In
addition, reductions in illness benefits paid by printing operations may directly affect individual
companies through a reduction in liability and health care insurance costs. While reductions in
insurance premiums as a result of pollution prevention are not currently widespread, the
opportunity exists for changes in the future.
DRAFT-September 1994 VII-12
-------
Appendix A
Glossary of Terms Used in the Environmental Fate Summaries
This Appendix defines the following terms, which are used in the environmental fate
summaries:
O acclimation
O activated sludge
O beta-oxidation
O bio concentration factor (BCF)
O biodegradation
primary degradation
ultimate degradation
O biochemical oxygen demand (BOD)
O gravitational settling
O Henry's Law constant (He)
O hydrolysis
O hydrophile/hydrophobe
O hydroxyl radical
O leaching
O mobility
O octanol/water partition coefficient (Kow)
O persistence
O photolysis
direct photolysis
indirect photolysis
O photooxidation
O screening test
O soil sorption constant (Kj
O STP fugacity model
O transformation
O transport
O vapor pressure
O volatilization
O water solubility
O wet deposition
Acclimation: process in which exposure of a microbial population to a chemical results in a
more rapid transformation of the chemical than initially observed
Activated sludge: the flocculated mixture of microorganisms and inert organic and
inorganic mated ' al normally produced by aeration of sewage. Constitutes the
biological treatment process most frequently employed for purification of domestic
sewage
Beta-oxidation: microbial degradation pathway in which fatty alkyl groups are
enzymatically degraded two carbons at a time, eventually resulting in total
DRAFT—September 1994 A
-------
APPENDIX A. WORKPLACE PRACTICES QUESTIONNAIRES FOR SCREEN PRINTERS
biodegradation of the alkyl group
Bioconcentration factor (BCF): equilibrium ratio of the concentration of a chemical in an
exposed aquatic organism to the concentration of the chemical in the surrounding
water
Biodegradation: the transformation of chemical compounds by living organisms. Not
confined to microorganisms (e.g., bacteria, fungi), but chiefly a microbial process in
nature
Primary degradation: any biologically induced structural transformation of the
parentcompound that changes its molecular identity
Ultimate degradation: any biologically mediated conversion of an organic compound
to inorganic compounds (e.g., CO, and H,O) and products associated with normal
metabolic processes.
Similar to Mineralization
Biochemical oxygen demand (BOD): the amount of oxygen consumed by microorganisms
when metabolizing a chemical compound
Gravitational settling: process by which particulate matter reaches land surfaces or water
bodies via deposition from the atmosphere
Henry's Law constant (H0): the air/water partition coefficient, usually estimated by
dividing the vapor pressure of a sparingly water soluble chemical substance by its
water solubility. H. , provides a measure of the volatility (see volatilization) of the
chemical from soil or water
Hydrolysis: transformation process in which a molecule, abbreviated RX, reacts with water,
forming a new chemical bond between R and oxygen derived from water, and cleaving
the bond between R and X. Webster's says "a chemical process of decomposition
involving splitting of a bond and addition of the elements of water"
Hydrophile: a molecular fragment that imparts increased water solubility, usually a
polyethoxylate, sulfonate, sulfate, quaternary ammonium, phosphate, or other
hydrophilic ("water-loving") group
Hydrophobe: a molecular fragment that imparts increased fat solubility and decreased
water solubility, usually an alkyl group with at least 10 carbons or a similarly
hydrophobic ("water hating") substituted benzene group
Hydroxyl radical: a strong oxidizing agent consisting of one oxygen atom and one hydrogen
atom, which is generated naturally by the action of sunlight and is the chief oxidizing
agent in the atmosphere (see photolysis/photooxidation)
DRAFT—September 1994 A
-------
APPENDIX A. WORKPLACE PRACTICES QUESTIONNAIRES FOR SCREEN PRINTERS
Leaching: transport process by which dissolved chemical substances move through soil
with the percolation of water
Mobility: ability of a chemical substance to move through soil with the percolation of water
Octanol/water partition coefficient (K0w): equilibrium ratio of a chemical's concentration
in the octanol phase to its concentration in the aqueous phase of a two-phase
octanol/water system. K0w is an important parameter because it provides an
indication of a chemical=s water solubility and its propensity to bio concentrate in
aquatic organisms and sorb to soil and sediment
Persistence: ability of a chemical substance to remain in a particular environment in an
unchanged form
Photolysis: transformation of a chemical induced by light energy
Direct photolysis: a photolytic process in which a chemical Itself absorbs solar
radiation and is subsequently transformed
Indirect photolysis: a photolytic process, also referred to as sensitized photolysis, in
which some other chemical absorbs solar radiation initially but then transfers
that energy to the chemical of interest, which is subsequently transformed
Photooxidation: a photolytic process in which solar radiation generates an oxidizing agent
(such as hydroxyl radicals) that reacts with the chemical, resulting in its
transformation
Screening test: broadly, a test in which the main goal is to gather preliminary, often
qualitative information for the purpose of making a decision as to the need for further,
more sophisticated testing. Most often used in connection with biodegradability
testing
Soil sorption constant (Koc): a measure of the extent to which a chemical partitions
between the solid and solution phases of a two-phase system, especially soil, sediment
or activated sludge. Usually expressed on an organic carbon basis, as the equilibrium
ratio of the amount of chemical sorbed per unit weight of organic carbon (oc) in the
soil, sediment or sludge to the concentration of the chemical in solution
STP fugacity model: a mathematical model of a typical sewage treatment plant (STP)
employing primary treatment, activated sludge secondary treatment, and secondary
settling, used to predict the fate of chemical substances of interest in treatment. The
STP model is based on the chemical principle of fugacity, which is a measure of the
tendency of a chemical to "flee" from one phase to another (e.g., from water to air)
Transformation: any environmentally induced change in the molecular structure of a
DRAFT—September 1994 A
-------
APPENDIX A. WORKPLACE PRACTICES QUESTIONNAIRES FOR SCREEN PRINTERS
chemical that includes the breaking or formation of a covalent chemical bond
Transport: movement of a chemical through one environmental phase or from one phase to
another
Treatability: the amenability of a chemical substance or waste stream to removal during
biological wastewater treatment, without adversely affecting the normal operation of
the treatment plant
Vapor pressure: the pressure that is exerted by a chemical substance in the vapor phase
when that phase is in equilibrium with its solid or liquid form
Volatilization: transport process by which a chemical substance enters the atmosphere by
evaporation from the solid or solution phase on land or in a water body
Water solubility: the maximum amount of a chemical that will dissolve in pure water at a
specified temperature, usually 25N C
Wet deposition: process by which a chemical that is dissolved in water in the atmosphere
reaches land or a water body via precipitation (synonym: atmospheric washout)
DRAFT—September 1994
-------
Appendix B
Workplace Practices Questionnaire for Screen Printers
This Appendix provides a reproduction of the blank questionnaire on workplace
practices used for evaluating workplace exposure as it appeared when sent to the
screen printers for completion.1
1 'University of Tennessee, Center for Clean Products and Clean Technologies, "Summary of Responses:
Workplace Practices Questionnaire for Screen Printers," Prepared for the Design for the Environment
Printing Project, (February 1994), Appendix A.
-------
WORKPLACE PRACTICES QUESTIONNAIRE
FOR
SCREEN PRINTERS
Prepared by
Screen Printing Association International
in cooperation with
University of Tennessee
Center for Clean Products and Clean Technologies,
and EPA Design for the Environment Staff
This questionnaire is designed to characterize typical screen printing facilities and
workplace practices associated with the screen printing/reclamation process. The
results of the questionnaire will be used to estimate exposure and characterize risk
from this process and to help identify pollution prevention opportunities. Pollution
Prevention is the use of materials, processes, practices or products that avoid, reduce
or eliminate wastes or toxic releases, through activities such as material substitution,
source reduction and closed loop recycling. This information is being developed for
industry use to help printers make informed choices about the environmental attributes
of alternative cleaning and reclamation products and technologies.
Please, mail completed questionnaires to: Marcia Y. Kinter
Director of Government Affairs
Screen Printing Association International
10015 Main Stract
Fairfax, VA 22031-3489
If you have questions about the questionnaire or would like a copy of the summary of
results, please contact Lori Kincaid from the Center for Clean Products and Clean
Technologies, University of Tennessee at 615/974-4251 (fax 6151974-1838).
Respondents to this questionnaire are guaranteed anonymity. Responses will not be
attributed to any individual or company in reports or other written documentation of
the results of this research. Company name and other information requested below
are optional.
Company Name
Address
Questionnaire Completed by
Title
Telephone Number
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
sc«a pnnui* fadfiM «d workplace pncucn anocwta
»«*
workplace pnaice, w*iu. *• «««n <
(Profik
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your pnxhica we pnaad on the
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a
a
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2) Pteate lift the major pfwten
produced it Jf our facility.
3)
Onerai Facility Information
Number of Employees
at this Location
'••
0-5 C
6-10 C
11-15 C
16-30 0
31-50 C
>50 C
issume * 5-day work we
. — "~
Number ot
Employees Involved
in lak Removal
1-3 C
1 £ C
7-10 C
>11 C
Number at Employee!
Involved ia Screen
Cleaning/Reclamation
1-3 C
4-6 C
7-10 C
>H D
specify
Average tua«
(hr/day) a single
individual it
involved w/ ink
remofii
<1 C
1-2 C
24 C
4-6 C
6-» C
other .C
Average time (far/day) a
single individual is loroived
screen
1-2 C
24 C
4-6 C
64 C
other C
DRAFT—September 1994
B-3
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCRIIN PRINTERS
A)
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da fan vn « t
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a- US
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NH-3(L*%J
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26 tafHodcaii
(22.6%)
NA - W (77.4%)
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Pink
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GIu.
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« (7.1%)
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10 (17%)
t (0.?%t
I (0.?%)
•{?.(»»
1 OJnr typo «< mk inc4ui« m«uUie mki. «
kttrn>doiM(W»9|>*alak.t»r'0'
See Table 2E - Total Ink Use
DRAFT—September 1994
B-4
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
B) ^vtoiHo****** ***•*"""*-******"**"'
'"Pie*** check the appropriate box!
- 5-10
2 10 45
Q > 45 Speoff.
» frame MM «yowi»edity>_;
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n\ Doyotiu.*.,.-— —
If ya, please cheek all that apply ui the toUowmi tibte.
Q yet O no
, emuUioo reroovai, and haze retnovai.
E)
!_i no
If yes. please check all ttot apply in the following table.
Combined area far ink removal and screen reclamation activities
Size of Combined Area (ftl)
<20
20-50
50-100
100-200
>200
Specify Size
a
a
a
a
a
Type of Venalmott
local (medMBiral)
plant (facUity-wide)
natural
other
-------
I
"S
to
O"
Barrier
Cram IS (14.0*,)
None Uted 2 (1.9%)
Otter
(.pecUy) 7 (6.5%)
boon)
NR-9 (1.4%)
Metiiod of Applying Ink
HcmovaJ Product
Pour from container onto
Dip rag or hruih into container
>nd wq» Kreen 14 ()l.t%)
Spray on witli noxaie
from ttnk )4 ()!!%)
Spny on with
ipny bonle 12 (2».4%)
tlat ipeddued .pnying
e<,dpm«, (vedfy) 11 (II. lit)
Oit«r (rptcify) ?(!!%)
ulttyoia
Kieza tcmbber
pour
Raw turn bruih
m**m
klquipmeat or
M«*ri Mmple ii« of II? rnpendenu.
i i»Me
a
-------
o
31
7"
CO
•o
S"
I
CO
CO
•U
6)
A)
Emulsion R»mov»l Procedures
What percent of the lime do you ute the following types of stencils?
Diieci photo stencils
Indirect photo stencils
Capillary film
<50%
D
D
D
50-95%
D
a
a
95-100%
G
a
-a
Are these dual cured?
yes D no CJ
ye» D no D
yes O no D
What emulsion removal products do you use? What type of personal protective equipment do you typically use when you remove emulsion? What are typical emulsion
removal pt"™1""* " y™" fagi%? fPJease check all that JPPJV )
Emulsion Removal Product
(Trade Name)
Annual Volume
of Emulsion
Removal
Product Used
(gallons)
Cost of Emulsion
Removal Product
(S/gallon)
Personal
Protective
Equipment
Used
0 loves D
Eye 0
prelection
Aprons D
Respiratory a
protection
None Used a
Other D
(specify)
Method of Applying Emulsion
Removal Product
Pour from container onto P
screen surface
Dip rag or brush into O
container and wipe screen
Spray on with nozzle from O
tank
Spray on with spray bottle P
i
Use specialized spraying n
equipment (specify)
Other (specify) D
Equipment or
Materials Used 10
Remove Emulsion
Brush O
Low-pressure a
Water-spray
High-pressure D
Water-spray
Water-blaster O
Automatic Screen D
Cleaning System
Disposable Rag D
Reusable Rag D
Other (specify) a
Ave, No. of Rags Used
Per Screen to Remove
Emulsion
0-2 0
2 4 tJ
46 t-l '
6-8 0
810 0
Other D
(Specify number >
00
-------
V)
ft)
1
er
(O
to
7l lUz* Removal Procedures
•V) Please complete the following chart if you use haze remover to remove ghost images.
Hare Removal Product
( Trade Name)
Annual Volume
oftitze
Removal
Product Used
(gallons)
Cost of Haze
Removal Product
($/gallon)
Percent of
Time Haze
Remover Used
05 D
5 25 n
25-50 0
. > so n
(specify )
Personal
Protective
Equipment
Used
Gloves D
Eye a
protect tun
Apions O
Respiratory D
protection
Bariicr n
Cream
None 1 Iscd D
Oilier D
(specify)
i
Method of Applying Haze
Removal Product
Pour from container onto a
screen surface
Dip rag or brush iiuo D
container and wipe screen
Spray on with nozzle Q
from tank
Spray on with spray D
bottle
Use specialized spraying U
equipment (specify)
Other (specify) D
Equipment or
Muerials Used to
Remove Haze
Brash a
taw-pressure D
Water-spray
High-pressure n
Wiler-spray
Waici hl.iMi-i i )
.SijUt-i-gCl- U
Disposable U
Rag
Reliable RiiB Q
Other Q
(specify) ;,
Ave r-
Rags Ui
Scice
Reni«v«
02
2 4
46
6 8
S H>
Other
(spccil) >
DO
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
Alttrnaiwej
Do you use i screen degicaser.1
Trade Name of Product
9)
Do you use a sep»M fflk degwiant before appiymg emnliwnrenwvtr.' (Answer yes only if the ink degndiM u
•jiffrm* IBM (be primary ink removal products? u yes D no- -
Trade Name of Product _—. . 4-
Material! Stonte ' -
Wte* do you ao« ink removal and KJten reciaa*»a prwtym ind in
Ink Removat md Sown Cleaning
Are*$>
30- or 55-g»Uoo drum with bung
hole kept open 3
30- or 55-gtllon drum with bung
bole kept closed -
30- or 55 -gallon dnim wiib lop
removed :"-
Openpdl -^
Closed paU -
Quart or smaller squin bonle O
Safety can O
Safety cabinet -
Not kept in the press room —
Other (specify below) D
(nk/Cbemicai Storage Room
30- or S5-galk» drum wun buag ocrie kept open
30- or 5 J-gaUoo drum with bung note kept elated
30- or 55-giiIon dram with top removed
Open pu!
dosed pail
.
Quart or smaller squirt bottle
Safety can
Safety cabinet
No separate storage area
Other (specify belowi
Size of storage room • !"s *
Q
O
n
'_4
^
Q
U
_
— '
—
~i
^
—
How do vou retrieve ink removal and screen reclamation product* from ink/chemical storage? If you **?*** taf!e,'*f**f
container* in the ink removal and screen cleantog/redaiiiation areas, bow do yon transfer the products from large conumcr. »
small containers for use?
Retrieval from Storage Room
Entire container moved to press room O
Pumped into smaller container Q
Pound inn smaller container Q
Ladled inio smaller container H
Othet (specify below) C
Transfer from Large to Small Container far Use^
Pumped into small container used at work station O
Poured inio smaller container Q
Ladled into smalkr container 9
Othet (speciry betow) D
DRAFT-September 1994
B-9
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
ruu
tndicaw in* OUJIKHV 01 wui« you oaoosc or
cxm toivrm
Nmbn ot SS ru dnm) OR
,N«nb*r « S5 5>L onamw OR _
Ol
Mfltoi •! S«oof» Poor to
Triiniiniiiiniiiiiiil'irriniiiil
rrmmmn ?* Pt.OW
.M2.l%)
MahDOo.T
Filter or tn* pnur to
6(5^*}
xvtr ! 1 ltOJ%)
Nl-20 {!?.«%)
Diioow M OOD-
1 Otter (tpcorr) 5 (4.7%)l
j • EOWCJ serrie*
11A
S« T«M« II* • Ii* «d Sou C/R T
&• TdU« 11C • Pradaai Fiuduwt ad WMUJ
Tin
HR-
34 (J1T»)
16(13.0*)
lt(10J%)
?{&}%)
Wim • !] (111%)
Noo-Hxaniom
mm if (17.1%)
NS.-24 (12.4%)
. NA-*(5.*%)
DRAFT—September 1994
B-10
-------
APPENDIX B. WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
C) How are waste rap contaminated wich ink removal and screen cleaning/reclamation products stored, treated or disposed
Method of Storage Prior to
PfCtreMfflcof of Disposii
bopeacauamm a
In closed coatiinen a
No specified contaiaeri a
MdtKKi Of PITtlTHfltffll
Centrifuge Q
Allow liquid to drain out a
Other (specify) a
None a
Melted of Recycle or Disposal
Oo-trte water laundry a
On-tite dry cleaner a
Off-Kit water laundry a
Off-wedry cleaner a
Hazmlooa wa«e a
Naa4M»tttoo* wane o
Doootuaengs a
Otter (tpeafy) a
10
DRAFT—September 1994
B-11
-------
o
3D
>
I
•s
O>
I
CD
2
CD
II)
Pollution Prevention Opportunities
I»H ynti have a pollution prevention, waste minimization, or source reduction program?
yes O If you answered j*i, weald you be willing to share » description of yes
your program with the DFE Printing Project?
Have you tried any different chemical products few environmental or worker safety reasons to
repine your current ink removal or screen cleaning/reclamation products?
If you have tried a different chemical product. Cleaner worked well:
please check the box that best describes your Cleaner was OK tut not as go.«l as old cleaner
t iperience with the product:' Cleaner was not satisfactory:
Other (please explain below):
-- — — ....... •H—IIIIIIIIIIIIIIIIIIIIIM ...... i ............... •••••^••••••••••HSgai
Besidei different chemical products, have you implemented any changes in equipment O, productsyes a
a, processes O, or work practices D thai reduced your use of ink removal or screen
cleaning/reclamation products? (If you h*ve implemented changes, please check all boxes that no
O If you have not Lack adequate information to evaluate
D tried a different environmental performance of atttrninvcs
chemical product. Operator* do not believe alternatives will wm k
pleaie check the Not impressed with product descriptions:
box Out beat Cost is prohibitive:
describes your Other (please explain below)
reason fur not
trying alternatives:
if you answered yet, would you be wilting i<> share the changes
with the DFE Printing Project?
increased decreased no change
II >im have implemented changes that reduced materials cost:
yixir use of ink removal or screen time required to dean the screen;
cleaning/reclamation products, how hive these disposal costs:
change! affected:
D
D
D
D
Q
a
D
O
a
If you should decide or nave decided to implement changes in your screen cleaning/reclamation
process to incorporate pollution prevention opportunities, which of Oie following factors would
have the greatest priority in this decision? Please rank these (actors from 1 to 6, with i indicating
the highest priority.
.cost
. regulations
. environmental hazard
. performance
. health hazard
. other (specify
' If you have tried more than one different chemical product, please fill out a copy of this section for each product.
-------
Appendix C
Summary of Responses to Workplace Practices Questionnaire for
Screen Printers
This Appendix provides a summary of the Information on workplace practices used to
evaluate workplace exposures to screen reclamation chemicals,1
'University of Tennessee, Center for Clean Products and Clean Technologies, "Summary of Responses: Workplace
Practices Questionnaire for Screen Printers," Prepared for the Design for the Environment Printing Project, {February
3, 1994), Appendix B.
DRAFT—September 1994 C-1
-------
Presentation of Results
The Workplace Practices Questionnaire for Screen Printers included check-off
type questions where respondents could check the response that best described their
facility, and fill-in-the-blank type questions where respondents were asked to list specific
information. The summary of responses to questions witB check-off categories is
presented directly on the questionnaire, instead of on a separate series of tables. This
makes the results easier to read and interpret for the screen printers and others who
have requested a copy of the summary of results. Responses to fill-in-the-blank
questions are listed in a series of tables attached to the questionnaire.
He total sample size (n) for the questionnaire was 115 respondents. This sample
size was used to calculate the percentages shown on pages two, three and 11. Of the 115
respondents, 107 were screen printers who primarily use solvent or UV-based inks
printed on plastic/vinyl substrates. Thus, n=107 was used to calculate the percentages
shown on the remainder of the questionnaire.
"NR* is used in the questionnaire to indicate the number of respondents who did
not respond to a question. "NA" is used to indicate the number of respondents for
whom a question was not applicable. A question was considered not applicable when:
1) the respondent indicated that a question is not applicable to his or her
facility, or
2) the respondent did not complete a question because his or her facility did
not meet the criteria specified for the question.
An example of the second case is Table 4-D) on page 4 of the questionnaire. If
respondents answered "no" to the question, "Do you have separate areas for ink removal
and screen cleaning/reclamation activities?", then "NA" was entered for each of the
columns in the following table.
Several sections of the questionnaire are in table format with each column of a
table representing a different question. At the top of these tables, we have listed the
sample size that pertains to that section of the questionnaire (e.g., n= 115 or n-107)
followed by the number of respondents who responded to at least part of the table. The
number who did not respond (NR) to any single column in the table is indicated at the
bottom of the column. (Sections 1 and 6-A are examples of exceptions to this rule, since
the columns in these tables do not represent different questions. For these sections, the
no response rate, NR, is shown above or to the side of the table instead of at the bottom
of each column.) For example, Section 3, General Facility Information, combines five
related questions on the number of employees and the average time an employee spends
in ink removal or screen cleaning into a single table of five columns. The sample size for
this table is 115, but only 114 respondents (99.1%) of the sample completed at least part
of the table. Furthermore, only 113 respondents (98.3%) completed column 1, "Number
of Employees at this Location." Thus, NR=2 (115-113) for this column.
DRAFT—September 1994
-------
APPENDIX C. SUMMARY OF RESPONSES TO WORKPUCI PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
WORKPLACE PRACTICES QUESTIONNAIRE
FOR
SCREEN PRINTERS
Prepared by
Screen Printing Association International
in cooperation with
University of Tennessee
Center for Cleaa Products and Cleaa Technologies,
and EPA Design for toe Environment Staff
This questionnaire is designed to characterize typical screen printing faqlMJBt and workplace
practices associated with the screen printttgfredamttkM process. The results of the
questionnaire will be used to estimate exposure and characterize risk from this process and to
help identify pollution prevention opportunities. Pollution Prevention is the use of mufcriiib.
processes, practices or products that avoid, reduce or eliminate wastes or toxic releases,
through activities such as material substitution, source reduction and closed loop recycling.
This information is being developed for industry use to help printers make informed choices
about the environmental attributes of alternative deeming and reclamation products and
technologies.
Please mail completed questionnaires to: Marcia Y, Klnter
Director of Government Affairs
Screen Printing Association International
10015 Main Street
Fairfex,VA 22031-3489
If you have questions about the questionnaire or would like a copy of the summary of results,
please contact Lori Kincaid from the Center for Clean Products and Clean Technologies,
University of Tennessee at 615/974-4251 (fax 615/974-1838).
Respondents to this questionnaire are guaranteed anonymity. Responses will not be attributed
to any individual or company in reports or other written documentation of the results of this
research. Company name and other information requested below are optional.
Company Name
Address
Questionnaire Completed by
Title
Telephone Number
DRAFT—September 1994 C-3
-------
APPENDIX C. SUMMARY OF RESPONSES TO WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
The purpose oi this questionnaire is «j eniractenze ivpieal screen priMing facilities and workplace practices associated
with the screen printing/ reclamation process. The business protile and general facility information requested below
allows us to understand vour •vornoiace practices within the context of your overail pnntin| business.
Business Protik
Approximately what
percentage of your products
are printed on the following
substrates? (Please check the
bates that apply.)
n-115
114 respondents (99.!%)
NR-1 (0.9%)
<50%
Pinna (njri/flcDM.) 31(27 J%)
Paecr (COMB or "frfTW^ 54(47.0%)
Moat 46(40.0%)
Cenait 1(7.0%)
GUa 12(ia4%)
Other (ipnrr b4o^ 20(17.4%)
50-W% «-!(»»
5fl(43J%) 27(233%)
13(11J%) 3(2.6%)
«5.2%) 10.6%)
0 0
2(17%) 0
*•*** 2(1^
2) Plea« Urt the im^r produea produced »t your f»dlky.
See Table 1
3) General Facility Information
How many staff do you employ? How tnaay hour* per day does your staff spend removing ink and
cleamns/reclaiming; screens} Ink remanl a the removal of the bulk of the ink from the screens prior to further
cieming/reclamation. Screen cleaning/reclamation actrritiej include residual ink removal, emulsion removal, and haze
removal. Questions about ink removal do not pertain to press-tide operations, unless this is the only site used for ink
removal. Please assume a $50 )3<2I.7%!
NR-J (1.7%)
rnKOMT Cf f«fttifmifftU:
InvoKrdmlnk
RtfRO**! •
1-J 62 (5J.SW
44 n (».!%}
7*10 IS (13.0%)
>ll 15(13-0%)
ipeeiff
rafi^K 0 lo 3S
>r 11 1 (0,»%)
ipwalf
!»«*: 13
avcnft: 12
MR - 1 (0.»%)
MA - 1 (9.9%)
Amagi time (Wdir}
a sra^e indmdunl »
Ur#ol«c4 w/ mk
remofal
< 1 44 (3t.9%)
M 44 %)
2-4 » <20,»%)
4-4 20 (17.4%)
« 26(21.4%)
-------
APPINDIX C. SUMMARY OF RESPONSES TO WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
A)
What types of and how «uci» ink do you u* «» y«w pn«"»g pwcesserf What do you use * a reducer/ retarder?
suwtme o« w mk «ch uik (ypri ffHut yhfA W fa l« *« «W
Vhat i. tht pr,m«v suwtme y
Tvpe of Ink
Traditional solvent-based
UV Curable
Water-based
Other (specify)*
Volume ot Ink
'.gallons)
Type of
Reducer/Retanier
.''••
Water D
Solvent O
.Water/Solvent
Q Mixture
(specify trade
tune)
Primary
Substrate
Plastic 0
Pitnmw I" 1
« ytOKT ™>
Metal Q
Glass Q
Ceraauc O
Other (specify) G
Plastic O
PafM* Q
Metal 0
Glass O
Ceramic O
Other (jpeofy) Q
Plastic D
Paper Q
Metal O
Glass Q
Ceramk O
Other (specify) D
Plastic Q
P*per E
Metal Q
Glass D
Cerainic. ^
Other (specify) Q
1 Other type* ot ink include metallic inks, etc.
k If you do not use a type of ink, enter "0"
DRAFT—September 1994
C-5
-------
APPENDIX C. SUMMARY OF RESPONSES TO WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
TTw nwMtng quc*>OM in CM* ,n mcttiK* to I«««M. or u V-hma mu onmrd on (Mime >nmt lumrwt, K »our iaoiu» DOO «
t««inlii.plnM«in«<«i>wiuiiirrnioinwa«Hio»wM. «»« ««««ii«» «i «« ««» IM, c™r,» M,««, aw oo, «
«l on n»tv*
t M UK
TtwnMf*. i nr MU DIM iniwiuci t
2)
a
D)
m am
numon 01 icnm ataiMO'nciiiRMa 200
NR-IO(*,3%)
NA-2I (26J2%)
4)<«U%)
NA-il (26.1%)
50-100
100-200
>200
U (IZl%»
2ica*%)
p - J to »
«lp>«j
R-t I }.?%>
y« n f«J%) NR.7 (4.SW 90 a (24J%>
51 RJ.M^
NR -7 (4J%>
Do you have * combined »««tor tnk removal and scnwfl
II ya. pwax diwit aii ttut apply « the toilawing uok. n-107
va 41 (10%) NR-TO.5%) r.o S9 «5.1%>
' Corabiatd «e> tor ink movri 200
Spca2r Size
14 (13.1%>
7(4.5%)
.-J16 10 SCO
NA.St (».!*>
Trp. « VraniMMi
NX-I (7.5%)
NA-
2(l,»%)
Thirteen rapondencs answemi ves to both questions 4-D) and 4-E).
DRAFT—September 1994
C-6
-------
S)
A)
B)
Ink Removal Procedures (NOT press-side/process cleaning)
If you recycle ink removal products in-house, how much material was recycled in 19921,
_gal.
Whit ink removal products do you purchase? What lype of personal protective equipment do yon typically UK when you remove ink? What are typical ink removal
procedures at your facility? These questions do not apply to process cleaning (e.g., press-side operations such as Ink removal before going to lunch.) (Please check
ajljto apply.)
Ink Removal Product
(Trade Name)
Annual Volume
of Ink Removal
Product
Purchased
(gallons)
COM of Ink
Removal
Product
(Vgallon)
Type of Ink with
which Product
Works Best
1
Solvent- D
based
UV 0
Curable .
Either" D
Solvent- O
based
i;v D
Curable
Either- D
Solvent- D
based
UV D
Curable
Either* O
Personal
Protective
Equipment
Used
Gloves D
Eye D'
protection
Aprons D
Respiratory: Q
protection
Barrier D
Cream
None Used Q
Other O
(specify)
Method of Applying Ink
Removal Product
POUT from container onto D
screen surface
Dip rag or brush into a
container mid wipe screen
Spray on with nozzle a
from tank
Spray oa with spray battle D
Use specialized spraying a
equipment (specify)
Other (specify) D
Equipment or
Materials Used
to Loosen Ink
Brush O
Squeegee :.. Q
Disposable D
Rag
Reusable a
Rag
Other O
(specify)
Ave. No- of Rags Used
Per Screen to Remove
ink
07 0
24 a
46 a
6-8 o
8-10 0
Other U
(specify nunibei )
1 e.g., ink removal product works equally well with either type of ink.
I
DC
a
-------
I-jmiUiitn UemovaJ l*iocciJuiej
W'lui peicera of tr« time do you Ult the fellrwng types ol stencils? n- 107 102 rctponJentt (»S 3%) NR-S (4.7%)
<50% SO9S% 95-100% Are these Jual currJ?
Diitct ph.,10 sierKilt -) fj 4%) J4 (21 4%) 52(484%) yes «j(« 2%) nn )>1 Whit type of personal piMwtive equipment .!„ you lypkjllv UM when you remove emulsion? What lit typical tmuhinn removal ptt>. t Juiel at y >ur |j. ,l,n >
n-107
Fn.niiyon Removal Product ^
(Tude N«m«)
10) if^.Mldmn (V, )%)
•
Animal -Volume
of Errfyktoi)
rtitwova!
Product UteJ
Cost of ErmiUton
Removal Product
($/g?Llon)
See Table 6
Equipment
Uled
Glovei 101 (94 4%)
ty.
Aprons &6(*I7%)
Hcspaitorr
proteciion 42 ()»}%)
None Used 1(04%)
CHUr
(ipetify) 12(11.2%)
tirplufJ
boon
ha ihitld
Hyit«»««
NR-4(1.7%)
Method of Applying imuliion
Removal ^rodun
four from container onto screen
lurfj.e ' J (17%)
Dip rag or hiusli into container and
wipe to ten 30 (21.0ft)
Spray
-------
en
'o
7) Hut Removal Procedural
A) Pit lit complete the follovini dan i/ jiou tat biz* rcmovtr lo remove rhoii un j
HJM Removal Product
fTriJt Nmw)
92 irsr,.,ijjnn (16.0%)
Annual Velunw ef
HutBuwmi
Product Died
(pllcn.)
See Table 7
Con of Km*
Rimevii Product
(I/»IM
Percent of Time
Haze iUmav*r
UM!
0-5 20(11.7%)
5-25 ZJ (21 S%)
p
»-M 9 (1 «%)
> 50 36 ()) *%}
sp«tify
ranfe: SO (o 100
»vera|e: 90
NR-.II {16.1%)
PtrtOnJ Protective
EWIMM
Uitd
Glawi »J (R.O%J
Ey«
proietnon II (M 3%)
Aptoni 69 (M .S%)
Refpiulory
prouoion 47 f4J.?»)
Barrier
Cream 10 (».)%}
None U«d 0
Other
(jjxcifrt 7 (« .5%)
NR- 16 (15.0%)
MciKod of App!yin| Hat Rrmovil
Produa
Pour from comiirxr omo tcrxn
wrfsKt & (1.4%)
Dip fig or bruih ima comuntr ind
wipt Kretn 70 <«,«%)
Spny on *tth noulc
from ttnk 1 (0,9%)
Sony on witK
tpraybonle I) (12.1%)
Ux specialized iprayinj
etjuipntmt (tptcifj) 1 (0,»%)
Other (ipecifr) } (2.1%)
NR- II (16,1%)
Equipment OE MMeriali
llicd 10 Remove HIM
Bnuh 4 (S 71t)
I.^w-|»rti»Hie
Wjicr iptjy 1 1 (!0.)>)
Ht^t-prcifiire
Vj»r>tpny » (45.411.)
W»er-W«sler 1 (1.4*)
S| I (0 Mi.)
RiuubleRii S(4J%)
Other (ip*"fx) 0
NK-ll (lt>8«.)
A>e. N.I oT tin
Ulfii Per Screen
to Remme H*fe
0-2 «
(It l|>t(.!,f ) Kl
.' < i 10 '/ •
« n 1 lJ '<-.
., S
1-10 1 |0-f^
Other
(ipKify)
NR-2J(JI J-S.)
z
f
tn
$
cc
Q
-------
APPENDIX C. SUMMARY OF RESPONSES TO WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
Do ?o» um *
.« IS 17? 4%)
Do you utt SMpu
dl&MK
TndiN
MjttnaU Sunfi
Wbmaafwra
w u>k ^-t-^"- Mora apply"* «»iMoc rtmoMrt (Amvcr ja 0017 J «h« ink ifcpiduit a
lhaa ti» pmurr ink nml prooua)> yet 2$ {27.1%) no ;i (72.9%)
•DW vl Prodis Set Tiblt 1*6 ^.-.:.
wmkrtawWiodw-ntwiaDiMpranicaaidcc
,.107 102 r«pood«« («.3%l
lok Htmonl ind Stno Oanun
A«Bi(4
30.«,SMI«.^««"-«W«^
Qng| ' C«'^ *^
JO- or SS^jlloo dram witk |MB| bolt Wpt
JO- or 55-plloe 4nm »*k top
Oo««ipol 32 (29,9%)
Safef an 30(210%)
Not Itfpc 12 the press foom 9 (8.4%)
Other (ijxafr bdowj 15 (14.%0
ipeajd 5 pj. lynmu: pour itwm,
rtcTti« Rnr tak. cbperxt 30 (ll.
febrc, taoki ouaide
NR-5 (4.7%)
bJt/ClKmjcii Siocift Room
}fr or SS-jJlominim »Ttli bu«« bok kq« opot 3 (Lt%)
30- «r 55^1)0. dmaxtk boat holt (up doMd «(4fc7%)
30-ar SS-^fendnininAtopnnond °
Op-p-l M«»«»
Qiun M mulkr Kfiurt boaW 10(»J%)
S^IKT *^»fnff ^ \IS^I%y
No Mjarw «on(t ma 15 (14.0%)
OUjei* (xpedfy Wow| 7 (6,5%)
outtiUcr conuintr 3(2
PMBI^W! iJiiwdy rawn *t o*« nKHtti e«tii«
eamiDa to ink removal roam.
0%)
1%)
J%)
8%)
7%)
NR.-9 (8.4%)
mniotbtiak
Tnmfcr from i-irp to SmaU Conuunr fcr U» .
Piimpai u*o «n»U CDMJMT oxd * wrk ttMjon 4J (*
Poured iixa uaalltr temmti 34 (3
CHhcr (tpcoty bdow) . 7(
U%)
J.4%)
0.1%)
«JW)
NR-16 (15.0%)
DRAFT—September 1994
C-10
-------
APPENDIX C. SUMMARY OF RESPONSES TO WORKPLACE PRACTICES QUESTIONNAIRE FOR SCREEN PRINTERS
Number of 55 gal. dnioaj
8"* OR
*1
Screen Ctemn/KedJnMboBWXM
Method of S«»ow»Prtoc
» Trenmeot and/or
In clo*ed container! Q
In open comiinm a
No Jpeafied a
Oilier (specify) a
RHerartns* O
prior to dispoul or
recycle
Send to rtcycter a
Recycle on lite a
Discharge to Kwer O
DUpoieu
bizardoui waste a
Dispose as DOC-
hazankMis waste
Other (speciiy)
Inclcued
Noipecified
cootauiem
prior to dfafMtti
orrecyck
Di»dwrteto
Hazudoui
Wtsw
N
-------
APPEND* C. SUMMARY OF RESPONSES TO WORKPLACE PRACTOES QUEST,ONNA,RE
FOR SCREEN PRINTERS
""" tt«'»»S''*:l»«<*>«
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^ Tin TTM-IT luaili;
QD-UM dry d»«ei
OiMiediydaaer
*0p7.4%)
23(214%)
14 (U4%)
2(1.9%)
NR-i (4J%)
10
C-12
-------
1) rotlnllnn PrermtJon OpeortonWet
r> r«" hive » polLition pnrrftwion. WMM mlntmintloil. •» «our« r**»ion prefnin?
n, torn rwhoSon. mi cWd loop recydiaf.
yel 33 (21.7%)
PoDuMiorrrentioii i. tH. imot«««itk pnoMi.•nafai or pwoWa «k*wo* «*»<
Hive you tried my JlHl*** chralirJ produm for «n»ireran«!ttl or wo.ker »fety "MOM ye. 17 (75 7%)
If rou h»»« tri«d «n lfc«tll««J»> QtiOtl "MM WiB:
chemkJ pred«t, pk«« clBtl. th. O«»t «• OK Warn « t~xl
21 (24.3%)
,,p,ri,nr, wiili trw pr
22 (!».!%)
14 (13.2%)
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coit
*«*. ih»n.Kire eh«mial producti. h«« r«» »|*n«n«i "T «*?•«• » «|«upm«m
2? (23 S%), proJuttt 30 (J».l«), pro<«.« JO (H IH». or «.rk pnmea 41 (35.7%) trot
rrdurVd rcut ««• »l W«nl»t n-nl.rO (I' TO« I"" implrmttnrd tlttrp., pleut th«k til
bone* tKit apply )
dev-npdon of your profrim with dw DFE Primint
If roa tniwerfd r", p!««* '"« tr» produa nnr
SctTibkU
If you hare not Lick tdeqiuu irA>m«ion to
tried in iltermtive mhuu twtironmtmil
chemied product, ptifemunet of •Itcmlfm:
pleiM check the Opemoit do not Mirn
box tint fc« ill«Mli»«« w3l work
Jacriba your Not impn»ed witti product
reuon for not ibfcriptkuiK
tr7in| (ltern»t«ej: Con tt prokAitire!
Other (pleue ejpliin below)
5 (4.3%)
3 (Z.6%)
-ll (15.7%)
If yog jrowered yet. would you he willing to ihirr the
chantrs with ihe DFE Printing Project?
II y..ii hjve in'flrmented eh«nje«
th« t'di.red yr-,ir UM of Mlnket
with. hi">- hi' ' ihew thmf'i
miterMI* Cost:
time required to clew the bllnket:
wiste-run reo,iiired to retch Kcrptihle print
quilfry:
U (22 4%) JO (36 1%)
II (15.7%) 2» (25.2%)
no chinge
14 (I3.t%)
21 (11.3%)
43 ()7.4%)
lfyouihoulddecieVorwo"tcf«.n ,
de«mn«/red«mitio« proem to intorpeciM pdhnlon prrremioB oppoituiiit«i, which of the
follow™, f^ior. wouM tm tht gmtat »ri»ri«f in thh deci,ion> Ple«e rink the« ficton
from 1 to *. with I indkitin*. the hif>e« priority.
.con
.rejulition.
fnvironmrntil hi
perform UKC
I heJth huird
. other (tpecify)
S«Tible13
!l »ou h«.r tri»H more thirl one iltem«i« chemicil product. rle»e fill out i copy of tr,i« .ection for exh product.
11
a>
.f
-------
Appendix D
Densities of Solutes In Aqueous Mixtures
In this report, the densities of solvents in nonaqueous mixtures are assumed to be the
same as their density as pure components. These values of density are then used to compute
the amount of each component in a given volume of mixture. For aqueous solutions, however,
all components of the mixture are assumed to have a density of 1 g.ec"1. This assumption is
made because of the difficulty of determining appropriate values for the densities of solutes on
polar solvents such as water. This Appendix describes the relationships between component
densities and intermolecular forces in liquid mixtures, and indicates the problems associated
with estimation of the density.
The density of a component i in solution at a given mole fraction jq can be related to a
quantity called the partial molar volume, V^;
where JW; is the molecular weight of the component. The partial molar volume Is defined by:
n, being the number of moles of i and V" the volume of one mole of the mixture. V and V", are
also related by:
.,
which allows us to determine the amount of component i in the mixture once VJ is known.
Now, it is shown in standard texts on thermodynamics {e.g., J.M. Smith and H.C. Van
Ness, Introduction to Chemfcol Engineering Thermodynamics) that the partial molar volume V; is
related to the chemical potential pt:
and the chemical potential can be divided into two parts, one part representing the chemical
potential of i in an ideal mixture (JIM), and the other part representing the excess (£3 chemical
potential due to the interaction of molecules of component i with other components of the
solution:
DRAFT—September 1994 D-1
-------
APPENDIX D. DENSITIES OF SOLUTES IN AQUEOUS MIXTURES
m
Substituting into eq. (4) gives:
The first term on the right is simply the molar volume of pure liquid I The second term
can be related to the activity coefficient 7, of C in solution:
In an ideal solution, such as those formed by mixtures of nonpolar solvents, the activity
coefficient of each component is approximately 1 and the pure component molar volume (or
density) can be used to find the amount of I in a given volume of the mixture. In polar
solvents such as water, the activity coefficients are usually far from 1, especially when the
mole fraction of i is small. In this case, we can replace the activity coefficient with the Henry's
constant:
where P,8** is the saturation vapor pressure of i at the temperature of interest. Henry's
constants are generally assumed to be .Independent of pressure, making evaluation of the
derivative impossible. Alternatively, we can use an activity coefficient correlation such as the
Wilson equation, which is generally valid for homogenous mixtures:
where
ex
the a,, terms being related to the energy of interaction of components i and J. In principle, the
effect of pressure on the activity coefficients can be taken into account by using the isothermal
compressibility p
DRAFT-September 1194
-------
.
APPENDIX D. DENSITIES OF SOLUTES IN AQUEOUS MIXTURES
VBP
to alter the pure-component molar volumes in eq. (10). However, the Wilson equation, and
most other activity coefficient correlations in current use, are derived from rigid-lattice models
that do not account for pressure effects. Therefore, partial molar volumes derived on this
basis are not likely to be correct. In a liquid, changes in external pressure result in changes in
the radial distribution function g(r):
P N - ,.„ 3.
* tr)4itr or
l ^
kT V 6kT V Jo dr
where u(rj is the energy of two molecules separated by a distance r and g(r) is the probability of
finding two particles separated by that distance (L.E, Reichl, A Modem Course in Statistical
Physics).
Increasing pressure will cause the molecules to assume more and more energetically
unfavorable configurations, both by moving closer together and by twisting Internally and
externally. The chemical potential of solute i is the work associated with bringing a molecule
of t into the solution from an infinite distance away (this is similar to the definition of
electrostatic potential). This can be mathematically represented by "hiding" the molecule's
force field from the surrounding liquid and then slowly making it visible, using a factor X that
is varied from 0 to 1 :
The chemical potential is then:
N /"I f-
-— / L u
•> O<>Q
MealGas N
—
Y •> O<>Q
Since water and most solutes of interest are not spherically symmetric, use of this
equation requires a series of molecular mechanics simulations over the range X = 0-»1. In
practice, it is found that for X = 0-*0.25, the solute molecule hardly interacts with the solvent
at all and drifts through it like a particle in a slightly nonideal gas. A relatively simple angle-
averaged calculation gives the contribution to the chemical potential in this region. However,
at least one or two simulations must still be performed at or near X = 1 with the complete
molecular geometry taken into account. At present, these types of calculations are too
compute-intensive to run on personal computers and must be run on workstations or
mainframes. Such simulations are used fairly widely in the pharmaceutical industry to study
the behavior of new drugs, but they are not yet routinely used to predict physical properties for
engineering purposes.
In addition to the issues noted above, two other problems arise in dealing with many
aqueoiis solutions. The first is that, in the case of weakly dissociating compounds such as
acetic acid, it is difficult to know what the mole fraction of each component in solution actually
is. The second problem is that, in the case of salts such as sodium chloride, one would need
DRAFT—September 1994 D-3
-------
APPENDIX D. DENSITIES OF SOLUTES IN AQUEOUS MIXTURES
to know the molar volume of pure liquid NaCl (Vr/j^=l,T,PJ). However, sodium chloride is a
solid below 804 °C and the properties of the hypothetical liquid state are not available.
DRAFT—September 1994 . . D4
-------
Appendix E
Review of Air Release Models
NIOSH has studied exposure to solvents at a number of screen printing facilities over the
past three decades. Some of the highest solvent concentrations were found in the screen
washing area at Impressions Handprinters in Chicago, in June 1984 (NIOSH Health Hazard
Evaluation Report 84-299-1543). The toluene concentrations in the screen-washing area
during the ink removal process ranged from 181-727 ppm. These concentrations exceed the
OSHA STEL for toluene (150 ppm). At other screen printing sites, NIOSH investigators
observed similar concentrations of organic solvents in the air. NIOSH observed airborne
toluene concentrations of 115-239 ppm during screen cleaning operations at the main U.S.
Post Office in Chicago in July 1981 (NIOSH Health Hazard Evaluation Report 81-383-1151).
NIOSH observed airborne cyclohexanone concentrations of 10-25 ppm during screen cleaning
at Downing Displays in Cincinnati, Ohio (NIOSH Health Hazard Evaluation Report 82-330-
1252). The CEB model predicts Cv = 22 ppm. NIOSH investigations are generally triggered by
union or management concern about working conditions, and therefore NIOSH data generally
reflects worst-case exposures. Thus, it appears that use of the "typical case" parameters in the
CEB model provides estimates of occupational exposure which are high, but within the range
of the observed data. Use of the "worst-case" parameters in the CEB model generates
estimates which are an order of magnitude greater than the field data.
SAIC reviewed the theoretical basis for CEB's air release model and compared it to other
mass transfer relationships in order to determine whether it might be possible to obtain even
better agreement with the NIOSH data, especially for the worst-case ventilation scenario. SAIC
also reviewed the results of Pace Laboratories' experimental measurements of liquid
volatilization, which were performed for CEB. These measurements mainly relate to high-
vapor pressure compounds evaporating under turbulent airflow conditions. For practical
reasons, Pace was unable to run the apparatus at airspeeds less than 100 ft.min"1, and
therefore could not obtain correlations specific to the laminar flow regime.
SAIC identified two problems that may cause eqs. (1) and (2) to overestimate airborne
concentrations. The first is that CEB's default assumptions for Q, the volumetric air flow rate,
may be inconsistent. CEB uses uz = 100 ft-min'1 in eq. (1). An air velocity of 100 ft.min'l
through a screen cleaning room 8 ft wide x 10 ft long x 10 ft high would imply Q = 8,000
ft3.min"1. The actual flowrate would be lower than this, since the maximum velocity would not
be reached in the corners of the room nor immediately adjacent to the walls. However, CEB
uses a typical air flow rate of Q = 3,000 ft3.min"1, which may be too low. Changing Q to 8,000
ft3.min"1 would reduce the predicted airborne concentrations in Example 1 by a factor of 2.3,
bringing the exposure estimates down to about 560 mg.m"3. The second source of possible
error identified by SAIC in the standard CEB approach seems to lies in the theoretical basis of
eq. (1).
The derivation of eq. (1) is given in Appendix K of the CEB Manual for the Preparation of
Engineering Assessments. The following general equation governs all mass transfer processes
in unreacting systems:
DRAFT-September 1994 E-1
-------
APPENDIX E. REVIEW OF AIR RELEASE MODELS
where
c = Concentration, mol.m"3
t = Time, s
v = Velocity vector, rn.s"1
Dab = Dlffusivity In air, m2.^1
p = Air density, kg.m"3
For steady, unidirectional flow of air over a pool of liquid as shown in Figure 1, this can be
simplified to:
where
uz = Velocity in the z direction, m.s"1
If uz is assumed not to vary with height above the liquid pool, this equation can be solved
analytically to yield eq. (1). However, this assumption is flawed. Because of viscous drag, a
laminar boundary layer develops when air begins to flow over a flat surface. This is illustrated
in Figure 2. The velocity varies vertically within this layer from zero at the surface to the
undisturbed flow velocity at the edge of the layer. The boundary layer construct is an
approximation to the truth, originally developed to simplify the analysis of airflow close to and
far from the surface of airfoils. However, the results of a boundary layer analysis can be made
as accurate as required. The flow regime within the layer is characterized by a boundary-layer
Reynolds number, Re*, computed as follows:
where
Rex = Reynolds number, dimensionless
p = Air density, kg.m"3
z = Length along surface from leading edge, m
]i = Air viscosity, kg.m"1.s"1
If the value of Rex is less than about 105, the flow in the layer will be laminar. Above this
value, the flow will become turbulent. For the case of a 100 ft.min"1 air stream flowing over a
2127 in2 silk screen, the Reynolds number is about 4,000 and the flow regime is laminar. If a
chemical is diffusing from the surface of the liquid pool, a concentration profile will develop
that has the same shape as the velocity profile within the boundary layer. However, the
diffusive boundary layer is thinner than the velocity boundary layer, meaning that, if one
moves vertically away from the pool surface, the concentration will be found to reach zero
before the air velocity has quite reached its free stream value. The thicknesses of the flow and
mass transfer boundary layers are related by the Schmidt number, Sc:
DRAFT-September 1994 E-2
-------
APPENDIX E. REVIEW OF AIR RELEASE MODELS
which is the ratio of the diffusion rates for mass and momentum. The mass transfer boundary
layer is thinner than the velocity boundary layer by a factor of Sc1/3. The rate of mass transfer
can be expressed in terms of another dimensionless group, the Sherwood number:
where:
Sh = Sherwood number, dimensionless
F = Mass flux, mol.m~2.s"1
c = Concentration at the pool surface, mol.m
-3
Both experimentally and theoretically, these three dimensionless groups are found to be
related as follows for the case of laminar flow over a surface (R.E. Treybal, Mass-Transfer
Operations, 3rd ed., p.66; J.M. Coulson, Chemical Engineering, vol.1, 3rd ed., p.332):
Sh 0.332
This equation is analogous to the following equation for heat transfer:
N 0.332
where:
Nu = Nusselt number, dimensionless heat transfer coefficient
Pr = Prandtl number, ratio of heat and momentum diffusivities
The latter equation can be tested very simply by placing thermocouples in the airflow over a
heated plate, thus providing additional validation for eq. (A-6). Equation (A-6) should work
best for low rates of volatilization, where the mass flux does not affect the airflow and the
latent heat of vaporization does not cause appreciable temperature changes in the liquid or air.
This corresponds to the case of a low-vapor pressure chemical, which is often the case of
greatest interest to CEB. According to eq. (A-6), the mass flux varies from place to place along
the pool. The average value is:
N 0.664
In deriving Eq. (1), the author states that an analogy may be drawn to a derivation in
§17.5 of Bird. Stewart, and Lightfoot's Transport Phenomena. However, in that example, the
DRAFT-September 1994 E'3
-------
chemical is being absorbed from the air into the boundary layer. The velocity at toe outside
H^nfthe boundary layer wtere most of the absorption occurs, is practically the same as the
frtt sl^m ye^Mthe present case, most of the concentration gradient lies within a thin
layer S^tfthe surf^e of the liquid pool, where the air velocity is very much lower than
the free stream velocity.
Example 1 Estimate the vapor generation rate and worker exposure awing removal of ink
a
factor of k = 0.5.
Toluene has the following physical properties:
Molecular weight: 92.14 g.moT
Vapor pressure: 28 mmHg at 25 °C
Diffusion coefficient: 0.076 cm'.sec
Using these values in eq. (1) gives:
Generation rate G: 0.28 g^m*
Airborne concentration: 141 ppm (Cv)
534 mg.m-3 (CJ
Exposure over 1 hour: 667 mg
If the CEB worst-case parameters are used in eq (2). i.e., a mixing factor of k =0^ and a
ventilation rate of 500 flf.mln-1. then the estimated airborne concentration is Cv = 4,216 ppm.
Exposures aS volatilization rates are calculated by multiplying the pure-component values
from Table Tby toe mole fraction of that component in the liquid phase. A typical screen has
^Ia of 2127 in2 - 1.37 m2. Each worker cleans screens for 1 hour per day. Amounts
released should be checked against amount used to ensure mass balance.
Example 2. Recalculate the vapor generation rate and worker exposure for Example 1 using
the laminar boundary-layer model
The results are:
Re^ = 3662
Sc = 21.35
Sh = 1H.5
The concentration at the pool surface can be estimated from the vapor pressure of toluene,
which is 28 mmHg:
c=_2§-x—!— x92.14
760 24.45
giving c = 0.139 kg.m-3. Substituting into the expression for Sh gives
F = 0.0995 g.s'.m2
Using this vapor generation rate and an air flow rate of 8,000 ft3.min l gives:
E-4
DRAFT-September 1994
-------
APPENDIX E. REVIEW OF Am RELEASE MODELS
Q, = 19 ppm
Cm = 71mg.m-3
resulting in a total worker exposure of 88 mg.
If the calculations are repeated with the air velocity set to u = 6.25 ft-min"1, corresponding to a
volumetric flowrate into an 8 x 10 x 10 ft room of 500 flf.min"1, therresults are:
Q, = 379 ppm
Cm = 1428 mg.m-3
and the total worker exposure is 1785 mg.day"1 inhaled. This result more closely approximates
the highest concentrations found by NIOSH in the field.
The CEB model was compared to the results of the PACE experiments and found to be in
moderately good agreement. This is not surprising, because most of the PACE data was
collected in the turbulent flow mode. In turbulent boundary layers, the velocity is almost
equal to the free stream value everywhere except in a very thin layer adjacent to the pool
surface. In this case the assumptions used in deriving eq. (1) are correct. In laminar
boundary layers, this is not the case, and eq. (A-7) should, in principle, provide a better
representation of the physical situation.
DRAFT-September 1994 E-5
-------
Appendix F
Screen Printers Technical Foundation (SPTF) Testing
Methodology
Purpose of Testing
Performance data will be collected for each product system in a
laboratory setting at the Screen Printing Technical Foundation (SPTF) and also
in production runs at 23 volunteer facilities. The testing methodology for the
both phases of the demonstrations was developed by consensus with the
involvement of EPA, product manufacturers, and screen printers. The protocol
was designed to allow the evaluation of the maximum number of product
systems given the resources available to the project.
The intent of the SPTF evaluations is to assure that the product systems
sent to printers would provide an acceptable level of performance. Screening at
SPTF will also provide another set of observations to compare with in-facility
demonstration results. All evaluations will be conducted under consistent
screen conditions (e.g., tension, mesh type, emulsion type, thread count, image)
and each product system will be tested on three imaged screens; one with
solvent-based ink, one with UV-cured ink and one with water-based ink.
Testing Methodology
Evaluate each product system as follows:
O Prepare three screens for printing according to the parameters listed in
section C.
O Place a sufficient quantity of the solvent-based ink in the stenciled screen
and thoroughly work into the screen with a squeegee. Card out extra ink
and allow the screen to sit for approximately 15 minutes. Remove the ink
from the screen following the instructions provided to SPTF by the
manufacturer. Wipe or wash off the ink (depending on instructions) until it
appears that no more ink is coming off on the cloth or in the rinse. Use only
enough product to accomplish ink removal to this degree. Record the
application procedure, the time it takes to complete the ink removal (time
using a digital stop watch), the amount of product used (measure to the
nearest 0.5 ounce), the temperature, humidity, product dilution ratio,
number of wipes used, ease of use, and comment on the product
performance.
O Repeat step 2 on the second screen using UV-cured ink and on the third
screen using water-based ink.
DRAFT—September 1994
-------
APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
O Allow each screen to sit for approximately 8 hours to simulate a shop
situation. Record the time delay for each screen. Apply the emulsion
remover to the screen according to the manufacturers instructions. Record
the application procedure, the time it takes to complete the emulsion
removal (time using a digital stop watch), the amount of product used
(measure to the nearest 0.5 ounce), product dilution ratio, number of wipes
used, and ease of use. Also document if the stencil dissolved easily or
slowly, an evaluation of how much scrubbing was needed, if any emulsion
was still present, and if any ink haze or stencil stain remained on the mesh.
If an initial attempt to remove all the stencil fails, record the screen
condition and apply the product again.
O Apply the haze remover product according to the instructions supplied by
the manufacturer. Record the application procedure, the time it takes to
complete the haze removal (time using a digital stop watch), the amount of
product used (measure to the nearest 0.5 ounce), product dilution ratio,
number of wipes used, and ease of use. Also report if any ink haze or stencil
stain is present on the mesh. If an initial attempt to remove the haze fails,
document the screen condition, and apply the product to the screen again.
O Based on the testing method described above, SPTF will determine the
effectiveness of all of the products submitted. This will include evaluating
the manufacturer's application instructions for each product and ensuring
that the application technique specified for that product will enable the
product to work effectively. If the application technique specified for a
particular product is determined to limit the effectiveness of the product or
in any other way negatively affect performance, a second application
technique will be chosen and tested. Only products deemed effective by
SPTF will be used in the field demonstration portion of the project.
Testing Parameters
For each ink type tested (solvent-based, UV-cured, and water-based), use
the following screen parameters:
Mesh Count per Inch/Thread
Diameter:
Supplier/Manufacturer:
Brand Name of Fabric:
Mesh Opening:
Fabric Thickness:
Twill or Plain Weave:
Suggested Tension:
Frame Type:
390/34 LE for UV ink
260/40 LE for solvent- and water-
based ink
Tetko/Swiss Silk of Switzerland
PeCap LE (Low Elongation)
26 microns
60 microns
Twill Weave
26 N/cm for UV ink
20 N/cm for solvent- and water-based
ink
Aluminum
DRAFT—September 1994
-------
APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
Frame Size:
Tensioning System:
Adhesive:
Tensioning Procedure:
18" x 20" Outside Dimensions
Tetko SST Pneumatic Clamp System
KIWO Kiwobond 1000 HMT
O Bring screen directly up to tension using predetermined pressure settings on
pneumatic gauges.
O Let screen set 5 minutes.
O Check tension, and retension if necessary.
O Adhere with frame adhesive.
O Check final tension and record.
Stencil Brand and Type:
Scoop Coater Brand and Edge:
Coating Method:
Image Description:
Exposure System Description:
Wipe Type:
Ink Types
O Solvent-based Ink:
9724 Black
O UVInk:
O Water-based Ink:
KIWO Poly Plus SRX dual cure direct
emulsion
Tetko Pro-EM round edged coater 12"
length
2 coats on print side, 3 coats on
squeegee side, wet on wet.
A 10" x 8" pattern of Va" checkers and
a ByChrome halftone exposure image
Olec 5KW Metal Halide lamp with 36"
distance and light integrator
Molnlycke brand P-Tork made from
rayon and pure cellulose.
Naz-Dar 9700 Series All Purpose Ink
Nor-Cote CD 1019 Opaque Black
TW Graphics WB-5018 Black
DRAFT—September 1994
-------
Appendix G
Facility Background Questionnaire
This Appendix provides a reproduction of the blank questionnaire on facility background as
it appeared when sent to the printers for completion.
DRAFT—September 1994
-------
APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
FACILITY BACKGROUND QUESTIONNAIRE
Design for the Environment Screen Printing Project
1. Business ProGle
a. Products
Approximately what percentage of your products are printed on the following substrates? (Please check all
boxes that apply).
Plastics (rigid/flexible)
Paper (coated or uncoated)
Metal
Ceramic
Glass
Other (specify)
< 50%
50 - 95%
95 - 100%
b. Please list the major products produced at your facility:
c. Approximately what percentage of your shippable product, by sales dollars, is produced through
screen printing?
d. Approximately how long is your typical run?
e. Approximately what percentage of your orders are repeat orders?
2. Screen Reclamation Operations
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
a. Screen Size: Specify the average size frame used at your facility:
(ft2 or in2)
b. Tracking: Describe how your screens are tracked or numbered in the facility:
c. Volume:
What is the average number of screens cleaned/reclaimed each day for future use?
(Please check the appropriate box)
0-5 5-10 10-15 >15 (specify )
d. Employees
Please fill in the table below. For the purposes of this questionnaire, "Ink Removal" is not defined as
press-side operations, unless this is the only site used for ink removal. Assume a 5-day work week
with one 8-hour shift each day. Please check all boxes that apply.
Number of Employees
at this Location
0-5
6- 10
11 - 15
16-30
31 -50
>50
Number of
Employees Involved
in Ink Removal
1 -3
4-6
7- 10
>11
specify
Number of Employees
Involved in Screen
Cleaning/Reclamation
1 -3
4-6
7- 10
>11
specify
Average time (hr/day)
a single individual is
involved w/ ink
removal
<1
1 -2
3-4
5-6
7-8
other, specify
Average time (hr/day) a
single individual is
involved w/screen
cleaning/reclaiming
<1
1 -2
3-4
5-6
7-8
other, specify
e. Ink Removal and Screen Reclamation Areas
Do you have separate areas for ink removal and screen reclamation activities? ("Ink removal" is
defined as activities after excess ink is carded off. It does not refer to ink removal activities during the
process).
Yes No
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
- If "yes", check all that apply in the first four columns of the table below.
- If "no", check all boxes that apply in the last two columns of the table below.
Separate areas for ink removal and screen
cleaning/reclamation activities
Ink
Removal
Area (ft2)
<20
20-50
50 - 100
100 - 200
>200
(specify) :
Type of Ventilation
local (mechanical)
plant (facility-wide)
natural
other
(specify) :
Screen
Reclamation
Area (ft2)
<20
20-50
50 - 100
100 - 200
>200
(specify) :
Type of Ventilation
local (mechanical)
plant (facility-wide)
natural
other
(specify) :
Combined Ink Removal/ Screen
Reclamation Areas
Size of
Combined
Area (ft2)
<20
20-50
50 - 100
100 - 200
>200
(specify) :
Ventilation
local
plant
natural
other
(specify) :
3. Rates
a. Record the electric rate:
b. Record the water rate:
c. Record the sewer rate:
d. Record the screen reclamation employee's wage rate:
e. Record the printer's wage rate:
determine if the print image quality is acceptable).
(Use the rate for the printer who would
4. Current Ink Remover Procedures (NOT process cleaning)
a. What type of ink(s) do you use?
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
b. Do you recycle ink removal products? Yes No
- Do you recycle on-site or off-site?
- Do you use the recycled product in-house? Yes No
If so, how much do you use annually? gallons
- If recycled off-site, does the recycler sell the recycled product?
- What are the costs and income associated with recycling ink removal products?
c. What is the average number of screens/day where ink remover is applied?
d. Describe the current method of applying ink remover:
e. Do you use a pressure washer (or other equipment) for ink removal?
- If so, specify the type of equipment, and the manufacturer and model (from nameplate):
- Specify the pressure (psi) and flowrate (gpm):
- What are the equipment energy use specifications (from nameplate):
- How long is it in use for each screen?
f. Fill in the table on the next page for each of your ink remover products.
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
Current Ink Removal Practices
Ink Removal
Product
(trade name and
description)
Annual Volume of
Product
Purchased
(gallons)
Cost of Ink
Removal Product
($/gallon)
Type of Ink
with which
Product
Works Best
Solvent-
based
UV Curable
Water-based
Any
Personal
Protective
Equipment
Used
Gloves
Eye
Protection
Aprons
Respiratory
protection
Barrier Cream
None Used
Method of Applying Ink
Removal Product
Pour from container onto screen
surface
Dip rag or brush into container
and wipe screen
Spray on w/ nozzle from tank
Spray on with spray bottle
Use specialized spraying
equipment (specify)
Other (specify)
Materials
Used to
Loosen
Ink
Brush
Squeegee
Disposable
rag
Reusable
rag
Other
(specify) :
Avg # of Rags
Used/Screen to
Remove Ink
0-2
2-4
4-6
6-8
8-10
Other (specify) :
f. List the types of materials used in ink removal that are frequently replaced (such as brushes, squeegees, wipes and filters) and their
costs. Note how often they are replaced and how much of your time does it take to order replacements?
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
5. Current Emulsion Remover Practices
a. Fill in the following information and the table below for each type of emulsion removal product you currently use:
Trade Name
Generic product description
Average # of screens/day where emulsion remover is applied:
Volume purchased in 1993 (gal.)
Purchase Price ($/gal.)
Personal Protective
Equipment Used
Method of Applying Emulsion
Removal Product
Equipment or Materials
Used to Remove
Emulsion
Equipment or Materials Description
(Include manufacturer, model #, pressure (psi) and flow rate (gpm) if
applicable, frequency of replacement, equipment energy requirements)
Gloves
Eye Protection
Aprons
Respiratory
protection
Barrier cream
Ear Protection
None Used
Other (specify):
Pour from container onto screen
surface
Dip rag or brush into container and
wipe screen
Spray on with nozzle from tank
Spray on with spray bottle
Use specialized spraying equipment
(specify)
Other (specify)
Brush
Low pressure
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
water spray
High-pressure
water spray
Water-blaster
Automatic Screen
Cleaning System
Disposable Rag
Reusable Rag
Other (specify):
6. Current Haze Remover Practices
a. Fill in the following information and the table below for each type of haze removal product you currently use:
Trade Name
Generic product description
Average % of screens reclaimed where haze remover is applied:
Volume purchased in 1993 (gal.)
Purchase Price ($/gal.)
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
Personal Protective
Equipment Used
Method of Applying Haze Removal
Product
Equipment or Materials
Used to Remove Haze
Equipment or Materials Description
(Include manufacturer, model #, pressure (psi) and flow rate (gpm) if
applicable, frequency of replacement, equipment energy requirements)
Gloves
Eye Protection
Aprons
Respiratory
protection
Barrier cream
None Used
Other (specify):
Pour from container onto screen
surface
Dip rag or brush into container and
wipe screen
Spray on with nozzle from tank
Spray on with spray bottle
Use specialized spraying equipment
(specify)
Other (specify)
Brush
Low pressure
water spray
High-pressure
water spray
Water-blaster
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
Automatic Screen
Cleaning System
Disposable Rag
Reusable Rag
Other (specify):
7. Materials Storage
a. Where do you store your ink removal and screen reclamation products and in what quantity? Please check one box for each column.
Storage Method
30- or 55-gallon
drum with bung
hole kept open
30- or 55-gallon
drum with bung
hole kept closed
How is ink removal
stored in the
application area?
(check all that apply)
How is ink removal
stored in the storage
room?
(check all that apply)
How is emulsion
remover stored in
screen cleaning area?
(check all that apply)
How is emulsion
remover stored in
storage area?
(check all that apply)
How is haze remover
stored in the
cleaning area?
(check all that apply)
How is haze
remover stored in
storage area?
(check all that apply)
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
30- or 55-gallon
drum with top
removed
Open pail
Closed pail
Quart or smaller
squirt bottle
Safety can
Safety cabinet
Not kept in the
press room
Other (specify)
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
8. Waste Disposal
a. Please indicate the quantity of waste you dispose of annually as hazardous waste for:
spent solvent waste: (gal. in bulk) OR (# of 55 gal. drums)
ink waste: (gal. in bulk) OR (# of 55 gal. drums)
used shop rag waste (gal. in bulk) OR (# of 55 gal. drums)
b. Ink Removal and Screen Cleaning Wastes
Fill in the table below to describe the treatment and disposal methods used for waste (not only
hazardous wastes) generated by the ink removal and screen cleaning/reclamation operations:
Ink Removal Area Wastes
Quantity
Generated
Annually (gal)
Method of
Storage Prior to
Treatment/
Disposal
In closed
containers
In open containers
No specified
container
Other
(specify) :
Method of
Treatment or
Disposal
Filter or treat prior to
disposal or recycle
Send to recycler
Recycle on site
Discharge to sewer
Dispose as hazardous
waste
Dispose as non-
hazardous waste
Other (specify)
Screen Cleaning/Reclamation Wastes
Quantity
Generated
Annually (gal)
Method of
Storage Prior
to Treatment/
Disposal
In closed
containers
In open
containers
No specified
container
Other
(specify) :
Method of
Treatment or
Disposal
Filter or treat
prior to disposal
or recycle
Send to recycler
Recycle on site
Discharge to
sewer
Dispose as
hazardous waste
Dispose as non-
hazardous waste
Other (specify)
9. Drying
a. Are screens dried between ink removal and emulsion removal?
- If yes, how are they dried? (air dried or dried with equipment such as fans, heater, etc.) - If
drying equipment is used, note:
- Duration of drying step:
- Manufacturer and model of the equipment:
- Energy use specifications:
DRAFT—September 1994
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APPENDIX F. SCREEN PRINTERS TECHNICAL FOUNDATION (SPTF) TESTING METHODOLOGY
b. Are screens dried between emulsion removal and haze removal?
- If yes, how are they dried? (air dried or dried with equipment such as fans, heater, etc.)
- If drying equipment is used, note:
- Duration of drying step:
- Manufacturer and model of the equipment:
- Energy use specifications:
DRAFT—September 1994
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Appendix H
Observers' Evaluation Sheet
This Appendix provides a reproduction of the blank evaluation sheet filled out
by the observers during the screen reclamation products performance demonstration.
DRAFT—September 1994 H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
Observer's Evaluation Sheet
Screen Reclamation Products Performance Demonstrations
Facility name:
Date: Time:
Location:
Facility contact name/phone:_
Screen reclamation employees(s):_
1. Type of Demonstration:
check one: Products curently used at facility
Alternative Products
2. Operating Conditions
Record the information on the screen being cleaned on the table below:
Screen Information
SCREEN CONDITION
Screen
identification and
history
Screen size
Number of
impressions of the
screen's last run
Screen degreaser
Ink type
Fill in the blank or circle the appropriate characteristic.
notes or comments in the spa.ce to
Enter the identification marking
the right.
Make any
code that is on the screen:
Estimate the number of impressions printed over the
screen:
Estimate how much ink was left
avg.)
X
life of this
on the screen? (< avg., avg., >
(specify units; in2
or ft?)
Specify manufacturer and series # or name:
Circle one:
Solvent-based, UV, or
water-based
DRAFT—September 1994
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APPENDIX F. OBSERVERS' EVALUATION SHEET
Observer's Evaluation Sheet
Screen Reclamation Products Performance Demonstrations
Specify manufacturer and series # or name:
Ink color
Circle one:
Blue, Black, Other (specify):
Emulsion type
Circle one:
Capillary film, Direct photo stencil, Dual cured, Other
(specify):
Specify manufacturer and series # or name:
Ink coverage
Check one:
0 - 25%... 25 - 50%... 50 - 75%... 75
100%...
Screen condition
Note any rips, holes, corrosion
Screen mounting
Is a retensionable frame used?
Is the screen glued to the frame?
Thread count
Thread diameter
threads/inch
(specify units)
Tension level
(measure both major
axes; specify units)
major axis:
minor axis:
N/cm
N/cm
Mesh type (record
type of mesh material)
Mesh treatment (has
DRAFT—September 1994
H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
the mesh been
abraded? calendared?
or treated?)
Calibration of
measurements
Temperature (in the
work area)
Humidity (in the work
area)
scoop(s) of haze remover = ounces
Ink removal area: F
Emulsion/ Haze removal area: F
Ink removal area: %
Emulsion/Haze removal area: %
3. Cleaning Procedure
Clean the screen using the application technique designated by SPTF for alternative
products or follow your typical screen reclamation procedure if demonstrating the
currently used products.
Observe all actions taken by the employee in reclaiming the screen and record any
differences between the technique used and the technique specified by SPTF for
alternative products or the technique documented in the facility questionnaire for
products currently used at the facility.
Cleaning Procedure:
For currently used products, are any variations of the reclamation procedure used, and
if so, under what circumstances? For what percentage of screens, or how often are these
method variations used?
Describe any temperature or humidity controls in the ink removal or reclamation area.
DRAFT—September 1994
H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
4. Performance
Complete the performance evaluation table on the next page for alternative products and
for currently used products.
Performance Evaluation
Enter quantity, comments, and notes
Drying Time
(specify units; hours or
mins.)
Time from end of press run to start of ink removal with
product:
Time from ink removal completed to start of emulsion
removal:
Time from emulsion removal completed to start of haze
removal:
Dilution
(record dilution ratio or
enter "None")
Ink Remover
Emulsion Remover
Haze Remover
(enter ratio) or "none"
(enter ratio) or "none"
(enter ratio) or "none"
Quantity of Product
Used
Ink Remover
Emulsion Remover
Haze Remover
scoops)
(enter # of ounces)
(enter # of ounces)
(enter # of ounces or
Time to clean
(do not include screen
positioning or
equipment clean up
time)
Ink Remover
Emulsion Remover
Haze Remover
minutes
minutes
minutes
Physical effort
required
(circle one for each step
and describe effort
used)
Ink Remover:
circle one: Low, Moderate, High. Describe:
Emulsion Remover:
circle one: Low, Moderate, High. Describe:
DRAFT—September 1994
H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
Haze Remover:
circle one: Low, Moderate, High. Describe:
If wipes were used for
ink removal, specify
the type, size and
quantity used.
Was a pressure
washer used? (check
one for each step)
For Ink Removal:
No Yes (specify length of time used
mins.)
For Emulsion Removal:
No Yes (specify length of time used
mins.
For Haze Removal:
No Yes
mins.)
(specify length of time used
Was tap water (NOT
pressure wash) used
in any part of screen
cleaning/reclamation
Was (non-pressurized) water used in (check all that apply):
Ink Removal... or Emulsion Removal... or Haze
Removal...
Flowrate:
(gallons/minute)
Length of time used:
or minutes)
(specify seconds
Examine screen after
ink removal.
Did the product effectively and easily remove the ink? Also
note any side effects of the product on the mesh):
Examine screen after
emulsion removal.
Is there any ink haze or stencil stain on the mesh? If so,
describe in detail:
If any emulsion is still present, describe the residue left on
the screen in detail:
DRAFT—September 1994
H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
Note any side effects on the screen (e.g., mesh damage,
corrosion, etc.)
Examine screen after
reclamation is
complete.
Can the screen be reused for all jobs? (check one) Yes
No
If "No", describe why the screen cannot be reused or what
limitations apply:
(e.g., Is there is a ghost image? Can the screen be used for
reverse printing? for close tolerance work? Can
transparent inks be used with it?)
Remeasure the
screen tension of
both major axes and
record (specify units)
major axis:
minor axis:
N/cm
N/cm
Examine the
substrate image after
the screen is reused.
Comment on the
print image quality.
Comments or suggestions - Use the back of this sheet to note anything unusual
about this demonstration, (e.g., did you have to reapply any of the products? was this
screen more difficult to clean than others?)
5. Experience with Alternative Screen Reclamation Products
a. Have you tried any alternative chemical products to replace your current screen
reclamation products?
- If yes, please list the product trade name(s) and the generic product type(s):
- Why were the alternative product(s) better, the same, or worse than your old
product?
- If you have not tried a different chemical product, please check the box that best
DRAFT—September 1994
H
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APPENDIX F. OBSERVERS' EVALUATION SHEET
describes your reason for not trying alternatives:
Lack of adequate information to evaluate environmental performance:
Operators do not believe alternatives will work:
Not impressed with product descriptions:
Cost is prohibitive:
Other: (please explain):
b. Besides alternative chemical products, have you implemented any changes in
equipment, procedures or work practices that reduced your use of screen reclamation
chemicals, or reduce the time, effort or water required to use those products? Yes
No
- If yes, please describe:
c. Does this facility have a pollution prevention, waste minimization, or source
reduction program?
- If yes, please describe:
DRAFT—September 1994 H
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Appendix I
Ink Remover Evaluation Sheet for Printers
This Appendix provides a reproduction of the blank evaluation sheet used by
printers to assess the effectiveness of ink removal products during the on-site
performance demonstration.
DRAFT—September 1994
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APPENDIX I. INK REMOVER EVALUATION SHEET FOR PRINTERS
INK REMOVER EVALUATION SHEET Evaluation #_
Facility name and location:
Date:
Time:
Ink Remover employee's name:
Fill in the blank or circle the appropriate characteristic.
Make any notes or comments in the space to the right.
Screen Condition
Screen identification and
history
Enter the identification marking (tracking) code for the
screen:
Estimate how much ink was left on the screen?
Screen size
inches x
inches
Screen condition and threads
per inch
Note screen condition including any rips, holes, corrosion:
Record the screen mesh size:
threads/inch
Mesh
(Record mesh material type and
type of mesh treatment, (e.g.,
abraded, calendared, etc.) if any)
Mesh type:
Mesh treatment:
Number of impressions of the
screen's last run
Circle one:
Ink type
Solvent-based, UV, Water-based
Specify manufacturer and series #:
DRAFT—September 1994
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APPENDIX I. INK REMOVER EVALUATION SHEET FOR RINTERS
INK REMOVER EVALUATION SHEET
Ink color
Blue, Black, Other (specify):
Emulsion type
Circle one:
Capillary film, Direct photo, Dual cure,
Specify manufacturer and series #:
Check one:
100%...
25-50%... 50-75%.
Time between end of press run and start of ink removal with
(hours or
Performance
Ink Remover Dilution
(enter ratio) or
Quantity of Ink Remover Used
oz.
(enter time from
application of ink remover
the next step)
Note: Do not include screen positioning or clean up time.
mins.
Physical effort required
Low, Moderate, High
DRAFT—September 1994
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LINK EMOVERE
SHEET ORP
INK REMOVER EVALUATION SHEET
Evaluation #
How many wipes did you use?
Was a pressure washer used?
Examine screen after ink
removal.
(check one) Yes No
Did the ink remover effectively and easily remove the ink?
(Also note any side effects of the product on the screen)
Comments or suggestions - Record any comments and note anything unusual about the
reclamation on a separate sheet of paper, (e.g. , did you have to reapply the product? why was
the screen hard to clean?)
-------
Appendix J
Emulsion Remover and Haze Remover Evaluation Sheet
This Appendix provides a reproduction of the blank evaluation sheet used by
printers to assess the effectiveness of emulsion removal products during the on-site
performance.
DRAFT—September 1994
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APPENDIX I. INK REMOVER EVALUATION SHEET FOR PRINTERS
EMULSION REMOVER AND HAZE REMOVER EVALUATION SHEET
Evalulation #
Facility name and location:
Date:
Time:
Screen Reclamation employee's name:
Fill in the blank or circle the appropriate characteristic.
Make any notes or comments in the space to the right.
Screen Tracking
Screen identification
Enter the identification marking (tracking) code for the
screen:
Performance
Drying Time
(Specify units; hours or mins.)
Time from ink removal completed to start of
emulsion removal:
Time from emulsion removal completed to start of
haze removal:
Dilution
Emulsion Remover
Haze Remover
none
(ratio) or none
(ratio) or
Quantity of Product Used
Enter # of ounces used:
Emulsion Remover
ounces
Enter # of ounces used:
Haze Remover
ounces
DRAFT—September 1994
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APPENDIX I. INK REMOVER EVALUATION SHEET FOR PRINTERS
EMULSION REMOVER AND HAZE REMOVER EVALUATION SHEET
Evalulation #
Product Use Time (enter time from
application of product until screen is
ready for the next step)
Emulsion Remover
Haze Remover
nuns.
nuns.
Was a pressure washer used?
For emulsion removal? (check one) Yes
No
For haze removal? (check one) Yes
No
Physical effort required
(circle one for each step and describe
the level of effort)
Emulsion Remover:
circle one: Low, Med., High; Describe if the stencil
dissolved easily or slowly, and if a great deal or very little
scrubbing took place:
Haze Remover:
circle one: Low, Med., High; Describe the effort
reqiredfor haze removal:
Examine screen after emulsion
removal.
Is there any ink haze or stencil stain on the mesh? If
so, describe:
If any emulsion is still present, describe the residue
left on the screen in detail:
DRAFT—September 1994
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APPENDIX I. INK REMOVER EVALUATION SHEET FOR PRINTERS
EMULSION REMOVER AND HAZE REMOVER EVALUATION SHEET
Evalulation #
Examine screen after reclamation
is complete.
Can the screen be reused for all jobs? check one: Yes
No
If "No", describe why the screen cannot be reused:
(e.g., Is there is a ghost image? Can the screen be used
for reverse printing? Can it be used for close tolerance
work? Can transparent inks be used with it?)
Examine the substrate image after
the screen is reused. Comment on
the print image quality.
Comments - Record any comments and note anything unusual about the reclamation on a
separate sheet, (e.g., did you have to reapply the product? why was this screen more difficult to
clean?)
DRAFT—September 1994
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Appendix K
Weekly Follow-up Call Guidance
This Appendix provides a reproduction of the blank form, used by observers to record
their weekly calls to the printers participating in the on-site performance demonstration.
DRAFT—September 1994 K
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APPENDIX K. WEEKLY FOLLOW-UP CALL GUIDANCE
Weekly Follow-up Call to Screen Printers
in the DfE Performance Demonstration Project
Once a week, the observer will contact the facility by phone. This form is to guide the conversation,
but let the printer discuss any problems, changes or concerns. Remind them to send in the
envelope with this week's forms.
1. In your opinion, is the performance of the alternative products better, worse or about the same
as the products you used before this demonstration? Why?
2. Have you found any conditions where the products did not work? (e.g., is there any ink type or
emulsion type where the product did not work?) If so, describe the condition(s).
3. Have you found any conditions (ink type, emulsion type, etc.) where the products work
particularly well? If so, please describe the condition(s).
4. Have you changed the application procedure in any way to improve product performance? If so,
please describe. For example,
do you apply the product to the screen sooner?
do you let the product sit/ soak on the screen longer?
have you used a different type of brush? or scrubber? or wipe?
5. Have you tried any different application techniques that did not improve performance?
What did you change?
Why did you make the change?
Was product performance worse after the change? How?
DRAFT—September 1994 K
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APPENDIX K. WEEKLY FOLLOW-UP CALL GUIDANCE
6. Have you changed the quantity of product you use? Why?
7. How are you timing how long you use each product? (i.e., are you estimating the time or are you
actually timing it?)
8. What measurement method are you using? Are you still using the same spray bottle and the
same scoop provided?
9. Do you think the screen failure rate has increased, decreased or remained the same as a result
of using the new product? What signs have you seen that suggest the failure rate may differ?
10. Do you have any other comments, concerns or problems regarding the alternative products?
DRAFT—September 1994 K
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Appendix L
Screen Printing Performance Demonstration Methodology
Note: This methodology incorporates comments from discussions with the Screen
Printing Technical Foundation, the Screen Printing Association International,
screen printers, and manufacturers and suppliers of screen reclamation products
and equipment.
Performance Demonstration Overview
Goal
The objective of this performance demonstration is twofold: (1) to obtain
specific information from printing facilities concerning the performance of
commercial chemical and mechanical screen reclamation systems; (2) to encourage
printers to experiment with new products and work practices that reduce human
health and environmental risk. This data will be incorporated into the Cleaner
Technologies Substitutes Assessment.
General Plan
The majority of printers participating in the performance demonstration will
evaluate the effectiveness of one manufacturer product line/system for screen
reclamation, using a method that includes the use of ink remover, emulsion
remover and haze remover products in screen reclamation. Each facility will be
responsible for reclaiming screens over a thirty-day period, utilizing the specified
product system. The performance of one or two substitution processes relying on
specially equipped mechanical and/or chemical reclamation cleaning systems will
be demonstrated, including: (1) high-pressure water blaster; (2) sodium
bicarbonate reclaim system.
Desired Characteristics to be Reported from Performance Demonstrations
Actual cost of chemical product or reclamation equipment
Definition: Cost per volume used per area of screen cleaned (ft2).
We will ask that product manufacturers include the average purchase price of
their individual products (haze remover, stencil remover, ink remover, reclamation
equipment) when the product/equipment is submitted for the performance
demonstration. The adjusted or actual cost of screen reclamation products will be
determined through incorporation of product purchase price, product application cost,
labor costs, and safety and disposal costs.
Product constraints
Example: Whether the product category (e.g. ink remover) is incompatible
with certain types of inks
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
This information should be submitted by the manufacturers and may also
be discovered as a result of the performance testing. If the manufacturer does not
provide any information regarding product incompatibilities, we will assume that
there are no incompatibility concerns.
Special storage, safety and disposal requirements
Examples: Flammability or volatility of the product
This information will be requested on the manufacturer questionnaire and
will vary according to the chemicals comprising the products/equipment to be
submitted. We will ask that manufacturers provide recommendations on disposal
or treatment of wastes associated with the use of their products. The storage costs
will be a factor in determining the adjusted cost of the product.
Ease of use
Definition: The physical effort required to effectively clean the screen using
the test product
This is a subjective standard based on the judgment of the screen cleaner
and printer. As a frame of reference, the screen reclamation employee or facility
point-of-con tact will be asked to describe their current work practices for screen
reclamation and the physical effort required with their current system. When the
performance information is tabulated for each manufacturer system demonstrated
at a facility, the data regarding the products currently used at the facility will also
be noted.
Duration of the Cleaning Cycle
Definition: The measured time of the screen cleaning process (e.g. beginning
with the application of ink removal product to the screen until the final water wash
is completed)
This will attempt to measure the labor costs associated with the use of the
products. Labor costs will be based on the time required for the screen reclamation
with the specific products and a standard screen cleaning wage.
Physical/Chemical properties of the screen reclamation system
Definition: Characteristics associated with use of the individual system,
such as chemical components or pressure at which chemicals are applied.
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
The chemical components of each product system must be submitted by
each manufacturer participating in the demonstration project. The physical
characteristics of each system as used, including such factors as water pressure
as applied and type of specialized equipment used, will be documented.
Effectiveness of the screen reclamation system
This is a subjective criteria and depends on the judgment of the printer and
the employee reclaiming screens at the facility. They will examine the screen after
the reclamation process is complete and answer two questions: (1) Can this screen
be reused for general screen printing purposes?; (2) Can this screen be used to
print a reverse image? These questions will not be answered solely on the basis of
the screen appearance. When the screen is reused for printing, any problems with
ghost images or weak screens will be documented.
Screen, stencil and ink information
The majority of screens reclaimed in the demonstration project should have
a monofilament polyester mesh with a nominal thread count in the range of 230-
390 Me/in. However, if the screen mesh thread count is outside of this range, the
data will be documented. Data recorded for each screen reclaimed should include
threads per inch, the age of the screen and the prior printing history of the screen.
The length of time between the end of the press run and the actual screen
reclamation should be estimated. The color and type of ink, and the type of
emulsion will also be reported. If possible, the tension level (N/m) of the screen
should be recorded. The condition of the screen (rips, tears) before and after the
test will be reported. The printing performance of the screen after it has been
reclaimed will also be documented. This descriptive information serves two
purposes: (1) it provides data to determine the specific effectiveness of the methods
and various product lines; (2) it may assist in discovering and reporting
incompatibilities between the products and types of inks and emulsions.
Methodology For On-Site Performance Demonstration
Selection of Products for the Performance Demonstration
O Products will be submitted by manufacturers in two shipments. One shipment
of screen reclamation products, in bucket containers with manufacturer labels,
will be sent to SPTF/SPAI, along with a standard OSHA MSDS; the quantity
shipped should be sufficient to clean 3 screens of 10 ft2 each. The
manufacturer will also ship to SPAI a quantity of product necessary to reclaim
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
50 screens at the volunteer printing facility. SPAI will determine the quantity
required for each site and notify the manufacturer prior to shipment.
O SPTF will determine the effectiveness of all of the products submitted. This will
include evaluating the standard manufacturer instructions for each product
and ensuring that the application technique specified for that product will
enable the product to work effectively. Any instructions for an individual
product pertaining to dilution or mixing will be followed. If the application
technique specified for a particular product is determined to limit the
effectiveness of the product or in any other way negatively affect performance, a
second application technique will be chosen and tested.
O The effectiveness of each product system will be tested with up to three
different ink types (solvent-based, UV-cured, and water-based), depending on
the recommendations of the manufacturer. The specific methodology for the
SPTF testing is detailed in a separate document (see Appendix G). Only
products deemed effective by SPTF will be used in the field demonstration
portion of the project.
O The selection of printers will take into account the type of inks primarily used
and any specialized application equipment. SPAI will match printers with
appropriate screen reclamation products. The in-field demonstrations will only
include screens on which solvent-based or UV inks have been used. However, if
screens on which water-based inks have been used are reclaimed with the
product system, the data will be documented.
O After SPTF has completed the initial screening of the effectiveness of products,
SPAI will ship the screen reclamation products to the screen printers
participating in the field demonstrations. Products will be packaged in generic
containers (no screen product manufacturer markings). The printer will receive
the masked product that has a masked OSHA MSDS and a generic label. For
all other aspects of the demonstration project, products will be identified only
by a letter code.
Documentation of Standard Work Practices at Facility
O The observer will visit the facility and explain the project thoroughly to both the
facility point-of-contact, and employees involved in printing and screen
reclamation. Prior to the observer's visit, the facility will have received a Facility
Background Questionnaire. When on-site, the observer will verify that this
questionnaire has been accurately completed. Information categories on the
questionnaire include: 1) general facility operations (types of products, number
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
of employees), 2) screen reclamation operations (equipment used, number of
screens reclaimed), 3) current reclamation products (application procedures,
trade names), 4) storage and disposal practices.
O The observer will verify the questionnaire and document any other relevant
information on the general facility operations. Recorded information will
include the types of products printed, the printing substrates, the typical run
length, and the water, sewer, and electric rates for the facility.
O The observer will verify the questionnaire and document any other relevant
information on the screen reclamation operations. The observer will
document the size and general specifics of the screen reclamation area(s),
including the type of ventilation. The observer will also briefly describe the
experience of the employee(s) participating in the test, including past
experiences with testing of screen reclamation products, and document any
potential biases.
O The observer will verify the questionnaire and document any other relevant
information on the facility's current reclamation products. The observer will
record the trade name and purchase price of the current screen reclamation
products. The observer will document the current work practices by observing
screen reclamation utilizing the present method and products used by the
facility. The specifics of the screen to be cleaned, such as threads per inch, ink
type, color of ink, emulsion type, age, size, tension level and printing history
(including estimated time between the end of the press run and reclamation),
will be recorded. The physical condition of the screen (small rips, etc.) will be
documented before and after the reclamation. The observer will note any pre-
application dilution of the product. The observer will measure the quantity of
each product applied to the screen and record the time required for each
cleaning step, and the overall cleaning of the screen, from application of the ink
remover product to the final water wash.
O The observer will verify the questionnaire and document any other relevant
information on the facility's storage and disposal practices. The observer will
note how the products are stored in bulk and in the screen reclamation area.
The current waste and rag disposal practices and costs will be documented by
the observer.
Phase I: Initial Demonstration and Evaluation at the Printing Facility
O The employee involved in the performance demonstration will prepare to clean
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
one screen using the masked products supplied for the ink removal, emulsion
removal and haze removal steps. The employee will use the application
technique designated by SPTF for each product. Prior to the reclamation
process, the observer will document any pre-application dilution of the
products that is necessary. The observer will note all characteristics of the
screen as outlined in B.4.
O The employee will begin screen reclamation. The observer will record the
quantity of each product that is applied to the screen. The observer will record
all actions taken by the employee in reclaiming the screen to ensure adherence
to any specific instructions. The observer will time the entire process, from the
application of the ink remover to the final water wash.
O The observer will record the effectiveness of the product system in reclaiming
the screen, based on visible appearance and the judgment of the printer and
the screen cleaning employee. The observer will ask if the screen can be used
again for printing and if there are any printing limitations, such as whether it
can be used to print a reverse. After the screen is used again for printing, any
problems with the screen, such as ghost images or damaged mesh, will be
documented by the printer.
O A second and third screen will then be cleaned using the same method. The
observer will follow the process outlined in steps 1-3. The purpose of cleaning
three screens is to ensure that the screen cleaning employee is familiar with the
cleaning method and products, before beginning longer-term testing.
Phase II: Further Demonstration of System Effectiveness at the Printing Facility
O After completion of the above demonstration, the screen reclamation
performance demonstration will continue to be performed by the facility
through the next thirty days. The masked products supplied by the
manufacturer will be used to reclaim these screens. The observer will not be
present during this phase of testing. The employee responsible for screen
reclamation will record the characteristics of each screen cleaned (see B.4.), the
volume of product used for each step in the process, and the effectiveness of
the manufacturer system in reclaiming the screen (taking into account future
printing performance of each screen). To simplify this process, a short
evaluation sheet will be used.
O During the thirty day demonstration period, the observer will interview the
facility contact every week over the telephone to document facts or perceptions
concerning the reclamation process that could be helpful in determining the
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APPENDIX L. SCREEN PRINTING PERFORMANCE DEMONSTRATION METHODOLOGY
effectiveness of the products used. The observer will determine if there has been
any deviation from the initial reclamation procedures. If there has been a
deviation, the observer shall record the reasons for the deviation. A work sheet
will be developed that will guide the observer through the questions they should
ask. The observer will document each conversation on the work sheet, which
will subsequently become the telephone log for the facility.
O If at any time during the long-term phase of the demonstration there is a
problem, the screen reclamation employee or facility point of contact will
document the specific problem and call SPTF for guidance. Any corrective
action will be documented by both the industry specialist and the facility
employee.
Trouble-shooting
O If problems arise during the field demonstration of the screen reclamation
methods and products, the following procedures will be followed. If the observer
is present, the problem will be documented and the observer will call
SPTF/SPAI for guidance. If the observer is not present, the facility employee will
document the problem and contact SPTF/SPAI.
O SPTF will first review the procedures used by the facility employee to ensure
they are in compliance with the instructions provided with the product. If the
procedures are correct, then SPTF will contact the manufacturer for assistance.
SPTF will relay and filter the recommendation of the manufacturer to the
printer. SPTF/SPAI will ensure the confidentiality of the products is maintained
during this period. The identity of the product in the field will remain masked.
The observer will document all actions taken.
O If the recommendations provided by SPTF/SPAI are unsuccessful, the facility
employee can attempt to solve the problem. The observer will document the
actions taken by the employee responsible for screen reclamation and the
success or failure of the actions.
O If a medical emergency arises, CHEMTREC, the emergency response center of
the Chemical Manufacturers Association, has volunteered to respond to
emergency phone calls to the manufacturer by identifying masked products
with chemical components and providing medical information. The phone
number for CHEMTREC will be the emergency phone number listed on the
MSDS.
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Appendix M
Ecological Hazard Profile Methodology
The environmental hazard assessment of chemicals consists of the
identification of the effects that a chemical may have on organisms in the
environment. And overview of this assessment process has been reported by
Zeeman and Gilford (1993a). The effects are expressed in terms of the toxicity
of a chemical on the organisms and are generally given as the effective
concentration (EC) that describe the type and seriousness of the effect for a
known concentration of a chemical. When the effective concentrations for a
range of species for a chemical is tabulated, the tabulation is called a Hazard
Profile or Toxicity Profile. A more detailed discussion of a comprehensive
hazard profile has been presented by now blahs, 1991. The most frequently
used hazard profile for the aquatic environment consists of six effective
concentrations as reported by Nabholz, et al., (1993 a). These are:
O A Fish Acute Value (usually a fish and 96-hour LCso value)
O An Aquatic Invertebrate acute value (usually a Daphnid 48-hour LCso
value)
O A Green Algal Toxicity value (usually an Algal 96-hour ECso value)
O A Fish Chronic value (usually it fish 28-day chronic value (ChV))
O An Aquatic Invertebrate Chronic value (usually a Daphnid 21-day ChV
value)
O An Algal Chronic value (usually an Algal 96-hour NEC value for
biomass)
For the acute values, the LCso (mortality) (ECso) (effects) refers to the
concentration that resulted in 50% of the test organism's affected at the end of
the specified exposure period, the chronic values represent the concentration
of the chemical that results in no statistically significant effects on the test
organism following a chronic.
The hazard profile can be constructed using effective concentrations
based on toxicity test data (measured) were estimated toxicity values based on
structure activity relationships (SARs). The measured values are preferred, but
in the absence of test data SAR estimates, if available for the chemical class,
can be used. Thus the Hazard Profile may consist of only measured data, only
projected values, or combination of both. Also, the amount of data in that has
a profile may range from a minimum of one acute or chronic in value to the full
complement of three acute values and three chronic the values.
In the absence of measured toxicity values, estimates of these values
can be made using the Structure Activity Relationships (SAR). But SAR
methods include Quantitative Structure Activity Relationships (QSARs),
qualitative SARs or use of the best analogue. The use of SARs buying OPPT
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APPENDIX M. ECOLOGICAL HAZARD PROFILE METHODOLOGY
has been described (Clemens, 1988, et al., 1994 in Press). The use and
application of the QSARs for the hazard assessment of new chemicals have
been presented (Clemens, et al., 1993a). The development, validation and
application of SARs in OPPT have been presented by OPPT staff (Zeeman, et al.,
1993; Boethling, 1993; Clemens, et al., 1993b; Nabholz, et al., 1993b;
Newsome, et al., 1993 and Lipnick, 1993).
The predicted equations (QSARs) are used in lieu of test data to
estimate a toxicity value for aquatic organisms within a specific chemical class.
Although the equations are derived from correlation and linear regression
analysis based on measure data, the confidence interval associated with the
equation are not used to provide a range of toxicity values. Even with measure
test data the use of the confidence limits to determine the range of values is not
used.
Determination of concern concentration
Upon completion of a hazard profile, it concern concentration is determined. Is
concerned concentration is the concentration of the chemical in the aquatic
and garment which, if exceeded, because is significant risk. Conversely, if the
CC is not exceeded, the assumption is made that probability of a significant
risks occurring is low and no regulatory action is required. The CC for each
chemical is determined by applying assessment factors to the effect
concentrations in the hazard profile.
Assessment factors incorporate the concept of the uncertainty associated with
(1) toxicity data; laboratory tests versus field test and measured versus
estimated that and (2) species sensitivity. For example, if only a single LCso
value for a single species, is available, but there several uncertainties to
consider. First, how good is the value itself? If the test were to be done again
by the same laboratory or a different laboratory, with the value defer? Second,
there are differences and sensitivity, and between species that have been
considered. Is the species tested the most or the least sensitive? In general, if
only a single toxicity value is available, there is a large uncertainty about the
applicability of is valued to other organisms in the firm in and large assessment
factor, that is, 1000, is applied to cover the breath of sensitivity known to exist
among and between organisms in the garment. The mercy, the more
information than is available results in more certainty concerning the toxicity
values and requires the use of a smaller assessment factor. For example, if
toxicity values are derived from field tests, then an assessment factor on one is
used.
Four AsFs are used by OPPT to set a CC for chronic rest: 1, 10, 100, and 1000.
The AsFs rule use is dependent on the amount and type of toxicity data
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APPENDIX M. ECOLOGICAL HAZARD PROFILE METHODOLOGY
contained in the hazard profile and reflects the amount of uncertainty about
the potential effects associated with a toxicity value. In general, the more
complete the hazard profile and the greater the quality of the toxicity data, is
smaller factor is used. Following discussion describes the use application of
the assessment factors:
1. If the hazard profile only contains one or two acute toxicity values, the
concern concentration is set at 1/1000 of the acute value.
2. If the hazard profile contains three acute values (base set), the concern
concentration is set at 1/100 of the lowest acute value.
3. If that has a profile contains one chronic value, but concerned
concentration is set at 1/10 of the cup chronic value of the value is for
the most sensitive species. Otherwise, it is 1/100 of the acute value for
the most sensitive species.
4. If the hazard profile contains three chronic values, the concern
concentration is set at 1/10 of the lowest chronic value.
5. If the hazard profile contains a measure chronic value from the field
study, then an assessment factor of 1 is used.
Hazard Ranking
Chemicals can also be ranked aCCording to hazard concern levels for the
aquatic environment. This ranking can be based upon the acute toxicity values
expressed in milligrams per liter (MG/L). The generally aCCepted scoring is as
follows:
High concern (H) D 1
Moderate concern (M) > 1 and < 100
Low concern (L) > 100
The ranking can also be expressed in terms of chronic values as follows:
High concern (H) D 0.1
Moderate concern (M) > 0.1 and < 10.0
Low concern (L) D 10.0
Chronic toxicity ranking takes precedence over the acute ranking.
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