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United States
Environmental Protection
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Pollution Prevention
and Toxics
(7406)
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=PA744R-94-005
eptember 1994
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*^& Cleaner TechnologieL
4 Substitutes Assessment
Executive Summary
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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
September 1994
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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
iv
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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 Bolding, 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 Bolding
(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 Teclmology, Inc.
1170 North Airmando 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
BurnsvUle, 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
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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., WilsonviUe, 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
VI
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Paul Quillen
Paul Randall
Heidi Siegelbaum
Chemical Engineering Branch, Economics, Exposure and
Technology Division, OPPT
Office of Research & Development, Cincinnati, Ohio
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-211 A)
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
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DRAFT—September 1994
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labile Of Contents
Section Page
Disclaimer iv
Acknowledgements v
Executive Summary ES-1
Structure of the CTSA ES-2
Profile of Screen Reclamation Use Cluster ES-2
Screen Reclamation Methods ES-2
Alternative Cleaning Processes ES-4
Chemical Profiles ES-4
Methodologies ES-5
Performance Demonstration Methodology ES-5
Chemical Usage Methodology ES-6
Cost Analysis Methodology ES-6
Functional Groups in Screen Reclamation ES-7
Substitute Comparative Assessment of Screen Reclamation Systems ES-7
Method 1 ES-8
Method 2 ES-8
Method 3 ES-8
Method 4 ES-8
Automatic Screen Washer ES-8
Screen Disposal as a Method of Pollution Prevention ES-9
Summary of Risk Conclusions ES-10
Performance and Cost Summary ES-10
Overall Pollution Prevention Opportunities in Screen Reclamation ES-11
Pollution Prevention Through Improved Workplace Practices ES-11
Pollution Prevention Through Equipment Modifications ES-13
Social Cost/Benefits of Alternative Screen Reclamation Processes ES-13
Energy and Natural Resource Considerations ES-14
Social Costs/Benefits Analysis ES-15
Conclusion ES-16
DRAFT-September 1994
IX
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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 indus,try 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 huma Ji 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 compsired. 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. i
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, and technologies so that businesses can make more informed
DRAFT-September 1994 ES-1
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
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 a particular product system, consisting of an ink remover, emulsion remover arid haze
DRAFT-September 1994 ~ ~^ ' .
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
DRAFT—September 1994
ES-3
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
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 screen printing industry identified seventy-two chemicals that are in use in screen
DRAFT—September 1994 ES-4
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
•executive Summary
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 fuH 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 fgr11 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; s > .-,..>. • -.-
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 arid
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.
j • ' '.' '
Cost Analysis Methodology' .'!,","" i
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 scre,en 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 in? 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 15 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 haz-ard rankings), purchase
cost, occupational exposures and risk conclusions, environmental releases and population
exposure conclusions. A process safety hazard evaluation was not :lnclu
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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.
Methods
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
mesh surface within a fully enclosed unit. The system can be selective, in that it can be used
DRAFT—September 1994 ES-8
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING ^
Executive Summary .
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
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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
o
Estimated worker dermal exposures to traditional and alternative screen :
reclamation products can be high if proper protective clothing is not worn.
All of the traditional products presented clear concerns for both inhalation
exposures and unprotected dermal exposures to workers.
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.
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.
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.
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. j
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 •_-^BB.—0^—
Executive Summary , •• r • _ • '
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
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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)
Methdd 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 title 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/benefits 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 chemical? 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
oh the screen
Recovers solvent for reuse
Captures chemical qverspray 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
CTSA 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 then: screens. The data collected during
the performance demonstration did not allow for clearcut extrapolation because of the variety
of conditions present m screen printing shops. As a result, quantitative analysis was not
DRAFT—September 1994
ES-14
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
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Executive Summary
possible. Summarized below are some of the,areas where energy,and. aatural resources may
be consumed as a result of the screen reclamation process.
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 washed may require more
energy than a non-pressurized water wash.
o Also during a water wash, the use of hot or. warm ;wateir 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 , v
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.
-:'.- ' . i ' . -
The risk assessment conducted as a partjof 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 us'ed 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 sc)cial cost/benefits ;
analysis compares in .general terms the costs and benefits (in terms of ireduced 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. . f ' :'
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. • ' :
DRAFT—September 1994 ES-15
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CLEANER TECHNOLOGIES SUBSTITUTES ASSESSMENT FOR SCREEN PRINTING
Executive Summary
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
traditional products. Rather the labor costs tended to depend on the mix of
chemicals and technologies (i.e., high pressure sprays) selected.
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.
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).
For all systems overall, alternative products are estimated to be less costly than
traditional systems depending on the technologies used (see table ES-1).
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
theCTSA. . ,
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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