®EPA
United States
Environmental Protection
Agency
Pollution Prevention
and Toxics
(7406)
EPA744R-94-005
September 1994
A/ | Cleaner Technologies
Substitutes Assessment
0s v
ERA
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
(Xy Recycl»d/Recyclablo
Primed with Soy/Canola Ink on paper that
contains at least 50% recycled fiber
-------
% Cleaner Technologies
Substitutes Assessment
EFA
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
-------
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—Sspt§mb«r 1994
iv
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Preface
The Cleaner Technologies Substitutes Assessment (CTSA) Is an analytical tool
developed by the Design for the Environment (DfE) Program at the U.S. Environmental
Protection Agency for use by industry. The CTSA Is intended to provide a flexible format for
systematically comparing the trade-off issues associated with traditional and alternative
products, processes and technologies. For each product, process or technology, the trade-offs
such as cost and performance are combined with environmental concerns, such as
comparative risk, environmental releases, energy impacts and resource conservation. The goal
of the CTSA is to offer a complete picture of the environmental impacts, cost and performance
issues associated with each option in order to allow for an informed decision about which
alternative is best for a particular situation. While a CTSA is a repository for all technical
information developed about a use cluster (in this case, screen reclamation), it is not intended
as a guidance document for easily enabling a small businessperson to make decisions. This
document could be used by technically Informed decision makers. For screen printing, user-
friendly information products based on the technical information in the CTSA will be developed
and disseminated to workgroup members, screen printers and other interested parties. These
information products may include case studies, data matrices, teleconferences, guidance
manuals, training videos and cost accounting methods geared toward screen printers.
The CTSA for Screen Printing Screen Reclamation Is one of the first two CTSAs
developed by the DfE program. Because this CTSA is Intended to serve as a model for future
CTSA documents, we have attempted to be more thorough and in-depth in the outline and
substance of the document than may be the case in future documents. This draft version
reflects the style, format and substance for the final CTSA document.
The CTSA for Screen Printing Screen Reclamation focuses on the use cluster of screen
reclamation, which is a process, rather than a specific set of chemicals or technologies.
Because screen reclamation Is a process and can be performed using several methods and
many different chemical products, the individual aspects of the process must be defined and
evaluated prior to comparing the trade-offs associated with each screen reclamation method.
The approach used In this CTSA could be viewed as a tiered or hlerarchial approach. The first
tier or step in evaluating the screen reclamation process is to define and evaluate the
chemicals used in the process. Chapter II is a compilation of the characteristics of chemicals
used in screen reclamation. The second tier Is to Identify the products, which are comprised of
the chemicals, that are used in various screen reclamation processes. For the purposes of this
CTSA, those products have been defined as ink remover, emulsion remover and haze remover,
and are referred to as functional groups of the screen reclamation process. Chapter IV
outlines the relevant characteristics of each of these functional groups. Lastly, the attributes
of the screen reclamation processes can be defined. The DfE Printing Project has identified five
individual methods and technologies through which screen reclamation can be performed; an
assessment of these methods is presented in Chapter V. Screen reclamation product systems,
consisting of primarily ink remover, emulsion remover and haze remover, have been defined
based on both actual commercial systems and on those chemicals which have been
traditionally used in screen reclamation. Product systems likely to be used in each screen
reclamation method have been specified; each product system and method are assessed in
terms of performance, cost, occupational and population exposure and comparative risk.
Overall pollution prevention opportunities for screen reclamation are also identified and
presented In Chapter VI. Chapter VII provides an analysis of social costs and benefits, and
also outlines issues associated with energy, natural resources, and international trade.
DRAFT—September 1994
v
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Acknowledgements
A special thanks Is extended to the Screen Printing Association International (SPAI),
particularly Marcl 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 Lorl Klncald 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
Image Technology, Inc.
1170 North Armando St.
Anaheim, CA 92806
Contact: Harry Emtiaz
(714) 632-5292
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 Sllney
(309) 452-7526
Hydro Engineering, Inc.
865 West 2600 South
Salt Lake City, UT 84119
Contact: Bob Roberts
(801) 247-8424
KIWO
P.O. Box 1009
Seabrook, TX 77586
Contact: Clark King
1-800-KIWO-USA
Nichols and Associates, Inc.
111575 Rupp Drive
Burnsvllle. 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
vi
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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
Arte raft, 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., Wllsonville, OR
Identification Products, Bridgeport, CT
Ivey-Seright International, Inc., Seattle, WA
Karagraphlc, Kent, WA
Leading Edge Grapjiics, Minnetonka, MN
M&M Displays Inc., Philadelphia, PA
Masterscreen Products Inc., Portland, OR
Mobius, Inc., Eugene, OR
Modagraphlcs, 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., Fredonla, 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
Kathiyn Ptrrotta Caballero
Jed Meline
RM-2 Workgroup:
Robert Boethllng
Richard Clements
James Dan-
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~S«ptMnbtr 1M4
vH
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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 industiy 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
vlii
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Table Of Contents
Section Page
Disclaimer iv
Preface v
Acknowledgements vi
Executive Summary ES-1
Chapter I. Profile of Screen Reclamation Use Cluster 1-1
Profile of Screen Printing 1-1
Overview of Screen Printing 1-1
Market Information on the Screen Printing Industry 1-2
Definition and Overview of Screen Reclamation 1-3
Definition of Screen Reclamation 1-3
Overview of Screen Reclamation 1-3
Identification of Screen Reclamation Functional Groups 1-7
Identification of Screen Printing Substitute Trees for Screen Reclamation 1-7
Potential Screen Reclamation Technologies I-11
Introduction I-11
Blasting Technologies I-11
Pulse Light Energy Technologies 1-13
Stripping Technologies 1-14
Stencils/Emulsions Chemistry 1-15
Conclusions 1-16
Alternative Sodium Bicarbonate Screen Reclamation Technology 1-17
General Summary of the Technology 1-17
Application Method 1-17
Alternative System Performance Results -.1-18
Technology Potential 1-19
Cost 1-20
Chapter II. Screen Reclamation Chemicals II-1
Introduction II-1
Categorization of Screen Reclamation Chemicals II-6
Information on Individual Printing Chemicals 11-7
Acetone II-7
Alcohols, C8-C10, Ethoxylated II-8
Alcohols, C12-C14, ethoxylated 11-10
Benzyl Alcohol II-11
2-Butoxyethanol 11-13
Butyl Acetate 11-14
Butyrolactone 11-16
Cyclohexanol 11-17
Cyclohexanone 11-19
Diacetone Alcohol 11-20
Dichloromethane 11-22
Diethyl Adipate 11-23
DRAFT—September 1994 lx
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Table of Contents
Section Page
Diethyl Glutarate 11-25
Diethylene Glycol 11-26
Diethylene Glycol Monobutyl Ether 11-28
Diethylene Glycol Butyl Ether Acetate 11-29
Diisopropyl Adipate II-31
Dimethyl Adipate 11-32
Dimethyl Glutarate 11-34
Dimethyl Succinate 11-35
Dipropylene Glycol Methyl Ether 11-36
Dipropylene Glycol Methyl Ether Acetate 11-38
Dodecyl Benzene Sulfonic Acid, Triethanol Amine Salt II-39
Ethyl Acetate 11-41
Ethyl Lactate II-42
Ethyl Oleate 11-44
Ethoxylated Castor Oil 11-45
Ethoxylated Nonylphenol 11-47
Ethoxypropanol 11-48
Ethoxypropyl Acetate 11-50
Furfuryl Alcohol 11-51
Isobutyl Isobutyrate 11-53
Isobutyl Oleate 11-54
Isopropanol II-55
d-Limonene 11-57
Methanol 11-58
Methoxypropanol Acetate 11-60
Methyl Ethyl Ketone 11-61
Methyl Lactate 11-62
Mineral Spirits (Naphtha, Heavy Straight-run) 11-64
Mineral Spirits (Distillates, Hydrotreated Light) 11-66
N-Methylpyrrolidone 11-68
2-Octadecanamine, N,N-dimethyl-, N-oxide 11-69
Periodic Acid II-70
Phosphoric Acid, Mixed Ester with Isopropanol and Ethoxylated Tridecanol . 11-72
Potassium Hydroxide 11-73
Propylene Carbonate II-75
Propylene Glycol II-76
Propylene Glycol Methyl Ether 11-78
Propylene Glycol Methyl Ether Acetate II-79
Silica II-81
Silica, Fumed (amorphous, crystalline-free) 11-82
Sodium Bisulfate 11-84
Sodium Hexametaphosphate 11-85
Sodium Hydroxide 11-87
Sodium Hypochlorite II-88
Sodium Lauiyl Sulfate 11-90
Sodium Metasilicate 11-91
Sodium Periodate 11-93
Sodium Salt, Dodecyl Benzene Sulfonic Acid 11-94
Solvent Naphtha, Petroleum, Light Aliphatic (VM&P Naptha) 11-96
Solvent Naphtha, Petroleum, Light Aromatic 11-98
Solvent Naphtha, Petroleum, Heavy Aromatic (Aromatic 150) 11-100
DRAFT—September 1994 x
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Table of Contents
Section Page
Tail Oil, Special 11-101
Terplneols 11-103
Tetrahydrofurfuryl Alcohol . 11-104
Toluene 11-106
1,1,1-Trichloroethane 11-107
1,2,4-Trimethyl Benzene 11-109
Tripropylene Glycol Methyl Ether II-110
Trisodlum Phosphate 11-112
Xylene II- L14
Federal Environmental Regulations that Affect Screen Reclamation Chemicals . . II-116
CWA 11-117
CAA 11-117
CERCLA II-118
SARA 313 II-118
RCRA II-118
Summary of the Environmental Hazard Assessment for the Screen Reclamation
Chemicals . . . . , II-120
Methodology 11-120
Environmental Hazard Ranking 11-121
Results II-122
Summary of Human Hazard Infoimatlon for Screen Reclamation Chemicals .... 11-130
Explanation of Table II-6 „ II-131
Chapter III. Background Information on Methodologies Used In Screen Reclamation
Risk, Performance and Cost Evaluation III-l
Overview of Data from the Screen Printing Industry Used in Risk Assessment Ill-1
Environmental Releases and Occupational Exposure Assessment III-2
Estimation Methodology III-3
Overview of Methodology III-6
Uncertainties III-9
Release Amounts vs. Occupational Exposures Ill-12
Population Exposure Assessment for Screen Reclamation Processes ........... Ill-14
Overview by Media 111-16
Background on Risk Assessment for Screen Reclamation Processes 111-18
Human Health Risk Ill-18
Ecological Risk 111-22
Background and Methodology for Performance Demonstrations 111-22
Background 111-22
Product System Summaries 111-26
Chemical Volume Estimates 111-26
Average Screen Size 111-27
Per Screen Product Usage III-28
Derivation of Market Share of Traditional and Alternative Screen Reclamation
Products m-28
Number of Screens Cleaned 111-29
National Estimates of Screen Reclamation Products 111-30
Estimates of Chemical Usage for Screen Reclamation 111-32
Cost Analysis Methodology 111-35
General Description of Costing Methodology 111-36
Details Related to Data Sources and Methodological Approach 111-39
DRAFT—September 1994 xi
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Table of Contents
Section Page
Chapter IV. Screen Reclamation Products: Functional Groups IV-1
Ink Removal Function IV-1
Substitute Comparative Assessment IV-1
Exposure Analysis & Risk Characterization IV-5
Emulsion Removal Function IV-13
Substitute Comparative Assessment IV-13
Exposure Analysis & Risk Characterization IV-15
Haze Removal Function IV-19
Substitute Comparative Assessment IV-19
Exposure Analysis & Risk Characterization IV-22
Manufacturing of Screen Reclamation Chemical Products IV-30
Manufacturing Process IV-30
Source Release Assessment: Product Formulation IV-31
Energy and Natural Resources Issues IV-31
Chapter V. Substitute Comparative Assessment. Screen Reclamation Methods V-1
Introduction V-1
Method 1: Traditional Reclamation V-l
Traditional System 1 V-l
Traditional System 2 V-8
Traditional System 3 V-14
Traditional System 4 V-23
Alternative System Chi V-32
Alternative System Beta V-38
Method 2: Traditional Reclamation With Haze Remover V-46
Traditional System 1 V-46
Traditional System 2 V-57
Traditional System 3 V-65
Traditional System 4 V-80
Product System Alpha V-91
Product System Chi V-107
Product System Delta V-l24
Product System Epsilon V-l38
Product System Gamma / V-157
Product System Mu V-l74
Product System Phi V-190
Product System Omicron-AE V-204
Product System Omicron-AF V-219
Product System Zeta V-234
Method 3: SPAI Workshop Process V-249
Method 3 Process V-249
System Omlcron Formulation V-251
Occupational Exposure V-252
Occupational Risk Conclusions and Observations V-252
Environmental Releases V-255
General Population Risk Conclusions And Observations V-258
Ecological Risks From Water Releases Of Screen Reclamation Chemicals . . V-258
Cost V-259
Method 4: Alternative Screen Reclamation Technology using High-Pressure Water
Blaster V-260
Method 4 Process V-260
DRAFT—September 1994 xil
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Table of Contents
Section Page
Alternative Technology Theta Chemical Formulations V-262
Occupational Exposure V-262
Occupational Risk Conclusions and Observations V-262
Environmental Releases V-264
General Population Risk Conclusions And Observations V-266
Ecological Risks From Water Releases Of Screen Reclamation Chemicals . . V-267
Performance V-267
Cost V-269
Method 5: Automatic Screen Reclamation Technology V-272
Features V-272
Feasibility V-272
Evaluation V-273
Process Description V-274
Occupational Exposure and Environmental Releases V-274
Occupational Risk Conclusions V-277
General Population Risk Conclusions And Observations V-281
Cost V-282
Chapter VI. Overall Pollution Prevention Opportunities for Screen Reclamation VI-1
Screen Disposal as a Method of Pollution Prevention VI-1
Pollution Prevention through Improved Workpractices VI-3
Responses to the Workplace Practices Questionnaire VI-3
Framework for Pollution Prevention VI-4
Conclusions VI-10
Pollution Prevention through Equipment Modifications VI-11
Sprayer/Application Systems VI-11
Washout Booths VI-13
Filtration Systems VI-18
Recirculation Systems VI-24
Distillation Equipment VI-27
Automatic Screen Washing Systems VI-31
Chapter VII. Macroeconomlc Issues VII-1
International Trade Issues VII-1
Energy and Natural Resource Issues VII-1
Screen Reclamation Processes VII-1
Collecting Data on Energy and Natural Resources Consumption VII-2
Energy Impacts VII-3
Materials Acquisition and Natural Resources Considerations VII-4
Cost/Benefit Analysis of Alternative Screen Reclamation Processes VII-4
Exposed Population V1I-5
Human Health Benefits VII-7
Associated Costs VII-8
Costs and Benefits by Method VII-8
Potential Benefit of Reducing Hazardous Waste Disposal VII-10
Potential Benefit of Avoiding Illnesses Linked to Exposure to Chemicals
Commonly Used in Screen Reclamation VII- II
DRAFT—September 1994 xlH
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Table of Contents
Section Page
Appendices
Appendix A. Glossary of Terms Used In the Environmental Fate Summaries A-l
Appendix B. Workplace Practices Questionnaire for Screen Printers B-1
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen
Printers C-l
Appendix D. Densities of Solutes In Aqueous Mixtures D-1
Appendix E. Review of Air Release Models E-1
Appendix F. Screen Printers Technical Foundation Testing Methodology F-1
Appendix G. Facility Background Questionnaire G-l
Appendix H. Observers'Evaluation Sheet H-l
Appendix I. Ink Remover Evaluation Sheet for Printers I-1
Appendix J. Emulsion Remover and Haze Remover Evaluation Sheet J-1
Appendix K. Weekly Follow-up Call Guidance K-1
Appendix L. Screen Printing Performance Demonstration Methodology L-1
Appendix M. Ecological Hazard Profile Methodology M-1
DRAFT-September 1994 xlv
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List Of Tables
Table Page
Note: This information will be provided in the flnrf draft
DRAFT—Saptwnbar 1994
xv
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List Of Figures
Figure Page
Note: This Information will be provided in the final draft
DRAFT—September 1994
xvi
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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, 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 and haze
DRAFT—September 1994
ES-2
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Disposal of
Screen Mesh
(No Reclamation
Occurs)
Figure ES -1
Screen Printing Substitutes Tree
Screen Reclamation
Method 1
i
Ink Removal
Emulsion
Removal/Water |
Wash
Product Groups
Include:
• QXDIZERS
• NON-OXlOtZERS
• SOLVENTS
• SURFACTANTS
Method 2
i
Products Used
Include:
• GLYCOL ETHER8
• SURFACTANTS
• OBASIC ESTERS
• HYDROCARBON SOLVHiTS
•TERPMEOLS
• ALCOHOLS
Ink Removal
See
Method 1
See
Method 1
Product Groups
Include:
• GLYCOL ETHERS
• CAUSTICS
• DIBASIC ESTERS
• SOLVENTS
• SURFACTANTS
I
Method 3
1
Method 4
Ink Removal
See
Method 1
Ink Degradant/
Water Rinse
Water Only
Product Groups
in Method 11nk
KOmOVBI
Screen
Degreaser
Emulsion
Removal
SOB
Method 1
Product Groups
in Method 11nk
Removal
High Pressure
Water Blast
(3000 psi)
Emulsion
Removal/Water
Wash
See
Method 1
Haze Removal/
* High Pressure
Rinse
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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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 deeming 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
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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 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. Hie 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
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Cleaner Technologies Substitutes Assessment for Screen Printing
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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
outllnesthe 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 rhemioal
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 irr 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.
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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. Hie 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-lncluslve 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.
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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 removed 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
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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.
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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
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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.
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Executive Summary
Table ES-1
Costs and Risk Trade-offs of Screen Reclamation Substitutes
System Evaluated
Cost/Screen
Cost/Facility
Risk Trade-offs
Baseline for Method 1 (Traditional System 4 - Haze
Remover)
$3.63
$5,446
Clear concern for worker dermal
risks and worker inhalation risks
Method 1: Chemical substitutes
for ink removal and emulsion
removal. No haze removal
required.
Chi (no haze
remover)
$1.95-2.83
$2,918-4,245
Moderate concern for worker
dermal risks and very low
concern for inhalation risks
Beta
$7.97
$11,958
Baseline for All Other Methods (Traditional System 4)
$6.27
$9,399
Clear concern for worker dermal
risks and worker inhalation risks
Method 2: Chemical substitutes
for ink removal, emulsion
removal and haze removal.
Alpha
$5.92-9.37
$8,886-
14,062
Moderate concern for worker
dermal risks and low concern for
inhalation risks
Chi
$3.25-3.89
$4,879-5,829
Delta
$3.28-7.66
$4,917-
11,489
Epsilon
$3.08-5.29
$4,624-7,930
Gamma
$5.06-5.61
$7,590-8,417
Mu
$4.79-9.33
$7,185-
13,997
Phi
$6.10-7.82
$9,233-
11,728
Omicron-AE
$5.49-10.85
$8,240-
16,278
Omicron-AF
$3.89-4.45
$5,836-6,675
Zeta
$5.39-8.99
$8,080-
13,479
Method 3: Chemical substitutes
for ink removal, degreasing and
emulsion removal. No haze
removal required.
Omicron
$5.57
$8,358
Moderate concern for worker
dermal risks and very low
concern for inhalation risks
Method 4: Technology
substitute of screen disposal in
lieu of reclamation.
Theta
$4.53
$6,797
Marginal concerns for worker
dermal risks and very low
concerns for worker inhalation
risks
Technology Substitute
Automatic Screen
Washer
$4.13-10.14
6,198-15,213
Moderate concern for worker
dermal risks and very low
concern for inhalation risks
Work Practice Substitute
Screen Disposal
$49.43
$74,141
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
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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/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.
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Cleaner Technologies Substitutes Assessment for Screen Printing
Executive Summary
Table ES-2: Workplace Practices and Their Benefits
Workplace Practices
Benefits
Keep chemical^ in safety cans or covered containers
between uses
Reduces materials loss; increases worker safety; reduces
worker exposure
Use plunger cans, squeeze bottles or specialized spraying
equipment to apply chemicals to the screen
Reduces potential for accidental spills; reduces materials
use; reduces worker exposure
Consider manual, spot-application of chemicals, where
applicable
Reduces materials use; reduces worker exposure if
aerosol mists are avoided
Use a pump to transfer cleaning solutions from large
containers to the smaller containers used at the work
station
Reduces potential for accidental spills; reduces worker
exposure
Reduce the size of the towel or wipe used during clean-up
More efficient use of the towel; reduces solvent use;
reduces worker exposure
Reuse shop towels on the first pass with ink remover
Reduces material (shop towel and ink remover) use;
reduces worker exposure
Evaluate alternative chemical: water dilution ratios
(increase the amount of water)
Reduces chemical usage with no loss of efficiency;
reduced worker exposure
Only apply chemicals where necessary
Reduces chemical usage; reduces worker exposure
Avoid delays in cleaning and reclaiming the screen
Simplify ink and emulsion removal; less potential for haze
on the screen
Gravity-drain, wring, or centrifuge excess solvent from rags
Recovers solvent for reuse
Place catch basins around the screen during the screen
cleaning/reclamation process
Captures chemical overspray for recovery and reuse
Use appropriate personal protective equipment (gloves,
barrier cream, respirator, etc.)
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 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
DRAFT—September 1994
ES-14
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Cleaner Technologies Substitutes Assessment for Screen Printing
Executive Summary
possible. Summarized below are some of the areas where energy and natural 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 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.
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.
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, epoxles. 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
flberboard to poster and cardboard.
aScreen Printing Association International, 1990 Industry ProJUe Study, (Fairfax, Va.: 1991), p. 9.
DRAFT—September 1994
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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 lndustiy are "captive ln-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 ln-
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
3Screen Printing Association International, J990 Industry Profile Study, (Fairfax, Va.: 1991), p. 9.
Correspondence between Kathryn Caballero, U.S. EPA, and Marcla Y. Klnter, Director of Government Affairs, SPAI,
May 1994.
sAir and Waste Management Association. Air Pollution Engineering Manual, Buonlcore, 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
SPAI 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 20257
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 Survev, Screen Printing Magazine
estimates the following size categories for screen printing facilities:
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 to $200 per week. In fabric costs from ruining screens or falling to reclaim them, can
eScreen 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, Buonlcore, Anthony and Davis, Wayne T.
(ed.), (New York:Van Nostrand Reinhold, 1992), p. 397.
^Ducdlli, S., "The 1992 Industry Survey: Safety and Environmental Practices in the Screen-Printing Industry," Screen
Printing Magazine, (April 1992), p. 50.
10Screen Printing Association International, 1990 Industry ProJUe Study, (Fairfax, Va.: 1991), p. 15.
11 Free ska, T.. Screen Printing Magazine. (1992), p. 120.
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I. Profile of Screen Reclamation Use Cluster
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
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 dally,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 dally 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 waip 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-Uke 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.
14Screen 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.
17Personal 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.
DRAFT-September 1994
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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
(UVJ-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 to reach certain chemical groups In the emulsion, it is more difficult to reclaim a water-
19Dlrect photostenclls are exposed in direct contact with the screen, alter 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
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I. Profile of Screen Reclamation Use Cluster
Definition and Overview of Screen Reclamation Overview of Screen Reclamation
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. Hie 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
aoDuccilll, S.. "The 1992 Industry Survey: Safety and Environmental Practices In the Screen-Printing Industry," Screen
Printing Magazine, (April 1992). p. 53.
DRAFT—September 1994
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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—Septtmbtr 19M
1-7
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I. Profile of Screen Reclamation Use Cluster
Identification of Screen Printing Substitute Trees for Screen Reclamation
Figure I -1
Identification Of Screen Reclamation Functional Groups
This Exhibit is an Integration of Screen Reclamation Methods
O470212
DRAFT—September 1994
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Disposal of
Screen Mesh
(No Reclamation
Occurs)
Figure I - 2
Screen Printing Substitutes Tree
Screen Reclamation
I
Emulsion
Removal/Water
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXHXZERS
• SOLVENTS
• SURFACTANTS
Products Used
Include:
• GLYCOL ETHERS
• SURFACTANTS
• DIBASIC ESTERS
• HYDROCARBON SOLVENTS
• TERPMEOLS
• ALCOHOLS
Method 2
I
Ink Removal
See
Method 1
Emulsion |
*
Removal/Water 1
Wash |
See
Method 1
Haze Removal/
Water Wash
I
Product Groups
Include:
• GLYCOL ETHERS
• CAUSTICS
• DIBASIC ESTERS
• SOLVENTS
• SURFACTANTS
Method 3
I
Method 1
Ink Degradant/
Water Rinse
Product Groups
in Method 11nk
Removal
Screen
Degreaser
Product Groups
in Method 1 ink
Removal
Emulsion
Removal/Water
Wash
See
Method 1
Method 4
I
Ink Removal
Water Only
Emulsion
Removal
See
Method 1
High Pressure
Water Blast
(3000 psi)
Haze Removal/
* High Pressure
Rinse
—
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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I. Profile of Screen Reclamation Use Cluster
Identification of Screen Printing Substitute Trees for Screen Reclamation
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.
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1. 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 coiiibined 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 industiy 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 fractloning
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. t?ut 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; C02 pellets, after impacting on the surface,
sublime rapidly to the gaseous state, thus leaving only the removed coating behind for disposal.
However, storage and pelletlzing of C02 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 refinlshing, and corrosion removal from process equipment.21
2'Annex Blast Media, (1993).
DRAFT—September 1994
H1
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Blasting Methods
Dry Abrasives
• PLASTIC BEADS
• WHEAT STARCH
• CARBON DIOXIDE
• ICE CRYSTALS
Wet Abrasives
Figure I - 3
Screen Printing Substitutes Tree
Undemonstrated Technologies In Screen Reclamation
(The cost and performance of these technologies in screen reclamation is undetermined)
/
Pulse Light Energy
\
Stripping Methods
Laser Stripping
Flashlamp Stripping
Dry or Wet Mechanical
Sanding
Heat Gun to Bum Off Ink
Liquid Nitrogen (cryogenic)
Spray With Dry Blast Media
Use Of
Water-Soluble
Stencils/Emulsion
To allow emulsion
removal with water only
• SODIUM BICARBONATE
effoza-tt
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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 C02 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 vaporize the coating a mlcrolayer at a time. Factors that contribute to the removal
^U.S. EPA Economics and Technology Division, Office of Toxic Substances. Redudng Risk in Paint Stripping,
(Washington:OPO 12-13 February. 1991).
a3IbId.
a4Ibld.
a8Ibld.
26Ibid.
37"Light Stripping," Manufacturing Engineering, (September, 1992).
^Ibld.
DRAFT—September 1994
H3
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I. Profile of Screen Reclamation Use Cluster
Potential Screen Reclamation Subrtltute Technologies Stripping Technologist
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 C02 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 reflnishing. These
technologies, however, have not been applied to small-scale operations?1,32 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 mlcrolayer 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
39U.S. EPA Economics and Technology Division, Office of Toxic Substances. Redudng Risk In Paint Stripping,
(Washlngton: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).
^U.S. EPA Economics and Technology Division, Office of Toxic Substances, Reducing Risk In Paint Stripping,
(Washington:GPO 12-13 February. 1991).
DRAFT—Saptember 1994
M4
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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 reflnished. 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 diy (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
M5
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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 removed. 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,
Knoxvllle, 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. Hie 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 mounted on the fan nozzle, so that the water and baking soda mixed together as they
DRAFT—September 1994
1-17
-------
I. Profile of Screen Reclamation Use Cluster
Alternative Sodium Bicarbonate Screen Reclamation Technology Alternative Syetem Performance Reeultt
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 psl
Water delivered at 200 to 250 psl
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 psl, 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 psl. This pressure proved
to be too high and the screen developed pin holes and eventually ripped. The pressure was
reduced to 5 psl. 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 delivezy 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.
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 diy process for the UV
DRAFT—September 1994
MS
-------
I. Profile of Screen Reclamation Use Cluster
Alternative Sodium Bicarbonate Screen Reclamation Technology Alternative System Performance Results
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 diy
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 deeming 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 diy 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 veiy 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 veiy 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
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
DRAFT—September 1994
M9
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I. Profile of Screen Reclamation Use Cluster
Alternative Sodium Bicarbonate Screen Reclamation Technology Cost
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
h20
-------
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
-------
II. Screen Reclamation Chemicals
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
CAS Number
Ink
Remover
Emulsion
Remover
Haze
Remover
Possible
Substitutes
Page
Number
Acetone
67-64-1
X
X
X
II-7
Alcohols, C8-C10, ethoxylated
71060-57-6
X
II-8
Alcohols, C12-C14, ethoxylated
68439-50-9
X
11-10
Benzyl alcohol
100-51-6
X
11-11
2-Butoxyethanol
111-76-2
X
11-13
Butyl Acetate
123-86-4
X
X
11-14
Butyrolactone
96-48-0
X
X
11-16
Cyclohexanol
108-93-0
X
11-17
Cyclohexanone
108-94-1
X
X
X
11-19
Diacetone alcohol
123-42-2
X
X
il-20
Dichloromethane
75-09-2
X
II-22
Diethyl adipate
141-28-6
X
li-23
Diethyl glutarate
818-38-2
X
II-25
Diethylene glycol
111-46-6
X
11-26
Diethylene glycol monobutyl
ether
112-34-5
X
X
X
11-28
Diethylene glycol butyl ether
acetate
124-17-4
X
X
X
11-29
Diisopropyl adipate
6938-94-9
X
11-31
Dimethyl adipate
627-93-0
X
X
II-32
Dimethyl glutarate
1119-40-0
X
X
II-34
Dimethyl succinate
106-65-0
X
X
II-35
Dipropylene glycol methyl ether
34590-94-8
X
X
II-36
Dodecyl benzene sulfonic acid,
triethanol amine salt
27323-41-7
X
11-39
DRAFT—September 1994
II*
-------
II. Screen Reclamation Chemicals
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
CAS Number
Ink
Remover
Emulsion
Remover
Haze
Remover
Possible
Substitutes
Page
Number
Ethyl acetate
141-78-6
X
X
11-41
Ethyl lactate
97-64-3
X
II-42
Ethyl oleate
111-62-6
X
II-44
Ethoxylated castor oil
61791-12-6
X
X
II-45
Ethoxylated nonylphenol (np 4-
9.5)
9016-45-9
X
X
X
II-47
Ethoxypropanol
52125-53-8
X
II-48
Ethoxypropyl acetate
54839-24-6
X
II-50
Furfuryl alcohol
98-00-0
X
11-51
Isobutyl isobutyrate
97-85-8
X
II-53
Isobutyl oleate
10024-47-2
X
II-54
Isopropanol
67-63-0
X
X
II-55
d-Limonene
5989-27-5
X
II-57
Methanol
67-56-1
X
II-58
Methoxypropanol acetate
84540-57-8
X
II-60
Methyl ethyl ketone
78-93-3
X
X
11-61
Methyl lactate
547-64-8
X
li-62
Mineral spirits (straight run
naphtha)
64741-41-9
X
X
li-64
Mineral spirits (light
hydrotreated)
64742-47-8
X
X
li-66
N-methylpyrrolidone
872-50-4
X
X
X
II-68
2-Octadecanamine, N,N-
dimethyl-, N-oxide
71662-60-7
X
II-69
Periodic add
13444-71-8
X
11-70
DRAFT—September 1994
-------
II. Screen Reclamation Chemicals
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
I CAS Number
Ink
Remover
Emulsion
Remover
Haze
Remover
Possible
Substitutes
Page
Number
Phosphoric acid, mixed ester
w/ispropanol and ethoxyiated
tridecanol
68186-42-5
X
11-72
Potassium hydroxide
1310-58-3
X
X
X
11-73
Propylene carbonate
108-32-7
X
11-75
Propylene glycol
57-55-6
X
X
11-76
Propylene glycol methyl ether
107-98-2
1320-67-8
X
X
11-78
Propylene glycol methyl ether
acetate
108-65-6
X
X
11-79
Silica
7631-86-9
X
11-81
Silica, fumed (amorphous,
crystalline-free)
112945-52-5
X
II-82
Sodium bisulfate
10034-88-5
X
11-84
Sodium hexametaphosphate
10124-56-8
X
X
11-85
Sodium hydroxide
1310-73-2
X
X
X
11-87
Sodium hypochlorite
7681-52-9
X
11-88
Sodium lauryl sulfate
151-21-3
X
11-90
Sodium metasilicate
6834-92-0
X
11-91
Sodium periodate
7790-28-5
X
li-93
Sodium salt, dodecyl benzene
sulfonic acid
25155-30-0
X
II-94
Solvent naphtha (petroleum),
light aliphatic
64742-89-8
X
II-96
Solvent naphtha (petroleum),
light aromatic
64742-95-6
X
11-98
Solvent naphtha (petroleum),
heavy aromatic
64742-94-5
X
11-100
Tall oil, special
68937-42-5
X
11-101
DRAFT—September 1994
IM
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II. Screen Reclamation Chemicals
Introduction
Table 11-1
Summary of Screen Reclamation Chemicals and Their Functions
Chemical
CAS Number
Ink
Remover
Emulsion
Remover
Haze
Remover
Possible
Substitutes
Page
Number
Terpineols
8000-41-7
X
X
11-103
T etrahydrof urf uryl alcohol
97-99-4
X
11-104
Toluene
108-88-3
X
11-106
1,1,1-Trichloroethane
71-55-6
X
11-107
1,2,4-trimethylbenzene
95-63-6
X
11-109
Tripropylene glycol methyl ether
25498-49-1
X
X
11-110
Trisodium phosphate
7601-54-9
X
X
11-112
Xylenes (dimethyl benzene)
1330-20-7
X
X
11-114
DRAFT—September 1994
ll-S
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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, dlisopropyl
adipate, et£.)
Table 11-2.
Categorization of Screen Reclamation Chemicals for
Use in Alternative System Formulations
Category
Chemicals from Screen Reclamation Use Cluster in Category
Alkali/caustic
Sodium hydroxide
Potassium hydroxide
Alkyl benzyl sulfonates
Dodecyl benzene sulfonic acid, triethanol amine salt
Sodium salt, dodecyl benzene sulfonic acid
Aromatic solvent naphtha
Solvent naphtha (petroleum), light aromatic
Solvent naphtha (petroleum), heavy aromatic
Derivatized plant oil
Tall oil, special
Ethoxylated castor oil
Dibasic esters
Diethyl adipate
Diethyl glutarate
Diisopropyl adipate
Dimethyl adipate
Dimethyl glutarate
Dimethyl succinate
Diethylene glycol series ethers
Diethylene glycol butyl ether
Diethylene glycol butyl ether acetate
Fatty alcohol ethers
Alcohols, C8-C10, ethoxylated
Alcohols, C12-C14, ethoxylated
Phosphate salt
Sodium hexametaphosphate
Trisodium phosphate
Propylene glycol series ethers
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
U
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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 lndustiy for screen reclamation.
Acetone
Chemical Properties and Information
Acetone [dimethyl ketone, 2-propanone]
CAS# 67-64-1
Molecular weight: 58.079
Melting Point: -95.4 to -94°C (M)
Water Solubility: Miscible
Vapor Pressure: 185 mm Hg (20°C)
Log K^: -0.24 (M)
Henry's Law Constant: 3.97 x 10 atm-nr/mole (M)
Chemistry of Use: Solvent
c3h6o
Structure: CH3COCH3
Boiling Point: 56.2°C (M)
Density: 0.7908420 g/ml (M)
Flash Point: -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 Schlff 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 dehydrogenatlon 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 endothermlc,
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
oxlde-zlrconlum 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.
DRAFT—September 1994
M-7
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Alcohols, Cg-C10, Ethoxylated
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 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 biodegradatlon. 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 biodegradatlon 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, C8-C10, Ethoxylated
ssssBasssBaBsaBBBBsaassHaa
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: Dispersabie (n=3 to 10) (E)
Vapor Pressure: <0.1 mm Hg (at 20°C) (E)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Molecular formula varies
Structure: R (0-CH2-CH2)n0H, R = C8 to C10
Boiling Point: Decomposes (E)
Density: 1.02g/cm3(E)
Flash Point: >100°C (E)
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
U
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Alcohols, C8-C10, 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 blodegradation 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 primaiy or secondary), or degree of ethoxylation. Blodegradation occurs by the |3-
oxidation of the alkyl chain, scission of the hydrophobic and hydrophic moieties and step-wise
removed 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 blodegradation 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,
Cg-Cio ethoxylated alcohols will be associated with aerosols and will be removed by wet and
dry deposition. Using a rapid blodegradation 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
ft******
DRAFT—September 1994
114
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Alcohols, C12-C14, ethoxylated
Alcohols, C12-C14, 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)
LogKow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Molecular formula varies
Structure: R (0-CH2-CH2)n0H, R = C12 to C14
Boiling Point: Decomposes (E)
Density: 0.95g/cm3(E)
Flash Point: >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 misclble 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-Ci0 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 blodegrade. Two
factors influencing blodegradatlon 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 blodegradabllity than the
hydrophobic chain length, point of attachment of the polyglycol chain (i.e., whether alcohol
DRAFT—September 1994
IMO
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Alcohols, C12-C14, ethoxylated
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-Cj4 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
jfc jjc
Benzyl Alcohol
Chemical Properties and Information
Benzyl alcohol [Benzenemethanol, Benzene carbinol, a-
Hydroxy toluene]
CAS# 100-51-6
Molecular weight: 108.13
Melting Point: -15.19°C (M)
Water Solubility: 40g/L(M)
Vapor Pressure: 0.048 mm Hg (at 20°C) (E)
1 mm Hg (at 58°C) (M)
Log Kow: 1.10 (M)
Henry's Law Constant: 2.1X10"' atm-m /mole (E)
Chemistry of Use: Solvent
C7H80
Structure:
Boiling Point: 204.7°C (M)
Density: 1.045 g/cm3 (M)
Flash Point: 101 °C (closed cup) (M)
104°C (open cup) (M)
K^: 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 atm-m /mole (E)
Chemistry of Use: Solvent
c6Hi4o2
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, esterifled,
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 summaiy. 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
bioconcentratlon in aquatic organisms are not expected to be Important transport processes
DRAFT—September 1994
IMS
-------
ll. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Butyl Acetate
for 2-butoxyethanol. Aqueous screening test data Indicate that blodegradation 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
diy soil surfaces will be Important. In the atmosphere, 2-butoxyethanol is expected to exist
almost entirely in the gas-phase and reactions with photochemlcally produced hydroxyl
radicals should be fast (estimated half-life of 5.6 hrs). Using a rapid blodegradation 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
ft***********
Butyl Acetate
in i iiaasa^aan Minim
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)
Log Kow= 1.82 (M)
Henry's Law Constant: 2.81 x 10"4 atm-m3/mole (M)
Chemistry of Use: Solvent
C6Hi202
Structure: CH3COOCH2CH2CH2CH3
Boiling Point: 125-6°C (M)
Density: 0.883 g/ml(M)
Flash Point: 29°C (M)
K*: 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 mlsclble
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
IM4
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Butyrolactone
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 blodegrade. 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 blodegrade 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
bloconcentratlon 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
photochemlcally 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 blodegradation rate in the STP fugaclty model results in 97 percent
predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
it***********
DRAFT—September 1994
0-15
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Butyrolactona
Butyrolactone
Chemical Properties and information
Butyrolactone [y-Butyrolactone; dihydro-2(3H)-furanone; 1,2-
butanolide; 1,4-butanolide; y-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 atm-m /mole (E)
Chemistry of Use: Solvent
c4h6o2
Structure:
Boiling Point: 204°C(M)
Density: 1.125 g/mi (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
JlciltilciltiicJieilc*****
Cyclohexanol
Chemical Properties and Information
Cyclohexanol [hexahydrophenol, hexalin]
CAS* 108-93-0
Molecular weight: 100.16
Melting Point: 23-25°C(M)
Water Solubility: 36 g/i (at 20°C) (M)
Vapor Pressure: 0.8 torr (at 20°C) (M)
^ IW 1-23 (M)
Henr/s Law Constant 1.02X10"4 atm-nr/mole (M)
Chemistry of Use: Solvent
C6Hi20
Structure:
OH
0
Boiling Point: 161°C(M)
Density: 0.962 g/cm3 (at 20°C) (M)
Flash Point 68°C (closed cup) (M)
Km: 111 and 13(E)
Above data are either measured (M) or estimated (E)
This chemical exists as hygroscopic ciystals and has a camphor-like odor. Cyclohexanol
is moderately flammable. It is miscible with ethanol, ethyl acetate, linseed oil, petroleum
solvent, and aromatic hydrocarbons.
Cyclohexanol is formed either by oxidation of cyclohexane, or hydrogenation of phenol.
DRAFT—September 1994
IM7
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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 11-4, Table 11-5 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 adsoib to sediment or
suspended particulate matter or to bloconcentrate 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 photochemlcally
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
IM8
-------
II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Cyclohexanone
Cyclohexanone
Chemical Properties and Information
Cyclohexanone [ketohexamethylene, pimelic ketone, cydohexyl
c6h10o
ketone, Hytrol 0, Anone, Nadone]
Structure:
CAS# 108-94-1
Boiling Point: 156.7°C(M)
Molecular weight: 98
Density: 0.9478 g/ml (M)
Melting Point: -47°C(M)
Flash Point: Closed cup: 42°C (M)
Water Solubility: 100 g/i (E)
Koc: 10(E)
Vapor Pressure: 3.975 mm Hg (M) (20°C)
109 Kow = 0.81 (M)
Henry's Law Constant: 9 x 1(r atm-m /mole (M)
Chemistry of Use: Solvent
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,
dimethyiacetonylcarbinoi, 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-m /mole (E)
Chemistry of Use: Solvent
C6Hi202
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 vaseyl
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
11-20
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diacetone 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
ft***********
DRAFT—September 1994
-------
II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Dlchloromethane
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)
Log Kow= 1.25 (M)
Henry's Law Constant: 3.25 x 10"° atm-nr/mole (M)
Chemistry of Use: Solvent
ch2ci2
Structure: CHgClg
Boiling Point: 40-41 °C (M)
Density: 1.33415g/ml (M)
Flash Point: -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 (s 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, dlchloromethane is expected to display high mobility. It may rapidly
volatilize from both moist and dry soil to the atmosphere. Aerobic blodegradatlon may be
Important for dlchloromethane in acclimated soils. If released to water, volatilization to the
DRAFT—September 1994
11-22
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diethyl 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 blodegrade under aerobic conditions.
It is also expected to slowly blodegrade 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 removed 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: 0.1 g/L (E)
Vapor Pressure: 0.8 mm Hg (25°C)(E)
Log 2.37(E)
Henry's Law Constant: 2.3 x 10 atm-m /mole (E)
Chemistry of Use: Lubricant, PiasUcizer
CioHi8°4
Structure: (C2HsO)CO(CH2)4OC(OC2H5)
Boiling Point: 245°C (M)
Density: 1.002 g/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 plasticlzers.
Diethyl adipate is the esteriflcation 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 plasticlzers 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 1094
11*23
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diethyl 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 than8). 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 veiy 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 summaiy
ft***********
DRAFT—September 1994
11-24
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diethyl 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)
Log Kow = 1.88(E)
Henry's Law Constant: 1.65 x 10 atm-rrr/mole (E)
Chemistry of Use: Plasticizer
c9Hi6o4
Structure: (C2H50)C0(CH2)3C0(0C2H5)
Boiling Point: 237°C(M)
Density: 1.022 g/ml(M)
Flash Point: 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.
Esterlflcation of glutaric acid followed by distillation gives adequate results.
Market Profile
In 1991, total U.S. production for glutarate plastlcizers 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 veiy high mobility.
Blodegradation 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 diy
DRAFT—September 1994
11-25
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diethyl Glutarate
soil may be significant. Chemical hydrolysis of the ester group is not expected to be significant
except for highly basic soils (pH greater than8). 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 veiy 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, l3,l3'-dihydroxydiethyl ether, dihydroxyethyl ether,
ethylene diglycol, 3-oxa-1,5-pentanediol, DEG, 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 at 25°C (M)
LoflKow' -1-47(E)
Henry's Law Constant: 2.03X10 atm-m /mole (E)
Chemistry of Use: Solvent
C4H10O3
Structure: HOCH2CH2OCH2CH2OH
Boiling Point: 245.8°C (M)
Density: 1.11 (M)
Flash Point: 138°C (M)
•V 4(E)
Above data are either measured (M) or estimated (E)
Diethylene glycol is readily esterifled with mono- and dlcarboxylic acids to yield
plastlcizers and resins. Diethylene glycol is similar In many respects to ethylene glycol but
contains an ether group. 1,4-Dloxane is prepared directly from diethylene glycol. It is mlsclble
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. Tills reaction yields approximately 9 to 10 percent diethylene glycol
as the primary by-product.
DRAFT—September 1994
H-26
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Diethylene 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 summaiy
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 bloconcentration
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 photochemlcally 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-© and accompanying suMmaiy
ft***********
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)
C8H18°3
ethanol; butyl ethyl Cellosolve; diethylene glycol butyl
Structure: C4H9OCH2CH2OCH2CH2OH
ether; butyl Carbitol; Dowanol DB; Poly-Solv DB;
Boiling Point: 231° C(M)
butoxydiglycol, butyl digol, butyl diicinol ]
Density: 0.954 g/ml (M)
CAS# 112-34-5
Flash Point: Open cup: 110°C(M)
Molecular weight: 162.2
Closed cup: 78°C (M)
Melting Point: -68°C (M)
Koc: 34(E)
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"a atm-irr/mole (E)
Chemistry of Use: Solvent
Above data are either measured (M) or estimated (E)
Glycol ethers are both ethers and alcohols. Their hydroxyl groups can be etherifled,
esterifled, 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
11-28
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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
ft***********
Diethylene Glycol Butyl Ether Acetate
Chemical Properties and Information
Diethylene glycol butyl ether acetate [2-(2-butoxyethoxy)
ethanol acetate; butyl diethylene glycol acetate; digfycol
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)
Ug*»"!.S . ,
Henry's Law Constant: 9.9 x 10 atm-nr/mole (E)
Chemistry of Use: Solvent
C10H20°4
Structure: C4H9(OC2H4)2OOCCH3
Boiling Point: 246.7°C(M)
Density: 0.9810 g/ml (M)
Flash Point: 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 esteriflcation of diethylene
glycol monobutyl ether with acetic acid or acetic anhydride.
DRAFT—September 1994
11-29
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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 summaiy
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 bloconcentration in aquatic organisms are not expected to be important
transport processes for diethylene glycol butyl ether acetate. Blodegradation 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 photochemlcally
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 blodegradation 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 summaiy
ft***********
DRAFT—September 1994
11-30
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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-dimethyibutyi
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)
Lo9KoW = 3-2 (E)
Henry's Law Constant: 1.3 x 10"° atm-rrr/mole (E)
Chemistry of Use: Lubricant, Plasticizer
^12^22^4
Structure: -/•C3H702C(CH2)4C02-AC3H7
Boiling Point: 257°C (at 760 mm Hg) (E)
Density: 0.9569 g/ml (M)
FiashPoint: 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 adiplc acid after
polyamides is the production of esters. These esters are marketed as plasticizers.
Diisopropyl adipate is the result of the esterlfication of adlpic 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 adlpic 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-Septomber 1994
-------
II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Dimethyl Adlpate
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 veiy 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 81. 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
ft***********
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)
Log 1^ = 1.39(E)
Henry's Law Constant: 1.3 x 10"7 atm-m3/mole (E)
Chemistry of Use: Lubricant, Plasticizer
^14^4
Structure: (CHgOJCOfCH^COIOCHg)
Boiling Point: 193.7°C (at 760 mm Hg)(E)
Density:1.063 g/ml (M)
Flash Point: 107°C (M)
Km: 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 adlpate Is the result of the esteriflcation of adlpic acid. Adipic acid Is produced
by the oxidation of cyclohexane first with air, then with nitric acid. The adlpic acid is then
methylated to produce the dimethyl adlpate.
DRAFT—September 1994
11-32
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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 plasticlzers 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 11-5 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 than8). 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
ft***********
DRAFT—September 1994
11-33
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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 K^: 0.90 (E)
Henry's Law Constant: 9.1X10 atm-m /mole (E)
Chemistry of Use: Solvent
^12^4
Structure: CH302C(CH2)3C02CH3
Boiling Point: 214°C (M)
Density: 1.088 g/cm3 (M)
Flash Point: 100°C (E)
•<«: 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 adsorptlvity 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 than8).
Volatilization, bloconcentratlon in aquatic organisms, and adsorption to sediment and
DRAFT-September 1994
11-34
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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: 6.3g/L(M)
Vapor Pressure: 0.1 mm Hg (E)
Log Kow: 0.19 (M)
Henry's Law Constant: 5.8X10"® atm-m3/rnole (E)
Chemistry of Use: Solvent
C6H10°4
Structure: CH302C(CH2)2C02CH3
Boiling Point: 196.4°C(M)
Density: 1.12 g/cm3 (M)
Flash Point 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 1904
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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 atm-rrr/mole (E)
Chemistry of Use: Solvent
®7^16®3
Structure: CH3CHOHCH2OCH2CH(OCH3)CH3
or
CH3CHCH2OCH2CHCH3
OH OCH,
Boiling Point: 188.3°C (M)
Density: 0.951 g/ml (M)
Flash Point: 75°C (M)
¦W 15 ©
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 phtftochemically 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 removed
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
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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 [Dowanoi 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 atm-nr/mole (E)
Chemistry of Use: Solvent
c9h18o4
Structure: CH3CHCH2OCH2CHCH3
OCHg OC-OCHg
Boiling Point: 200°C(E)
Density: 0.90g/ml(E)
Flash Point: 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 bloconcentration in aquatic organisms are not expected to be Important
transport processes for dipropylene glycol methyl ether acetate. Biodegradation is likely to be
DRAFT—September 1994
IW8
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Dipropylene Glycol Methyl Ether Acetate
an 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 biodegradatlon 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
*9|C3|C!|(i|Cl|c4C!|tJ|lJ|lj|Ca|C
Dodecyl Benzene Sulfonic Acid, Triethanol Amine Salt
Chemical Properties and Information
Dodecyl benzene sulfonic acid, triethanol amine salt
[benzenesulfonic acid, dodecyl-, compd. with
^'^'-nitrilotrislethanolKI: 1)]
CAS# 27323-41-7
Molecular weight: 475.5
Melting Point: Not available
Water Solubility: Low Solubility (E)
Vapor Pressure: <10'5mmHg(E)
Log Kow: -1.49(E)
Henry's Law Constant: Not applicable
Chemistry of Use: Surfactant
C^NOeS
Structure:
r /== °]~r "f
C12H25--^^-|0 WN(CH2CH2OH),
Boiling Point: Not available
Density: 1.09g/cm3(M)
Rash Point: Not available
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.
DRAFT-September 1994
1149
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Dodecyl Benzane Sulfonic Acid, "Methanol Amine Salt
Aquatic Toxicity
See Table 11-4, Table II-5 and accompanying summaxy
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 bloconcentrate 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 biodegradatlon rate for the parent acid in the
STP fugaclty 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 summaiy
************
DRAFT—September 1994
11*40
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Ethyl Acetate
Ethyl Acetate
SSSSSESESSSSSSSSSSSSSSSaB
Chemical Properties and Information
Ethyl acetate [Acetic ester]
CAS# 141-78-6
Molecular weight: 88
Melting Point: -83.6°C (M)
Water Solubility: 77 g/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
c4h8o2
Structure: CH3COOCH2CH3
Boiling Point: 77.1°C (M)
Density: 0.884 g/ml(M)
Flash Point: -4.4°C (M)
K*: 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 summaiy
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
DRAFT—Septembtr 1994
(Ml
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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
ft***********
Ethyl Lactate
Chemical Properties and Information
Ethyl lactate [(S)-Ethyl lactate; ethyl-2-hydroxypropanate;
Acytolj
CAS# 97-64-3
Molecular weight: 118.13
Melting Point: -260C(M)
Water Solubility: Miscible
Vapor Pressure: 5 mm Hg (E) (25°C)
Log Kw»-0.180(E)
Henry's Law Constant: 5.8 x 10 atm-m /mole (E)
Chemistry of Use: Solvent
C5H10O3
Structure: CH3CH(OH)COOCH2CH3
Boiling Point: 154°C(M)
Density: 1.042 g/ml (M)
Flash Point: 48°C (M)
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 esterlficatlon 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.
DRAFT—September 1994
1142
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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 veiy high mobility. Blodegradatlon
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 than8, chemical hydrolysis of ethyl lactate may
occur. If released to water, aerobic blodegradatlon may be rapid especially in acclimated
waters. Ethyl lactate Is not expected to bloconcentrate 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 blodegradatlon 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
ft***********
DRAFT—September 1994
11-43
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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 atm-rrr/mole (E)
Chemistry of Use: Solvent
C2oH38®2
Structure: CH3(CH2)7CH=CH(CH2)6CH2COOCH2CH3
Boiling Point: 205-208°C (M)
Density: 0.870 g/ml(M)
FlashPoint: 175°C(M)
K^: >10,000 (E)
Physical state: Colorless, oily liquid
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 than8). Volatilization of ethyl oleate
from moist soil to the atmosphere may be a significant process although it is likely to be
DRAFT—September 1994
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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
* * sjc s|c sjc )|c s|c s|c sjc
Ethoxylated Castor Oil
Chemical Properties and Information
Ethoxylated castor oil [cosmetol, ricinus oil, neoloid
CAS# 61791-12-6
Molecular weight: 298.47 (rlcinoleic) +135 (ethoxy)
Melting Point: 5.5°C(M)
Water Solubility: 0.003 g/L (E)
Vapor Pressure: <0.1 mm Hg at 20°C (M)
Log Kow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Drying/coating agent
C-jgH^Og (ricinoleic) + (C2H50)3 (ethoxy)
Structure:
CH3(CH2^HCH2CHC^(CH2)7C00H (rlcinoleic)
OCHjCHj 0CH2CH3 OCH2CHj
Boiling Point: 313°C(M)
Density: 0.961 (M)
Rash Point: 299°C (M)
Km: 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 rlcinoleic acid, palmitic acid, stearic acids, oleic acids, and several
ethoxy groups. Rlcinoleic 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 i9olutlon. In the polyethoxylation reaction the hydroxyl groups undergo alkylation
to produce the polyethoxyl triglyceride fatty acid. Common catalysts for the dehydration
procedure are sulftxric acid and its acid salts.
DRAFT—September 1994
IMS
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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 blodegrade as do linear
primarily alcohol ethoxylates. Biodegradation occurs by the fi-oxldatlon of the alkyl chain,
scission of the hydrophobic and hydrophlc 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 fugaclty model results in 100 percent predicted total removal from wastewater
treatment plants.
Health Hazard
See Table II-6 and accompanying summary
************
DRAFT—September 1994
11-46
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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), a-
(nonylphenyl)-Cl-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"® mm Hg (E)
L°B KoW: 3.93 (E) (np ¦ 7)
Henry's Law Constant: 1.81X10"22 atm-nr/mole (E)
(np = 7)
Chemistry of Use: Nonionic surfactant
C34H62°io(forn=9-5)
Structure:
n * 9.5 (for screen printing formulotion product)
Boiling Point: >300°C (E) (decomposes)
Density: 0.8g/cm3(E)
FlashPoint: 200 - 260°C(E)
K^: 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.
DRAFT—September 1994
11-47
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Ethoxypropanol
The mobility of ethoxylated nonylphenols varies with the number of ethoxy groups. Estimates
based on molecular structure indicates that 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 blodegradation. 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 primaiy blodegradation 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
ft***********
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: 2.45X1 Or atm-nr/mole (E)
Chemistry of Use: Solvent
C5H12O2
Structure: CHgC^OCHgCHOHCHg
Boiling Point: 132°C (M)
Density: 0.895 g/cm3 (at 25°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 etherifled,
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 dlpropylene 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.
DRAFT—September 1994
IMS
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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 blodegrade under aerobic conditions
and it may be rapid if acclimated organisms are present. It is expected to display high
mobility; however, rapid blodegradatlon 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 blodegrade under aerobic
conditions and It may be rapid if acclimated organisms are present. Neither bioconcentratlon
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 photochemlcally 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 blodegradatlon rate
in the STP fugaclty 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
1149
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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# 54889-24-6
Molecular weight: 146.1
Melting Point: -100°C(E)
Water Solubility: Miscible
Vapor Pressure: 3.5 mm Hg (at 20°C) (E)
Log K- -0.46(E)
Henry's Law Constant: 9.09X10'1Z atm-m3/mole (E)
Chemistry of Use: Solvent
C|H,A
Structure: CHgC^OC^CHOOCCHg
1
CHg
Boiling Point: 153.2°C(E)
Density: 1.0g/cm3(E)
Flash Point: 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. Etherificatlon is by
reaction with ethanol. Esteriflcatlon 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
DRAFT—September 1994
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Ethoxypropyl Acetate
be important although it may slowly volatilize from dry soil. If released to water, ethoxypropyl
acetate Is expected to blodegrade 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 photochemlcally 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
fugaclty 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
Ik********)!!**
Furfuryl Alcohol
Chemical Properties and Information
Furfuiyl alcohol [2-Furanmethanol; 2-Furylcafbinol;
2-Hydroxymethyifuran)
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 K^: 0.28 (M)
Henry's Law Constant: 7.86X10"® atm-nr/mole (E)
Chemistry of Use: Solvent
C5H6°2
Structure;
/°\,ch2oh
Boiling Point 170°C(M)
Density: 1.13g/cm3(M)
Flash Point: 75°C (M)
K*: 8.5(E)
Above data are either measured (M) or estimated (E)
Furfuiyl 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 Canntzzaro 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.
DRAFT—September 1994
11-51
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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 miscibillty 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
3|ta|ca|t9|c4ea|e3|cj|c4es|e3|e3|e
DRAFT—September 1994
II-52
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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 gl/L (M)
Vapor Pressure: 3.2 mm Hg (at 20°C) (M)
Log Kow: 2.68 (E)Henry's Law Constant: 8.22 x 104atm-
nrnmole (M)
Chemistry of Use: Solvent
^16®2
Structure: (CH3)2CHCOOCH2CH(CH3)2
Boiling Point: 147°C (M)
Density: 0.855 g/cm3 (at 20°C) (M)
Flash Point: 38°C (closed cup) (M)
44°C (open cup) (M)
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 blodegradatlon. Volatilization of Isobutyl Isobutyrate from both
moist and dry soli 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 bloconcentration in fish and aquatic organisms nor adsorption to sediment and
suspended organic matter are expected to be Important. Volatilization of isobutyl isobutyrate
DRAFT—September 1994
IM53
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Isobutyl Oleate
from water to 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
ft***********
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'' atm-m /mole (E)
Chemistry of Use: Numerous
^22H42®2
Structure: CH3(CH2)7CH=CH(CH2)6CH2COO-/-C4H1.
Boiling Point: 226°C(M)
Density: 0.86g/ml(M)
Flash Point: 180°C (M)
K^.: >10,000 (E)
Physical state: Oily liquid
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 esterificatlon 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. Esterificatlon 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 llnolerlc 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.
DRAFT—September 1994
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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 than8) . 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, secpropyl 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 Kw* 0.05 (M)
Henry's Law Constant: 8.1 x 10"6 atm-m3/mole (M)
Chemistry of Use: Solvent
C3H80
Structure: (CH^CHOH
Boiling Point: 164°C(M)
Density: 0.7849 g/ml (M)
Flash Point: Tag Open Cup: 17.2°C(M)
Koc-' 25(E)
Physical State: Colorless, volatile, flammable liquid
Closed Cup: 11.7°C(M)
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 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, etherifled, aminated, 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 + H20 <-> (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
11-56
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals cf-Limonene
d-Limonene
Chemical Properties and Information
cf-Limonene [1 -methyl-4-(1 -methyiethenyi) cyclohexene;
^10^16
(+)-carvene; citrene; 1,8-p-menthadiene; 4-isopropenyl-1-
Structure:
methylcyclohexene cinene; cajeputene; kautschin]
Boiling Point: 176°C(M)
CAS# 5989-27-5
Density: 0.84g/ml(M)
Molecular weight: 136
Flash Point: 48°C (M)
Melting Point: -74°C (M)
K^: 1,000 - 4.800(E)
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-m9/mole (E)
Chemistry of Use: Wetting and Dispersing Agent
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-menthadlenes 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 veiy 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 dQ. Nonetheless, the
characteristic odor and flavor of lemon comes not from limonene, but from cltral 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
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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 blodegrade 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 ai&n
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
ch4o
alcohol]
Structure: CH3OH
CAS# 67-56-1
Boiling Point: 64.7°C(M)
Molecular weight: 32.04
Density: 0.792 g/cm3 (M)
Melting Point: -97.8°C (M)
Flash Point: 12°C (closed cup) (M)
Water Solubility: Miscible (M)
not available
Vapor Pressure: 93.7 mm Hg (at 20°C) (M)
Log ^ -0.770 (M)
Henry's Law Constant: 4.55X10"6 atm-nr/mole (M)
Chemistry of Use: Solvent
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.
DRAFT—September 1994
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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 biodegradatlon 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 biodegradatlon in
anoxic sediments is also expected to occur. Neither volatilization to the atmosphere,
bioconcentratlon 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 hydroxy] 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 biodegradatlon 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 summaxy
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"° atm-nr/mole (M)
Chemistry of Use: Solvent
^6H12®3
CH, 0
i i
Structure: CH3OCH2CHOCCH3
Boiling Point: 140°C (M)
Density: 0.97g/cm3(M)
Flash Point: 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 veiy 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
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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 bloconcentration 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
ft***********
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: 24g/L(M)
Flash Point: -7°C
Log K^- 0.29 (M)
Henry's Law Constant: 5.69 x 10'5 atm-frr/mole (M)
Chemistry of Use: Solvent
c4h8o
Structure: H3CCH2COCH3
Boiling Point: 79.6°C (M)
Density: 0.8049420 g/mi (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 misclble 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 blodegrade. If methyl ethyl ketone
leaches to groundwater, biodegradabillty studies In anaerobic systems suggest slow
biodegradatlon after a long acclimation period. In surface waters, methyl ethyl ketone will
volatilize, photolyze, or blodegrade. 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 photochemlcally-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 biodegradatlon 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
~ >li * *
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: Misdble
Vapor Pressure: 7.7 mm Hg (E) (25°C)
Log K„w =-0.67(E)
Henry's Law Constant: 8.5 x 10"* atm-nr/mole (E)
Chemistry of Use: Solvent
ester; lactic C.HaO,
w4n8w3
Structure: CH3CH(OH)COOCH3
Boiling Point: 145°C(M)
Density: 1.0939g/ml(M)
Flash Point 49°C (M)
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 Chemical! 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 esteriflcation 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 11-4, 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 veiy 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 veiy slow. In basic soil with a pH greater than8, 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 bloconcentrate 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 veiy 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.
t
Health Hazard
See Table II-6 and accompanying summaiy
DRAFT—September 1994
\m
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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)
Log Kow = 3.4 - >6 (E)
Henry's Law Constant: 1.5x10 -13 atm-nr/mole (E)
Chemistry of Use: Solvent
Molecular formula: CnH2n+2 (paraffin) and CnH,n
(cycloparaffin)
Structure: Typical structures include normal paraffins,
CH3(CH2)nCH3P branched paraffins, and cycloparaffins
Boiling Point: 160-200°C(M)
Density: 0.78 g/ml (M)
Flash Point: 43°C (M)
K^: 500->5000 (E)
Physical State: Liquid
Above data are either measured (M) or estimated (E)
The term mineral spirits refers to a rsinge 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
blodegrade at a moderate rate under aerobic conditions, although some of the cycloalkanes
may be resistant to biodegradatlon. 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 blodegrade 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 blodegrade 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
************
DRAFT—September 1994
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Mineral Spirits (DlHllates, 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 ^ow = 4-76 - 8.25 (E)
Henry's Law Constant: 0.2 - 3.4 atm-m3/mole (E)
Chemistry of Use: Solvent
Molecular formula: C^^ (paraffin) and CnH^
(cycloparaffm)
Structure: Typical structures include normal paraffins,
CH3(CH2)nCH3l branched paraffins, and cycloparaffins
Boiling Point: 140-180°C (M)
Density: 0.78g/ml(M)
Flash Point: <43°C (M)
K^: 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
cycloparafflns, 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 Chemical* Mineral Spirits (Dlrtfflatea, 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
alicycllc 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 diy 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 adsoib 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
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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-py rro li done; 1 -
methylazacyclopentan-2-one; N-methyl-Y-butyrolactam]
CAS# 872-50-4
Molecular weight: 99.13
Melting Point: -17to-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 atm-m /mole (E)
Chemistry of Use: Solvent
CjHgNO
Structure:
CH,
I J
cr
Boiling Point: 202°C (M)
Density: 1.03 g/ml (M)
Flash Point: 96°C (M)
Koc: 10(E)
Physical State: Colorless liquid with mild amine odor
Above data are either measured (M) or estimated (E)
N-Methylpyrrolldone 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
DRAFT—September 1994
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals 2-Octadecanamine, N,N-dlmethyl-, 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
2-0ctadecanamine, N,N-dimethyl-, N-oxide
Chemical Properties and Information
2-0ctadecanamine, 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"® mm Hg (E)
Log 9.2 (E)
Heniys Law Constant: 3.62X10"* atm-m3/mole (E)
Chemistry of Use: Surfactant
C^NO
Structure:
0"
l +
ch3 —n— ch3
ch3(ch2)15chch3
Boiling Point: Not applicable
Density: Not available
Flash Point: Not available
K^: 880,000 (E)
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
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Periodic Acid
Regulatory Status
2-Octadecanamine, N,N-dimethyl-t 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 blodegrade. 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-oxlde 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]
hio4
CAS# 13444-71-8
Structure: HI04
Molecular weight: 191.9
Boiling Point: Not applicable
Melting Point: 130° C (M) decomposes
Density: 3.0 g/ml (E)
Water Solubility: 3,700 g/l (M)
Flash Point: Not applicable
Vapor Pressure: Negligible (E)
Physical State: White crystals
Chemistry of Use: Oxidizing agent
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 summaiy
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 summaiy
DRAFT—September 1994 K-71
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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) a-tridecyl-
co-hydroxy-, 1-methylethyl phosphate]
CAS# 68186-42-5
Molecular weight: >540
Melting Point: Not available
Water Solubility: Soluble/Dispersable
Vapor Pressure: <10"® mm Hg (E)
LogKow: Not available
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Varies
Structure:
0 CH,
II I 3
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 summaiy
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 blodegrade. 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/lsopropanol and ethoxylated tridecanol
DRAFT—September 1994
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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
>ki|c>|ci|ci|(>|c)|e9|ci|ci|c9|c3|c
Potassium Hydroxide
Chemical Properties and Information
Potassium hydroxide [caustic potash]
KOH
CAS# 1310-58-3
Structure: KOH
Molecular weight: 56
Boiling Point: 1320-1324°C (M)
Melting Point 380°C(M)
Density: 2.0 g/ml(E)
Water Solubility: 1500 g/L (E)
Rash Point: Not applicable
Vapor Pressure: Not applicable
Physical State: Solid, white or slightly yellow lumps, rods,
Chemistry of Use: Caustic
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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Information on Individual Printing Chemicals
Regulatory Status
See Table II-3 and accompanying summary
Hazard Summary
Potassium Hydroxide
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, humlc 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
ft***********
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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: 100 g/L (E)
Vapor Pressure: 0.44 mm Hg (E) (25°C)
Log KqW = 0.54 (E)
Henry's Law Constant: 3.6 x 10 atm-m /mole (E)
Chemistry of Use: Solvent
C4H6°3
Structure:
0
"O
Boiling Point: 241.7°C(M)
Density: 1.20 g/ml
Flash Point: 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 C02. 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.
Biodegradatlon 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)
LcgK0W: -.920 (M)
Henry's Law Constant: 1.3x10'oatm-nr/mole (E)
Chemistry of Use: Solvent
c3h8o2
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. TTie 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 summaiy
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 summaiy
************
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemical*
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 atm-m7mole (E)
Chemistry of Use: Solvent
w2
Structure: CH30CH2CH(CH3)0H
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 hydroxy! groups can be etherifled,
esterifled, chlorinated, or otherwise modified. Propylene glycol methyl ether Is mlscible with
acetone, benzene, carbon tetrachloride, ethyl ether and petroleum ether. Glycol monoethers
are prepared by conventional etherlficatlon procedures, Including the reaction of an alkali
metal glycolate with an alkyl hallde, 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 categoiy of glycol ethers is listed as Hazardous Air Pollutants in the
Clean Air Act.
Hazard Summary
Aquatic Toxicity
See Table 11-4, 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-
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Information on Individual Printing Chemical* Propylene Glycol Methyl Ether
week BOD of 88-92 percent of theoretical. If released to soil, propylene glycol methyl ether is
expected to display very high mobility. Volatilization from diy 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
ft***********
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; Miscibie
Vapor Pressure: 2 mm Hg (E) (25°C)
Log l^. 0.56 (M)
Henry's Law Constant: 4.26 x 10"° atm-nr/mole (M)
Chemistry of Use: Solvent
C6H12°3
ch3o
I 1
Structure: CHgOCHjCHOCCHg
Boiling Point 140eC(E)
Density; 0.90 g/ml(E)
Flash Point: 40°C (E)
K*: 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 acetylatlon.
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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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 than8).
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
ft***********
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Silica
Silica
Chemical Properties and Information
Silica [silicon dioxide]
Si02
CAS# 7631-86-9
Structure: Occurs as a variety of minerals including quartz:
Molecular weight: 60
crystals are hexagonal
Melting Point: 1550°C(M)
Boiling Point: Density: 2.65 (quartz) (M); 2.2 (amorphous)
Water Solubility: Practically insoluble; vitreous form more
Flash Point: (E)
soluble than quartz
K^: Not applicable
Vapor Pressure: (E)
Log K^: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Anticaking/defoaming agent
III III l' I III 3SSSSSSS
Above data are either measured (M) or estimated (E)
Silica combines with many elements and oxides in the general realm of ceramic
chemistiy. 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 P4 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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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 veiy 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,
biodegradatlon, 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 diy
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 complexatlon with
metals.
Health Hazard
See Table II-6 and accompanying summary
ft***********
Silica, Fumed
(amorphous, crystalline-free)
Chemical Properties and Information
Silica, fumed [pyrogenic silica, aerosil, amorphous silica]
CO
p
CAS# 112945-52-5
Structure: Lack of crystalline structure
Molecular weight 60
Boiling Point: 2950°C (E)
Density: 2.16g/cm3(M)
Melting Point: 1550°C(E)
Water Solubility: 0.1 g/L (E)
Flash Point: Not available
Vapor Pressure: Not applicable
Kg.: Not applicable
Log K^: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Thickener/reinforcer
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 S1C14 with H2 and 02 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 blodegrade 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, blodegradatlon, and bioconcentratlon 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 complexatlon with metals.
Health Hazard
See Table II-6 and accompanying summary
************
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemical* Sodium Blsulfate
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: 1250 g/L (M)
Vapor Pressure: Not applicable
Log Kow: Not applicable
Henry's Law Constant: Not applicable
Chemistry of Use: Salt
H3NaOsS
Structure: H0S03Na-H20
Boiling Point: Not Applicable
Density: >2g/cm3(E)
Flash Point: Not applicable
Kg.: 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 NaHS04.
Market Profile
No Information on production volumes of sodium blsulfate 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 blsulfate for use in screen reclamation was
estimated to be 2.35 million pounds.
Regulatory Status
Sodium blsulfate 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 blsulfate 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 (HS04~). In water,
the blsulfate ion will rapidly dissociate to the sulfate ion (S04"2) and a hydronium ion (H30+).
Sodium ions are naturally present In surface water, groundwater, and rainwater as are sulfate
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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 Feleased 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
a|ea|c4es|e4ea|e3|ea|cs|t4ca|c4c
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
(NaPOg)e
Structure: 12 member ring with alternating P and 0 atoms
Na'VW6
Boiling Point: Not available
Density: 2.4g/cm3(E)
Flash Point Not available
K^: 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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Information on Individual Printing Chemicals
Regulatory Status
See Table II-3 and accompanying summary.
Hazard Summary
Sodium Hexametaphosphate
Aquatic Toxicity
See Table 11-4, 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 bloconcentratlon 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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Information on Individual Printing Chemicals Sodium Hydroxide
Sodium Hydroxide
Chemical Properties and Information
Sodium hydroxide [caustic soda; lye; sodium hydrate; soda
NaOH
lye]
Structure: NaOH
CAS# 1310-73-2
Boiling Point: 1390°C(M)
Molecular weight: 39.9
Density: 2.13 g/ml (M)
Melting Point: 323°C (M)
Flash Point: Not applicable
Water Solubility: 1,180 g/L (E)
Physical State: Deliquescent orthorhombic white powder
Vapor Pressure: Negligible (E)
1 mm Hg (M) (739°C)
Chemistry of Use: Caustic
Above data are either measured (M) or estimated (E)
Sodium hydroxide is an important Industrial alkali. It readily reacts with atmospheric
C02 to form Na^Og. 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 Na2C03 or NaHC03 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
DRAFT—September 1994
IM7
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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
ft***********
Sodium Hypochlorite
Chemical Properties and Information
Sodium hypochlorite [chloric(l) acid, sodium salt;
NaOCI
hypochlorous acid, sodium salt; Clorox, Dazzle, Eau de
Structure: NaOCI
Labarraque]
Boiling Point: Not applicable
CAS# 7681-52-9
Density: 1.21 g/ml (M)
Molecular weight: 74.4
Flash Point: Not applicable
Melting Point: 18° C (M) crystals decompose
Water Solubility: 260g/l(M)
Vapor Pressure: Not applicable
Chemistry of Use: Oxidizing agent
———— ' ———
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 CI2 through aqueous NaOH in the
presence of C02. It is manufactured by the electrolysis of brine.
DRAFT—September 1994
11-88
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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
DRAFT—September 1994
11-89
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Sodium Lauryl Sulfate
ft****)!!*** **!!!
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
Log Kow: L7 (E)
Henry's Law Constant: Not available
Chemistry of Use: Detergent
C12H25Na04S
Structure: C^CH^OSOg'Na
Boiling Point: Decomposes
Density: 1 g/cm3 (E)
Flash Point: Not applicable
K^: 80.000(E)
Above data are either measured (M) or estimated (E)
Sodium lauiyl 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 lauiyl sulfate is synthesized by sulfation of lauiyl alcohol, followed by
neutralization with sodium carbonate.
Market Profile
No market information was available for this chemical.
Regulatory Status
Sodium lauiyl 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 lauiyl sulfate is chemically stable In neutral and
alkaline solutions, but readily hydropses in the presence of acids. Since the sodium bisulfate
produced in the hydrolysis is strongly acidic, once hydrolysis starts it is autocatalytic.
DRAFT—September 1994
11-90
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Sodium Metasilicate
Although sodium 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 tall of the molecule. Volatilization of sodium lauryl sulfate from surface soil will
not be significant. If released to water, sodium lauiyl 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 lauiyl 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
ft***********
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 coid water (M)
Vapor Pressure: <10*® torr (E)
Log Kow: Not applicable
Heniy*s Law Constant: Not applicable
Chemistry of Use: Corrosion inhibitor
Na^Si
Structure:
r° r2
+ i
2 No Si—0
I
Lo J
Boiling Point: Not awiicabie
Density: 2.614 g/cnr(M)
Rash Point: Not available
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 organlcs and alcohols. Sodium metasilicate is
prepared from sand (S102) and soda ash (Na^O-j) by fusion.
Market Profile
In 1992, total U.S. production was 106 million pounds. In 1992, for all metasillcates,
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.
DRAFT—September 1994
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Sodium MetaslHcate
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 ollgomerlc 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, blodegradatlon, 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 ollgomerlc sodium metasilicates may not undergo
significant removal in wastewater treatment plants. Removal by blodegradatlon and
volatilization of sodium metasilicate from wastewater treatment plaints is expected to be
negligible.
Health Hazard
See Table II-6 and accompanying summary
******* * ****
DRAFT—September 1994
11-92
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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
Nal04
iodate(VII); lodic(VII) acid, sodium salt; periodic acid,
Structure: Na+I04"
sodium salt]
Boiling Point: Not applicable
CAS# 7790-28-5
Density: 3.865 g/ml (M)
Molecular weight: 213.8
Flash Point: Not applicable
Melting Point: 300° C (M) decomposes
Physical State: Colorless tetragonal crystals
Water Solubility: 140 g/l (M)
Vapor Pressure: Negligible (E)
Chemistry of Use: Oxidizing agent
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 NaIOa using 02 in the presence of an alkali at 300°C and 34
atm. It is also a product of the thermal decomposition of NaH4I06 • HaO.
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 dxy 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
DRAFT—September 1994
IW3
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Sodium Salt, Dodecyl Benzene Sulfonic Acid
removal through the oxidation of numerous organic, Inorganic, or metallic species present in
the wastewater.
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"® mm Hg (E)
Log Kow: 1.96 (M)
Henry's Law Constant: Not available
Chemistry of Use: Surfactant
Structure:
0
C12h25-^V|°" No+
Boiling Point Not available
Density: 0.5 gfcm3 (E)
Flash Point: Not available
100,000 (M)
Above data are alther 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.
DRAFT—September 1994
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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
bloconcentration 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 biodegradatlon 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-© and accompanying summary
ft***********
DRAFT—September 1994
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Solvent Naphtha, Petroleum,
Light Aliphatic (VM&P Naptha)
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; 112 for
ethycyclohexane, 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"° - 5 atm-m7mole (E)
Chemistry of Use: Solvent
Molecular Formula: CnH2fH2 (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)
Flash Point: 0°C (E)
K^.: 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
11-96
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Solvent Naphtha, Petroleum,
Light Aliphatic (VM&P Naptha)
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 blodegrade at a fast to moderate rate under aerobic conditions. Some components
of solvent naphtha, light aliphatic may adsorb veiy strongly to soil. Solvent naphtha, light
aliphatic may rapidly volatilize from both moist and diy 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 blodegrade at a fast to moderate rate under
aerobic conditions. Some components may significantly bloconcentrate 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 thanlOO 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 blodegrade rapidly and display moderate sludge adsorption or are
moderately biodegradable and display strong adsorption to sludge, the STP fugaclty 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
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Solvent Naphtha, Petroleum, Light Aromatic
Solvent Naphtha, Petroleum, Light Aromatic
^BB^ssasssssBsssaKBBsaBnmasBBBBaBEBaBasaBBX
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)
Log K„w= 3.0 -3.5(E)
Henry's Law Constant: 4.8 x 10 - 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)
Flash Point: 38°C (E)
K^: 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 aromatic 8, but they also may contain up to 30 percent
paraffins and cycloparafllns
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 directiy 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
11-98
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemical* Sotwnt Naphtha, Pttrotoum, Light Aromatic
Environmental Fate
Solvent naphtha, light aromatic Is a mixture of components, chiefly C8-C10 aromatlcs.
If released to soli, 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 11-6 and accompanying summary
* *
DRAFT—Septtmbsr 1994
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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: 8x10-8x 10 atm-m7mole (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: 0.87g/ml(E)
Flash Point: 38°C (E)
K^: 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 C16
aromatics, but they also may contain up to 30 percent paraffins and cycloparaffins. It is
soluble in petroleum solvents and other organlcs.
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 hydroreflnlng 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 IMOO
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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 bloconcentrate 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
ft***********
Tall Oil, Special
Chemical Properties and Information
Tall oil, special [fatty acids, C16 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: dO"3 mm Hg (E)
Log K^: Not available
Henry's Law Constant: Not available
Chemistry of Use: Solvent
and
Structure: CHgfCH^gCOOCHj
and CHgfCH^CH-CHJCHjJTCOOCHg
Boiling Point 325°C(E)
Density: 0.88g/cm3(E)
Flash Point: 200°C (E)
Kg.: 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 add with p-toluene sulfonic acid in
methanol.
DRAFT—September 1994
N-101
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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 blodegrade by p-oxidation. Henry's Law constants estimated for the principal
components of special tall oil range from 2 x 10"5 to 7 x 10"6 atm-m3/mole. If released to soil,
special tall oil would initially be expected to adsorb strongly to soil and readily blodegrade. If
released in water, special tall oil would be expected to rapidly blodegrade 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 biodegradatlon 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
ft***********
DRAFT—September 1994
IM02
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals
Terpineols
Terpineols
Chemical Properties and Information
Terpineols [r-Butyroiactone; dihydro-2(3H)-furanone,
terpineol 318]
CAS# 8000-41-7
Molecular weight: 154
Melting Point: NA
Water Solubility: 2g/L(M)
Vapor Pressure: 0.023 mm Hg (M) (20°C)
Log KqW = 3.33 - 3.46 (E)
Henry's Law Constant: 3x10*® atm-m3/mole (E)
Chemistry of Use: Cleaner/Disinfectant
Ck^is0
Structure: a-terpineol fJ-terpineol y-terpineol
(98-55-5) (1380-87-4) (586-81-2)
Boiling Point: 218°C(M)
Density: 0.9412 g/ml(M)
Flash Point: 75°C (E)
K^: 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-terplneol is made by partial
dehydration of terpln 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 oc-terplneols 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—Septwnbw 1994 N-103
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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 terplneol 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 terplneol In air. If released to
soil, terplneol Is expected to exhibit low adsorption potential. One biological treatment study
suggests that blodegradation may be fast in soil and water; however, data are limited. In
water, hydrolysis, adsorption to sediment, and bloconcentration in aquatic organisms are not
expected to be important for terplneol. Vplatlllzation half-lives for a-terplneol of 15 and 110
days have been estimated for a model river (one meter deep) and a model environmental lake,
respectively. Using a fast blodegradation rate for terplneol In the STP fugaclty model results in
99 percent predicted total removal from wastewater treatment plants; a moderate
blodegradation rate results in 92 percent total removal.
Health Hazard
See Table II-6 and accompanying summaiy
***** * * *****
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)
Log K^: -0.11 (E)
Henry's Law Constant: 4.09X10"9 atm-m3/mole (E)
Chemistry of Use: Solvent
Wa
Structure:
^QNy,CH2OH
Boiling Point: 178°C (M)
Density: 1.0543g/crrr (M)
Flash Point: 84°C (open cup) (M)
Koc: 0.5(E)
Above data are either measured (M) or estimated (E)
This chemical is a hygroscopic and Is colorless. It is flammable In air. It Is mlsclble with
alcohol, ether, acetone, chloroform, benzene. Tetrahydrofurfuiyl alcohol Is manufactured by
catalytic hydrogenation of furfural or furfuiyl alcohol.
DRAFT—September 1994
IM04
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemical* 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
Tetrahydrofurfuiyl 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, tetrahydrofurfuiyl alcohol will be expected to exhibit very high
mobility, based upon its estimated soil adsorption coefficient. Two biodegradation screening
studies have found tetrahydrofurfuiyl alcohol to be readily biodegradable and biodegradation
should be the dominant degradatlve process in soil. Volatilization of tetrahydrofurfuiyl alcohol
from moist soil should not be important, however, some volatilization would occur from diy
surface soil and other dry surfaces. Biodegradation Is expected to be the dominant
environmental fate process for tetrahydrofurfuiyl alcohol in water. Chemical hydrolysis,
volatilization, adsorption to sediment, and bioconcentration are not expected to be
environmentally important. In the atmosphere, tetrahydrofurfuiyl alcohol is expected to exist
almost entirety in the vapor phase. It will degrade In the ambient atmosphere by reaction with
photochemlcally-produced hydroxyl radicals (estimated half-life of 13 hours). Physical removal
from air via wet deposition is probable since tetrahydrofurfuiyl alcohol Is misclble 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—Stptembtr 1094
11-105
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Toluene
Toluene
esssBBHnan
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: 0.5g/L(M)
Vapor Pressure: 55 mm Hg (M) (25°C)
Log K„w= 2.73 (M)
Henry's Law Constant: 6.64 x 10 atm-nr/mole (M)
Chemistry of Use: Solvent
CtH8
Structure:
CH,
0
Boiling Point: 110.6°C(M)
Density: 0.8660420 g/ml (M)
Flash Point: 4°C (M)
K^,: 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 disproportionatlon 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 mlsclble 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-Al203-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
IH06
-------
II. Screen Reclamation Chemicals
Information on Individual Printing Chemical* 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 bloconcentrate 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-© and accompanying summary
a************
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 l^. 2.49 (M)
Henr/s Law Constant 1.72 x 10'2 atm-m3/mole (M)
Chemistry of Use: Solvent
CjHjCIj
Structure: CCigCH,
Boiling Point: 74.2°C (M)
Density: 1.33 g/ml (M)
Flashpoint Not applicable
•V 107 (M)
Physical State: Liquid with sweetish, chloroform-like odor
Above data are either measured (M) or estimated (E)
DRAFT—September 1994
11-107
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals 1,1,1-Trichloroethane
Releases of 1,1,1-trlchloroethane 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-trlchloroethane is expected to rapidly volatilize from both moist
and dry soil to the atmosphere. Blodegradatlon 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 blodegradatlon 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 primaiy 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-trlchloroethane 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-trlchloroethane underwent 99 percent removal due
entirely to volatilization and not blodegradatlon.
DRAFT—September 1994
IM08
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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 ^ 3.78 (M)
Henry's Law Constant: 6.16X10 atm-rrr/mole (M)
Chemistry of Use: Solvent
CjH^
Structure:
iX;
Boiling Point: 169-171°C(M)
Density; 0.876 gfem3 (M)
Flash Point: 54.4°C (M)
K^: 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 C8 hydrocarbon reformate by
superfractlonatlon.
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
IM09
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemical* 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
photochemlcally 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. Blodegradatlon 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-trlmethylbenzene in water. Bioconcentratlon
in fish may be important. Assuming a fast blodegradatlon rate for 1,2,4-trlmethylbenzene in
the STP fugaclty model results in greater thandd 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 miecible In water (E)
Vapor Pressure: 0.022 torr (at 75°C) (E)
0.002 torr (at 20°C)(E)
Log K^: 0.56(E)
Henry's Law Constant: 2.02x10*atm-nr/moie (E)
Chemistry of Use: Solvent
^10H22°4
Structure:
HOCH,CHOCHoCHOCH,CHOCH,
1 1 2| 3
^^3 ^3 CH3
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-1 -methyl ethoxy)-1 -methyl ethoxy]-), which has
CAS number 20324-33-8. It is mlscible 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. Biodegradatlon 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
biodegradatlon 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
-------
II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Tripropylene Glycol Methyl Ether
Health Hazard
See Table II-6 and accompanying summary
ft***********
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
Na^Pty
Structure: NaglPCty
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 Na4P207 +
Na2C03 at 800° or NagHPC^ + NajCOg 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 dlsodlum 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 summaiy
DRAFT—September 1994
IM12
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II. Screen Reclamation Chemicals
Information on Individual Printing Chemicals Trlsodium 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 trisodlum phosphate is
expected to participate in the biological assimilation and mobilization inherent in the natural
phosphorous cycle. If released to soil, trisodlum 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. Trisodlum phosphate may also be
removed from soil during Its assimilation as a nutrient in the metabolism of other organic
compounds. Trisodlum phosphate loss by volatilization to the atmosphere is expected to be
negligible. If released to water, trisodlum phosphate will dissociate into H2P04', HP04"2, and
P04 ions depending on the pH of the receiving medium. In seawater (pH = 8), 87 percent of
inorganic phosphate exists as HP04"2, 12 percent as P04"3, and 1 percent as H2P04" 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 trisodlum phosphate is likely to undergo removal by both wet
and dry deposition processes. If released to a wastewater treatment plants, essentially
complete removal of trisodlum phosphate by precipitation Is expected when aluminum and
iron salts are added.
Health Hazard
See Table II-6 and accompanying summaiy
DRAFT—September 1094
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: 0.1 g/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
5
^Vio
Structure: o-xylene m-xylene p-xylene
ch3 ch3 ch3
Cr d, o
ch3
o-xyl«n« m-xylan* p-xyl«n»
Boiling Point: 137-140°C (M)
Density: 0.864 g/ml(M)
FiashPoint: o: 17°C(M)
m: 29°C(M)
p: 27°C (M)
K^: 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 gallnr^
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
IM14
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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 lnocula 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 fugaclty model
results in 94 percent predicted total removal from wastewater treatment plants.
Health Hazard
See Table II-6 and accompanying summary
DRAFT—September 1994
lt-115
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II. Screen Reclamation Chemicals
Federal Environmental Regulations that Affect Sewn 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 Regulations8
Chemical
CAS*
CWA
Raportablt
Quantity (be)
CWA
IWInsllii
roomy
PoButant
CM
Hazardous Air
PoNutant*
CERCLA
Reportable
Quantity (Ibe)
SARA 313
(TRI)
RCRA
Hazardous
Wasts Code
Acetone
67-64-1
5,000
X
U0O2
Butylacetate
123-86-4
5,000
5,000
Cyctohexanone
108-94-1
5,000
U057
Dichloromethana
75-09-2
X
X
1,000
X
U060
Ethyl acetate
141-78-6
5,000
U112
l8opropanoi
67-63-0
X
Methanol
67-56-1
X
5,000
X
U154
Methyl ethyl ketone
76-93-3
X
5,000
X
U159
D035°
Potassium hydroxide
1310-58-3
1,000
1,000
Sodium hexametaphosphate
10124-56-8
5,000 '
5,000
Sodium hydroxide
1310-73-2
1,000
1,000
Sodium hypochlorite
7681-52-9
100
100
Sodium salt, dodecyl
benzene sulfonic acid
25155-30-0
1,000
1,000
1,1,1-Trichloroethane
71-55-6
X
X
1,000
X
U208
Triethanol amine salt, dodecyi
benzene sulfonic acid
27323-41-7
1,000
1,000
1,2,4-Trimethyftenzene
95-63-6
X
Trisodlum phosphate
7601-54-9
5,000
5,000
Toluene
108-68-3
1,000
X
X
1,000
X
U220
Xylene
1330-20-7
1,000
X
1,000
X
U239
' See following pages foe i description of tach acronym and regulation.
The generic category of glycol e*iers am alio Mid as Hazardous Air Potolants in fte Clean Air Act Amendments.
c In addition to being Deled at a U waste, metiyl athyl ketone also exhMU a characteristic of toxicity which causes it to be considerad hazardous waste.
DRAFT—September 1994
IM16
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II. Screen Reclamation Chemicals
Federal Environmental Regulation 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 Paul 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. Hie 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
Achievable Control Technology (MACT) standards for source categories that emit at least one of
DRAFT—September 1994
IM17
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II. Screen Reclamation Chemicals
Federal Environmental Regulations that Affect Screen Reclamation Chemicals CAA
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 Superfimd
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 (Rg); 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
management requirements. A facility should always check with the State when analyzing
which requirements apply to their activities.
1 The national toll-free number for the National Response Center Is (800)-424-8802; in Washington, D.C., call
(202J-426-2675.
DRAFT—September 1994
H-118
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II. Screen Reclamation Chemicals
Federal Environmental Regulations that Affect Screen Reclamation Chemicals RCRA
Assuming the material Is a solid waste, the first evaluation to be made 1s 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 "fall" a
characteristic test, such as the RCRA test for ignitabillty.
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 lbs.) of hazardous waste per month, or greater than 1 kg (2.2
lbs) of acutely hazardous waste3 per month.
o Small Quantity Generators (SQG) — These facilities generate greater than 100 kg
(approx. 220 lbs.) but less than 1000 kg of hazardous waste per month, and up to
1 kg (2.2 lbs) per month of acutely hazardous waste.
2 Lists of the "F, P, K and U" hazardous wastes can also be obtained by calling the EPA RCRA/Superftind/EPCRA
Hotline at (600) 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 as
in use In the commercial screen printing Industry. (See 40 CFR 261.31-33 for more information).
DRAFT—September 1994
(M10
-------
II. Screen Reclamation Chemicals
Federal Environmental Regulations that Affect Screen Reclamation Chemicals RCRA
o Conditionally exempt small quantity generators (CESQG) — These facilities
generate no more than 100 kg (approx. 220 lbs) per month of hazardous waste and
up to 1 kg (2.2 lbs) 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 tirpp
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
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:
DRAFT-September 1994
11*120
-------
II. Screen Reclamation Chemicals
Summary of the Environmental Hazard Assessment
for the Screen Reclamation Chemicals
Methodology
o Fish acute value (Usually a Fish 96-hour LC50 value)
o Aquatic invertebrate acute value (Usually a Daphnid 48-hour LCg0 value)
o Green Algal Toxicity value (Usually an Algal 96-hour ECgg value)
o Fish Chronic value (Usually a Fish 28-day early life stage no effect concentration
o Aquatic Invertebrate Chronic value (Usually a Daphnid 21-day NEC.
o Algal Chronic value (Usually a Algal 96 hour NEC value for blomass)
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:
See Appendix M for the basis and citations supporting these criteria.
The results of this ranking are summarized in Table II-5. Hie 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 oxldlng agents and highly reactive.
The concern for trisodium phosphate is for phosphorus enrichment of receiving waters leading
to algal blooms.
(NEC).
£ 0.1 mg/L
£ 0.1 to £ 10 mg/L
> 10 mg/L
High
Moderate
Low
DRAFT—Stptembar 1994
IM21
-------
II. Screen Reclamation Chemicals
Summary of the Environmental Hazard Assessment
for the Screen Reclamation Chemicals Results
This relative ranking of toxicity, provides guidance to the selection and use of chemicals
that Eire 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 Eire 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 of fish, 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.
Naphtha Solvents
The monomers associated with the various naphtha mixtures Include linear and
branched paraffins, cyclic paraffins and aroma tics such as naphthalene. The carbon rhn
-------
II. Screen Reclamation Chemicals
Summary of the Environmental Hazard Assessment for the Screen Reclamation Chemicals Hazard Ranking
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
IM23
-------
Table 11-4
Estimated Aquatic Toxicity Values
(Values in mg/L)
riia,iin ¦!
wnenuai
Fish
Acute
Daphnid
Acute
Algal
Acute
Fish
Chronic
Daphnid
Chronic
Algal
Chronic
Concern
Cone."
Acetone
>1000
>1000
>1000
490
100
76
7.6
Alcohols, C8-C10< Ethoxyteted
24
24
24
2.4
2.4
2.4
0.24
Alcohols, C12-C14, Ethoxylated
2.2
22
22
0.22
0.22
0.22
0.020
Benzyl alcohol
56.6
13.5
33.0
8 2
6.07
2.0
0.20
2-Butoxyethanol
>1000
>1000
620
120
33
32
0.32
Butyl Acetate
25
160
1.9
2.5
16
1.4
0.14
Butyroiactone
140
>1000
>1000
14
>100
7.5
0.75
Cyctohexanolt
1.4
Cyctohexanone
950
950
550
100
29
28
2.8
d-Limonene
0.86
1.1
0.76
0.16
0.14
0.27
0.014
Diacetone alcohol
>1000
>1000
>1000
745
154
124
12.4
Dichloromethane
320
320
190
36
12
13
1.2
Diethyl adipate
44
295
3.4
4.4
29.5
2.6
0.26
Diethyl glutarate
78
830
6.0
7.8
83
4.6
0.46
Diethylene glycol
>1000
>1000
>1000
>1000
>1000
656
70.0
Diethytene glycol monobutyl ether
>1000
>1000
760
140
41
40
4.0
Diethylene gyteol butyl ether acetate
41
263
3 2
4.1
26.3
3.1
0.31
Disopropyl adipate
24
94
1.9
2.4
9.4
1.5
0.15
Dimethyl acfyate
140
>1000
11
14
>100
8.4
0.84
8 Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
t Data wi be inserted in the final version.
-------
Table 11-4 (cont)
Estimated Aquatic Toxicity Values
(Values in mg/L)
| Chemical
Fish
Acule
Daphnid
Acute
Algal
Acute
Fish
Chronic
Daphnid
Chronic
Algal
Muinnln
wnromc
Concern
Cone*
Dimethyl glutarate
246
>1000
18.3
25.0
650
13.6
1.0
Dimethyl succinate
165
>1000
12.4
17.0
530
9.2
1.0
Dipropylene glycol methyl e#wr
>1000
>1000
>1000
184
149
877
14.9
Dtpropylene glycol metfiyl etor
800MB
674
>1000
49
67.4
>100
36
3.6
Dodecyl benzene sulonic acid
2.6
2.6
0.5
0.4
0.4
0.13
0.01
kbIbIb
64
>1000
4.8
6.4
>100
3.6
0.36
QImJ
tnyi wtiflB
143
>1000
11
14.3
>100
8
0.8
Bhyloleoto
N.E.S.b
N.E.S.
N.E.S.
N.E.S.
N.E.S.
N.E.S.
N.E.S.
unxyunea casior oi
0.07
0.10
0.08
0.02
0.03
0.07
0.002
EfaxybtiBd nonylphenol
(np 4-9.5)
10
2.0
2.0
02
0.2
0.5
0.02
EVraiypropanol
>1000
>1000
>1000
>1000
311
227
20.0 |
Bhaxypropyt acetate
80.0
>1000
6.1
8.0
102
4.5
0.5 |
Furfuryl alcohol
>1000
>1000
>100
147
31.6
25.9
3.0 I
Isobutyl bobutyrate
12.7
45.6
1.03
1.3
4.6
0.8
0.06 |
bobutyl obate
N.E.S."
N.E.S.
N.E.S.
N.ES.
N.E.S.
N.E.S.
N.E.S. I
a Concern concentration is derived by (fviting tie lowest chronic value (in mg/L) by 10.
b N.ES. - No Adverse Effects expected in a saturated solution during the specified exposure period.
e Estimated toxicity at pH 7.0.
d Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United Stales Atomic Energy Commission, June 1973.
(Environmental Effects Rtes)
t Data wtt be inserted in the final version.
-------
Table 11-4 (cont)
Estimated Aquatic Toxicity Values
(Values in mg/L)
Chemical
Rsh
Acute
Daphnid
Acute
Algal
Acute
Fish
cnronic
Daphnid
Chronic
Algal
Chronic
Concern
Cone.*
Isopropanol
>1000
.1000
>1000
285
62
51
5.1
Methanol
>1000
>1000
>1000
777
128
90.0
9.0 I
Metwxypropanoi acetate
305
>1000
22.4
30.5
>1000
16.6
2.0 I
1 Moiiyt 4 (1-methyi-ethenyt)
cydohrane (fenonene)
0.86
1.1
0.76
0.16
0.14
027
0.014 |
Metiyleliyl ketone
>1000
>1000
>1000
224
53
45
4.5 I
Methyl lactate
243
>1000
18
24.3
>100
13
1.3
Mfceral spirits (straight run naptha)
Cw Linear
N.E.S.
N.E.S.
0.02
0.004
0.008
0.021
0.001
Mmrai spviB (RQni nyanaroatea)
Linear
N.E.S.
N.E.S.
0.02
0.004
0.006
0.008
0.001
|l I,,, nltii 1 IT 1
THimnfpfmm*
>1000
>1000
>1000
>1000
373
265
26.5
2-Octadecanamine, N,N-dmethyl N-
l-i.i
09008T
0.002
PeriodfcAdd
SI
£1
£1
<0.1
£0.1
£0.1
£0.01 I
Phosphoric Add, mixed ester, with
Bopropanoi ara enoxyiaiea
tridecanotf
0.018
Potassium hydroxide^
>1000
>1000
>1000
>100
>100
>100
>10
a Concern concenfralion is derived by (Striding 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 Fies)
t Data wM be inserted in the final version.
-------
Table 11-4 (conl)
Estimated Aquatic Toxicity Values
(Values in mg/L)
1 Chemical
Rah
Acute
Daphnid
Acute
Algal
Acute
Fish
Chronic
Daphnid
Ahrnriln
UnfOutC
Algal
Chronic
Concern
Cone."
Propylene carbonate
177
>1000
13
17.7
>100
10
1.0
Propylene glycol
>1000
>1000
>1000
>1000
495
329
30.0
Propylene glycol methyl ether
>1000
>1000
>1000
>1000
210
158
15.8
Propylene glycol melhy! ether acetate
304
>1000
22
30.4
>100
17
1.7
jShi
NES
NES
NES
NES
NES
NES
NES
Sica, fumed
NES
NES
NES
NES
NES
NES
NES
Sodum bisuKato
>100
>100
>100
10.0
10.0
10.0
1.0
Sodum hexameta-phosphate
>100
>100
<1.0
0.1
>10.0
0.06
0.006
Sodum hydroxide"*
>1000
>1000
>1000
>100
>100
>100
>10
Sodum hypochlorite1'*
<1.7
<2.0
<2.0
<0.17
<05
<0.2
<0.02
Sodum lauryl sulfate
2.6
2.6
0.5
0.4
0.4
0.13
0.01
sodum measacater
a
Sodum periodale
£1
£1
£1
£0.1
£0.1
£0.1
£0.01
Sodum sak, dodecyl benzene sulfonic
add
2.6
2.6
0.5
0.4
0.4
0.13
0.01
Solvent Naphtha Bght alphatic C5 -
s
0.64
0.86
023
0.05
0.05
0.11
0.005 |
a Concern concentration is derived by dvidng 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.
No adverse effects expected in a saturated solution during prescribed test duration,
t Data w9 be inserted in ftie final version.
-------
Table 11-4 (cont)
Estimated Aquatic Toxicity Values
(Values in mg/L)
I Chemical
Fish
Acute
m 1—»-¦
impnnw
Acute
Algal
Acute
Fish
Chronic
Dephnkl
Chronic
Algal
Chronic
Concern I
Cone.* |
I Solvent Naphtha ight aromatic C8-
c»
5.6
6.7
4.5
0.9
0.6
1.0
Solvent Naphtfia heavy aromatic C8 -
c,8
5.6
6.7
4.5
0.9
0.6
1.0
0.06 1
Tafloi,speciaft
a
Terpineoks (Mxed Isomers)
28
31
20
4.0
2.1
3.0
0.21
Tetrahydrofurfuryl alcohol
>1000
>1000
>1000
268
64.6
56.7
6.0
| Toluene
14
16
10
2.0
1.1
1.6
0.11
1,1,1-TricNoroefcane
34
38
24
4.8
2.4
3.2
0.24
1£4-trimethyt>enzenet
0.015
Trisodkim phosphate5
>100
>100
<1
.10
>10
0.06
0.006
Xylenes, (mixed isomers)
3.5
4.1
2.8
0.57
0.40
0.64
0.04
* Concern concentration is derived by dividing the lowest chronic value (in mg/L) by 10.
b Estimated toxicity at pH 7.0.
0 Toxicity of Power Plant Chemicals to Aquatic Life. WASH-1249, United States Atomic Energy Commission, June 1973.
(Environmental Effects Rtes)
f Data wi be inserted in the final version.
-------
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
Lowest Value (mg/L)
Chronic Eco Hazard Rank
Solvent naphtha (light aliphatic)
0.004
H
Mineral spirits (light hydrotreated)
0.004
H
Mineral spirits (straight run)
0.004
H
Trisodium phosphate
0.06
H
2-Octadecanamine, N,N-dimethly N-oxide
0.02
H
Alcohols, ethoxyiated C12-C14
0.1
H
Periodic acid
0.10
H
Sodium periodate
0.10
H
Phosphoric Acid, mixed ester, with
isopropanol and ethoxyiated tridecanol
0.18
H
1 -methyl-4-(1 -methylethenyl) cyciohexane
(limonene)
0.14
M
1,2,4-trimethylbenzene
0.15
M
Sodium hypochlorite
0.17
M
Xylenes
0.40
M
Solvent naphtha (light aromatic)
0.60
M
Solvent naphtha (heavy aromatic)
0.60
M
Toluene
1.1
M
Butyl acetate
1.4
M
Diisopropyl adipate
1.5
M
Terpineols
2.1
M
1,1,1-trichloroethane
2.4
M
Alcohols, ethoxyiated, C8-C10
2.5
M
Diethyl adipate
2.6
M
Diethylene glycol butyl ether acetate
3.1
M
Ethyl acetate
3.6
M
Diethyl glutarate
4.6
M
Butyrolactone
7.5
M
Ethyl lactate
8.0
M
Dimethyl adipate
8.4
M
DRAFT—September 1994
IM29
-------
II. Screen Reclamation Chemicals
Summary of Aquatic Hazard Information for Scraen Reclamation Chemicals Table 11-5
Table 11-5
Ecological Hazard Ranking of Screen Reclamation Chemicals Based on the Estimated
Chronic Values
Chemical
Lowest Value (mg/L)
Chronic Eco Hazard Rank
Propylene carbonate
10
M
Dichloromethane
12
L
Methyl lactate
13
L
Cyclohexanone
28
Cyclohexanol
14
L
Propylene glycol methyl ether acetate
17
L
2-Butoxyethanol
32
L
Dipropylene glycol methyl ether acetate
36
L
Diethylene glycol monobutyl ether
40
L
Methyl ethyl ketone
45
L
Isopropanol
51
L
Acetone
76
L
Sodium hydroxide
100
L
Potassium hydroxide
100
-
L
Tripropylene glycol methyl ether
120
L
Diacetone alcohol
124
L
Dipropylene glycol methyl ether
149
L
Propylene glycol methyl ether acetate
158
L
N-methylpyrrolidone
265
L
Isobutyl oleate
a
L
Ethyl oleate
a
L
Sodium metasilicate
a
L
Tall oil, special
a
L
a 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
-------
II. Screen Reclamation Chemicals
Summary of Aquatic Hazard Information for Sewn Reclamation Chemicals Table 11-5
Explanation of Table 11-6
The TOX ENDPOINT" column lists adverse toxlcologlcal 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. Hie 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. Hie RfD is usually expressed as an oral dose in
mg/kg/day. The RflC 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). Hie 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. B1 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
IM31
-------
II. Screen Reclamation Chemicals
Summary of Human Hazard Information
for Screen Reclamation Chemicals Explanation of Table ll-€
o Group D — not classifiable as to human carcinogenicity
o Group E — evidence of noncarcinogenicity for humans
DRAFT—September 1994
IM32
-------
Table 11-6
Human Health Hazard Effects
fll. , ail, ,1
u»m m
CasNo.
Tox
Endpoint
RfCVRfC
N0AEL7
LOAEL
Slope/
Unit Risk
WOE
Comment
Acetone
67-64-1
neur, chron
-0.1 mg/kg/day
(kidney)
D
Alcohols, ettioxyiated
C8-C10
71060-57-6
no data found
Alcohols, ettwxytated
C12-C14
68439-50-9
Benzyl alcohol
100-51-6
dev, neur,
chron
0.3 mg/kg/day
(forestom.
hyperplasia)
not care in NTP
study,not mutag. in
several tests
2-Butaxyrihanol
111-76-2
dev, chron
RfC in review
NTP carcinogenicity
study in review
Butyl acetate
123-86-4
dev, new,
chron
Butyroiactone
96-48-0
dev*, repro,
neur, chron
Cydohexanol
108-93-0
dev, repro,
neur, chron
Cydohexanone
108-94-1
gene.dev.rep
ro,neur,chron
5 mg/kg/day
(decreased wt
gain)
1000
ppm-N,650
ppm-N
1000 ppm NOAEL for
repro tox, 650 ppm
NOAEL for dev tox
Diacetone alcohol
123-42-2
neur, chron
-------
Table 11-6 (cont.)
Human Health Hazard Effects
vnenm ravno
Cm No.
Tax
Endpoint
RfEVRfC
NOAEU
LOAEL
Slope/
Unit Risk
WOE
Comment
Dichloromethane
75-09-2
car, gene,
dev.neur,
chron
0.06 mg/kg/day
(Bver)
4.7E-7/ug/
m3
B2
RfC in review
Diethyl acipale
141-28-6
gene, dev
Diethyl glutarate
818-38-2
Diethytene glycol
111-46-6
dev.neur,
chron
negative in Salmonella
mutagenicity test
Diethytene glycol monobutyl
dher
112-34-5
dev, chron
51
mg/kg/day-
L, 2000
mg/kg/day-
N
LOAEL for chronic,
deimal NOAEL for dev
tox
Diethytene glycol butyl efter
acetate
124-17-4
dev, chron
RfC in review, sec. 4
data
DSsopropyl adipate
6938-94-9
Dimethyl adpate
627-93-0
dev, chron
chron, repro(- result)
studies on mixture of
dibasic esters
Dimethyl glutafate
1119-40-0
chron
chron, dev(- result),
repro(-) studies on
mixture of dibasic
eaerc
-------
Table 11-6 (cont.)
Human Health Hazard Effects
g"-l 1 111 1 ,1
WilBRNCM IWN
Cat No.
Tox
Endpoint
RfDffifC
NOAEL/
LOAEL
Slope/
Unit Risk
WOE
Comment
DimeBiyt succinate
106-65-0
chron
chron, dev(- result), I
repro{-) studies on 1
mixture of dtoasic
esters
^propylene glycol methyl
«tar
34590-94-8
neur, chron
health effects at high
concentrations
Dipropytono glycol methyl
ether tcstalB
88917-22-0
Dodecyl benzene sulfonic
acid, TEA sal
27323-41-7
only acute toxicity data
found
Bhoxytated castor ol
61791-12-6
very little data
EttoxytalBd nonytphenoi
9016-45-9
Bhontypropanol
52125-53-8
dev. chron
0.7 mgfc^day
dev tox at high doses |
Etaxypropyt acetate
54839-24-6
Bhyl acetate
141-78-6
neur, chron
health effects at high 1
dose |
m,. j
BCMB
97-64-3
new*
Ely OMR
111-62-6
Ethylene glycol propyl eiwr
2807-30-9
dev. chron
Furiwyl alcohol
98-00-0
neur
NIOSH 40 mg/m3 TWA; 1
60 mg/m3 STEL (skin); |
NT? carc in progress |
-------
Table 11-6 (cont.)
Human Health Hazard Effects
Chemical Nnw
CasNo.
Tox
rn Ai nl«t
enopomc
RfDIRfC
NOAEL/
LOAEL
Slope/
Unit Risk
WOE
Comment
Isobutyl isobutyrate
97-85-8
no effects in subchronic
rat study up to 1000
mg/kg/day
Isobutyl oteate
10024-47-2
Isopropanol
67-63-0
dev.neur,
chron
limited chronic data |
rftimonene
5989-27-5
dev, chron
150
mg/kg/day
LOAEL
-
LOAEL on kidney effect
Methanol
67-56-1
gene, dev,
neur, chron
0.5 mg/kg/day
(liver)
in review at NTP
Methyl ethyl ketone
78-93-3
dev.neur,
chron
0.6 mg/kg/day,
1.0mg/m3
D
RfD/RfC on
developmental toxicity
Methyl lactate
547-64-8
Mineral spirits (straight run
naphtha)
64741-41-9
Mineral spirits (Bght
nyarovMteaj
64742-47-8
N-methylpyrro#done
872-50-4
dev. repro,
chron
175
mg/kg/day
NOAEL
NOAEL on
developmental toxicity
2-Octadecanamine,
N,N-dimethyl, N-oxide
71662-60-7
-------
Table 11-6 (cont.)
Human Health Hazard Effects
Chanted Name
CasNo.
Tok
*—¦ — »-«
cflQpOHlK
RflVRfC
NOAELV
LOAEL
Slope/
UnHRisk
WOE
Comment
Periodfcadd
13444-71-8
omfizer
Phosphoric acid, mixed ester
wfjsopropanol and
¦ ^ i f-• - -*
iwroiOMq twecanot
68186-42-5
Potassium hydroxide
1310-58-3
corrosive
Propylene carbonate
106-32-7
CTFA assess; tech
grade may contain
propylene oxide, a
carcinogen
Propylene glycol
57-55-6
chron
20mg/kg/day
negative Genetox for
SCEandceH
transformation
Propylene glycol mefiyl
elwr
107-98-2
dev.neur
RID 0.7
mg/kgfday, RfC
2.0mg/m3
3000
Ppm-L
LOAEL ondev, RfCon
neur, RID on liver,
kidney
Propylene glycol mefiyl
juui^iLk
6Vi6v
108-65-6
SHca
7631-66-9
carc, chron
crystalline sHca is IARC
2A carcinogen
Sica, fumed
112945-52-5
Sodum bisutfate
10034-88-5
corrosive
-------
Table 11-6 (cont)
Human Heath Hazard Effects
vVMHQi raBnB
Cm No.
Tot
Endpoint
RfDffifC
NOAEL/
LOAEL
Slope/
Unit Risk
WOE
Comment I
Sodwm hexamrtaphosphate
10124-56-8
chron
not mutagenic in
Salmonella or S.
cerevisiae; chron
effects at high doses
SocHum hydroxide
1310-73-2
corrosive
Sodum hypochlorite
7681-52-9
gene, dev.
chron
oxidizer
SodfembuiylsuKate
151-21-3
dev, chron
300
mg/kg/day,
400
mg/kg/day-
N
NOAELS are 300
mg/kg/day de/t tox and
400 mg/kg/day chronic
tox
Sodum metasflcate
6834-92-0
dev.
corrosive
booum penooaie
7790-28-5
oxidizer
fclnnliA ii H L
rapnra, ijni a^xiaac
64742-89-8
It ii.Lii i ilxa at
Napma,agraaromasc
64742-95-6
dev
developmental toxicity
data on C9 fraction
Socflum sal, dodecyf
benzenesuKonic add
25155-30-0
Solvent naphtia, heavy
aromatic
64742-94-5
Tafl oi, special
68937-81-5
I
-------
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
IIM
-------
III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Environmental Release* 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 115
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
111-2
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III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Environmental Releases and Occupational Exposure Assessment
Step 3. Haze removed
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 11-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 1994. 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
Average value
Number
Units
Number of employees involved in ink removal
3
employees
Hours per employee per day in ink removal
1
hours
Number of employees in screen reclamation
2
employees
Hours per employee per day in screen reclamation
1.5
hours
Average number of screens cleaned per day
6
screens
Average screen size
2,127
in2
Size of combined screen reclamation/ink removal area
80
ft2
Amount of ink remover per screen
8 (traditional)
4 (alternative)
oz
Amount of emulsion remover per screen
3.5
oz
Amount of haze remover per screen
3
oz
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
111-3
-------
III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Environmental Release* and Occupational Exposure Aaaewment 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 1. Actual screen cleaning operations. Air releases are due to volatilization
of chemicals from the screen surface. Unvolatillzed 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 pall.
° 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 Omlcron.
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
o volatilization from waste dirty rags
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
IIM
-------
III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Environmental Release* 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 removed 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
landfllling 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 Omlcron 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
o generation and ventilation rates are constant over time
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III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
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Environmental Releases and Occupational Exposure At—Mment Estimation Methodology
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 pall 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 corroslvlty 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:
where
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Environmental Relesses and Occupational Exposure Assessment Overview of Methodology
^ O.QflMP
~kF~ \|
(1)
nz
G = Volatilization rate, g.m^.s"1
M s Molecular weight, g.mol"1
P « Vapor pressure, mm Hg
R = Gas constant, 0.0624 mmHg.m3.mor1 .K"1
T = Temperature, K
Dab = Diffusivity, cm2,^1
vz « Air velocity, m.s"1
z = Distance along pool surface, m
The air velocity is assumed to be vz ¦ 100 ft.min'1. Since *>ab is not available for many of the
chemicals of interest to CEB, the following estimation equation is used:
D -4.09xlQ-5r1J(l/29+l/M)a5M-°33 (2)
ab p
where
"ab " Diffusion coefficient in air, cm2.sec"1
T » Temperature, K
M ¦ Molecular weight, g.mol'1
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:
r l.lxltfTGA \
v= AfQk
where
C,
T
G
M
A
0
k
Airborne concentration, ppm
Ambient temperature, K
Vapor generation rate, g.m'2.sec'1
Molecular weight, g.mol"1
Area of surface, rrr
Ventilation rate, ft.min*1
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 ft^.min"1 to 3,500 ft.min"1. An effective
ventilation rate of 250 ft®/min was used, which was equal to the mixing factor of 0.5
multiplied by the lowest ventilation rate (500 ft^/minj. Hie value of from equation (3) is
converted to mass/volume units as follows:
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Environmental Releases and Occupational Exposure Assessment Overview of Methodology
(4)
M
where
Cm = Airborne concentration, mg.m"3
c(, = Airborne concentration, ppm
M = Molecular weight, g.mol
Vm = Molar volume of an ideal gas, l.mol"1
At 25 °C, Vm has the value 24.45 Lmol"1. 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 C
has been determined. Equations (3) and (4) can be combined to yield the following, given the™
"typical case" choice of ventilation parameters:
I=0.48GAt (5)
where
I = Total amount inhaled, mg.day"1
G = Vapor generation rate, g.m^.s"1
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
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 how each
day in a room with a ventilation rate of3,000fP.mtn"1. The screen area is 2,217 in2. Assume
a mixing factor ofk = 0.5.
Toluene has the following physical properties:
Molecular weight: 92.14 g.mol
1
Vapor pressure: 28 mmHg at 25 °C
Diffusion coefficient: 0.076 cm .sec
Using these values in equation (1) gives:
Generation rate G: 0.28 g.s^.m'2
Airborne concentration: 141 ppm (Gy)
534 mg.m"3 (Cm)
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"1, then the estimated airborne concentration Is Cy « 4,216 ppm.
Exposures and volatilization rates are calculated by multiplying the pure-component values
from Exhibit 4 by the mole fraction of that component in the liquid phase. A typical screen
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Environmental Release and Occupational Exposure Assessment Uncertainties
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 = 1107 g
The amount volatilized will be:
0.01087 g.m^.s"1 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:
1.49 x 1.37 x 3600 s - 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 tiy 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.
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Environmental Release and Occupational Exposure Awsment 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 a i on
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
the details of the screen cleaning process at each site, the solvent temperature, the air
2Sources: Health Hazard Evaluation Report No. HETA 84-299-1543, (Chicago, ILiImpressions Hand printers).
Health Hazard Evaluation Report No. HETA 81-383-1151, (Chicago, IL:Main Post Office).
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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 cnr) 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 Jar the Preparation qf
Engineering Assessments. (February 28, 1991), p. 4-36.
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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:
8.24 x 10"8M0,835P(— +—)°'25v°5/if
Ofe- 29 M (6)
0.5
where:
GAt = Mass released (= flux x area x time)
M = Molecular weight (g.mol"1)
P = Vapor pressure (mmHg)
vz = Air velocity (fiLmin*1)
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 uz are
assigned fixed values. These are 298 K, 1 atmosphere, and 100 ft.mln"1, respectively. In
addition, the surface is taken to be square, so that z = A05. Thus, the mass of material
released has the following dependencies:
GAt<*M0Xii(— +—)025 (7)
29 M '
GAt<*P (8)
QAt<*A015 (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:
QAt=—— (10)
(24.45)(760) }
where:
M = Molecular weight (g.mol*1)
P = Vapor pressure (mmHg)
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Release Amounts
vs. Occupational Exposures
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 1s 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
/ = Inhaled dose (mg.day'1)
Q = Ventilation rate (ft^min"1)
k = Mixing factor (dimenslonless)
In this report, Q is fixed at 3,000 ft^min"1 and k ¦ 0.5. Thus,
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 M°,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 Fonder and Guggenheim {Statistical
Thermodynamics, Cambridge, 1956), for a liquid whose intermolecular potential energy can be
represented by the Lennard-Jones function:
(13)
/«0.48GAf
(14)
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III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
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Environmental Release and Occupational Exposure Assessment Release Amounts
vs. Occupational Exposures
p=1158-^c'8136(e/*r) (16)
As noted In the development of an expression for Dab, the dlffusivity, in Appendix K of the CEB
Manual, the quantities e and o can be roughly correlated with molecular weight. When these
parameters Eire regressed against experimental data for C^-Cg and substituted into the
expression for vapor pressure, a relationship of the following form is observed:
/?«M0,23e -M°S1 <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
M069e "M°" (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
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
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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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Overview by Media
Air
Releases to air are from evaporation of chemicals during the process. This may be from
allowing screens to diy 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 countxy 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 countxy 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/m . We would say that
there is less than an order of magnitude difference.
Methodology References
Air Modeling Parameters for ISCL.T90
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 Padllty 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)
o Standard Polar grid, with 3 calculations per segment.
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o Single point of release at the facility location.
o Release height of 3 meters for fugitive releases from an area
source of 10 meters by 10 meters (100 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 vaiy 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
The methodology used is outlined in its entirety in a report from VERSAR,
Inc for Task 1-11, subtask 101, from Contract 68-D3-0013. Copies of this
report are available from either VERSAR, Inc or from Sondra Hollister at EPA.
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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
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.
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Population Exposure Assessment for Screen Reclamation Processes Methodology References
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 welght-of-
evidence categories listed below.
0 Group A - human carcinogen
o Group B - probable human carcinogen. B1 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 noncarclnogenicity 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 dally 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.
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Population Exposure Assessment for Screen Reclamation Processes Methodology References
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 subchronlc 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.
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. Hie major manifestations of developmental toxicity Include: (1)
death of the developing organism. (2) structural abnormality. (3) altered growth, and (4)
functional deficiency.
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Population Exposure Assessment for Screen Reclamation Processes Methodology References
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 RfDjyj. 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 RfC^) 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: Hie 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 toxlcologlcal 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 dally 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.
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.
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Background and Methodology for Performance Demon«tratlon» . Background
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 them 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. Hiis
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, 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.
Product systems are whatever combination of specific ink removers, emulsion removers, and haze removers
the participating manufacturer submitted or recommended.
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Background and Methodology for Performance Demonstrations Background
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 veiy 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 UV-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 Demonstration*
SPA] 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.
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;
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Background and Methodology for Performance Demonstrations Background
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 Qnk
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 Collection
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).
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.
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Background and Methodology for Performance Demonstration! Background
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:
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.
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Background and Methodology for Performance Demonstrations Background
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 summaiy 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 summaiy statistics from the performance
demonstrations at the volunteer printing facilities and at SPTF (for three ink types). For a
quick summaiy of the results, the table providing summary statistics is very helpful.
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
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Chemical Volume Estimates
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 th6 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
estimated to be 2,916 square inches. This value differs from the average in the appendix due
to this normalization to Incorporate incomplete responses.
sSRI. selected reports from 1985 to 1993. Chemical Economics Handbook. SRI International. Menlo Park,' CA.
®USrrc. 1993 and 1994 Synthetic Organic Chemicals: United States Production and Sales. 1991. U.S.
International Trade Commission, Washington, DC.
7Manvffle. selected reports from 1990 -1993. Manvllle 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)
9Klrk-Othmer, 1981, "Olls.essentlal." Om: Klrk-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.
1 'Screen Printing Association International, 1990 Industry Profile Study, (Halifax, Va.: 1991).
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Screen Reclamation Chemical Usage Number of Screens Cleaned
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 Share^ = AMt/AMt+Tra Market Share^ = ATra/AAlt+Tra
Where:
denotes Alternative Product
Tra denotes Traditional Product F
A = total screen area cleaned dally - £ [# 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 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
12 A substantia] 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.
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Screen Reclamation Chemical Usage Number of Screen* Cleaned
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 dally 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 of272,710 screens cleaned per
day.
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—Stptwnbw 1994 M-29
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III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Screen Reclamation Chemical Usage National Eatimatea of Screen Reclamation Producta
Table 111-2
Information for Screen Reclamation
Chemical Volume Estimates
Description
Data
Average screen size8
2916 sq
in
Per screen product usage8
Product
Oz/Screen (Gal/Screen)
ink remover (traditional)
98 (0.7663)
Ink remover (alternative)
22 (0.1731)
Emulsion remover
8.8 (0.0685)
Haze remover
2 (0.0160)
Ink remover market sharea,d
Traditional - 65.6%
Alternative - 34.4%
Screens cleaned per day5
Range of # of Screens
Value used
% of facilities
1 to 10
5.5
57.0
11 to 20
15.5
23.2
21 to 30
25.5
9.8
31 to 40
35.5
4.1
41 or more
50
5.9
Number of screen printing facilities0
20,000
Number of screens cleaned per day11
272,710
'Based on raw data from WPQ for screen printing adjusted for incomplete responses.
bSPAPs 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
111-30
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ill. 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 | Market Share (%)
Ink Remover, Traditional Formulations
Xylene
20
Mineral spirits
20
Acetone
20
Lacquer thinner*
40
Ink Remover. Alternative Formulations
Propylene glycol methyl ether
10
Methoxypropanol acetate
10
Dibasic esters6
30
Diethylene glycol
3
Propylene glycol methyl ether acetate
5
Terpineois/d-limonene (50/50)
7
Propylene glycol
5
Tripropylene glycol methyl ether
15
Diethylene glycol butyl ether
10
Cyclohexanone
5
Emulsion Remover
Bleach (sodium hypochlorite) (12% solution in water)
10
Sodium metaperiodate (4% solution in water)
80
Periodic acid (10% solution in water)
5
Sodium blsulfate (50% solution in water)
5
Haze Remover
Sodium hydroxide (20% solution in water)
25
Potassium hydroxide (20% solution in water)
25
Sodium hypochlorite (12% solution in water)
10
Mixture of 65% Glycol ethers6 and 35% N-methylpyrrolidone
10
DRAFT—September 1994
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III. Background information on methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation _
Screen Reclamation Chemical Usage Estimate, of Chemical Usage for Screen Reclamation
Table III-3
Estimated Market Share for Screen Reclamation Products
Chemical
Market Share (%)
Mixture of 10% d-limonene, 20% Sodium hydroxide, and 70% water
10
Mixture of 10% Xylene, 30% Acetone, 30% Mineral spirits, and 30% Cyclohexanone
20
®The 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%
"This category includes dimethyl glutarate, dimethyl adipate, dimethyl succinate in a 2:1:1 ratio.
^is 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) an>j
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 111-2) 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
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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
Volume
(Gallons)
Weight
(Pounds)
Acetone
6,920,000
Alcohols, C8-C10, ethoxylated
NAa
NA
Alcohols, C12-C14, ethoxylated
NA
NA
Benzyl alcohol
NA
NA
2-Butoxyethanol
NA
NA
n-Butyl acetate
1,920,000
Butyrolactone
NA
NA
Cyclohexanol
NA
NA
Cyclohexanone
270,000
Diacetone alcohol
NA
NA
Dichloromethane
NA
NA
Diethyl adipate
NA
NA
Diethyl glutarate
NA
NA
Diethylene glycol
122,000
Diethylene glycol monobutyl ether
420,000
NA
Diethylene glycol butyl ether acetate
NA
NA
Diisopropyl adipate
NA
NA
Dimethyl adipate
2,700,000
Dimethyl glutarate
609,000
5,500,000
Dimethyl succinate
304,000
Dipropylene glycol methyl ether
NA
NA
Dipropylene glycol methyl ether acetate
NA
NA
Dodecyl benzene sulfonic acid, methanol amine salt
NA
NA
Ethoxylated castor oil
NA
NA
Ethoxylated nonylphenol
NA
NA
Ethyl acetate
NA
NA
DRAFT—September 1994
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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
Volume
(Gallons)
Weight
(Pounds)
Ethyl lactate
NA
NA
Ethyl oleate
NA
NA
Fumed silica
NA
NA
Furfuryl alcohol
NA
NA
Isobutyl isobutyrate
2,630,000
Isobutyl oleate
NA
NA
Isopropanol
NA
NA
d-Limonene
1,100,000
Methoxypropanol acetate
420,000
Methanol
610,000
Methyl ethyl ketone
3,720,000
Methyl lactate
NA
NA
Mineral Spirits
6,920,000
N-Methyl pyrrolidone
38,000
2-Octdecanamine, N.Ndimethyl, Noxide
NA
NA
Periodic acid
1,020,000
Phosphoric acid, mixed ester w/isopropanol and ethoxylated tridecanol
NA
NA
Potassium hydroxide
1,060,000
Propylene carbonate
NA
NA
Propylene glycol
203,000
Propylene glycol methyl ether
418,000
Propylene gycol methyl ether acetate
217,000
Silica
NA
NA
Silica, fumed (amorphous, crystalline-free)
NA
NA
Sodium bisulfate
2,350,000
Sodium hexametaphosphate
NA
NA
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 lil-4
Estimated Annual Amount of Chemicals Currently Used in Screen Reclamation
(Liquids are reported by volume, solids by weight)
Volume
Weight
Chemical
(Gallons)
(Pounds)
Sodium hydroxide
1,450,000
Sodium hypochlorite
69,000
Sodium lauryl sulfate
NA
NA
Sodium metasilicate
NA
NA
Sodium periodate
11,700,000
Sodium salt, dodecylbenzene sulfonic acid
NA
NA
Solvent naphtha, heavy aromatic
NA
NA
Solvent naphtha, light aliphatic
2,160,000
Solvent naphtha, light aromatic
NA
NA
Special tall oil
NA
NA
Terpineols
1,100,000
Tetrahydrofurfuryl alcohol
NA
NA
Toluene
2,670,000
1,1,1-Trichloroethane
NA
NA
1,2,4-Trimethylbenzene
NA
NA-
Triethanolamine salt, dodecyl benzene sulfonic acid
NA
NA
Tripropylene glycol methyl ether
623,000
Trisodium phosphate
NA
NA
Xylene
6,880,000
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
DRAFT—September 1994
111-35
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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
information for the cost estimates. Information from the performance demonstrations was
sunnlemented by several other sources, including (1) product evaluations undertaken by the
Screen Printing Technical Foundation (SPTF), (2) equipment specifications from manufacturers
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 in ) 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:
° 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
DRAFT—September 1994
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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
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 industry multiplier of 2.01 (calculated from SPAI's 1992 Operating Ratios Study)
to account for fringe and overhead costs.
o 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
Ink Remover
Emulsion Remover
Haw Remover
Alpha
$18.18/gallon
(5 gallons/$91)
(55 gallons/$850)
$4.00/gallon
$9.39/gallon
(5 kg/$50)
Beta
$15.10/gallon
Ink remover only
Ink remover only
Chi
$31,20/gallon
(5 gallons/$156)
(55 galions/$1,315)
$32.00/gallon
(5 gallons/$160)
(15gallons/$438)
(55 galk>ns/$1,238)
$31.20/gailon
(5 gallons/$156}
(55gallons/$1,315)
Delta
$20.00/gallon
(5 gallons/$100)
(55 gallons/$900)
$32.00/gallon
(5 gallons/$160)
(15 galtons/$438)
(55gallons/$1,238)
$20.00/gallon
(5gallons/$100)
(55 gattons/$900)
Epsilon
$7.80/gallon
(5 gallons/$39)
$13.54/gallon
(5 kg/$149)
$1.09/galion
(15 kg/$36)
Gamma
$10.90/gallon
(25 liters/$72)
(5 gallons/$55)
$1.60/lb
(15 kg/$53)
$9.39/gallon
(25 liters/$62)
(5 galk>ns/$52)
Mu
($7.76/gallon)
(20 liters/$41)
(5 gallons/$39)
$10.34/gallon
(3 five liter units/$41)
(5 gallons/$52)
$7.57/gal!on
(5 five liter units/$50)
(5 galtons/$189)
Phi
$24.95/gallon
$24.95/gallon
$39.95/gallon
DRAFT-September 1994
111-37
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III. BACKGROUND INFORMATION ON METHODOLOGIES USED IN SCREEN RECLAMATION RISK, PERFORMANCE AND COST
Evaluation
C.ost Analysis Methodology G*"eral ^P*'0" 0< Co8tin9 ^odology
Table 111-5
Alternative Screen Printing Systems: Manufacturer Pricing
System
Ink Remover
Emulsion Remover
Haze Remover
Omicron
$13.40/gallon
(5 gallons/$67)
(55 gallons/$540)
$11.00/gallon
(5 gallons/$55)
(55 gallons/$530)
$18.00/gallon
(5 gallons/$90)
Theta
No ink remover costs
Other costs: $5,170
$21.95/gallon
$43.00/gallon
Zeta
$23.00/gallon
$23.00/gallon
$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.
> 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.
3 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 disDOsal. 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.
DRAFT-September 1994
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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
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.
Table 111-6
Alternative Screen Printing Systems: Determination of RCRA Hazardous Waste Listing
System
Ink remover
Emulsion remover
Haze remover
Alpha
RCRA Characteristic waste (ignitable)
Flashpoint = 101°F/38°C
None
None
Beta
None
Ink remover only
Ink remover only
Chi
None
None
None
Delta
None
None
None
Epsilon
RCRA Listed waste (cyclohexanone - all
other components qualify as listed under
mixture rule). Also Characteristic waste
(ignitable)
Flashpoint = 46°C/115°F
None
1:1 dilution with ink remover. All
components quality as hazardous
waste under mixture rule.
Gamma
None
None
None
Mu
RCRA Characteristic waste (ignitable)
Flashpoint = 131°F/55°C
None
None
Phi
None
None
None
Omicron (AE &
AF)
None
None
None
Theta
No ink remover
None
RCRA Listed waste
(cyclohexanone - all other
components qualify as listed under
mixture rule)
Zeta
RCRA Characteristic waste (ignitable)
Flashpoint = 101°F/38°C
None
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
DRAFT—September 1994
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III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
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 aire described as follows:
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 55-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.
Cost Analysis Methodology
Details Related to Data Sources and Methodological Approach
Ink reipover
Emulsion remover
Haze remover
lacquer thinner
1.25% sodium periodate in water
10% xylene (by weight)
30% acetone
30% mineral spirits
30% cyclohexanone
DRAFT—September 1994
111-40
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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
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 removed. 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
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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
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 (dally) 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
HI-42
-------
III. Background Information on Methodologies Used In Screen Reclamation Risk, Performance and Cost
Evaluation
Cost Analysis Methodology Details Related to Data Sourest 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 toted 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
-------
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 severed 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 workpractlce changes and
equipment modifications is discussed in Chapter VI.
DRAFT—September 1994
IV-1
-------
IV. Screen Reclamation Products: Functional Groups
Ink Removal Function Subrtttute 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
-------
IV. Screen Reclamation Products: Functional Groups
Ink Removal Function Substitute Comparative Assessment
Table IV-1
Hazard Summaries and Costs: Ink Removers
Formulation
%voc
Rash PL
V.P."
Hazard Summary
Purchase Cost
Health Effects
Description
Aquatic
Hazard
Ranklngsb
Traditional Systems
System 1
100%
109 F
1 mm Hg
limited hazard data
High
$4.00/galion
100% Mineral spirits
System 2
100% Acetone
100%
OF
185 mm Hg
neurotoxicity; chronic
toxicity
Low
$3.00/gallon
Svstem 3 & System 4
100%
developmental toxicity;
genetic toxicity?;
neurotoxicity-, chronic
toxicity
Low
Medium
Low
High
Medium
Medium
$3.50/gallon
100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% Butyl acetate
5% Methanol
20% Naphtha, light aliphatic
20% Toluene
10% Isobutyl isobutyrate
Alternative Systems
Alpha
Aromatic solvent naphtha
Propylene glycol series ethers
100%
101 F
<4mmHg
developmental toxicity;
neurotoxicity
Low
Low/Medium
$10.18/gallon
(5 gallons/ $91
55 gallons/$850)
Beta
2-Octadecanamine, N.N-dimethyK N-
oxide or a modified amine from
unsaturated soy bean oil fatty acid
Water
0%
205 F
NAC
limited hazard data
High
$15.10/gallon
(estimated)
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
96%
< 200 F
< 0.1 mm Hg
developmental toxicity;
reproductive toxicity;
neurotoxicity; chronic
toxicity
Low/Medium
Low/Medium
Low
Medium
$31.20/gailon
(5 gallons/$156
55
galk>ns/$1t315)
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
94%
< 200 F
<1.0mmHg
developmental toxicity;
chronic toxicity
Medium
Low/Medium
Medium
$20.00/gallon
(5 gallons/$100
55 galk>ns/$900)
DRAFT—September 19M
IV-3
-------
IV. Screen Reclamation Products: Functional Groups
ink Removal Function Substitute Comparative Assessment
Table IV-1
Hazard Summaries and Costs: Ink Removers
Hazard Summary
Formulation
%voc
Flash Pt.
V.P.*
Health Effects
Description
Aquatic
Hazard
Rankingsb
Purchase Cost
Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
65%
115 F
unknown
developmental toxicity;
reproductive toxicity;
genetic toxicity;
neurotoxicity; chronic
toxicity
Low
Medium
Low
Medium
Low
Medium
Low/High
$7.80/gallon
(5 gallons/$39)
Gamma
Tripropylene glycol methyl ether
Diethylene glycol butyl ether acetate
Dibasic esters
Fatty alcohol ethers
Derivatized plant oil
40%
76 F
10.9 mm Hg
developmental toxicity;
chronic toxicity
Low
Medium
Medium
Medium/High
Low/High
$10.90/gallon
(25 liters/$72)
Mu
Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
50%
131 F
< 0.3 mm Hg
developmental toxicity;
chronic toxicity
Medium
Medium
Medium
High
Low/High
$7.76/gallon
(20 liters/$41)
Phi
Dibasic esters
NA
< 160 F
NA
developmental toxicity;
chronic toxicity
Medium
$24.95/gallon
Omicron AE & Omicron AF
Diethylene glycol butyl ether
Propylene glycol
30%
214 F
0.04 mm Hg
developmental toxicity;
chronic toxicity
Low
Low
$l3.40/gal!on
(5 gallons/$67
55 galk>ns/$540)
Zeta
Propylene glycol series ethers
100%
101 F
0.4-10.5 mm
Hg
developmental toxicity;
neurotoxicity; chronic
toxicity
Low/Medium
$23.00/ga!lon
Yp. means vapor pressure.
kfhe hazard rankings shown identify the categories (low, medium, or high) Into which the individual components of the product system fan. 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 aH 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.
DRAFT-September 1994
-------
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
Inhalation Exposures, by Scenario
(mg/day)
Dermal Exposures, (mg/day)
Systsni
1
11
III
IV
Routine
Immersion
Traditional Systems
Svstem 1
Mineral spirits- light hydrotreated
26
0.1
0
0.3
1560
7280
System 2
Acetone
539
11
5
38
1560
7280
Svstems 3 & 4
Methyl ethyl ketone
165
5.3
3
20
468
2180
Butyl acetate, normal
44
1.3
1
5.3
234
1090
Methanol
27
4.7
2
15
78
364
Naphtha, light aliphatic
98
1.6
1
6.2
312
1460
Toluene
110
2.3
1
9.2
312
1460
isobutyl isobutyrate
7
0.4
0
1.7
156
728
Alternative Systems
Alpha
Aromatic solvent naphtha
13
0.1
0
0.2
1250
5820
Propylene glycol series ethers
56
0.6
0
2.6
312
1460
Beta
2-Octadecanamine, N.N-dimethyK N-oxide
292
4.3
3
0
1530
7130
or a modified amine from unsaturated soy
bean oil fatty acid
Water
0
0
0
0
31
146
Chi
Diethylene glycol series ethers
0
0
0
0
312
1456
Propylene glycol series ethers
0
0
0
0
858
4000
N-methylpyrrolidone
3
0
0
0.1
312
1460
Ethoxylated nonylphenol
0
0
0
0
78
364
Delta
Dibasic esters
2
0
0
0.1
702
3280
Propylene glycol series ethers
0
0
0
0
780
3640
Ethoxylated nonylphenol
0
0
0
0
78
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
Inhalation Exposures, by Scenario
(mg
/day)
Dermal Exposures, (mg/day)
System
I
II
III
IV
Routine
Immersion
Epsilon
Cyclohexanone
39
0.3
0.2
1.4
468
2180
Methoxypropanol acetate
17
0.4
0.2
1.7
234
1090
Diethylene glycol
0
0
0
0
312
1460
Benzyl alcohol
0.1
0
0
0
101
473
Derivatized plant oil
0.1
0
0
0.2
55
255
Aromatic solvent naphtha
1.6
0.1
0
0.2
156
728
Diacetone alcohol
4.6
0.1
0.1
0.4
234
1090
Gamma
Diethylene glycol butyl ether acetate
0
0
0
0
62
291
Tripropylene glycol methyl ether
0
0
0
0
780
3640
Derivatized plant oil
0.2
0
0
0.2
62
291
Fatty alcohol ethers
0.4
0
0
0.1
187
873
Dibasic esters
1.3
0
0
0.2
468
2184
Mu
Dibasic esters
3
0
0
0.2
1014
4728
Methoxypropanol acetate
31
0.4
0
1.7
312
1460
<*-Limonene
21
0.6
0
2.4
156
728
Ethoxylated nonylphenol
0
0
0
0
94
437
Derivatized plant oil
0
0
0
0.2
62
291
Phi
Dibasic esters
4
0
0
0.2
1561
7270
Omicron AE & Omicron AF
Diethylene glycol butyl ether
0
0
0
0
984
4590
Propylene glycol
17
0.1
0
0.4
576
2690
Zeta
Propylene glycol series ethers
139
0.6
0
2.8
1560
7280
Method 5 (Automatic Screen Washer)
Ink remover solvent (mineral spirits or
266
3900
lacquer thinner)8
®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 il • pouring 1 ounce of fluid (or 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
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.
System 2
Hazard quotient calculations indicate clear concerns for chronic dermal and inhalation exposures
to workers using acetone in ink removal.
Systems 3 & 4
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
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 hi ink removal or haze removal can be high, although
the risks could not be quantified because of limitations in hazard data.
Beta
Both inhalation and dermal exposures to woikers 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.
Chi
Clear concerns exist for chronic dermal exposures to diethyiene 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.
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
Delta
Although no risks couid 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.
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 E*Powre AnalVti» * R1* 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.
Lacauer 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 A Risk Characterization
Table IV-4
Environmental Releases in Screen Cleaning Operations:
Ink Removers
Release Under Each Scenario
(g/day)
1
It
III
IV
System
Air
Water
Land
Air
Air
Air
Water
Traditional Systems
Svstem 1
Mineral spirits - light hydrotreated
54
0
1050
0.2
0.1
0.6
1350
Svstem 2
Acetone
1120
0
0
22
11
80
1270
Svstems 3 & 4
Methyl ethyl ketone
344
0
0
11
5.7
42
363
Butyl acetate, normal
92
0
80
2.6
1.5
11
191
Methanol
57
0
0
9.8
4.1
30
37
Naphtha, light aliphatic
204
0
25
3.2
1.7
13
257
Toluene
229
0
0
4.8
2.6
19
251
Isobutyl isobutyrate
15
0
100
0.8
0.5
3.4
132
Alternative Systems
Alpha
Aromatic solvent naphtha
27
0
473
0.1
0.1
0.5
1080
Propylene glycol series ethers
117
0
8
1.3
0.7
5.4
265
Beta
2-Octadecanamine, N,N-dimethyK
609
0
0
9.1
6.3
0
O
N-oxide or a modified amine from
unsaturated soy bean oil fatty acid
Water
0
0
12
0
0
0
0
Chi
Diethylene glycol series ethers
0.1
0
138
0
0
0
270
Propylene glycol series ethers
0.1
0
381
0
0
0
742
N-methylpyrrolidone
6.8
0
132
0.1
0
0.2
270
Ethoxylated nonylphenol
0
0
35
0
0
0
67
Delta
Dibasic esters
3.7
0
319
0
0
0.2
608
Propylene glycol series ethers
0.1
0
359
0
0
0
675
Ethoxylated nonylphenol
0
0
36
0
0
0
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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
Air
Water
Land
Air
Air
Air
Water
EDsilon
Cyclohexanone
82
0
126
0.7
0.4
2.9
402
Methoxypropanol acetate
36
0
68
0.8
0.5
3.6
199
Diethylene glycol
0
0
138
0
0
0
270
Benzyl alcohol
0.2
0
45
0
0
0
88
Derivatized plant oil
0.2
0
24
0.1
0
0.3
47
Aromatic solvent naphtha
3.2
0
66
0.1
0.1
0.5
135
Diacetone alcohol
9.6
0
94
0.2
0.1
0.8
202
Gamma
Diethylene glycol butyl ether acetate
0
0
28
0
0
0
54
Tripropylene glycol methyl ether
0.1
0
355
0
0
0
675
Derivatized plant oil
0.3
0
28
0.1
0
0.3
54
Fatty alcohol ethers
0.8
0
84
0
0
0.1
162
Dibasic esters
2.7
0
210
0
0
0.3
405
Mu
Dibasic esters
5.1
0
446
0
0
0.3
877
Methoxypropanol acetate
64
0
75
0.8
0.5
3.6
266
d-Limonene
43
0
27
1.2
0.7
5.1
130
Ethoxylated nonylphenol
0
0
42
0
0
0
81
Derivatized plant oil
0.3
0
27
0.1
0
0.3
54
Phi
Dibasic esters
8.1
0
766
0
0
0.3
1349
Omicron AE & Omicron AF
Diethylene glycol butyl ether
0
0
440
0
0
0
852
Propylene glycol
35
0
222
0.2
0.1
0.7
497
Zeta
Propylene glycol series ethers
290
0
375
1.4
0.8
5.8
1345
Method 5 (Automatic Screen
Washed Usina Mineral SDirits
15.1
NAa
NA
NA
NA
NA
NA
Mineral Spirits
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
Release Under Each Scenario
(g/day)
1
II
III
IV
Air
Water
Land
Air
Air
Air
Water
Method 5 (Automatic Screen
Washer) Usina Lacauer Thinner
Methyl ethyl ketone
335
NAa
NA
NA
NA
NA
NA
Butyl acetate, normal
27.7
NA
NA
NA
NA
NA
NA
Methanol
91.5
NA
NA
NA
NA
NA
NA
Naphtha, light aliphatic
57.7
NA
NA
NA
NA
NA
NA
Toluene
80.7
NA
NA
NA
NA
NA
NA
Isobutyl isobutyrate
4.6
NA
NA
NA
NA
NA
NA
"This 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
DRAFT—September 1994
IV-13
-------
IV. Screen Reclamation Products: Functional Groups
Emulsion Removal Function Substitute Comparative Assessment
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 emulsion remover products sold is not available.
Table IV-5
Hazard Summaries and Cost: Emulsion Removers
Formulation*
%voc,
Flash PL,
V.P.b,
(per
formulation)
Hazard Summary
Purchase Cost
Health Effects
Description
Aquatic
Hazard
Rankings6
Traditional Systems
Systems 1.2. & 3
12% Sodium hypochlorite (bleach)
88% Water
0%
NA
NA
developmental
toxicity; genetic
toxicity; chronic
toxicity
Medium
$1.80/gallon
System 4
1% Sodium periodate
99% Water (as applied)
0%
NA
NA
NA
High
$23.00/gallon (5%
sodium periodate)
Alternative Systems
Alpha
Sodium periodate
Water
0%
NA
NA
High
$4.00/gallon
Chi
Sodium periodate
Water
0%
NA
NA
NA
High
$32.00/gallon
(5 gallons/$160
15 gallons/$438
55 gallons/$1,238)
Delta
Sodium periodate
Water
0%
NA
NA
NA
High
$32.00/gallon
(5 galtons/$160
15 gallons/$438
55 gallons/$1,238)
Eosilon
Sodium periodate
Sulfate salt
Water
0%
NA
unknown
corrosive
High
Medium
$13.54/pound
(5 kg/$149)
Gamma
Sodium periodate
Sulfate salt
Phosphate salt
Water
0%
NA
23.4 mm Hg
(water)
chronic toxicity;
corrosive
High
Medium
High
$1.60/pound
(15 kg/$53)
DRAFT—September 1994
-------
IV. Screen Reclamation Products: Functional Groups
Emulsion Removal Function Exposure Analysis & Risk Characterization
Table IV-5
Hazard Summaries and Cost: Emulsion Removers
Formulation"
%VOC,
Flash Pt.,
V.P.b,
(per
formulation)
Hazard Summary
Purchase Cost
Health Effects
Description
Aquatic
Hazard
Rankings6
Mu
Periodic acid
Water
0%
NA
NA
NA
High
$10.34/gallon
(three 5-liter units/$41
(5 gailons/$51.73))
Phi
Sodium periodate
Ethoxylated nonylphenol
Other
Water
0%
NA
23.4 mm Hg
(water)
NA
High
Medium
Low
$24.95/gallon
Omicron AE & Omicron AF
Sodium periodate
Ethoxylated nonylphenol
Water
0%
NA
23.4 mm Hg
(water)
NA
High
Medium
$11.00/gallon
(5 gallons/$55
55 gallons/$530)
Theta
Sodium periodate
Water
0%
NA
NA
NA
High
$21.95/gallon8
Zeta
Sodium periodate
Water
0%
NA
20 mm Hg
NA
High
$23.00/gallon
®While many of these formulations may seem similar, they may vary in the composition of specific components.
VP. means vapor pressure.
^he 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 11-2), 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.
eProduct 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 Exposure Analysis & Risk Characterization
Table IV-6
Occupational Exposures: Emulsion Removers
Inhalation Exposures, by Scenario
(mg/day)
Dermal Exposures, (mg/day)
System
1
II | III
IV
Routine
Immersion
Traditional Product Systems
Systems 1 & 3 (Bleach)8
Sodium hypochlorite (12%)
0
0
0
0
187
874
Water
0
0
0
0
1370
6410
Systems 2 & 4 (Zeta diluted 1:4)
Sodium periodate (1%)
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Alternative Systems
Aloha (diluted to 0.8%)
Sodium periodate
0
0
0
0
12
58
Water
0
0
0
0
1550
7220
Chi (diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Delta (diluted 1:4)
Sodium periodate
0
0
0
0
39
182
Water
0
0
0
0
1520
7100
Epsilon (3% chemicals. 97% water)
Sodium periodate
0
0
0
0
23
109
Sulfate salt
0
0
0
0
23
109
Water
0
0
0
0
1510
7060
Gamma
Sodium periodate
0
0
0
0
39
182
Sulfate salt
0
0
0
0
16
73
Phosphate salt
0
0
0
0
117
546
Other
0
0
0
0
117
546
Water
0
0
0
0
1270
5930
Mu
Periodic acid
0
0
0
0
156
728
Water
0
0
0
0
1400
6550
Phi
Sodium periodate
0
0
0
0
47
218
Water
0
0
0
0
1210
5640
Ethoxylated nonylphenol
0
0
0
0
123
575
Other
0
0
0
0
181
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
Inhalation Exposures, by Scenario
(mg
/day)
Dermal Exposures, (mg/day)
System
1
II
Hi
IV
Routine
immersion
Omicron AE & Omicron AF
Sodium periodate
0
0
0
0
47
218
Ethoxylated nonyiphenol
0
0
0
0
31
146
Water
0
0
0
0
1480
6920
Zeta (diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Theta (Method 4)b
Sodium periodate
0
0
0
0
1250
5820
Water
0
0
0
0
312
1460
Theta (Method 4) (diluted 1:3)
Sodium periodate
0
0
0
0
312
1460
Water
0
0
0
0
1250
5820
aDermal exposures presented are worst-case and the use of gloves is expected due to irritation and corrosive effects.
''This 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 paU; 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. Hie 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
Release Under Each Scenario
-
(g/day)
1
II
III
IV
System
Air
Water
Land
Air
Air
Air
Water
Traditional Product Systems
Systems 1 & 3 (Bleach)
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
0
0
0
0
0
System 2 & 4 (Zeta diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Alternative Systems
Aloha (diluted to 0.8%)
Sodium periodate
0
5
0
0
0
0
0
Water
0
616
0
0
0
0
0
Chi (diluted 1:4)
Sodium periodate
0
• 6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Delta (diluted 1:4)
Sodium periodate
0
16
0
0
0
0
0
Water
0
605
0
0
0
0
0
Eosilon (diluted to 3%)
Sodium periodate
0
9
0
0
0
0
0
Sodium salt
0
9
0
0
0
0
0
Water
0
602
0
0
0
0
0
Gamma
Sodium periodate
0
16
0
0
0
0
0
Sulfate salt
0
6
0
0
0
0
0
Phosphate salt
0
47
0
0
0
0
0
Other
0
47
0
0
0
0
0
Water
0
506
0
0
0
0
0
Mu
Periodic acid
0
62
0
0
0
0
0
Water
0
559
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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
Air
Water
Land
Air
Air
Air
Water
Phi
Sodium periodate
0
19
0
0
0
0
0
Water
0
481
0
0
0
0
0
Ethoxylated nonyiphenol
0
49
0
0
0
0
0
Other
0
72
0
0
0
0
0
Omicron AE & Omicron AF
Sodium periodate
0
19
0
0
0
0
0
Ethoxylated nonyiphenol
0
13
0
0
0
0
0
Water
0
603
0
0
0
0
0
Zeta (diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Theta (Method 4)
Sodium periodate
0
177
0
0
0
0
0
Water
0
44
0
0
0
0
0
Theta (Method 4) (diluted 1:3)
Sodium periodate
0
44
0
0
0
0
0
Water
0
177
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 gator drum to a 5 gafcn pail; Scenario IV ¦ transferring waste rags from a storage dun 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 ecotoxlclty 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
%VOC
Flash Pt
V.P.*
Hazard Summary
Purchase Cost
Health Effects
Description
Aquatic
Hazard
Rankings6
Traditional Product Systems
Svstems 1.2.3. & 4
10% Xylene
30% Acetone
30% Mineral spirits
30% Cyclohexanone
100%
developmental toxicity;
reproductive toxicity;
genetic toxicity;
neurotoxicity; chronic
toxicity
Medium
Low
High
Low
$5.12/gallon
Alternative Systems
Alpha
Alkali/caustic
Tetrahyd rofu rfu ryI alcohol
Water
<15%
183 F
NAC
corrosive
Low
Medium
$9.39/gallon
(5 kg/$50)
Chi
Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
94%
< 200 F
< 0.1 mm Hg
developmental toxicity;
reproductive toxicity;
chronic toxicity
Low/Medium
Low/Medium
Low
Medium
$31.20/gallon
(5 gallons/$l56
55 gailons/$1,315)
Delta
Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
94%
< 200 F
< 1.0 mm Hg
developmental toxicity;
chronic toxicity
Medium
Low/Medium
Medium
$20.00/gallon
(5 gallons/$100
55 gallons/$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
Hazard Summary
Formulation
%voc
Flash Pt
V.P.a
Health Effects
Description
Aquatic
Hazard
Rankings6
Purchase Cost
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
unknown
NA
unknown
developmental toxicity;
reproductive toxicity;
genetic toxicity;
neurotoxicity; chronic
toxicity; corrosive
Medium
Medium
High
Low
Low/High
Low
Medium
Low
Medium
Low
Medium
Low/High
$1.09/lb
(15 kg/$36)
Gamma
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Water
0%
NA
< 0.2 mm Hg
(® 70 F)
developmental toxicity,
genetic toxicity; chronic
toxicity; corrosive
Medium
Low
Medium
$9.39/ga!lon
(25 liters/$62))
Mu
Sodium hypochlorite
Alkali/caustic
Sodium alkyl sulfate
Water
0%
NA
NA
developmental toxicity;
genetic toxicity; chronic
toxicity; corrosive
Medium
Low
Medium
$7.57/gallon
(five 5-liter
units/$50))
Phi
N-methyl pyrrolidone
Dibasic esters
NA
> 185 F
0.195
developmental toxicity;
reproductive toxicity;
chronic toxicity
Low
Medium
$39.95/gallon
Omicron AE
Ethoxylated nonylphenol
Phosphate surfactant
Other
Water
unknown
210 F
0.1 mm Hg
limited hazard data
Medium
High
Low
$18.00/gallon
(5 gallons/$90)
Omicron AF
Ethoxylated nonylphenol
Phosphate surfactant
Alkali/caustic
Other
Water
unknown
unknown
< 1 mm Hg
corrosive
Medium
High
Low
Low
$18.00/gallon
5 gallons/$90
DRAFT—September 1994
-------
IV. Screen Reclamation Products: Functional Groups
Haze Removal Function Exposure Analysis & Risk Characterization
Table IV-8
Hazard Summaries and Cost: Haze Removers
Formulation
%voc
Flash Pt.
V.P.'
Hazard Summary
Purchase Cost
Health Effects
Description
Aquatic
Hazard
Rankings1*
Theta
Alkali/caustic
Cyclohexanone
Furfuryl alcohol
unavailable
171 F
NA
developmental toxicity;
reproductive toxicity;
genetic toxicity;
neurotoxicity; chronic
toxicity; corrosive
Medium
Low
Medium
$43.00/gallond
Zeta
Alkali/caustic
Propylene glycol
Water
100 %
101 F
0.4-10.5 mm
Hg
corrosive
Low
Low
$30.00/gallon
aV.P. means vapor pressure.
^he 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 11-2), 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. Screen Reclamation Products: Functional Groups
Haze Removal Function Exposure Analysis & Risk Characterization
Table IV-9
Occupational Exposures: Haze Removers
Inhalation Exposures, by Scenario
(mg/day)
Dermal Exposures, (mg/day)
System
I
II | III
IV
Routine
Immersion
Traditional Systems
Systems 1.2.3. and 4
Xylenes (mixed)
21
0.9
1
0
156
728
Acetone
64
11
5
0
468
2180
Mineral spirits-light hydrotreated
7
0.1
0
0
468
2180
Cyclohexanone
27
0.3
0
0
468
2180
Alternative Systems
Alpha
Alkali/caustic8
0
0
0
0
390
1820
T etrahydrofurf uryl alcohol
1
0.1
0
0
234
1090
Water
0
0
0
0
936
4370
Chi
Diethylene glycol series ethers
0
0
0
0
312
1456
Propylene glycol series ethers
0
0
0
0
858
4000
N-methylpyrrolidone
3
0
0
0
312
1460
Ethoxylated nonylphenol
0
0
0
0
78
364
Delta
Dibasic esters
2
0
0
0
702
3280
Propylene glycol series ethers
0
0
0
0
780
3640
Ethoxylated nonylphenol
0
0
0
0
78
364
EDSilon
Cyclohexanone
12
0.3
0.2
0
234
109
Methoxypropanol acetate
5.2
0.4
0.2
0
117
546
Diethylene glycol
0
0
0
0
156
728
Benzyl alcohol
0
0
0
0
51
273
Derivatized plant oil
0
0
0
0
27
127
Aromatic solvent naphtha
0.5
0.1
0
0
78
364
Diacetone alcohol
1.4
0.1
0.1
0
62
291
Alkyl benzene sulfonates
0
0
0
0
140
655
Ethoxylated nonylphenol
0
0
0
0
62
291
Phosphate salt
0
0
0
0
117
546
Alkali/caustic8
0
0
0
0
408
1890
Water
0
0
0
0
109
510
Gamma
Sodium hypochlorite8
0
0
0
0
585
2730
Alkali/caustic8
0
0
0
0
39
182
Water
0
0
0
0
827
3860
Sodium alkyl sulfate
0
0
0
0
109
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
Inhalation Exposures, by Scenario
(n»S
l/day)
Dermal Exposures, (mg/day)
Mu
Sodium hypochlorite8
0
0
0
0
585
2730
Alkali/caustic8
0
0
0
0
39
182
Water
0
0
0
0
827
3860
Sodium alkyl sulfate
0
0
0
0
109
510
Phi
N-methylpyrrolidone
6
0
0
0
780
3640
Dibasic esters
1
0
0
0
780
3639
Omicron AE
Other
0
0
0
0
109
510
Ethoxyiated nonylphenol
0
0
0
0
16
73
Phosphate surfactant
0
0
0
0
78
364
Water
0
0
0
0
1360
6330
Omicron AF
Ethoxyiated nonylphenol
0
0
0
0
16
73
Alkali/caustic8
0
0
0
0
156
728
Phosphate surfactant
0
0
0
0
78
364
Other
0
0
0
0
109
510
Water
0
0
0
0
1200
5610
Zeta
Alkali/caustic8
0
0
0
0
234
1090
Propylene glycol
0
0.1
0
0
62
291
Water
0
0
0
0
1260
5900
Theta (Method 4)
Alkali/caustic8
0
0
0
0
515
2400
Cyclohexanone
25
0.3
0
0
515
2400
Furfural alcohol
0
0
0
0
530
2480
"Dermal exposures presented are woist-case and the use of gloves is expected due to irritation and corrosive effects.
Scenario I» reclaiming 6 screens per day, each iciMn It approximately 2100 in*; Scenario II ¦ pouring 1 ounce of fluid for sampling; Scenario III *
transferring chemicals from a 55 gallon drum to a 5 gallon pit; Scenario IV ¦ transferring waste rags from a storage drum to a 'laundry bag.'
DRAFT—September 1994
-------
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,
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.
2,3, & 4
Alternative Systems
Alpha
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.
Chi
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.
Delta
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.
EDSilon
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,
although dermal exposures to all components could be relatively high.
DRAFT—September 1994
IV-25
-------
IV. Screen Reclamation Products: Functional Groups
Haze Removal Function
Exposure Analysis A 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 ail 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.
Phi
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-
methyipyrrolidone 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. 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 4)
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. Screen Reclamation products: Functional Groups
Haze Removal Function Exposure Analysis & Risk Characterization
Table IV-11
Environmental Releases in Screen Cleaning Operations:
Haze Removers
System
Release Under Each Scenario
(g/day)
I
II
ill
IV
Air
Water
Land
Air
Air
Air
Water
Traditional Product Systems
Svstems 1,2,3, & 4
Xylenes (mixed isomers)
44
0
0
1.9
1.1
0
0
Acetone
133
0
0
22
11
0
0
Mineral spirits- light hydrotreated
15
119
0
0.2
0.1
0
0
Cyclohexanone
57
76
0
0.7
0.4
0
0
Alternative Systems
Alpha
Alkali/caustic
0
133
0
0
0
0
0
Tetrahydrofurfuryl alcohol
1.5
78
0
0.1
0.1
0
0
Water
0
319
0
0
0
0
0
Chi
Diethylene glycol series ethers
0.1
104
0
0
0
0
0
Tripropylene glycol series ethers
0.1
286
0
0
0
0
0
N-methylpyrrolidone
6.8
97
0
0.1
0
0
0
Ethoxylated nonylphenol
0
26
0
0
0
0
0
Delta
Dibasic esters
3.7
239
0
0
0
0
0
Tripropylene glycol series ethers
0.1
269
0
0
0
0
0
Ethoxylated nonylphenol
0
27
0
0
0
0
0
Eosilon
Cyclohexanone
25
55
0
0.7
0.7
0.4
0
Methoxypropanol acetate
11
29
0
0.8
0.8
0.5
0
Diethylene glycol
0
53
0
0
0
0
0
Benzyl alcohol
0.1
17
0
0
0
0
0
Derivatized plant oil
0.1
9.3
0
0.1
0.1
0
0
Aromatic solvent naphtha
1
26
0
0.1
0.1
0.1
0
Diacetone alcohol
2.9
37
0
0.2
0.2
0.1
0
Alkyl benzene sulfonates
0
48
0
0
0
0
0
Ethoxylated nonylphenol
0
21
0
0
0
0
0
Alkali/caustic
0
138
0
0
0
0
0
Water
0
37
0
0
0
0
0
Phosphate salt
0
21
0
0
0
0
0
DRAFT—September 1994
-------
IV. Screen Reclamation Products: Functional Groups
Haze Removal Function Exposure Analysis & Risk Characterization
Table IV-11
Environmental Releases in Screen Cleaning Operations:
Haze Removers
QiUflAA
noiVMe
Under Each Scenario
(g/day)
I
II
III
IV
System
Air
Water
Land
Air
Air
Air
Water
Gamma
Sodium hypochlorite
0
200
0
0
0
0
0
Alkali/caustic
0
13
0
0
0
0
0
Water
0
282
0
0
0
0
0
Sodium alkyl sulfate
0
37
0
0
0
0
0
Mu
Sodium hypochlorite
0
200
0
0
0
0
0
Alkali/caustic
0
13
0
0
0
0
0
Water
0
282
0
0
0
0
0
Sodium alkyl sulfate
0
37
0
0
0
0
0
Phi
N-methylpyrrolidone
12
270
0
0.1
0
0
0
Dibasic esters
3.1
279
0
0
0
0
0
Omicron AE
Other
0
43
0
0
0
0
0
Ethoxylated nonylphenol
0
6.2
0
0
0
0
0
Phosphate surfactant
0
31
0
0
0
0
0
Water
0
540
0
0
0
0
0
Omicron AF
Ethoxylated nonylphenol
0
5.6
0
0
0
0
0
Alkali/caustic
0
56
0
0
0
0
0
Phosphate surfactant
0
28
0
0
0
0
0
Other
0
39
0
0
0
0
0
Water
0
428
0
0
0
0
0
Zeta
Alkali/caustic
0
80
0
0
0
0
0
Propylene glycol
0.7
21
0
0.2
0.1
0
0
Water
0
431
0
0
0
0
0
Theta (Method 4)
Alkali/caustic
0
291
0
0
0
0
0
Cyclohexanone
53
239
0
0.7
0.4
0
0
Furfural alcohol
0
300
0
0
0
0
0
Scenario I = reclaiming 6 screens per day, each screw It approximately 2100 in2; Scenario H ¦ pouring 1 ounce of fluid tar sampling; Scenario III ¦
transferring chemicals from a 55 gallon drum to a 5 galon pail; Scenario IV ¦ transferring was* rags Irom 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
vessels (e.g., 55 gallon drums). Employees wear gloves, goggles, and respirators when needed.
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
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 disposed; 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.
• 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.
DRAFT—September 1994
IV-31
-------
IV. Screen Reclamation Products: functional Groups
Manufacturing of Screen Reclamation Chemical Product* Energy and Natural Resources Issues
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 Amwiwiiti Screen
Method 1: TndltloMl BedaMtta. i T"d"-1 S"tem '
Figure V -1
Process Steps Included in Method 1
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 1: Traditional Reclamation Traditional Syatem t
Occupational Exposure
Table V-1
Occupational Exposure Estimates for Method 1, Traditional System 1
Inhalation (mg/day
Dermal (mg/day)
1
II
III
IV
Routine
Immersion
Ink Remover
Mineral spirits- light hydrotreated
26
0.1
0
0.3
1560
7280
Emulsion Remover
Sodium hypochlorite
0
0
0
0
187
874
Water
0
0
0
0
1370
6410
Scenario f« reclaiming 6 Kmni par day, each terser it approximately 2100 in2; Scenario II* pouring 1 ounce of fluid for sampling; Scenario
III - transferring chemicals (ram a 55 galon drum to a 5 gallon paU; 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
I
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 Svstemel
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, Epsllon, 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 19M
V-3
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1; Traditional Reclamation Traditional System 1
Environmental Releases
Table V-2
Estimated Environmental Releases for Screen Cleaning Operations
Method 1, Traditional System 1
System
Release Under Each Scenario
(g/day)
I
II
III
IV
Air
Water
Land
Air
Air
Air
Water
Ink Remover
Mineral spirits- light hydrotreated
54
0
1050
0.2
0.1
0.6
1350
Emulsion Remover
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
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 lor sampling; Scenario III =
transferring chemicals from a 55 gallon drum to a 5 galon pall; 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
To Air
To Water
To Landfill
Mineral Spirits
54.9 g/day
1350 g/day'
1050 g/day8
Sodium Hypochlorite
75 g/day
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 gfclay. 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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Amount Released
to Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste Water
Treatment
Daily Stream
Concentration, ug/L*
for 1000 MLD
Receiving Water
Mineral Spirits
1350 g/day at
laundry
94%
81 g/day
8 X10'2
Sodium Hypochlorite"
75 g/day
100%
0
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 Klrkwood 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 1: 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
Total Amount
Released to
Water from All
Facilities
Waste Water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River,
ug/L (ppb)
Mineral Spirits
182 kg/day at
laundry
94%
11 kg/day
1
Sodium Hypochlorite
10 kg/day
100 %
0
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
Amount of Releases per
day
Highest Average
Concentration 100 M
away
Annual Potential Dose,
mg/year4
Mineral Spirits
54.9 g/day
1 x 10'1 ug/m3
7 X 10"1
®This 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 lOOO for a LOAEL indicate very low
risk.
DRAFT—September 1994
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Total Amount
Released to
Water from All
Facilities
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste
water Treatment
Daily Stream
Cone. In
Meramec
River, ug/L
(PPb)
ECO CC
(ug/l)
ECO Risk
Indicator
(Stream
Cone/
ECO CC)
Mineral Spirits
16 kg/day +
182 kg/day at
laundry
94%
960g/day
11 kg/day
1 x 10"1
1
1
1.1
Sodium
Hypochlorite
10 kg/day
100%
0
0
<20
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 1: 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
Inhalation (mg/day)
Dermal (mg/day)
I
II
III
IV
Routine
Immersion
Ink Remover
Acetone
539
11
5
38
1560
7280
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210 |
Scenario I - reclaiming 6 tenant per day; tact) screen it approximately 2100 in2; Scenario II - pouring 1 ounce of fluid for sampling; Scenario III =
transferring chemicals from a 55 gallon drum to a 5 galton pal; 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 1W4
-------
Table V-9
Occupational Risk Estimates for Method 1, Traditional System 2.
Margin Of Exposure*
Hazard Quotient1'
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
NA
NA
NA
NA
Acetone
84
22
1,040
NA
NA
NA
NA
NA
NA
Emulsion Remover (Zeta diluted
M
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
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.
''NOAEL means No Observed Adverse Effect Level.
"LOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation
Traditional System 2
Environmental Releases
Table V-10
Estimated Environmental Releases in Screen Cleaning Operations
Method 1, Traditional System 2
Release Under Each Scenario
(g/day)
I
II
III
IV
System
Air
Water
Land
Air
Air
Air
Water
Ink Remover
Acetone
1120
0
0
22
11
80
1270
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
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 laundiy.
Table V-11
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Method 1, Traditional System 2
Substance
To Air
To Water
To Landfill 1
Acetone
1,233 g/day
1,270® g/day
1,270s g/day l
Sodium Periodate
6 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 1: 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
Amount Released
to Water from
Facility
Waste Water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1,000 MLD
Receiving Water
Acetone
1270 g/day
87%
165 g/day
0.2
Sodium Periodate
6 g/day
100%
0 g/day
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 Braidstreet 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
Total Amount
Released to
Water from All
Facilities
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Acetone
171 kg/day
87%
22,3 kg/day
3
Sodium
Periodate
810 g/day
»99%
« 8.1 g/day
« 8 x 10-4
-»is very mu
i,«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
Amount of Releases per
day
Highest Average
Concentration 100 M
away
Annual Potential Dose,
mgfyeai*
Acetone
1233 g/day
3 ug/m3
20
®This 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 lOOO 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 1: 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
Dally
Waste
Stream
ECO RISK
Total Amount
water
Amount to
Cone. In
INDICATOR
Released to
Treatment
Water After
Meramec
(STREAM
Water from All
Removal
Wastewater
River, ug/L
ECO CC
CONC/
Substance
Facilities
Efficiency
Treatment
(PPb)
(ug/L)
ECO CC)
Acetone
171 kg/day
87%
22.3 kg/day
3
7600
4x10"4
Sodium
810 g/day
»99%
« 8.1 g/day
«8x10-4
<10
-10"5
Periodate
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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
immersion
Ink Remover
Methyl ethyl ketone( 2-butanone)
165
5.3
3
20
468
2180
Butyl acetate normal
44
1.3
1
5.3
234
1090
Methanol
27
4.7
2
15
78
364
Naphtha, light aliphatic
98
1.6
1
6.2
312
1460
Toluene
110
2.3
1
9.2
312
1460
Isobutyl isobutyrate
7
0.4
0
1.7
156
728
Emulsion Remover (Bleach)
Sodium hypochlorite
0
0
0
0
187
874
Water
0
0
0
0
1370
874
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 psH; 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
-------
Table V-17
Occupational Risk Estimates for Method 2, Traditional System 3.
Margin Of Exposure*
Hazard Quotient6
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL6
L0AELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Methyl ethyl ketone (2-butanone)
9.2
22
103
NA
NA
NA
NA
NA
NA
Butyl acetate normal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methanol
1.4
2.2
10
NA
NA
NA
NA
NA
NA
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Toluene
17.
44.
208.
NA
NA
NA
NA
NA
NA
Isobutyl isobutyrate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (Bleach)
Sodium hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
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.
"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 urtikely to occur.
°NOAEL means No Observed Adverse Effect Level.
^LOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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 (AH 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Methyl ethyl ketone( 2-butanone)
344
0
0
11
5.7
42
363
Butyl acetate normal
92
0
80
2.6
1.5
11
191
Methanol
57
0
0
9.8
4.1
30
37
Naphtha, light aliphatic
204
0
25
3.2
1.7
13
257
Toluene
229
0
0
4.8
2.6
19
251
Isobutyl isobutyrate
15
0
100
0.8
0.5
3.4
132
Emulsion Remover (Bleach)
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
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.
DRAFT—September 1994
V-16
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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:
To Air:
To Water:
To Landfill:
Methyl ethyl ketone
403 g/day
363 g/day at laundry
n-butyl Acetate
107 g/day
191 g/day at laundry8
80 g/day®
Methanol
101 g/day
37 g/day at laundry
Naphtha, light aliphatic
222 g/day
257 g/day at laundry
25 g/day
Toluene
255 g/day
251 g/day at laundry
Isobutyl isobutyrate
19.7 g/day
132 g/day at laundry
100 g/day
Sodium hypochlorite
75 g/day
"The 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 1: 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
Amount Released
to Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Mean Daily
Concentration, ug/L*
for 1000 MLD
Receiving Water
Methyl Ethyl Ketone
363 g/day at
laundry
84%
58 g/day
6 X 10'2
n-butyl acetate
191 g/day at
laundry
97%
5.7 g/day
6 x 10"3
Methanol
37 g/day at laundry
97%
1.1 g/day
1 x 10"3
Naphtha, light aliphatic
257 g/day at
laundry
94%
15 g/day
2 x 10"2
Toluene
251 g/day at
laundry
92%
20 g/day
2 X 10*
Isobutyl isobutyrate
132 g/day at
laundry
98%
2.6 g/day
3 x 10"3
Sodium Hypochlorite11
75 g/day
100%
0
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
DRAFT—September 1994
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Traditional System 3
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-21
Estimated Cumulative Releases to Water for St. Louis County, MO
Method 1, Traditional System 3
Substance
Total Amount
Released to
Water from All
Facilities
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
n-butyl acetate
26 kg/day
97%
8 x 10'1 kg/day
1 x10"1
Methanol
5 kg/day
97%
150 g/day
2 x 10"2
Naphtha, light aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10"1
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10"1
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 x 10"2
Sodium Hypochlorite
10 kg/day
» 99%
«100 g/day
«1 x 10'2
DRAFT—September 1994
V-19
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Amount of Releases per
Highest Average
Annual Potential
Substance
day
Concentration 100 M away
Dose, mg/year*
Methyl Ethyl Ketone
403 g/day
8 x 10'1 ug/m3
6
n-butyl acetate
107 g/day
2 x 10"1 ug/m3
1
Methanol
101 g/day
2 x 10"1 ug/m3
1
Naphtha, light aliphatic
222 g/day
4 x 10"1 ug/m3
3
Toluene
255 g/day
5 x 10"1 ug/m3
4
Isobutyl isobutyrate
19.7
4 x 10"2 ug/m3
0.3
This 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. Margln-of-Exposure (MOE) values
above 100 for a NOAEL or above lOOO for a LOAEL indicate very low risk.
DRAFT—September 1994
V-20
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Traditional System 3
Table V-23
Risks from Potential Drinking Water Exposures
Screen Reclamation Method 1, Traditional System 3
Substance
Daily Stream
Concentration In
Meramec River, ug/L
(PPb)
Daily dose from
Drinking Water
(mg/kg)
RfD (mg/kg)
Hazard
Quotient
(dose/RfD)
Methyl ethyl ketone
1
3x10'5
0.6
5x10"5
n-butyl acetate
1 x 10"1
3x10"6
not available
Methanol
2 x 10'2
6x10"7
0.5
1X10"6
Naphtha, light aliphatic
3x10'1
9x10"6
not available
Toluene
3 x 10"1
9x10"®
0.2
4x10"5
Isobutyl isobutyrate
4x10"2
1X10-6
not available
Sodium Hypochlorite
«1 x 10"2
«3x10"7
not available
Table V-24
Estimated Risks from Ambient Air Releases from a Single Model Facility
Screen Reclamation Method 1, Traditional System 3
Substance
Highest Avg
Concentration 100 M
away
Daily Potential
Dose, (mg/kg)
RfD/RfC (mg/kg,
mg/m3)
Hazard
Quotient(dose
or conc/RfDor
RfC)
Methyl Ethyl Ketone
8 x 10"1 ug/m3
2x10"4
1 mg/m3
8x104
n-butyl acetate
2 x 10"1 ug/m3
4x10"5
not available
Methanol
2 x 10"1 ug/m3
4x10"5
0.5 mg/kg
8x10"5
Naphtha,light aliphatic
4x 10"1 ug/m3
1x104
not available
Toluene
5 x 10"1 ug/m3
2x10"4
0.4 mg/m3
1x10"3
Isobutyl isobutyrate
4 x 10"2 ug/m3
1x10"®
not available
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
o None of the components of Method 1, Traditional System 3 reached an ecotoxiclty
concern concentration, even when considering the cumulative releases from all
shops In the area.
DRAFT—September 1994
V-21
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Traditional System 3
o None of the single facility releases of Method 1, 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.
Table V-25
Estimated Cumulative Releases to Water for St. Louis County, MO
Screen Reclamation Method 1, Traditional System 3
Substance
Total Amount
Released to
Water from All
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to
Water After
Waste water
Treatment
Daily
Stream
Cone. In
Meramec
River, ug/L
(PPb)
ECO CC
(ug/L)
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
4500
2x10"4
n-butyl acetate
26 kg/day
97%
8 x 10"1 kg/day
1 x 10'1
140
7x10"4
Methanol
5 kg/day
97%
150 g/day
2 x 10'2
9000
2x10"®
Naphtha, light
aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10"1
5
0.06
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10"1
110
3x10"3
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 x 10"2
80
5x10"4
Sodium
Hypochlorite
10 kg/day
» 99%
«100 g/day
«1 x 10*2
<20
-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 1: 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
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
immersion
Ink Remover
Methyl ethyl ketone( 2-butanone)
165
5.3
3
20
468
2180
Butyl acetate normal
44
1.3
1
5.3
234
1090
Methanol
27
4.7
2
15
78
364
Naphtha, light aliphatic
98
1.6
1
6.2
312
1460
Toluene
110
2.3
1
9.2
312
1460
Isobutyl isobutyrate
7
0.4
0
1.7
156
728
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Scenario I * reclaiming 6 screens per day; each screen is approximately 2100 In2: Scenario II - pouring 1 ounce of fluid tor 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
Margin Of Exposure8
Hazard Quotient1*
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Methyl ethyl ketone (2-butanone)
9.29
22
103
NA
NA
NA
NA
NA
NA
Butyl acetate normal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methanol
1.4
2.2
10.4
NA
NA
NA
NA
NA
NA
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Toluene
17
46
210
NA
NA
NA
NA
NA
NA
Isobutyi isobutyrate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover fZeta diluted
M
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
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 (RfO) 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.
''LOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Methyl ethyl ketone( 2-butanone)
344
0
0
11
5.7
42
363
Butyl acetate normal
92
0
80
2.6
1.5
11
191
Methanol
57
0
0
9.8
4.1
30
37
Naphtha, light aliphatic
204
0
25
3.2
1.7
13
257
Toluene
229
0
0
4.8
2.6
19
251
Isobutyl isobutyrate
15
0
100
0.8
0.5
3.4
132
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
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 gaton 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 1: 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:
To Air:
To Water:
To Landfill:
Methyl ethyl ketone
403 g/day
363 g/day at laundry
n-butyl Acetate
107 g/day
191 g/day at laundry"
80 g/day"
Methanol
101 g/day
37 g/day at laundry
Naphtha, light aliphatic
222 g/day
257 g/day at laundry
25 g/day
Toluene
255 g/day
251 g/day at laundry
Isobutyl isobutyrate
19.7 g/day
132 g/day at laundry
100 g/day
Sodium periodate
6 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-28
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste Water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Methyl Ethyl Ketone
363 g/day at
laundry
84%
58 g/day
6 x 10"2
n-butyl acetate
191 g/day at
laundry
97%
5.7 g/day
6 x 10"3
Methanol
37 g/day at laundry
97%
1.1 g/day
1 x 10"3
Naphtha, light aliphatic
257 g/day at
laundry
94%
15.4 g/day
2 x 10"2
Toluene
251 g/day at
laundry
92%
20 g/day
2 x 10"2
Isobutyl isobutyrate
132 g/day at
laundry
98%
2.6 g/day
3 x 10'3
Sodium periodate
6 g/day
100%
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 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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Traditional System 4
Table V-31
Estimated Cumulative Releases to Water for St. Louis County, MO
Method 1, Traditional System 4
Substance
Total Amount
Released to
Water from All
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
n-butyl acetate
26 kg/day
97%
0.8 kg/day
1 x 10'1
Methanol
5 kg/day
97%
150 g/day
2 x 10"2
Naphtha, light aliphatic
35 kg/day
94%
2.1 kg/day
3 X 10"1
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10'1
Isobutyi isobutyrate
18 kg/day
98%
360 g/day
4 x 10"2
Sodium Periodate
810 g/day
» 99%
« 8.1 g/day
«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 1: 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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year8
Methyl Ethyl Ketone
403 g/day
8 x 10'1 ug/m3
6
n-butyl acetate
107 g/day
2 x 10*1 ug/m3
1
Methanol
101 g/day
2 x 10*1 ug/m3
1
Naphtha, light aliphatic
222 g/day
4 x 10'1 ug/m3
3
Toluene
255 g/day
5 x 10"1 ug/m3
4
Isobutyl isobutyrate
19.7
4 x 10"2 ug/m3
3 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 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 lOOO 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 1: 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
Total Amount
Released to
Water from All
Facilities
Waste
water
Treatment
Removal
Efficiency
Amount to
Water After
Waste water
Treatment
Daily
Stream
Cone. In
Meramec
River, ug/L
(PPb)
ECO CC
(ug/L)
ECO RISK
INDICATOR
(STREAM
CONC/
ECO CC)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
4500
2x10"4
n-butyi acetate
26 kg/day
97%
0.8 kg/day
1 x 10'1
140
7x10"4
Methanol
5 kg/day
97%
150 g/day
2 x 10'2
9000
2X10"6
Naphtha, light
aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10"1
5
0.06
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10"1
110
3x10"3
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 x 10'2
80
5x10"4
Sodium Periodate
810 g/day
» 99%
«8.1 g/day
«1 x 10'3
<10
-10*1
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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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)
2,127
Average # screens/day
6
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
12.9
2.82
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
Haze Remover
Average Volume (oz.)
Cost ($)
—
Hazardous
Waste Disposal
Amount (g)
Cost ($)
34
0.02
Totals
Total Cost($/Screen)
3.63
Total Cost($/year)
5,446
DRAFT—September 1994
V-31
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product System Qhl
Alternative System Chi
Formulation
Ink Remover: Diethylene glycol series ethers
Propylene glycol series ethers
N-methyl pyrrolidone
Ethoxylated nonylphenol
Emulsion Remover: Sodium periodate
Water
Occupational Exposure
Table V-35
Occupational Exposure Estimates for Method 1, Alternative System Chi
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Diethylene glycol series ethers
0
0
0
0
312
1456
Tripropylene glycol methyl ether
0
0
0
0
858
4000
N-methylpyrrolidone
3
0
0
0.1
312
1460
Ethoxylated nonylphenol
0
0
0
0
78
364
Emulsion Remover (diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Scenario I - reclaiming 6 screens per day; each screen Is approximately 2100 m2; Scenario II» pouring 1 ounce of fluid for sampling; Scenario III *
transferring chemicals from a 55 gallon drum to a 5 gallon pall; Scenario IV • storing waste rags In a drum and transferring them to a laundry.
Occupational Risk Conclusions and Observations
Ink Remover
o Clear concerns exist for chronic dermal exposures to the diethylene glycol series
ethers used in ink removal based on the calculated marglns-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.
DRAFT-September 1994 V-32
-------
Table V-36
Occupational Risk Estimates for Method 1, System CHI
F*
3-
8.
Margin Of Exposure*
Hazard Quotient6
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Dietfryiene glycol series ethers
NA
NA
NA
NA
NA
1,800
46
380
9.8
Tripropytene glycol series ethers
NA
NA
NA
NA
NA
NA
NA
NA
NA
N-methytpyrrolidone
NA
NA
NA
3,600
NA
39
NA
8.4
NA
Ethoxytated nonyiphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (diluted 1:4)
-
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
at
&
o
3
9
s
D»
3
n
aMargin 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.
'h.OAEL means Lowest Observed Adverse Effect Level.
I
I
I
3
O
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product Svrtwn 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
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol series ethers
0.1
0
138
0
0
0
270
Tripropylene glycol series ethers
0.1
0
381
0
0
0
742
N-methylpyrrolidone
6.8
0
132
0.1
0
0.2
270
Ethoxylated nonylphenol
0
0
35
0
0
0
67
Emulsion Remover (diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
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.
DRAFT-September 1994
V-34
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product Systom Chi
Table V-38
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 1, Alternative System Chi
Substance:
To Air:
To Water:
To Landfill:
Diethylene glycol series ethers
0.1 g/day
270 g/day at laundry
138 g/day
Propylene glycol series ethers
0.1 g/day
742 g/day at laundry
381 g/day
N-methyl pyrrolidone
7.1 g/day
270 g/day at laundry
132 g/day
Ethoxylated nonylphenol
67 g/day at laundry
35 g/day
Sodium Periodate
6 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
Amount
Released to
Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste
water Treatment
Daily Stream
Concentration, ug/L*
for 1000 MLD
Receiving Water
Diethylene glycol series ethers
270 g/day at
laundry
83%
46 g/day
4 x 10"2
Propylene glycol series ethers
742 g/day at
laundry
83-97%
126 g/day
1 x 10"1
N-methyl pyrrolidone
270 g/day at
laundry
97%
8.1 g/day
8 X10"3
Ethoxylated nonylphenol
67 g/day at
laundry
100%
0 g/day
0
Sodium periodate
6 g/day
»99%
«.06 g/day
« 6 x 10"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 1: 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
Amount of Releases
per day
Highest Average
Concentration 100 M
away
Annual Potential
Dose, mg/year*
Diethylene glycol series ethers
0.1 g/day
2 x 10"4 ug/m3
1 x 10'3
Propylene glycol series ethers
0.1 g/day
2 x 10"4 ug/m3
1 x 10"3
N-methyl pyrrolidone
7.1 g/day
1 x10'2ug/m3
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 lOOO 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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation PfPdUCt System Chi
Cost
Table V-41
Method 1: Summary of Cost Analysis for Method 1, Alternative System Chi
Baseline
(Traditional
Alternative System Chi
Cost Element Description
System 4 -
Haze Remover)
Facility 3
Facility 21
Facility Characteristics
Average screen size (in2)
2,127
1,977
1,088
Average # screens/day
6
15
23
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
12.9
2.82
9.4
2.07
4.5
0.98
Materials and
Equipment
# of rags used
Cost {$)
3
0.45
1.2
0.18
1.2
0.19
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
1.1
0.21
1.1
0.21
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
2.1
0.07
1.5
0.05
Haze Remover
Average Volume (oz.)
Cost ($)
...
...
...
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
3.63
2.53
1.43
Normalized'
3.63
2.83
1.95
Total Cost ($/year)
5,466
9,497
8,005
Normalized1
5,446
4,245
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 rot 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 1: 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: 2-octadecanamine, N, N-dimethyl-, N-oxide or a modified amine
from unsaturated soy bean oil fatty acid/ water
Emulsion Remover: Sodium periodate
Water
Occupational Exposure
Table V-42
Occupational Exposure Estimates for Method 1, Alternative Beta
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
Immersion
Ink Remover
2-Octadecanamine, N,N-dimethyl, N-oxide
292
4.3
3
0
1530
7130
Water
0
0
0
0
31
146
Emulsion Remover (diluted 1:4)
Sodium periodate
0
6
0
0
0
0
Water
0
615
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.
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. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
2-Octadecanamine, N.N-dimethyl, N-
oxide
609
0
0
9.1
6.3
0
0
Water
0
0
12
0
0
0
0
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Scenario I ¦ reclaiming 6 screens per day; each screen it approximately 2100 in*; Scenario II ¦ pouring 1 ounce of fluid for sampling; Scenario 111 *
transferring chemicals from a 55 gallon drum to a 5 gdon pal; (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 1: 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:
To Air:
To Water:
To Landfill:
2-octadecanamine, N,N-dimethyl,
N-oxide
624 g/day
Sodium periodate
5 g/day
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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Sodium periodate
5 g/day
100%
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 Faculties
Table V-46
Air Releases, Concentrations and Potential Dose Estimates from
a Single Model Facility
Using Screen Reclamation Method 1, Alternative System Beta
Substance
Amount of
Releases per day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
2-Octadecanamine, N,N-dimethyl, N-oxide
624 g/day
1.3 ug/m3
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:
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
DRAFT—September 1994
V-41
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 1: Traditional Reclamation Product System Beta
inks) use high pressure water and rinse all the Ink residue from the screen. For tests
done at SPTF, a 1000 psl 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.
Aiternative 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 V-47
Performance Summary for Ink Remover BETA
Component
Performance
n.111.1 mti n¦! ^nn rlilt ri n ¦
UeilMWTKMI UNMUOni
Avg Drying
Tine Before
Using Product
Average
Quantity
Apptod
Average
Owning
Time
Average
Effort
Required
Performance for
Each System
Component
Overal System
Ink
type(s)
Emulsion
type
Mesh
«*pe;
Thread
count
Average
Screen
Size
In-MdDM
nonstiatxre at Volunteer Printing FacBties
i~i ma
racMj
12
Irk remover
3.9 ± 8.2 his
(n=15)
4.2 ± 1.5 OZ.
(n=17)
24.6 ± 5.4
mins(n=17)
Moderate
Removed ink but
took a long time
and left an oiy
residue.
¦ Not
Solvent-
based ink
Capiaryflm
Polyester
1089 in2
demonstrated as
part of a system.
abraded;
195 - 390
ttveads/
inch
Laboratory Ta
sting at SPTF
SPTF
Sofcent-
based
Ink
Ink Remover
15mins
2JS oz.
9.1 mins
Moderate
Ink cfssotved wefi, but 7 rags were
needed and tie standi started to
deteriorate.
Solvent-
based
Dual am
drect
Polyester
; 260
threads/
inch
360 in2
SPTF
UV-
curaMe
Ink
ilk Remover
15mins
25 oz.
6.3 mins
Moderate
Ink dfesoived wet, but 6 rags were
needed and the sterol started to
deteriorate.
UV-
curable
Dual cure
drect
Polyester
; 390
threads/
Inch
360 in2
SPTF
«Mar-
Ink
Irk Remover
15 mis
3.0 oz.
12.0 mins
Moderate
Ink dissolved weft, but it took a long
time (8 rags were needed) and the
stencil started to deteriorate.
Water-
based
Dual cure
direct
Polyester
; 260
threads/
Inch
360 in2
-------
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 dally.
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).
° 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 diy.
° 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 1: Traditional Reclamation Product System Beta
Cost
Table V-48
Method 1: Summary of Cost Analysis for Alternative Beta
Baseline
(Traditional
Alternative
System Beta*
Description
System 4 minus
Haze Remover)
Facility 12
Facility Characteristics
Average screen size (in2)
2,127
1,089
Average # screens/day
6
15
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
12.9
2.82
29.4
6.43
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
2.2
0.34
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
4.2
0.50
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
1.8
0.06
Haze Remover
Average Volume j(oz.)
Cost ($)
...
—
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
Total Costs
Total Cost ($/screen)
3.63
17.33
Normalizedb
3.63
7.97
Total Cost ($/year)
5,446
27,477
Normalized15
5,446
11,958
aThe emulsion removal use and cost per screen were taken
rom performance demonstration results for
product system Zeta.
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
V45
-------
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 sire 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 dally in the average small/medium screen printing facility.
Because Method 2 is most representative of current screen reclamation practices, the
majority of alternative systems Eire 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:
Emulsion Remover:
Haze Remover:
100% Mineral spirits
12% Sodium hypochlorite (bleach)
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 I
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
Haze Removal/
Water Wash
I
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 Wijh Haze Remover
Traditional System 1
Occupational Exposure
Table V-49
Occupational Exposure Estimates For Method 2, Traditional System 1
System
Inhalation Exposures, by
Dermal Exposures, (mg/day)
Scenario (mg/day)
I
II
111
IV
Routine
Immersion
Ink Remover
Mineral spirits- light hydrotreated
26
0.1
0
0.3
1560
7280
Emulsion Remover
Sodium hypochlorite
0
0
0
0
187
874
Water
0
0
0
0
1370
6410
Haze Remover
Xylenes (mixed)
21
0.9
1
0
156
728
Acetone
64
11
5
0
468
2180
Mineral spirits-light hydrotreated
7
0.1
0
0
468
2180
Cyclohexanone
27
0.3
0
0
468
2180
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
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
-------
Table V-50
Occupational Risk Estimates for Method 2, Traditional System 1
Margin Of Exposure*
Hazard Quotient
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELb
LOAELc
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Mineral spirits- fight hydrotreated
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover
Sodum hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Xylenes (mixed isomers)
02
1.1
5 2
NA
NA
NA
NA
NA
NA
Acetone
11
66
311
NA
NA
NA
NA
NA
NA
Mineral spirits-fight hydrotreated
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cyciohexanone
0.08
1.3
6 2
180
NA
NA
NA
NA
NA
®NA means Not Available.
bNOAEL means No Observed Adverse Effect Level.
tOAEL means Lowest Observed Adverse Effect Level.
-------
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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Mineral spirits- light hydrotreated
54
0
1050
0.2
0.1
0.6
1350
Emulsion Remover
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
0
0
0
0
0
Haze Remover
Xylenes (mixed isomers)
44
0
0
1.9
1.1
0
0
Acetone
133
0
0
22
11
0
0
Mineral spirits- light hydrotreated
15
119
0
0.2
0.1
0
0
Cyclohexanone
57
76
0
0.7
0.4
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
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
To Air
To Water
To Landfill
Mineral Spirits
69.5 g/day
119 g/day
1350 g/day6
1053 g/day8
Sodium Hypochlorite
74.5 g/day
Acetone
167 g/day
Xylene
47.5 g/day
Cyclohexanone
58.1 g/day
76.5 g/day
®This 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
Amount Released to
Water from Facility
Wastewater
Treatment Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/L*
for 1000 MLD
Receiving Water
Mineral Spirits
119 g/day
1350 g/day at laundry
99%
1.2 g/day
13.50 g/day
1.2x10"®
Xylenes
75%
Cyclohexanone
76.5 g/day
90%
7.6 g/day
7.6 x 10"3
Sodium
Hypochlorite11
74.5 g/day
»c99%
«.7 g/day
«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 Klrkwood 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
Total Amount Released
to Water from All
Facilities
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration in
Meramec River,
ugfl. (ppb)
Mineral Spirits
16 kg/day + 182 kg/day
at laundry
99%
160 g/day
1.8 kg/day
1.6 x10"1
1.8
Cyclohexanone
10 kg/day
90%
1 g/day
1 x 10"3
Sodium Hypochlorite
10 kg/day
» 99%
«100 g/day
«1 x 10"1
Releases to Air from Individual Screen Printing Facilities
DRAFT—September 1994
-------
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
Amount of Releases
per day
Highest Average
Concentration 100 M away
Annual Potential Dose,
mg/year*
Mineral Spirits
69.5 g/day
3 x 10"1 ug/m3
1.1
Acetone
167 g/day
23 ug/m3
2.6
Xylene
47.5 g/day
9x10"2ug/m3
0.7
Cyclohexanone
58.1 g/day
1 x 10"1 ug/m3
0.9
"This 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
Ambient Air
(Health)
Ambient Water
(Health)
Ambient Water
Conc/Eco CC
Mineral spirits
See note 1
See note 1
2
Sodium hypochlorite
Air releases not expected
See note 2
-10"3
Xylene
Hazard Quotient = -10'5
Water releases not
expected
Water releases not
expected
Acetone
Hazard Quotient = -10"3
Water releases not
expected
Water releases not
expected
Cyclohexanone
Hazard Quotient = -10'5
Hazard Quotient = -10"®
-10"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.
1 5.4 x 10 4
2 5.0 x 10'4
3 l.OxlO"4
4 5.0 x 10'5
5 1.8 xlO"5
* = Population Centrold - Weighted center of population of one census block group.
There are roughly 800 to 1200 people represented by each centrold.
Distances are In kilometers
DR AFT—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
Total Amount
Released to
Water from All
Facilities
Waste
water
Treatment
Removal
Efficiency
Amount to
Water After
Wastewater
Treatment
Dally
Stream
Cone, in
Meramec
River, ug/L
(PPb)
ECO CC
(ug/l)
ECO RISK
INDICATOR
(STREAM
CONG/
ECO CC)
Mineral Spirits
16 kg/day +
182 kg/day at
laundry
94%
960 g/day
11 kg/day
1 x 10"1
1
1
1.1
Cyclohexanone
10 kg/day
83%
1.7 kg/day
2 x 10"1
2800
7x10'5
Sodium
Hypochlorite
10 kg/day
100%
0
0
<20
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
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
Inhalation (mg/day)
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Acetone
539
11
5
38
1560
7280
Emulsion Remover (Bleach)
Sodium hypochlorite
0
0
0
0
187
874
Water
0
0
0
0
1370
6410
Haze Remover
Xylenes (mixed isomers)
21
0.9
1
0
156
728
Acetone
64
11
5
0
468
2180
Mineral spirits- light hydrotreated
7
0.1
0
0
468
2180
Cyclohexanone
27
0.3
0
0
468
2180
Scenario I - reclaiming 6 screens per day; each screen it 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 paH; Scenario IV - storing waste rags in a drum and transferring them to a laundry.
Ink Remover
Emulsion Remover
Haze Remover
DRAFT—September 1994
-------
Table V-59
Occupational Risk Estimates for Method 2, Traditional System 2
Margin Of Exposure*
Hazard Quotient*3
Dermal
Dermal
Inhalation
Routine
Immersion
| Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
I Ink Remover
| Acetone
84
23
1,040
NA
NA
NA
NA
NA
NA
B Emulsion Remover (Bleach)
1 Sodium hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Xylenes (mixed isomers)
02
1.1
5.2
NA
NA
NA
NA
NA
NA
Acetone
11
66
311.
NA
NA
NA
NA
NA
NA
Mineral spirits- light hydrotreated
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cydobexanone
0.07
1.3
6.2
180
NA
NA
0
0
0
aMargin 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.
'tlOAEL means No Observed Adverse Effect Level.
^LOAEL means Lowest Observed Adverse Effect Level.
-------
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
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Acetone
1120
0
0
22
11
80
1270
Emulsion Remover (Bleach)
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
0
0
0
0
0
Haze Remover
Xylenes (mixed isomers)
44
0
0
1.9
1.1
0
0
Acetone
133
0
0
22
11
0
0
Mineral spirits- light hydrotreated
15
119
0
0.2
0.1
0
0
Cyclohexanone
57
76
0
0.7
0.4
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.
DRAFT—September 1994
-------
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
1233 g/day to air
1270 g/day to water
From Emulsion Remover:
Sodium Hypochlorite
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:
To Air.
To Water:
To Landfill:
Acetone
1,399 g/day
1270® g/day
1270® g/day
Sodium Hypoclorite
75 g/day
Mineral Spirits
15.3 g/day
119 g/day
Xylenes
47 g/day
Cyclohexanone
58.1 g/day
76 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. 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
fort 000 MLD
Receiving Water
Acetone
1270 g/day
87%
165 g/day
0.2
Cyclohexanone
76 g/day
83%
12.9 g/day
1 x 10"2
Mineral spirits
119 g/day
94%
7.14 g/day
7 x 10"3
Sodium Hypoclorite
75 g/day
»99%
«1 g/day
«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. 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
Total Amount
Released to
Water from All
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Acetone
171 kg/day
87%
22.3 kg/day
3
Mineral Spirits
16.1 kg/day
94%
964 g/day
0.1
Cyclohexanone
10.3 kg/day
83%
1.7 kg/day
0.2
Sodium
Hypochlorite
10.1 kg/day
»99%
«100 g/day
«1 x 10"1
u» is very much grea
ter 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
Amount of Releases per
day
Highest Average
Concentration 100 M
away
Annual Potential Dose,
mg/year"
Mineral Spirits
15.3 g/day
3x10"2ug/m3
0.2
Acetone
1399 g/day
3 ug/m3
20
Xylenes
47 g/day
9 x 10'2 ug/m3
0.7
Cyclohexanone
58.1 g/day
1x10° ug/m3
0.7
"This 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 veiy
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 conclusion^. 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
Total Amount
Released to
Water from Ail
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to
Water After
Waste water
Treatment
Daily
Stream
Cone, in
Meramec
River, ug/L
(PPb)
ECO CC
(ug/L)
ECO RISK
INDICATOR
(STREAM
CONC/
ECO CC)
Acetone
171 kg/day
87%
22.3 kg/day
3
7600
4x10"4
Mineral Spirits
16.1 kg/day
94%
964 g/day
0.1
1
0.1
Cyclohexanone
10.3 kg/day
83%
1.7 kg/day
0.2
2800
7x10"5
Sodium
Hypochlorite
10.1 kg/day
»99%
«100 kg/day
«1 x 10"1
20
«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. 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: 100% Lacquer Thinner, consisting of:
30% Methyl ethyl ketone
15% n-butyl acetate
5% Methanol
20% Naphtha light aliphatic
20% Toluene
10% Isobutyl lsobutyrate
Emulsion Remover: 12 wt% Sodium hypochlorite/88 % water
Haze Remover: 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
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
Immersion
Ink Remover
Methyl ethyl ketone( 2-butanone)
165
5.3
3
20
466
2180
Butyl acetate, normal
44
1.3
1
5.3
234
1090
Methanol
27
4.7
2
15
78
364
Naphtha, light aliphatic
98
1.6
1
6.2
312
1460
Toluene
110
2.3
1
9.2
312
1460
Isobutyl isobutyrate
7
0.4
0
1.7
156
728
Emulsion Remover (Bleach)
Sodium hypochlorite
0
0
0
0
187
874
Water
0
0
0
0
1370
874
Haze Remover
Xylenes (mixed isomers)
21
0.9
1
0
156
728
Acetone
64
11
5
0
468
2180
Mineral spirits- light hydrotreated
7
0.1
0
0
468
2180
Cyclohexanone
27
0.3
0
0
468
2180
Scenario I - reclaiming 6 screens per day, each screen is approximately 2100 in2; Scenario II» pouring 1 ounce ol 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 both toluene and methyl
ethyl ketone with respect to chronic dermal and Inhalation exposures to workers
using these chemicals in ink removal.
o Hazard quotient calculations indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
o 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
Margin Of Exposure*
Hazard Quotient
Dermal
Dermal
UImI
¦Vial
alion
Routine
Immersion
"
IMN
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Methyl ethyl ketone (2-butanone)
9.29
23
103
NA
NA
NA
NA
NA
NA
Butyl acetate normal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methanol
1.4
22
10
NA
NA
NA
NA
NA
NA
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Toluene
17
44
208
NA
NA
NA
NA
NA
NA
tsobutyt isobutyrate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (Bleach)
Sodium hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Xylenes (mixed isomers)
0.2
1.1
52
NA
NA
NA
NA
NA
NA
Acetone
11
66
311
NA
NA
NA
NA
NA
NA
Mineral spirits- light hydrotreated
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cydohexanone
0.07
1.3
6.2
180
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.
''LOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haz» 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 perlodate 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
Release Under Each Scenario
(g/day)
I
II
III
IV
air
water
land
air
air
air
water
Ink Remover
Methyl ethyl ketone( 2-butanone)
344
0
0
11
5.7
42
363
Butyl acetate, normal
92
0
80
2.6
1.5
11
191
Methanol
57
0
0
9.8
4.1
30
37
Naphtha, light aliphatic
204
0
25
3.2
1.7
13
257
Toluene
229
0
0
4.8
2.6
19
251
Isobutyl isobutyrate
15
0
100
0.8
0.5
3.4
132
Emulsion Remover (Bleach)
Sodium hypochlorite
0
75
0
0
0
0
0
Water
0
546
0
0
0
0
0
Haze Remover
Xylenes (mixed isomers)
44
0
0
1.9
1.1
0
0
Acetone
133
0
0
22
11
0
0
Mineral spirits- light hydrotreated
15
119
0
0.2
0.1
0
0
Cyclohexanone
57
76
0
0.7
0.4
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
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:
To Air:
To Water:
To Landfill:
Methyl ethyl ketone
403 g/day
363 g/day at laundry
n-butyl Acetate
107 g/day
191 g/day at laundry8
80 g/day8
Methanol
101 g/day
37 g/day at laundry
Naphtha, light aliphatic
222 g/day
257 g/day at laundry
25 g/day
Toluene
255 g/day
251 g/day at laundry
Isobutyl isobutyrate
19.7 g/day
132 g/day at laundry
100 g/day
Bleach
75 g/day
Mineral Spirits
15.3 g/day
119 g/day
Acetone
166 g/day
Xylenes
47 g/day
Cyclohexanone
58.1 g/day
76 g/day
"The 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 Syetem 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Mean Daily
Concentration, ug/L*
for 1000 MLD
Receiving Water
Methyl Ethyl Ketone
363 g/day at
laundry
84%
58 g/day
6 x 10"2
n-butyl acetate
191 g/day at
laundry
97%
5.7 g/day
6 x 10"3
Methanol
37 g/day at laundry
97%
1.1 g/day
1 x 10'3
Naphtha, light aliphatic
257 g/day at
laundry
94%
15 g/day
2 x 10"2
Toluene
251 g/day at
laundry
92%
20 g/day
2 x 10"2
Isobutyl isobutyrate
132 g/day at
laundry
98%
2.6 g/day
3x 10"3
Mineral Spirits
119 g/day
94%
7.1 g/day
7x10"®
Cyclohexanone
76 g/day
83%
13 g/day
1 x10'2
Sodium Hypochloriteb
75 g/day
100%
0
0
aug/L is Micrograms per liter, which is parts per billion for a substance in water. MLD is Million liters per day.
bConcentrated 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
DRAFT—September 1994
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 3
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-71
Estimated Cumulative Releases for St. Louis County, MO
Method 2, Traditional System 3
Substance
Total Amount
Released to
Water from All
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
n-butyl acetate
26 kg/day
97%
8 x 10"1 kg/day
1 x 10'1
Methanol
5 kg/day
97%
150 g/day
2 X 10"2
Naphtha, light aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10"1
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10"1
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 X 10'2
Mineral Spirits
16 kg/day
94%
960 g/day
1 x 10'1
Cyclohexanone
10 kg/day
83%
1.7 kg/day
2 x 10"1
Sodium Hypochlorite
10 kg/day
» 99%
«100 g/day
«1 x 10"2
DRAFT—September 1994
-------
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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Methyl Ethyl Ketone
403 g/day
8 x 10"1 ug/m3
6
n-butyl acetate
107 g/day
2 x 10"1 ug/m3
1
Methanol
101 g/day
2 x 10"1 ug/m3
1
Naphtha, light aliphatic
222 g/day
4 x 10"1 ug/m3
3
Toluene
255 g/day
5 x 10"1 ug/m3
4
Isobutyl isobutyrate
19.7
4x10'2ug/m3
0.3
Mineral Spirits
15.3 g/day
3 x 10"2 ug/m3
0.2
Acetone
166 g/day
3 x 10'1 ug/m3
2
Xylenes
47 g/day
9 x 10"2 ug/m3
0.7
Cyclohexanone
58.1 g/day
1 x 10"1 ug/m3
0.7
''This 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 lOOO 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
Daily Stream
Concentration in
Meramec River, ug/L
(PPb)
Daily dose from
Drinking Water
(mg/kg)
RfD (mg/kg)
Hazard
Quotient
(dose/RfD)
Methyl ethyl ketone
1
3x10"5
0.6
5x10"5
n-butyl acetate
1 x 10"1
3x10"®
not available
Methanol
2 x 10"2
6x10"7
0.5
1x10"®
Naphtha, light aliphatic
3 x 10"1
9x10"6
not available
Toluene
3 x 10"1
9x10"®
0.2
4x10'5
Isobutyl isobutyrate
4 x 10"2
1x10"®
not available
Mineral Spirits
1 x 10'1
3x10"®
not available
Cyclohexanone
2 x 10'1
6x10"®
5
1x10"®
Sodium Hypochlorite
«1 x 10"2
«3x10'7
not available
DRAFT—September 1994
-------
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
Highest Avg
Concentration 100 M
away
Daily Potential
Dose, (mg/kg)
RfD/RfC (mg/kg,
mg/m3)
Hazard
Quotient(Dose
or Conc/RfD or
RfC)
Methyl Ethyl Ketone
8x 10'1 ug/m3
2x10"4
1 mg/m3
8x10"4
n-butyl acetate
2 x 10"1 ug/m3
4x10'5
not available
Methanol
2 x 10"1 ug/m3
4x10"5
0.5 mg/kg
8x10'5
Naphtha, light aliphatic
4 x 10"1 ug/m3
1X10"4
not available
Toluene
5 x 10"1 ug/m3
2x10-4
0.4 mg/m3
1x10'3
Isobutyl isobutyrate
4 x 10"2 ug/m3
1 x10'5
not available
Mineral Spirits
3 x 10'2 ug/m3
8x10"6
not available
Acetone
3 x 10'1 ug/m3
8x10"5
0.1 mg/kg
8x104
Xylenes
9 x 10'2 ug/m3
3x10"5
2 mg/kg
1x10"5
Cyclohexanone
1 x 10'1 ug/m3
3x10'5
5 mg/kg
6x10"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. 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
Total Amount
Released to
Water from All
Facilities
Waste
water
Treatment
Removal
Efficiency
Amount to
Water After
Waste water
Treatment
Daily
Stream
Cone, in
Meramec
River, ug/L
(PPb)
ECO CC
(ug/L)
ECO RISK
INDICATOR
(STREAM
CONC/
ECO CC)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
4500
2x104
n-butyl acetate
26 kg/day
97%
8x10"1 kg/day
1 x 10"1
140
7x10"4
Methanol
5 kg/day
97%
150 g/day
2 X 10'2
9000
2x10"6
Naphtha light
aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10'1
5
0.06
Toluene
34 kg/day
92%
2.7 kg/day
I
O
X
CO
110
3x10'3
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
X
o
rb ,
80
5x10"4
Mineral Spirits
16 kg/day
94%
960 g/day
1 x 10'1
1
0.1
Cyclohexanone
10 kg/day
83%
1.7 kg/day
2 X 10"1
2800
7x10"5
Sodium
Hypochlorite
10 kg/day
» 99%
«100 g/day
«1 x 10"2
<20
-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 remcver. 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 tetrahydrofurfuiyl 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. 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 bv 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
that point, the test had to be aborted and the emulsion remover and haze remover were not
applied.
DRAFT—September 1994
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 3
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
-------
Table V-76
Performance Summary For Traditional Product System 3
System
Component
Performance
Demonstration Conditions
Avg Drying Tine
Before Using
Product
Average
Quantity
Appfied
Average
Cleaning Time
Average
Effort
Required
Overall System Performance
Ink type
Emulsion
type
Mesh type;
Thread
count
Average
Screen Size
| Laboratory Testing at SPTF
Solvent-
baaed Ink
Ink Remover
15 mins
3 J5 oz.
8.7 mins
High
Removed ink with a lot of scrubbing.
Gray haze remained on entire
screen.
Solvent-
based
Dual-cure
direct
Polyester;
245
threads/inch
360 in2
Emulsion
Remover
24 hours
3.0 oz.
22.5 mins
High
Standi dissolved stowty with
vigorous scrubbing. Heavy ink
residue and stain remained in Image
areas.
Haze
Remove?
Omhs
1.5 oz.
11.0 mins
Low
Removed all residue and stain.
UV-
curabie
M
Ink Remover
15 mins
2.5 oz.
7.4 mins
Moderate
Removed ink with moderate
scrubbing. A gray haze remained on
the screen.
UV-cured
Dual-cure
direct
Polyester;
390
threads/inch
360 in2
Emulsion
Remover
24 hours
3.0 oz.
17.7 mins
High
Stenci dfesotved slowly with
vigorous scrubbing and excessive
rinsing. Ink residue and stain
remained in image areas.
Haze
Remove?
Omins
1.0 oz.
12.0 mins
Low
Removed al residue and stain.
Watar-
baaedM
Ink Remover
15 mins
not recorded
not recorded
not recorded
The ink solidified across the entire
screen when the ink remover was
applied. Testing was stopped at this
point
Water-
based
Dual-cure
direct
Polyester;
245
threads/inch
360 in2
Emulsion
Remover
not used
not used
not used
not used
Test aborted after ink remover
failure.
Haze Remover
not used
not used
not used
not used
Test aborted after ink remover
failure.
a a haze remover other tian the formulation specified by the manufacturer and evaluated in the risk assessment for this system was used during the performance demonstration. See General Summary of
Tiadttionai System 3 Performance for details.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover 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 alipahtic
20% Toluene
10% Isobutyl isobutyrate
Emulsion Remover: 1% Sodium periodate/ 99% water
Haze Remover: 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
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
Immersion
Ink Remover
Methyl ethyl ketone( 2-butanone)
165
5.3
3
20
468
2180
Butyl acetate normal
44
1.3
1
5.3
234
1090
Methanol
27
4.7
2
15
78
364
Naphtha, light aliphatic
98
1.6
1
6.2
312
1460
Toluene
110
2.3
1
9.2
312
1460
Isobutyl isobutyrate
7
0.4
0
1.7
156
728
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Haze Remover
Xylenes (mixed isomers)
21
0.9
1
0
156
728
Acetone
64
11
5
0
468
2180
Mineral spirits- light hydrotreated
7
0.1
0
0
468
2180
Cyclohexanone
27
0.3
0
0
468
2180
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 paH; 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 both toluene and methyl
ethyl ketone with respect to chronic dermal and inhalation exposures to workers
using these chemicals in ink removal.
o Hazard quotient calculations Indicate marginal concerns for chronic inhalation
exposure to workers using methanol in ink removal.
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 cyclohexanone in haze removal.
DRAFT—September 1994
V-81
-------
Table V-78
Occupational Risk Estimates for Method 2, Traditional System 4
Margin Of Exposure*
Hazard Quotient6
Dermal
Dermat
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Methyl ethyl ketone (2-butanone)
9.3
22
103
NA
NA
NA
NA
NA
NA
Butyl acetate normal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methanol
1.4
22
10
NA
NA
NA
NA
NA
NA
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Toluene
17
44
208
NA
NA
NA
NA
NA
NA
Isobutyl isobutyrate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Xylenes (mixed isomers)
0.2
1.1
5.2
NA
NA
NA
NA
NA
NA
Acetone
11
66
310
NA
NA
NA
NA
NA
NA
Mineral spirits- light hydrotreated
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cydohexanone
0.07
1.3
6 2
180
NA
NA
NA
NA
NA
"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 (RfO) or the Reference Concentration (RfC). Hazard Quotient values less than 1 imply that adverse
effects are very unlraly to occur.
°NOAEL means No Observed Adverse Effect Level.
'lOAEL means Lowest Observed Adverse Effect Level.
-------
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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Methyl ethyl ketone( 2-butanone)
344
0
0
11
5.7
42
363
Butyl acetate, normal
92
0
80
2.6
1.5
11
191
Methanol
57
0
0
9.8
4.1
30
37
Naphtha, light aliphatic
204
0
25
3.2
1.7
13
257
Toluene
229
0
0
4.8
2.6
19
251
Isobutyl isobutyrate
15
0
100
0.8
0.5
3.4
132
Emulsion Remover (Zeta diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Haze Remover
Xylenes (mixed isomers)
44
0
0
1.9
1.1
0
0
Acetone
133
0
0
22
11
0
0
Mineral spirits- light hydrotreated
15
119
0
0.2
0.1
0
0
Cyclohexanone
57
76
0
0.7
0.4
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.
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:
To Air:
To Water:
To Landfill:
Methyl ethyl ketone
403 g/day
363 g/day at laundry
n-butyl Acetate
107 g/day
191 g/day at laundry8
80 g/day8
Methanol
101 g/day
37 g/day at laundry
Naphtha, light aliphatic
222 g/day
257 g/day at laundry
25 g/day
Toluene
255 g/day
251 g/day at laundry
Isobutyl isobutyrate
19.7 g/day
132 g/day at laundry
100 g/day
Sodium periodate
6 g/day
Mineral Spirits
15.3
119 g/day
Acetone
166 g/day
Xylenes
47 g/day
Cyclohexanone
58.1 g/day
76 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Methyl Ethyl Ketone
363 g/day at
laundry
84%
58 g/day
6 x 10'2
n-butyl acetate
191 g/day at
laundry
97%
5.7 g/day
6 x 10"3
Methanol
37 g/day at laundry
97%
1.1 g/day
1 x 10'3
Naphtha, light aliphatic
257 g/day at
laundry
94%
15.4 g/day
2 x 10'2
Toluene
251 g/day at
laundry
92%
20 g/day
2 x 10"2
Isobutyl isobutyrate
132 g/day at
laundry
98%
2.6 g/day
3x10"3
Mineral Spirits
119 g/day
94%
7.1 g/day
7 X 10"3
Cyclohexanone
76 g/day
83%
13 g/day
1 x 10'2
Sodium periodate
6 g/day
100%
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 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
DRAFT—September 1994
V-86
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Traditional System 4
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-82
Estimated Cumulative Releases for St. Louis County, MO
Method 2, Traditional System 4
Substance
Total Amount
Released to
Water from All
Facilities
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Average
Concentration in
Meramec River, ug/L
(PPb)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
n-butyl acetate
26 kg/day
97%
0.8 kg/day
1 x 10"1
Methanol
5 kg/day
97%
150 g/day
2 x 10"2
Naphtha, light aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10"1
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10"1
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 x 10"2
Mineral Spirits
16 kg/day
94%
960 g/day
1 x 10"1
Cyclohexanone
10 kg/day
83%
1.7 kg/day
2 x 10'1
Sodium Periodate
810 g/day
» 99%
« 8.1 g/day
«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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Methyl Ethyl Ketone
403 g/day
8 x 10"1 ug/m3
6
n-butyl acetate
107 g/day
2 x 10'1 ug/m3
1
Methanol
101 g/day
2 x 10"1 ug/m3
1
Naphtha, light aliphatic
222 g/day
4 x 10"1 ug/m3
3
Toluene
255 g/day
5 x 10'1 ug/m3
4
Isobutyl isobutyrate
19.7
4x10"2ug/m3
3 x 10'1
Mineral Spirits
15.3 g/day
3 x 10'2 ug/m3
2 x 10"1
Acetone
166 g/day
3 x 10"1 ug/m3
2
Xylene
47 g/day
9 x 10"2 ug/m3
7 x 10"1
Cyclohexanone
58.1 g/day
1 x 10*1 ug/m3
7 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 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
Total Amount
Released to
Water from All
Facilities
Waste
Water
Treatment
Removal
Efficiency
Amount to
Water After
Waste water
Treatment
Daily
Stream
Cone, in
Meramec
River, ug/L
(PPb)
ECOCC
(ug/L)
Eco Risk
Indicator
(Stream
Cone/
ECO CC)
Methyl ethyl ketone
49 kg/day
84%
7.8 kg/day
1
4500
2x10"4
n-butyl acetate
26 kg/day
97%
0.8 kg/day
1 x10"1
140
7x10"4
Methanol
5 kg/day
97%
150 g/day
2 x 10'2
9000
2x10*
Naphtha, light
aliphatic
35 kg/day
94%
2.1 kg/day
3 x 10*1
5
0.06
Toluene
34 kg/day
92%
2.7 kg/day
3 x 10'1
110
3x10'3
Isobutyl isobutyrate
18 kg/day
98%
360 g/day
4 x 10"2
80
5x104
Mineral Spirits
16 kg/day
94%
960 g/day
1 x 10"1
1
0.1
Cyclohexanone
10 kg/day
83%
1.7 kg/day
2 x 10'1
2800
7x10'5
Sodium Periodate
810 g/day
» 99%
« 8.1 g/day
«1 x 10"3
<10
-10-4
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)
2,127
Average # screens/day
6
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost {$)
24.4
5.33
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
Totals
Total Cost ($/screen)
6.27
Total Cost ($/year)
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: Aromatic solvent naphtha
Propylene glycol series ethers
Emulsion Remover: Sodium periodate/water
Haze Remover: Alkali/Caustic
Tetrahydrofurfuiyl alcohol
Water
Occupational Exposure
Table V-86
Occupational Exposure Estimates for Method 2, Alternative System Alpha
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
Immersion
Ink Remover
Aromatic solvent naphtha
13
0.1
0
0.2
1250
5820
Propylene glycol series ethers
56
0.6
0
2.6
312
1460
Emulsion Remover (diluted to 0.8%)
Sodium periodate
0
0
0
0
12
58
Water
0
0
0
0
1550
7220
Haze Remover
Alkali/Caustic
0
0
0
0
390
1820
Tetrahydrofurfuiyl alcohol
1
0.1
0
0
234
1090
Water
0
0
0
0
936
4370
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 paH; 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
Margin Of Exposure*
Hazard Quotient"
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Propylene glycol series ethers
1.4
7.4
34
230
NA
NA
NA
NA
Emulsion Remover (diluted to 0.8%)
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Alkali/Caustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
T etrahydrofu rfu ryl alcohol
NA
NA
NA
NA
NA
NA
NA
NA
NA
water
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.
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.
'h.OAEL means Lowest Observed Adverse Effect Level.
-------
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, Omlcron, 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Aromatic solvent naphtha
27
0
473
0.1
0.1
0.5
1080
Propylene glycol series ethers
117
0
8
1.3
0.7
5.4
265
Emulsion Remover (diluted to 0.8%)
Sodium periodate
0
5
0
0
0
0
0
Water
0
616
0
0
0
0
0
Aloha - Haze Remover
Alkali/Caustic
0
133
0
0
0
0
0
Tetrahydrofurfuryl alcohol
1.5
78
0
0.1
0.1
0
0
Water
0
319.
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.
Table V-89
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 2, Alternative System Alpha
Substance:
To Air:
To Water:
To Landfill:
Aromatic solvent naphtha
27.7 g/day
1080 g/day at laundry
473 g/day
Propylene glycol series ethers
124 g/day
265 g/day at laundry
8 g/day
Sodium periodate
5 g/day
Alkali/caustic
133 g/day
Tetrahydrofurfuryl alcohol
1.7 g/day
78 g/day
DRAFT—September 1994
-------
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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste
water Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Aromatic solvent naphtha
1080 g/day at
laundry
92-96 %
43 g/day
4 x 10'2
Propylene glycol series
ethers
265 g/day at
laundry
83-84 %
45.1 g/day
5 x 10"2
Sodium periodate
5 g/day
100 %
0
Alkali/caustic
133 g/day
100%
0
T etrahydrof u rf u ryl alcohol
78 g/day
97%
2.3 g/day
2 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 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
Amount of
Releases per day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Aromatic solvent naphtha
27.7 g/day
5.6 x 10"2 ug/m3
4x10'1
Propylene glycol series ethers
124 g/day
2.5 x 10'1 ug/m3
2
T etrahydrof urfuryl alcohol
1.7 g/day
3 x 10'3 ug/m3
2 X10"2
"This 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 Hi. 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 Aloha 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
DRAFT—September 1994
V-96
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
standard 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. 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 system. For these reasons, the printing manager made the decision to discontinue
DRAFT—September 1994
V-98
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
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.
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
DRAFT—September 1994
V-99
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
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 axe 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.
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-llmonene (<20%). As an emulsion remover, they use a
DRAFT—September 1994
V-100
-------
o
3}
>
3
0
3
7
1
Table V-92
On-Site Performance Summary For System Alpha
System
Component
Performance
Demonstration Conditions
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
1
In-lield Demonstrations at Volunteer Prating Faci
Sties
| Factty
1 '
Ink remover
10.8 ± 17.6 hrs
(n=50)
1.7 ±0.8 oz.
(n=50)
5.9 ± 2.5 mins
(n=32)
Moderate
Good on 40% of
screens; Fair on
22%; Poor on
38%
•20% of
screens
required
additional
cleaning before
reusing them.
¦ Needed to use
hot water to get
the emulsion to
breakdown.
Solvent-
based
vinyl and
epoxy
inks
Indirect
photo
stencil
Monofilame
nt Polyester;
195 - 330
threads/inch
823 in2
Emulsion
Remover
1.8 ±4.2 mins
(n=50)
1.0±02oz.
(n=50)
9.0 ± 3.9 mins
(n=50)
Moderate
With hot water,
removed stencil.
Haze
Remover
1.1 ±3.5mins
(n=50)
1.0±0.0oz.
(n=39)
7.6 ± 2.5 mins
(n=39)
Moderate
Haze was not
removed from
20% of screens.
FBCflty
13
Ink Remover
1.5 ±3.0 hrs
(o=15)
2.5 ± 0.8 oz.
(n=15)
15.5 ±8.0 mins
(n=15)
Moderate
Removed the ink
but required extra
time and effort
¦ Most screens
had to be re-
deaned with the
standard haze
remover before
the could be
reused.
UV-
curable
and
Solvent-
based
inks
Direct
photo
stencil
Abraded
polyester;
155-390
threads/inch
1591 in2
Emulsion
Remover
5.7 ± 5.8 mins
(n=6)
3.9 ± 2.0 oz.
(n=7)
11.7± 4.5 mins
(<*=7)
Moderate
Removed stencil,
but required extra
time and effort.
Haze
Remover
5.7 ± 4.0 mins
(n=3)
1.310.5 oz.
(n=4)
9.5 ± 2.4 mins
(n=4)
Moderate
Did not effectively
remove the haze.
8.
fO
Q.
S
O
33
3
Q>
8
3D
T3
3"
-------
0
3D
1
"O
S"
3
g-
S
3
•a
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
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.
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.
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 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 diy.
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 12ft2 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
humidity). Rags used for screen reclamation are washed by an Industrial laundiy 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.
DRAFT—September 1994
V-104
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Alpha
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.
° 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
Baseline
(Traditional
System 4)
Alternative System Alpha
Cost Element Description
Facility 8
Facility 13
Facility 14
Facility Characteristics
Average screen size (in2)
2,127
823
1,591
1,577
Average # screens/day
6
12.5
20
12
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
22.5
4.92
36.7
8.02
15.3
3.34
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
1.1
0.17
4.1
0.61
0
0
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
1.8
0.21
2.5
0.31
4.4
0.53
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
1.0
<0.01
3.9
0.01
4.1
0.01
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
1.0
0.30
1.3
0.37
4.0
1.18
Hazardous
Waste Disposal
Amount (g)
Cost ($)
34
0.02
31
0.02
60
0.04
59
0.04
Totals
Total Cost ($/screen)
6.27
5.62
9.36
5.10
Normalized®
6.27
6.79
9.37
5.92
Total Cost ($/year)
9,399
17,574
46,800
15,313
Normalized®
9,399
10,183
14,062
8,886
formalized values adjust product usage, number of screens cleaned, and number ol 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
Inhalation (mg/day)
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Diethylene glycol series ethers
0
0
0
0
312
1456
Tripropylene glycol methyl ether
0
0
0
0
858
4000
N-methylpyrrolidone
3
0
0
0.1
312
1460
Ethoxylated nonylphenol
0
0
0
0
78
364
Emulsion Remover (diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Haze Remover
Diethylene glycol series ethers
0
0
0
0
312
1456
Tripropylene glycol methyl ether
0
0
0
0
858
4000
N-methylpyrrolidone
3
0
0
0
312
1460
Ethoxylated nonylphenol
0
0
0
0
78
364
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 In2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario I
transferring chemicals from a 55 gallon drum to a 5 gallon pall; 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
Margin Of Exposure*
Hazard Quotientb
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Diethyiene glycol series ethers
NA
NA
NA
NA
NA
1,800
46
380
9.8
| Tripropytene glycol series ethers
NA
NA
NA
NA
NA
NA
NA
NA
NA
N-methylpyrroBdone
NA
NA
NA
3,600
NA
39
NA
8.4
NA
Ethoxytated nonytpbenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (dihjted 1:4}
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Diethyiene glycol series ethers
NA
NA
NA
NA
NA
1,800
46
380
9.8
Tripropylene glycol series ethers
NA
NA
NA
NA
NA
NA
NA
NA
NA
N-methylpyiTofidone
NA
NA
NA
37
NA
39
NA
8.4
NA
Ettwxylated nonyiphenol
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.
''NOAEL means No Observed Adverse Effect Level.
^LOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product SygtOTI 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 margln-of-exposure. Similar
calculations for inhalation exposures to N-methylpyrrolidone indicate very low
concern.
o Inhalation exposures to other ink remover components are veiy 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 perlodate 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
Release Under Each Scenario
(g/day)
1
II
III
IV
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol series ethers
0.1
0
138
0
0
0
270
Tripropylene glycol series ethers
0.1
0
381
0
0
0
742
N-methylpyrrolidone
6.8
0
132
0.1
0
0.2
270
Ethoxylated nonylphenol
0
0
35
0
0
0
67
Emulsion Remover (diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Haze Remover
Diethylene glycol series ethers
0.1
104
0
0
0
0
0
Tripropylene glycol series ethers
0.1
286
0
0
0
0
0
N-methylpyrrolidone
6.8
97
0
0.1
0
0
0
Ethoxylated nonylphenol
0
26
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 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 Removar 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:
To Air:
To Water;
To Landfill:
Diethylene glycol series ethers
0.2 g/day
104 g/day
270 g/day at laundry
138 g/day
Propylene glycol series ethers
0.2 g/day
286 g/day
742 g/day at laundry
381 g/day
N-methyl pyrrolidone
14 g/day
97 g/day
270 g/day at laundry
132 g/day
Ethoxylated nonylphenol
26 g/day
67 g/day at laundry
35 g/day
Sodium periodate
6 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Diethylene glycol series
ethers
104 g/day
270 g/day at
laundry
83%
18 g/day
46 g/day
2 x 10"2
4 X 10"2
Propylene glycol series
ethers
286 g/day
742 g/day at
laundry
83-97 %
49 g/day
126 g/day
5 x 10"2
1 x 10"1
N-methyl pyrrolidone
97 g/day
270 g/day at
laundry
97%
3 g/day
8.1 g/day
3 x 10'3
8 x 10"3
Ethoxylated nonylphenol
26 g/day
67 g/day at
laundry
100 %
0 g/day
0 g/day
0
Sodium periodate
6 g/day
100 %
0 g/day
0
a 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
Amount of
Releases per day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Diethylene glycol series ethers
0.2 g/day
3.5 xlO"4 ug/m3
3 x 10'3
Propylene glycol series ethers
0.2 g/day
3.5 x 10"4 ug/m3
3 x 10'3
N-methyl pyrrolidone
14 g/day
2.9 x 10"2 ug/m3
2 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 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
Daily Stream
Concentration, (ug/L)
Daily Dose from
Drinking Water
(mg/kg)
NOAEL or
LOAEL (mg/kg)
MOE -
NOAEL or
LOAEL/Dose
Diethylene glycol series
ethers
5.8 x 10"2
2x10"®
51 LOAEL
3x107
Propylene glycol series
ethers
1.5 x10"1
4x10"6
not available
N-methyl pyrrolidone
1.1 X10'2
3x10"7
175 NOAEL
6x108
Ethoxylated nonylphenol
0
0
not available
Sodium periodate
0
0
not available
Table V-102
Risk Estimates for Ambient Air Releases from a Single Model Facility
Screen Reclamation Method 2, Alternative System Chi
Substance
Highest Avg
Concentration 100 M
away
Daily Potential
Dose, (mg/kg)
NOAEL or
LOAEL (mg/kg)
MOE-
NOAEL or
LOAEL/
Dose
Diethylene glycol series ethers
3.5 x 104 ug/m3
1x10"7
51 LOAEL
5x108
Propylene glycol series ethers
3.5 x 10"4 ug/m3
1x10"7
not available
N-methyl pyrrolidone
2.9 x 10"2 ug/m3
8x10"6
175 NOAEL
2x107
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 gin 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
DRAFT—September 1994
V-114
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
decals and vacuum formed sheets; Facility 21 prints decals for glass and ceramics. During the
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:
° 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 Svatem C^l
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
demonstrations.
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 Sy«t«^
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.
° 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.
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
DRAFT—September 1994
V-118
-------
30
>
I
-o
«
3
?
Table V-103
On-Site Performance Summary For System Chi
8.
PO
a
2
o
S
92.
JO
s
M
3
5
3
»
®
3
I
System
Component
Performance
A vg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Requited
Performance for
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
type(«)
Emulsion
type
Mestitype;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Facilities
p. , Tlta
rflCMjf
3
Ink remover
Emulsion
Remover
Haze
Remover
7 2 ± 3.6 mins
(r»=50)
15.1 ± 21.7 hrs
(n=50)
02 ±05 mins
M7)
1.1 ±0.4oz.
(n=50)
2.1 ±0.4oz.
(n=50)
Z\ ± 0.3 oz.
(n=47)
6.6 ± 2.3 mins
(n=50)
2.9 ± 0.3 mins
(n=50)
2.9 ±0.3 mins
(n=47)
Moderate
Low
Low
Dissolved ink with
extra effort
Removed stencil
Ghost Images built
¦ All screens
could be reused.
¦ Printer was
concerned with
effect of possfcle
haze build 14)
overtime.
Solvent-
Dual Cure
Polyester.no
treatment;
180 - 370
threads/inch
1977 in2
r. .m>. ,
mny
21
Wr Remover
7.6 ±12.6 hrs
(n=51)
1.1 ±0.3oz.
(n=48)
2.0 ±1.5 mins
(n=47)
Low
Dissolved ink with
extra effort
Bnulsion
Remover
4.7 ±8.6 mins
(n=51)
1.5± 1.4oz.
(n=48)
2.5 ±22 mins
(n=48)
Low
Removed stencil
easily.
Haze
Remover
15.0 mins
(n=1)
ZQoz.
(n=1)
3.5 ± 0.7 mins
(n=2)
Moderate
Several applications
needed to remove
haze.
-All screens
could be reused
for future print
jobs.
- Haze removal
step rarely
needed.
- Worked wen on
metaMcinks.
Solvent-
CapMaiyfflm
and Direct
photo stencil
Polyester, half-
calendared or
low elongation
threads;
60-390
threads/inch
1088 in
TJ
I
a
52
o
-------
Table V-104
Laboratory Testing Performance Summary For System Chi
9|1M
Component
Rsituiinance
Demonstration CondMona II
Avg Drying Tinw
>«-«
MM USSlQ
Product
Average
Quantity
AooM
Avenge
Owning Time
Avaiage Effort
Required
Pm Iui i nance for
Each System
Component
Overal System
Performance
Ink
typ«(s)
Emulsion
type
Mesh type;
Thread count
Average |
Screen I
Size |
Laboratory Tasting at SPTF
SPTF
Ink
Ink ftfivMr
15 mins
not recorded
7J5 mins
Moderate
Heavy ink residue. Started to remove
stencl.
Solvent-
based
Dual cure
direct
Polyester; 255
tveadsflnch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
3.3 mins
low
Dissolved standi easiy. Heavy ink
residue remaining.
Hta
Remover
Omins
2.5 oz.
4.7 mins
Low
Lightened Ink stain.
SPTF
UV-
cunfale
Ink
Ink Remover
15mins
1.0 oz.
4.0 mins
Low
Dissolved (he ink but left a grey haze
owr entire screen.
UV-
curable
Dual cure
dsect
Polyester, 390
tveadsfinch
360 in2
fiixdntn
Remover
24 hours
IX) or
4.0 mins
Low
Dissolved stand easiy.
Haze
Remover
Omins
1.0 oz.
4.0 mins
Low
Lightened t» ink stain.
SPTF
band
Ink
Ink Remover
15 mins
2.0 oz.
4 JS mins
Moderate
Light ink residue. Stenci started
peeing.
Water-
based
Dual cure
direct
Polyester; 255
threads/inch
360 in2
Emulsion
Remover
24 hours
1.5 oz.
4.1 mins
Low
Dissolved stand easily. Heavy ink
stain and light residue.
Haze
Remover
Omins
1.5 oz.
3.3 mins
Low
Lightened ink stain.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Chi
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:
° 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.
° 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).
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
DRAFT—September 1994
V-121
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Ch|
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
Baseline
Alternative System Chi
Cost Element Description
(Traditional
System 4)
Facility 3
Facility 21
Facility Characteristics
Average screen size (in2)
2,127
1,977
1,088
Average # screens/day
6
15
23
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
12.3
2.69
8.0
1.74
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
1.2
0.18
1.2
0.19
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
1.1
0.21
1.1
0.21
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
2.1
0.07
1.5
0.05
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
2.1
0.39
2.0
0.37
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
6.27
3.55
2.56
Normalized8
6.27
3.89
3.25
Total Cost ($/year)
9,399
13,312
14,413
Normalized®
9,399
5,829
4,879
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
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
Product System Delta
Formulation
Ink Remover: Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Emulsion Remover: Sodium periodate
Water
Haze Remover: Dibasic esters
Propylene glycol series ethers
Ethoxylated nonylphenol
Occupational Exposure
Table V-106
Occupational Exposure Estimates for Alternative System Delta
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Dibasic esters
2
0
0
0.1
702
3280
Propylene glycol series ethers
0
0
0
0
780
3640
Ethoxylated nonylphenol
0
0
0
0
78
364
Emulsion Remover fdiluted 1:1)
Sodium periodate
0
0
0
0
39
182
Water
0
0
0
0
1520
7100
Haze Remover
Dibasic esters
2
0
0
0
702
3280
Propylene glycol series ethers
0
0
0
0
780
3640
Ethoxylated nonylphenol
0
0
0
0
78
364
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II - pouting 1 ounce of Mi for sampling; Scenario III •
transferring chemicals from a SS gallon drum to a 5 gallon pail; Scenario IV » storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994
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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 perlodate or a strong base such as sodium hydroxide. The
haze removers in Alpha, Epsilon, Gamma, Mu, Omlcron, 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
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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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Dibasic esters
3.7
0
319
0
0
0.2
608
Tripropylene glycol series ethers
0.1
0
359
0
0
0
675
Ethoxylated nonylphenol
0
0
36
0
0
0
67
Emulsion Remover (diluted 1:1)
Sodium periodate
0
16
0
0
0
0
0
Water
0
605
0
0
0
0
0
Haze Remover
Dibasic esters
3.7
239
00
00
00
00
00
Tripropylene glycol series ethers
0.1
269
0
0
0
0
0
Ethoxylated nonylphenol
0
27
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 a
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
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
From Emulsion Remover:
Sodium perlodate
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:
To Air:
To Water:
To Landfill:
Dibasic esters
7.6 g/day
239 g/day
608 g/day at laundry
319 g/day
Propylene glycol series ethers
0.2 g/day
269 g/day
675 g/day at laundry
359 g/day
Ethoxylated nonylphenol
27 g/day
67 g/day at laundry
36 g/day
Sodium periodate
16 g/day
DRAFT—September 1994
V-127
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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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste
water Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Dibasic esters
239 g/day
608 g/day at
laundry
84-97 %
22 g/day
55.1 g/day
2 x 10'2
6 x 10'2
Propylene glycol series
ethers
269 g/day
675 g/day at
laundry
83-97 %
35 g/day
88 g/day
3 x 10"2
9 x 10"2
Ethoxylated nonylphenol
27 g/day
67 g/day at
laundry
100 %
0
0
Sodium Periodate
16 g/day
100 %
0
0
a 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
Amount of Releases
Highest Average
Annual Potential
Substance
per day
Concentration 100 M away
Dose, mgfyear*
Dibasic esters
7.6 g/day
1.6 x 10"2 ug/m3
1.1 x 10"1
Propylene glycol series ethers
0.2 g/day
3.5 x 10"4 ug/m3
3 x 10"3
®This 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
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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
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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
DRAFT—September 1994 V-130
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
reapplication of the ink remover removed the residue, but did not lighten the stain
significantly.
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 diying 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
DRAFT—September 1994
V-131
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
like to use this product system at his facility. The application procedures for the alternative
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 unnecessaiy. 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 them 5% of their orders are repeat orders. Of the approximately 25 employees at this
DRAFT—September 1994
V-132
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Table V-111
On-Site Performance Summary For System Delta
System
Component
Performance
Demonstration Conditions
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Ink
type(s)
Emulsion
type
Mesh
type;
Thread
count
Average
Screen
Size
MmU Demonstrations at V
ofunteer Printing Facilities
Facttty
10
Ink remover
17.4 ± 40.9 hr
(n=18)
9.9 ± 4.2 oz.
(n=18)
92 ±2.1 mins
(n=16)
Moderate
Removed ink well
on 67% of
screens; Slight
residue on 33%.
¦ This facility used
their own haze
remover on most
screens.
< Ink remover
performance was
considered
average.
uv-
curable
Direct photo
stencil
Twill
weave;
305 - 390
threads/
inch
7767 in2
Envision
Remover
17.2 ± 32.7 hr
(n=18)
8.6±1.5oz.
(n=18)
4.7 ± 22 mins
(n=18)
Moderate
Easily removed
stencil.
Haze
Remover
3.0mins
(n=1)
1.0 oz.
(n=1)
17.0 mins
(n=1)
Moderate
Did not remove
haze.
Facfity
11
Ink Remover
11.4±22.2hr
(r*=30)
7.7 ± 3.5 oz.
(n=29)
6.3 ± 3.3 mins
(n=29)
Low/
Moderate
Consistently
removed ink well.
• All screens were
reusable.
< Print mage
quality was
excellent.
• No haze remover
needed.
UV-
curable
Direct photo
stencil
Mortofilam
ent twill
weave;
390
threads/
inch
5291 in2
Emulsion
Remover
4.7 ± 14.4 min
(n=31)
8.0 ± 3.5 oz.
(n=30)
6.0 ± 3 2 mins
(n=31)
Low/
Moderate
Easily removed
stencil.
Haze
Remover
not needed
not needed
not needed
not needed
Not needed.
-------
Table V-112
Laboratory Performance Summary For System Delta
System
Component
Performance
Demonstration Conditions
Avg Drying
Time Before
Using
Product
Average
Quantity
AooHod
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Ink
type(s)
Emulsion
type
Mesh
type;
Thread
count
Average
Screen
Size
I
Laborato
ry Testing at SPTF
SPTF
UV-
curable
ink
Ink Remover
15 mins
1.0 oz.
3.5 mins
Med
Moderate ink residue remaining. Half of
stencil peeled off.
uv-
curable
Dual cure
drect
Polyester;
390
threads/in
ch
360 in2
Emulsion
Hammer
24 hours
1.0 oz.
4.8 mins
Med
Removed stentf. Ink residue remaining.
Haze
Remover
Omins
1.5 oz.
2.5 mins
Low
Removed residue. Dark ink stain left
SPTF
Solvent
-baaed
Ink
Ink Remover
15 mins
1.0 oz.
4.5 mins
Med
Moderate ink residue remaining; some
stencil deterioration.
Solvent-
based
Dual cure
direct
Polyester
255
threads/in
ch
360 in2
Emulsion
Remover
24 hours
1.5 oz.
3.7 mins
Med
Removed standi completely. Ink residue
remaining.
Haze
Remover
Omins
2.0 oz.
35 mins
Low
Removed residue; moderate ink stain left.
SPTF
Water-
baaed
Ink
Ink Remover
15 mins
2.5 oz.
7.1 mins
Med
Sight ink residue remaining. Dissolved
most of the stencil.
Water-
based
Dual cure
direct
Polyester,
255
threads/in
ch
360 in2
Emulsion
Remover
24 houre
1.0 oz.
3.8 mins
Low
Removed stand completely. Sight ink
residue and some ink stain remaining.
Haze
Remover
Omins
1.5 oz.
2.8 mins
Low
Removed residue. Sight ink stain left
-------
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 Eire 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. Screens with a monofilament twill weave and a mesh count of 390 threads/inch were
DRAFT—September 1994
V-135
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Delta
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).
° 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.
° 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
Baseline
Alternative System Delta
Cost Element Description
(Traditional
System 4)
Facility 11
Facility 10
Facility Characteristics
Average screen size (in2)
2,127
5,292
7,767
Average # screens/day
6
5
8
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
12.3
2.69
30.9
6.76
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
0.0
0.0
6.5
0.97
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
7.7
0.99
9.9
1.27
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
8.0
0.28
8.6
0.30
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
not
used
1.0
0.13
Hazardous
Waste Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
6.27
3.96
9.43
Normalized®
6.27
3.28
7.66
Total Cost ($/year)
9,399
4,953
17,675
Normalized8
9,399
4,917
11,489
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-137
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Epsilon
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Dlacetone 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
Dlacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
Product System Epsilon
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
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Cyclohexanone
39
0.3
0.2
1.4
468
2180
Methoxypropanol acetate
17
0.4
0.2
1.7
234
1090
Diethylene glycol
0
0
0
0
312
1460
Benzyl alcohol
0.1
0
0
0
101
473
Derivatized plant oil
0.1
0
0
0.2
55
255
Aromatic solvent naphtha
1.6
0.1
0
0.2
156
728
Diacetone alcohol
4.6
0.1
0.1
0.4
234
1090
Emulsion Remover (diluted 1:4)
Sodium periodate
0
0
0
0
23
109
Sulfate salt
0
0
0
0
23
109
Water
0
0
0
0
1510
7060
Haze Remover
Cyclohexanone
12
0.3
0.2
0
234
109
Methoxypropanol acetate
5.2
0.4
0.2
0
117
546
Diethylene glycol
0
0
0
0
156
728
Benzyl alcohol
0
0
0
0
51
273
Derivatized plant oil
0
0
0
0
27
127
Aromatic solvent naphtha
0.5
0.1
0
0
78
364
Diacetone alcohol
1.4
0.1
0.1
0
62
291
Alkyl benzene sulfonates
0
0
0
0
140
655
Ethoxylated nonylphenol
0
0
0
0
62
291
Phosphate salt
0
0
0
0
117
546
Alkali/Caustic
0
0
0
0
408
1890
Water
0
0
0
0
109
510
Scenario I - rectalming 6 screens per day; each screen Is approximately 2100 In2; Scenario II - pouring 1 ounce of fluid tor sampling; Scenario III =
transferring chemicals from a 55 gallon drum to a 5 gallon pal; 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
Margin Of Exposure*
Hazard Quotient19
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Cydohexanone
0.12
1.3
6.2
120
NA
NA
NA
NA
NA
Methoxypropanol acetate
0.45
5.6
26
0
NA
NA
NA
NA
NA
Diethylene glycol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Benzyl alcohol
0.004
4.8
23
NA
NA
NA
NA
NA
NA
Derivatized plant oil
NA
NA
NA
NA
NA
NA
NA
NA
NA
Aromatic solvent naphtha
NA
NA
NA
NA
NA
NA
NA
NA
NA
Diacetone alcohol
NA
NA
NA
Emulsion Remover (diluted to 3%)
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Sulfate salt
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
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.
'NOAEL 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 Epsilon
Environmental Releases
Table V-117
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Epsilon
Release Under Each Scenario
(g/day)
I
ii
III
IV
System
air
land
water
air
air
air
water
Ink Remover
Cyclohexanone
82
126
00
0.7
0.4
2.9
402
Methoxypropanol acetate
36
68
0
0.8
0.5
3.6
199
Diethylene glycol
0
138
0
0
0
0
270
Benzyl alcohol
0.2
45
0
0
0
0
88
Derivatized plant oil
0.2
24
0
0.1
0
0.3
47
Aromatic solvent naphtha
3.2
66
0
0.1
0.1
0.5
135
Diacetone alcohol
9.6
94
0
0.2
0.1
0.8
202
Emulsion Remover (diluted to 3%)
Sodium periodate
0
0
9
0
0
0
0
Sodium salt
0
0
9
0
0
0
0
Water
0
0
602
0
0
0
0
Haze Remover
Cyclohexanone
25
0
55
0.7
0.7
0.4
0
Methoxypropanol acetate
11
0
29
0.8
0.8
0.5
0
Diethylene glycol
0
0
53
0
0
0
0
Benzyl alcohol
0.1
0
17
0
0
0
0
Derivatized plant oil
0.1
0
9.3
0.1
0.1
0
0
Aromatic solvent naphtha
1
0
26
0.1
0.1
0.1
0
Diacetone alcohol
2.9
0
37
0.2
0.2
0.1
0
Alkyl benzene sulfonates
0
0
48
0
0
0
0
Ethoxylated nonylphenol
0
0
21
0
0
0
0
Alkali/Caustic
0
0
138
0
0
0
0
Water
0
0
37
0
0
0
0
Phosohate salt
r_L
_§L
rn_JL
0
o
o
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.
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
Dlethylene 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:
To Air:
To Water:
To Landfill:
Cyclohexanone
113 g/day
55 g/day
402 g/day at laundry
126 g/day
Methoxypropanol acetate
54 g/day
29 g/day
199 g/day at laundry
68 g/day
Diethylene glycol
53 g/day
270 g/day at laundry
138 g/day
Benzyl alcohol
0.3 g/day
17 g/day
88 g/day at laundry
45 g/day
Derivatized plant oil
0.9 g/day
9.3 g/day
47 g/day at laundry
24 g/day
Aromatic solvent naphtha
5.3 g/day
26 g/day
135 g/day at laundry
66 g/day
Diacetone alcohol
14.1 g/day
37 g/day
202 g/day at laundry
94 g/day
Alkyl benzene sulfonates
48 g/day
Ethoxylated nonylphenol
21 g/day
Phosphate salt
21 g/day
Alkali/Caustic
138 g/day
Sodium periodate
9 g/day
Sulfate salt
9 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
Amount Released
to Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/L."
for 1000 MLD
Receiving Water
Cyclohexanone
55 g/day
402 g/day at
laundry
83%
9.4 g/day
68.3 g/day
9 x 10'3
7 x 10'2
Methoxypropanol acetate
29 g/day
199 g/day at
laundry
97%
9 x 10"1 g/day
6 g/day
9 x 10"4
6 x 10"3
Diethylene glycol
53 g/day
270 g/day at
laundry
84%
8.5 g/day
43.2 g/day
9 x 10"3
4 x 10"2
Benzyl alcohol
17 g/day
88 g/day at laundry
97%
5 x 10 1 g/day
3 g/day
5X10"4
3 x 10*3
Derivatized plant oil
9.3 g/day
47 g/day at laundry
100%
0 g/day
0
Aromatic solvent naphtha
26 g/day
135 g/day at
laundry
92-96%
2 g/day
10.8 g/day
2 x 10'3
1 x 10"2
Diacetone alcohol
37 g/day
202 g/day at
laundry
83%
6.3 g/day
34 g/day
6 x 10"3
3 x 10"2
Alkyl benzene sulfonates
48 g/day
97%
1.4 g/day
1 x 10"3
Ethoxyiated nonylphenol
21 g/day
100%
0 g/day
0
Phosphate salt
21 g/day
100%
0 g/day
0
Sodium hydroxide
138 g/day
100%
0 g/day
0
Sodium periodate
9 g/day
100%
0 g/day
0
Sulfate salt
9 g/day
100%
0 g/day
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 Epsllon
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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year"
Cyclohexanone
113 g/day
2.3 x 10"1 ug/m3
2
Methoxypropanol acetate
54 g/day
1.1 x 10"1 ug/m3
8 x 10"1
Derivatized plant oil
0.9 g/day
1.8 x 10"3 ug/m3
1 x 10"2
Aromatic solvent naphtha
5.3 g/day
1.1 x 10"2 ug/m3
8 x 10"2
Benzyl alcohol
0.3 g/day
6 x 10"4 ug/m3
4 x 10"3
Diacetone alcohol
14.1 g/day
3 x 10"2 ug/m3
2 x 10"1
''This 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 Epsllon.
Although air releases were evaluated for only a single facility, It Is veiy 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 veiy low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above lOOO 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:
° 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 Epsllon
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 em 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
demonstrations.
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
L
Performance
OemwwUaUon Condition*
Syatem
Component
Avg Drying
Ttate BifoN
Ustog Product
Average Quantity
AddM
"lT"B
Average
Clecnhg Time
Average
Effort
Required
Performance lor
Each System
Component
Overal System
Performance
Ink
typ«(»)
Emulsion
«YP®
Mesh type;
Thread
count
Average
Screen
Size
In-IWd Demot
titration* at Volu
mot miunj mcmr
•
FadRy
20
Mr remoter
no data
3.0 oz. (n=1)
no dtia
Moderate
Removed Wtwel,
but look some
extra time.
¦ Data forms were
not received from
HsfacBy.
Solvent-
based
vinyl,
Dual cure
Polyester;
83 - 280
•veadsfinch
2538 in2
Ernutaion
Remover
no data
3.3 ± 0.6 oz.
(n=3)
no data
Moderate
Easly removed
stencil.
- Al nfotmaKon is
based on weekly
phone cals.
enamels
Hue
Remover
no data
4.0 ± 1.7 oz.
(n=3)
no data
Moderate
Lightened ink stah.
rKny
24
Ink Remover
10.3 ±26.1 hrs
(n.14)
42 ± 1.7 oz.
(n=14)
3.7 ±15 mins
(n=13)
Moderate
Removed ink wed,
especialy UV ink.
- Al screens could
be reused after
reclamation.
•Some screens
could not be used
tor reverse printing.
Solvent-
based
andUV-
curable
Direct
photo
stencil
Monofitame
nt Polyester,
no
treatment;
355
Ihreadsfinch
1296 in2
Emulsion
Remover
13.8 ± 122 hrs
(r*=14)
42±1.9oz.
(n=13)
3.7 ±1.1 mins
(n=14)
Low
Easly removed
stencH.
Haze
Remover
2.9 ± 2.1 mins
(n=14)
1.5 ±0.5 oz.
(n=14)
10.9 ± 4.7 mins
(n=14)
Low
Usualy removed
haze.
Light ink stain
remained.
-------
0
5
1
¦p
0
3
ST
1
Table V-122
Laboratory Performance Summary For System Epsilon
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
ink
t*pe(s)
Emulsion
type
Mesh
type;
Thread
count
Average
Screen
Size
Laboratory Toting a
SPTF
SPTF
Sotont-
faaaad
Ink
Ink Remover
15mins
1.5 oz.
3.9 mins
Low
Dissolved ink well; gray haze left on
screen.
Solvent-
based
Dual cure
direct
Polyester;
260
threads/inc
h
360 in2
Emulsion
Remover
24 hours
1.0 oz.
3.4 mins
Moderate
Dissolved stenci; medium ink stain
remaining.
Haze
Remover
Omins
1.0 OZ.
31.8 mins
Low
Lightened ink stain.
SPTF
UV-
curable
Ink
Irk Remover
ISmins
15 oz.
3.3 mins
Low
Dissolved ink well; has unpleasant odor.
UV-
curabie
Dual cure
direct
Polyester;
390
threads/inc
h
360 in2
Emulsion
Remover
24 hours
15 oz.
3.8 mins
Moderate
Dissolved stenci; light ink stain remaining.
Haze
Remover
Omins
1.0 oz.
22 mins
Low
Lightened ink stain.
SPTF
Water-
hiifrt
I Mc
Ink Remover
15mins
15 oz.
5.6 mins
Moderate
Dissolved ink with scrubbing.
Water-
based
Dual cure
direct
Polyester;
260
threads/inc
h
360 in2
Emulsion
Remover
24 hours
1.0 oz.
32 mins
Moderate
Dissolved stenci; light ink stain remaining.
Haze
Remover
Omins
1.0 oz.
32.8 mins
Low
Lightened ink stain.
&
ro
o
3
»
33
3
a>
3
a
a
o
3
%
o>
8
3"
i
s
TJ
I
I
#
£
3
m
I
s
-------
V^ubstitut^omparatlv^ssessment^c^
Method 2: Traditional Reclamation With Haze Remover Product System Epsllon
reclamation activities. The facility uses a variety of solvent-based inks including vinyl, enamel,
Mid 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 sorav 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
cprpen Thev use a direct photo stencil and a monofilament (untreated) polyester mesh. All
screens used in 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.
DRAFT—September 1994 V-154
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Epsilon
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
(<15%).
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
Baseline
(Traditional
System 4)
Alternative System Epsilon
Cost Element Description
Facility 20
Facility 24
Facility Characteristics
Average screen size (in2)
2,127
2,538
1,296
Average # screens/day
6
8
1
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
9.7
2.12
18.3
4.00
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
7.0
1.05
3.8
0.57
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
3.0
0.18
4.2
0.26
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
3.3
0.09
4.2
0.11
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
4.0
0.27
1.5
0.10
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
112
0.08
57
0.04
Totals
Total Cost ($/screen]
6.27
3.79
5.08
Normalized8
6.27
3.08
5.29
Total Cost ($/year)
9,399
7,097
1,269
Normalized8
9,399
4,624
7,930
"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-156
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
Product System Gamma
Formulation
Ink Remover
Emulsion Remover
Haze Remover
Propylene glycol series ethers
Diethylene glycol series ethers
Dibasic esters
Fatty alcohol ethers
Derivatized plant oil
Sodium periodate
Sulfate salt
Phosphate salt
Water
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
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
immersion
Ink Remover
Diethylene glycol butyl ether acetate
0
0
0
0
62
291
Tripropylene glycol methyl ether
0
0
0
0
780
3640
Derivatized plant oil
0.2
0
0
0.2
62
291
Fatty alcohol ethers
0.4
0
0
0.1
187
873
Dibasic esters
1.3
0
0
0.2
468
2184
Emulsion Remover
Sodium periodate
0
0
0
0
39
182
Sulfate salt
0
0
0
0
16
73
Phosphate salt
0
0
0
0
117
546
Water
0
0
0
0
1270
5930
Haze Remover
Sodium hypochlorite
0
0
0
0
585
2730
Alkali/Caustic
0
0
0
0
39
182
Water
0
0
0
0
827
3860
Sodium alkyl sulfate
0
0
0
0
109
510
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.
DRAFT-September 1994
V-158
-------
Exhibit V-125
Occupational Risk Estimates for System Gamma
Margin Of Exposure*
Hazard Quotient5
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL0
LOAEL*
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Diethylene glycol butyl ether acetate
NA
NA
NA
NA
NA
2258
57
481
12
Tripropylene glycol methyl ether
NA
NA
NA
NA
NA
NA
NA
NA
NA
Derivatized plant oil
NA
NA
NA
NA
NA
NA
NA
NA
NA
Faffly alcohol ethers
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dfcasic esters
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover
Sodium penodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Sulfate salt
NA
NA
NA
NA
NA
NA
NA
NA
NA
Phosphate salt
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
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.
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.
cNOAEL means No Observed Adverse Effect Level.
^LOAEL means Lowest Observed Adverse Effect Level.
-------
Exhibit V-126
Occupational Risk Estimates for Alternative System Gamma
Name
Hazard Quotient'3
Margin Of Exposure*
Inhalation
Dermal
Inhalation
Dermal
Routine
Immersion
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Haze Remover
Sodium hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
NA
Afcali/Caustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Sodium alkyl sulfate
NA
NA
NA
NA
NA
192
NA
41
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.
'ftOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
-------
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 dlethylene glycol butyl ether
acetate used In Ink removal based on the calculated margln-of-exposure.
o Developmental toxicity risks from dermal exposures to dlethylene glycol butyl ether
acetate are very low based on the calculated margln-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 (AH Systems)
o All of the systems that employ an emulsion remover use either a strong oxidizer
such as hypochlorite or perlodate 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol butyl ether acetate
0
0
28
0
0
0
54
Tripropylene glycol methyl ether
0.1
0
355
0
0
0
675
Oerivatized plant oil
0.3
0
28
0.1
0
0.3
54
Fatty alcohol ethers
0.8
0
84
0
0
0.1
162
Dibasic esters
3.0
0
210
0
0
0.3
405
Emulsion Remover
Sodium periodate
0
16
0
0
0
0
0
Sulfate salt
0
6
0
0
0
0
0
Phosphate salt
0
47
0
0
0
0
0
Water
0
506
0
0
0
0
0
Haze Remover
Sodium hypochlorite
0
200
0
0
0
0
0
Alkali/Caustic
0
13
0
0
0
0
0
Water
0
282
0
0
0
0
0
Sodium alkyl sulfate
0
37
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
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:
To Air:
To Water:
To Landfill:
Diethylene glycol butyl ether acetate
54 g/day from laundry
28 g/day
Tripropylene glycol methyl ether
0.1 g/day
675 g/day from laundry
355 g/day
Derivatized plant oil
0.7 g/day
54 g/day at laundry
28 g/day
Fatty alcohol ethers
0.9 g/day
162 g/day at laundry
86 g/day
Dibasic esters
3.0 g/day
405 g/day at laundry
210 g/day
Sodium periodate
16 g/day
Sulfate salt
6 g/day
Phosphate salt
47 g/day
Other
47 g/day
Sodium hypochlorite
200 g/day
Alkali/caustic
13 g/day
Sodium alkyl sulfate
37 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste
water Treatment
Daily Stream
Concentration, ugfl."
for 1000 MLD
Receiving Water
Diethylene glycol butyl ether
acetate
54 g/day at
laundry
83%
9.2 g/day
9 x 10"3
Tripropylene glycol methyl
ether
675 g/day at
laundry
83%
115 g/day
1 x 10'1
Derivatized plant oil
54 g/day at
laundry
100 %
0
0
Fatty alcohol ethers
162 g/day at
laundry
100%
0
0
Dibasic esters
405 g/day at
laundry
84-97 %
28.3 g/day
3 x 10"2
Sodium Periodate
16 g/day
100 %
0
0
Sulfate salt
6 g/day
100%
0
0
Phosphate salt
47 g/day
100%
0
0
Other
47 g/day
100%
0
0
Sodium hypochlorite
200 g/day
100%
0
0
Alkali/caustic
13 g/day
100%
0
0
Sodium alkyl sulfate
37 g/day
100%
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
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gtimma
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
Amount of Releases
per day
Highest Average
Concentration 100 M
away
Annual Potential
Dose, mg/year4
Tripropylene glycol methyl ether
0.1 g/day
2 x 10"4 ug/m3
1 x 10"3
Derivatized plant oil
0.7 g/day
1.4 xlO"3 ug/m3
1 x10'2
Fatty alcohol ethers
0.9 g/day
2x10"3 ug/m3
1 x 10'2
Dibasic esters
3.0 g/day
5 x 10"3 ug/m3
5 x 10"2
®This 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
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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 ail 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 varied depending on the type of ink used. The emulsion remover and haze
DRAFT—September 1994
V-166
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Gamma
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 veiy 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 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
DRAFT—September 1994
V-167
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
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.
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
DRAFT—September 1994
V-168
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Gamma
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 perlodate. Their haze remover is a formulation which contains
100% sodium perlodate.
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.
° 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. Walt 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 diy before applying the haze remover.
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.
DRAFT—September 1994
V-169
-------
Table V-131
On-Site Performance Summary For Alternative System Gamma
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity
AooHed
* Tr"" "
Average
Cleaning
Time
Avg Effort
Req'd
Performance for
Each System
Component
Overall System
Performance
ink
«*!»(»)
Emulsion
typ®
Mesh type;
Thread count
Average
Screen 1
Size |
in-field Dem
onstraHons at Volunteer Printing Facilities
Fadtty
16
Ink remover
3.0 ± 2.4 mins
(n=7)
5.0 ± 2.0 OZ.
(n=7)
11.1 ±6.6
mins (n=7)
Med
Inkandoiy
residue left in
mesh.
• Did not use the
ink remover or
haze remover due
to poor
performance.
Solvent-
based
Capillary film
Polyester,
untreated or
abraded;
200 - 390
threads/
inch
2294 in2 1
Emulsion
Remover
52.4 ±272.0 mins
(n=55)
2.3 ±1.3 oz.
(n=51)
1.8 ±1.8
mins
(n=50)
Low
Easiy removed
stencil on all
screens.
Haze Remover
0.0 ± 0.0 mins
(n=55)
3.3 ± 1.5 OZ.
(1=3)
3.0 ±0.0
mins
(n=1)
Med
Did not remove
ghost images.
Facility
25
Ink Remover
19.2 ± 15.0 mins
(n=23)
10.8 ± 4.6 oz.
(n=22)
11.7 ±52
mins
(n=22)
High
Excessive ink
residue left in
screen.
¦ Stopped using
ink remover and
haze remover
after 2 weeks due
to poor results.
Solvent-
based
Direct photo
stencil
Polyester, no
treatment or
abraded;
175 - 420
threads/
inch
1848 in2
Emulsion
Remover
132 ±31.1 hrs
(n=54)
12±0.4oz.
(n=50)
3.0 ±0.3
mins
(n=50)
Low
Quickly, easily
removed sterol
Haze Remover
4.6 ±11.8 hrs
(n=54)
55 ± 72 OZ.
(n=23)
22 ± 0.4
mins
M2)
Low
Ink haze
remained in
screen.
-------
Table V-132
Laboratory Performance Summary For Alternative System Gamma
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity Applied
Average
Cleaning Time
Avg Effort
Req'tf
Performance for
Each System
Component
Overall System
Performance
lnktype(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
I
Laboratory Testing at SPTF
[ SPTF
Soivent-
I h—^
| Ink
Wt Remover
15 mins
1.5 oz.
3.8 mins
Low
Ink dissolved well. No effect on stand.
Solvent-
based
Dual cure
direct
Polyester,
260 threads/
inch
360 in2
Emulsion
Remover
24 hows
1.0 02.
3.9 mins
Low
Removed standi easily. Moderate ink stain
remaining.
HazaRamom
0 mins
1.0 oz.
1.8 mins
Low
Lightened stain.
SPTF
UV-
cunbte
Ink
Ink Remover
15 mins
1.5 02.
3.5 mins
Low
Ink dissolved well. No effect on stencfl.
UV-curable
Dual cure
direct
Polyester;
390 threads/
inch
360 in2
Emulsion
Remover
24 hours
15 oz.
4.8 mins
Low
Removed stencl easily. Moderate ink stain
remaining.
Haze Remover
Omins
05 02.
1.8 mins
Low
Lightened stain.
SPTF
MIMar-
baaad
Ink
Ink Remover
15 mins
2.0 oz.
5.8 mins
Med
Heavy scrubbing required to dissolve ink.
Parts of stand deteriorated.
Water-
based
Dual cure
direct
Polyester:
260 threads/
inch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
4.8 mins
Low
Removed standi easily. Moderate ink stain
remaining.
Haze Remover
Omins
1.0 oz.
2.0 mins
Low
Lightened stain.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product Syrtem Gamma
General Facility Background tor Facility 25
Facility 25 prints polnt-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 dally.
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%), trlmethylbenzenes
(<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
Baseline
Alternative System Gamma
Cost Element Description
(Traditional
System 4)
Facility 16
Facility 25
Facility Characteristics
Average screen size (in2)
2,127
2,294
1,848
Average # screens/day
6
20
25
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
15.9
3.48
16.9
3.70
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
5.0
0.75
7.0
1.04
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
5.0
0.43
10.8
0.92
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
2.3
0.24
1.2
0.12
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
3.3
0.24
5.3
0.39
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
o o
o o
Totals
Total Cost ($/screen)
6.27
5.14
6.17
Normalized8
6.27
5.06
5.61
Total Cost ($/year)
9,399
25,708
38,547
Normalized8
9,399
7,590
8,417
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«173
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
Product System Mu
Formulation
Ink Remover Dibasic esters
Methoxypropanol acetate
d-Limonene
Ethoxylated nonylphenol
Derivatized plant oil
Emulsion Remover Periodic acid
Water
Haze Remover Sodium hypochlorite
Alkali/Caustic
Sodium alkyl sulfate
Water
DRAFT-September 1994
V-174
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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
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Dibasic esters
3
0
0
0.2
1014
4728
Methoxypropanol acetate
31
0.4
0
1.7
312
1460
Limonene
21
0.6
0
2.4
156
728
Ethoxylated nonylphenol
0
0
0
0
94
437
Derivatized plant oil
0
0
0
0.2
62
291
Emulsion Remover
Periodic acid
0
0
0
0
156
728
Water
0
0
0
0
1400
6550
Haze Remover
Sodium hypochlorite
0
0
0
0
585
2730
Alkali/Caustic
0
0
0
0
39
182
Water
0
0
0
0
827
3860
Sodium alkyl sulfate
0
0
0
0
109
510
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario ill = ¦
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
Name
Hazard Quotient6
Margin Of Exposure*
Inhalation
Dermal
Inhalation
Dermal
Routine
Immersion
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Mu - Ink Remover
Dibasic esters
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methoxypropanol acetate
0.8
7.4
35
NA
600
NA
NA
NA
NA
Limonene
NA
NA
NA
NA
432
NA
67
NA
14
Ethoxylated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Derivatized plant oil
NA
NA
NA
NA
NA
NA
NA
NA
NA
Mu - Emulsion Remover
Periodic acid
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Mu - Haze Remover
Sodium hypochlorite
NA
NA
NA
NA
NA
NA
NA
NA
NA
Alkali/Caustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Sodium lauryl sulfate
NA
NA
NA
300
NA
190
NA
41
NA
aMargin 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.
-------
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 perlodate 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 eiiiulsion removers present significant inhalation
risks.
DRAFT—September 1994
V-177
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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
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Dibasic esters
5.1
0
446
0
0
0.3
877
Methoxypropanol acetate
64
0
75
0.8
0.5
3.6
266
Limonene
43
0
27
1.2
0.7
5.1
130
Ethoxylated nonylphenol
0
0
42
0
0
0
81
Derivatized plant oil
0.3
0
27
0.1
0
0.3
54
Emulsion Remover
Periodic acid
0
62
0
0
0
0
0
Water
0
559
0
0
0
0
0
Haze Remover
Sodium hypochlorite
0
200
0
0
0
0
0
Alkali/Caustic
0
13
0
0
0
0
0
Water
0
282
0
0
0
0
0
Sodium alkyi sulfate
0
37
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
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:
To Air:
To Water:
To Landfill:
Dibasic esters
5.4 g/day
877 g/day at laundry
446 g/day
Methoxypropanol acetate
68.9 g/day
266 g/day at laundry
75 g/day
Limonene
50 g/day
130 g/day at laundry
27 g/day
Ethoxylated nonylphenol
81 g/day at laundry
42 g/day
Derivatized plant oil
0.7 g/day
54 g/day at laundry
27 g/day
Periodic acid
62 g/day
Sodium hypochlorite
200 g/day
Alkali/caustic
13 g/day
Sodium alkyl sulfate
37 g/day
DRAFT—September 1994
V-179
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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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Watte water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Dibasic esters
877 g/day at
laundry
84-97 %
42.5 g/day
5 x 10'2
Methoxypropanol acetate
266 g/day at
laundry
97%
8 g/day
8 x 10'3
Limonene
130 g/day at
laundry
>99%
<1.3 g/day
<1 x 10"3
Ethoxylated nonylphenol
81 g/day at laundry
100%
0
0
Derivatized plant oil
54 g/day at laundry
100 %
0
0
Periodic acid
62 g/day
100%
0
0
Sodium hypochlorite
200 g/day
100 %
0
0
Alkali/caustic
13 g/day
100%
0
0
Sodium alkyl sulfate
37 g/day
100%
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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential Dose,
mg/year*
Dibasic esters
5.4 g/day
1.1 x10"2ug/m3
8 x 10"2
Methoxypropanol acetate
68.9 g/day
1.4 x 10'1 ug/m3
1
Limonene
50 g/day
1 x 10"1 ug/m3
7 x 10"1
Derivatized plant oil
0.7 g/day
1.4 x 10"3 ug/m3
1 x 10"2
"This 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 lOOO 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
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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:
° 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.
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-
DR AFT—September 1994
V-182
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
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 Detailt 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 sill 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 Detailt 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
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
DRAFT—September 1994
V-183
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
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 wert 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 17
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.
Current Screen Reclamation Products at Facility 17
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
DRAFT—September 1994
V-184
-------
Table V-140
On-Site Performance Summary For System Mu
System
Component
Performance
Demonstration Conditiora
Avg Drying
Time Before
Using Product
Avenge
Quantity
Aooied
I^WII
Avenge
Ctoming
Time
Average
Effort
Required
nnonnnce ror
Each System
Component
OvanH
System
Performance
Ink
typ«<»)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
In-fieid DemonttrMion* at
Volunteer Printing Fi
-»¦«*«- -
CWDW
f* ¦ ¦ MT>i
rtcwy
17
Ink remover
13.9 ± 16.9 hrs
(n=19)
2.7 ± 0.7 oz.
(n=18)
7.0 ±3.9
mins
(n=19)
Moderate
Removed ink
wel.
¦ Haze
remover
required at
least one hour
of wait time.
AS screens
wttUVink
WBIB
reusable.
UV ink
(one
screen
with
solvent-
based
ink)
Direct
photo
stencil
Mesh type
not
recorded;
280 - 390
threads/inch
2270 in2
Emulsion
Remover
4.9±1.7hre
(n=19)
2.6 ± 0.6 oz.
-------
Table V-141
Laboratory Performance Summary For System Mu
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall
System
Performance
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
.aboratory Tesi
ing at SPTF
SPTF
Sotwert-
hnnnrt
Ink
Ink Remover
15mins
1.0 02.
3.5mins
Low
Dissolved ink easily.
Solvent-
based
Dual cure
direct
Polyester;
260
threads/inch
360 in2
Emulsion
Remover
24 hours
0.5 oz.
3.6 mins
Med
Dissolved stencil well. Moderate ink
stain remaining.
Haze
Remover
Omins
1.0 oz.
2.0miris
Low
Haze remover did not lighten ink stain.
SPTF
UV-
curable
Ink
Ink Remover
15mins
1.5 0Z.
2.9mins
Low
Dissolved Ink very easily.
UV-
curable
Dual cure
direct
Polyester;
390
threads/inch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
3.3 mins
Med
Dissolved stencil well. Light ink stain
remaining.
Haze
Remover
Omins
0.5 oz.
2.0mins
Low
Lightened ink stain.
SPTF
-
wrar*
bitml
Ink
Ink Remover
ISmins
2.0 oz.
6.1 mins
High
Excessive scrubbing and product
required to remove dried ink.
Water-
based
Dual cure
direct
Polyester;
260
threads/inch
360 in2
Emulsion
Remover
24 hours
1.5 oz.
3.1 mins
Med
Dissolved stencil well. Light ink stain
remaining.
Haze
Remover
Omins
0.5 oz.
2.0 mins
Low
Lightened Ink stain.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Mu
which contains periodate salt (<10%). For haze removal, they use a proprietary aqueous
mixture with sodium hydroxide (< 15%).
Current Screen Reclamation Practices in Facility 17
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 fined 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 tor 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 dally.
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.
Waste water from the washes of the emulsion remover and haze remover is not recycled or
filtered at this facility.
DRAFT—September 1994
V-187
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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 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:
° 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
Baseline
Alternative System Mu
Cost Element Description
(Traditional
System 4)
Facility 17
Facility 22
Facility Characteristics
Average screen size (in2)
2,127
2,270
1,520
Average # screens/day
6
25
12
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
17.2
3.75
34.6
7.58
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
1.0
0.15
10.8
1.61
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
2.7
0.16
11.6
0.70
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
2.6
0.21
1.1
0.09
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
2.9
0.17
1.3
0.08
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
110
0.08
73
0.05
Totals
Total Cost ($/screen)
6.27
4.53
10.11
Normalized®
6.27
4.79
9.33
Total Cost ($/year)
9,399
28,295
30,338
Normalized8
9,399
7,185
13,997
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-189
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
Product System Phi
Formulation
Ink Remover Dibasic esters
Emulsion Remover Sodium periodate
Water
Ethoxylated nonylphenol
Other
Haze Remover N-methyl pyrrolidone
Dibasic esters
Occupational Exposure
Table V-143
Occupational Exposure Estimates for Alternative System Phi
inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Dibasic esters
4
0
0
0.2
1561
7270
Emulsion Remover
Sodium periodate
0
0
0
0
47
218
Water
0
0
0
0
1210
5640
Ethoxylated nonylphenol
0
0
0
0
123
575
Other
0
0
0
0
181
844
Haze Remover
N-methylpyrrolidone
6
0
0
0
780
3640
Dibasic esters
1
0
0
0
780
3639
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
DRAFT—September 1994
V-190
-------
Table V-144
Occupational Risk Estimates for Alternative System Phi
Margin Of Exposure*
Hazard Quotient1*
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Dibasic esters
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Ethoxytated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
N-mettiylpyrroiiclone
NA
NA
NA
2076
NA
16
NA
3.3
NA
Dibasic esters
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.
"LOAEL means Lowest Observed Adverse Effect Level.
-------
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-methylpyrrolldone during haze removal present a concern
for developmental toxicity risk based on the calculated marglns-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, Epsllon, 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-192
-------
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
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Dibasic esters
8.1
0
766
0
0
0.3
1349
Emulsion Remover
Sodium periodate
0
19
0
0
0
0
0
Water
0
481
0
0
0
0
0
Ethoxylated nonylphenol
0
49
0
0
0
0
0
Other
0
72
0
0
0
0
0
Haze Remover
N-methylpyrrolidone
12
270
0
0.1
0
0
0
Dibasic esters
3.1
279
0
0
0
0
0
Scenario I - reclaiming 6 screens per day; each screen Is approximately 2100 in2; Scenario I) - pouring 1 ounce of fluid for sampling; Scenario ill *
transferring chemicals from a 55 gallon drum to a 5 gallon paK; 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-193
-------
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:
To Air:
To Water:
To Landfill:
Dibasic esters
11.5 g/day
279 g/day
1349 g/day at laundry
766 g/day
Sodium periodate
19 g/day
Ethoxylated nonylphenol
49 g/day
Other
72 g/day
N-methyl pyrrolidone
12.1 g/day
270 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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration,
ug/L* for 1000
MLD Receiving
Water
Dibasic esters
279 g/day
1349 g/day at
laundry
84-97 %
13.8 g/day
66.4 g/day
1 x 10"2
6 x 10'2
Sodium periodate
19 g/day
100 %
0
0
Ethoxylated nonylphenol
49 g/day
100%
0
0
Other
72 g/day
100%
0
0
N-methyl pyrrolidone
270 g/day
97%
8.1 g/day
8 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.
DRAFT—September 1994
V-194
-------
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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year"
Dibasic esters
11.5 g/day
2.3 x 10'2 ug/m3
2 x 10"1
N-methyl pyrrolidone
12.1 g/day
2.5 x 10'2 ug/m3
2 x 10"1
"This 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 veiy low risk. Margin-of-
Exposure (MOE) values above 100 for a NOAEL or above lOOO 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
primarily used solvent-based vinyl inks, but they also tried System Phi on acrylic vinyl, epoxy,
DRAFT—September 1994
V-195
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Phi
and 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 Phf 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. Walt 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-196
-------
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 ^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-197
-------
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
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
DRAFT—September 1994
V-198
-------
3)
>
I
¦o
»
3
f
Table V-149
On-Site Performance Summary For Alternative System Phi
&
ro
System
Component
Performance
Avg Drying Time
Before Using
Product
Avenge
Quantity
Average
Cleaning Time
Average
Effort
Requited
Performance foe
Each System
Component
Overall System
Performance
Demonstration Conditions
Ink
typ«
-------
Table V-150
Laboratory Performance Summary For Alternative System Phi
——-
Performance
Demonstration Conditions
System
Component
Avg Drying Time
Before liting
Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
Laboratot
y Testing at SPTF
| SPTF
Ink Remover
15min$
2.5 oz.
6.7mins
Low
Ink dissolved easiy.
Solvent-
Dual cure
Polyester; 255
360 in2
Solvent-
baaed Ink
Emulsion
Remover
24 hours
0.5 oz.
6.4mins
Low
Stencil dtesotod easily; sight ink residue
and light stain remaining.
based
direct
threads/inch
Haze Remover
Omins
1.0 oz.
5.6mins
Low
Lightened stain sightly; removed residue.
SPTF
Ink Remover
15mins
2.0 oz.
5.5mins
Low
Ink dissolved very sasity.
UV-curable
Dual cure
Polyester; 390
360 in2
UV-
cunbto
Ink
Emulsion
Remover
24 hours
0.5 oz.
5.5mins
Low
Stenci tSssoived easily
remaining.
dark ink stain
direct
threads/inch
Haze Remover
Omins
0.5 oz.
6.2mins
Low
Lightened ink stain, but did not remove it
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
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 dally.
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 removed 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
diy 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
removed, 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
pressure wash. Apply the second part of the haze remover product with a brush.
Wait for one minute. Rinse with a high pressure wash.
DRAFT—September 1994
V-201
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Phi
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 removed. 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-202
-------
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
Baseline
Alternative System Phi
Cost Element Description
(Traditional
System 4)
Facility 5
Facility 23
Facility Characteristics
Average screen size (in2)
2,127
2,815
883
Average # screens/day
6
3
4
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
8.0
1.74
22.0
4.81
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
2.9
0.43
1.3
0.19
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
1.3
0.25
2.0
0.39
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
1.7
0.33
1.0
0.19
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
1.1
0.35
1-2
0.37
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
6.27
3.11
5.96
Normalized8
6.27
6.10
7.82
Total Cost ($/year)
Normalized8
9,399
1,991
5,957
9,399
9,233
11,728
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-203
-------
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 Dtethylene glycol butyl ether
Propylene glycol
Emulsion Remover Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover Ethoxylated nonylphenol
Phosphate surfactant
Water
Other
Occupational Exposure
Table V-152
Occupational Exposure Estimates for Alternative System Omicron-AE
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Diethylene glycol butyl ether
0
0
0
0
984
4590
Propylene glycol
17
0.1
0
0.4
576
2690
Emulsion Remover
Sodium Periodate
0
0
0
0
47
218
Ethoxylated nonylphenol
0
0
0
0
31
146
Water
0
0
0
0
1480
6920
Haze Remover
Other
0
0
0
0
109
510
Ethoxylated nonphenol
0
0
0
0
16
73
Phosphate surfactant
0
0
0
0
78
364
Water
0
0
0
0
1360
6330
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
DRAFT—September 1994
V-204
-------
Table V-153
Occupational Risk Estimates for Alternative System Omicron AE
Margin Of Exposure*
Hazard Quotient
Dermal
Dermal
Inhalation
Routine
Immersion
H
Name
Inhalation
Routine
Immersion
NOAEL0
LOAEL*
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Oiethyiene glycol butyt ether
NA
NA
NA
NA
NA
142
3.6
30
0.8
Propylene glycol
0.01
0.4
1.9
NA
NA
NA
NA
NA
NA
Emulsion Remover
NA
NA
NA
NA
NA
NA
NA
NA
NA
Sodium periodafe
NA
NA
NA
NA
NA
NA
NA
NA
NA
Ethoxylated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Ethoxylated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
| Phosphate surfactant
NA
NA
NA
NA
NA
NA
NA
NA
NA
| Water
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.
''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.
cNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omlcron-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 (Ail 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-206
-------
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
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol butyl ether
0
0
440
0
0
0
852
Propylene glycol
35
0
222
0.2
0.1
0.7
497
Emulsion Remover
Sodium periodate
0
19
0
0
0
0
0
Ethoxylated nonylphenol
0
13
0
0
0
0
0
Water
0
603
0
0
0
0
0
Haze Remover
Other
0
43
0
0
0
0
0
Ethoxylated nonphenol
0
6.2
0
0
0
0
0
Phosphate surfactant
0
31
0
0
0
0
0
Water
0
540
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 SS 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 Removed 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-207
-------
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:
Othey
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:
To Air:
To Water:
To Landfill:
Diethylene glycol butyl ether
852 g/day at laundry
440 g/day
Propylene glycol
36 g/day
497 g/day at laundry
222 g/day
Sodium periodate
19 g/day
Ethoxylated nonylphenol
19.2 g/day
Other
43 g/day
Phosphate surfactant
31 g/day
DRAFT—September 1994
V-208
-------
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
Amount
Released to
Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Diethylene glycol butyl ether
852 g/day at
laundry
83%
145 g/day
1 x 10"1
Propylene glycol
497 g/day at
laundry
97%
14.9 g/day
1 x 10"2
Sodium periodate
19 g/day
100%
0
0
Ethoxylated nonylphenol
19.2 g/day
100%
0
0
Other
43 g/day
100%
0
0
Phosphate surfactant
31 g/day
100%
0
0
a 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
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Propylene glycol
36 g/day
7.3 x 10"2 ug/m3
5 x 10'1
"This 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-209
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omlcron-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 sin 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 them 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 them 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.
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
DRAFT—September 1994 V-210
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
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.
Alternative System Performance Details
Performance Detalla 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
DRAFT—September 1994
V-211
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
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 veiy 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.
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
DRAFT-September 1994
V-212
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
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 Eire 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 Complied 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
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 dally.
Screen Reclamation Area in Facility 2
DRAFT—September 1994
V-213
-------
Table V-158
On-Site Performance Summary For Alternative System Omicron AE
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity
Appfied
Average
Cleaning Time
Avenge
Effort
Required
Performance for
Each System
Component
Overall System
Performance
Ink
type«
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-field Demonstrations at Volunteer Printing Fadtties
TbiiMIii
rSCMKy
2
Irk remover
7.1 ± 9.3 hrs
("=14)
12.6 ± 13.1 oz.
(1=7)
18.6 ±15.5
mins (n=7)
Moderate
Ink residue not
removed from mesh.
• Only 7 screens
rectamined
wfeystem, due to
poor
performance.
Solvent-
based
inks
Direct
photo
stencil
Mesh type not
specified;
230 threads/in.
5663 in2
Emulsion
remover
1.3 ±3.7 hrs
(n=30)
7.5 ± 3.7 oz.
(n=26)
6.6 ± 3.4 mins
(n=26)
Low
Easily, completely
removed stenci.
Haze remover
22 ± 6.7 hrs
(n=30)
14.6 ±5.1 oz.
(n=7)
15.0 ±4.1 mins
(n=7)
Low
Seemed to have no
effect on the haze.
FadMy
19
Ink remover
3.7 ±1.5 hrs
(n=3)
2.3 ± 1.2 oz.
(n=3)
7.3 ±4.5 mins
(n=3)
High
Ink remained in
screen after several
applications
• Did not
participate after
observer's visit,
due to
poor product
performance.
Solvent-
based
Direct
photo
stencil
PeKap;
156 - 390
threads/in.
957 in2
Emulsion
Remover
not recorded
(n=0)
1.3±0.6oz.
(n=3)
3.3 ± 0.6 mins
(n=3)
Moderate
Reapplication needed
to remove emulsion.
Haze
Remover
3.0mins
(n=1)
2.3 ± 2.5 oz.
(n=4)
10.0 ± 9.3 mins
(n=4)
High/
Moderate
Lightened the ink
stain.
-------
o
30
Table V-159
Laboratory Performance Summary For Alternative System Omicron AE
System
Component
Performance
Demonstration Conditions
Avg Drying Time
PofoiB Using Product
Average
Quantity
Appled
Average
Cleaning Tine
Average
Effort
Required
Pel (millanep for
Each System
Component
Overal
System
Performance
WctypeW
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
Laboratory Testing at SPTF
SPTF
Soivant-
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
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.
° 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
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
DRAFT—September 1994
V-216
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-AE
44% relative humidity). Rags used for ink removal sire 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-217
-------
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
Baseline
Alternative System Omicron-AE |
Cost Element Description
(Traditional
Svstem 4)
Facility 2
Facility 19 ]
Facility Characteristics
Average screen size (in )
2,127
5,663
957
Average # screens/day
6
6
70
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
40.2
8.80
20.7
4.52
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
16
2.43
0
0
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
12.6
0.96
2.3
0.18
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
7.5
0.56
1.3
0.10
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
12.6
0.89
2.3
0.16
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
6.27
13.65
4.96
Normalized®
6.27
10.85
5.49
Total Cost ($/year)
9,399
20,470
86,787
Normalized3
9,399
16,278
8,240
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-218
-------
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 Diethylene glycol butyl ether
Propylene glycol
Emulsion Remover Sodium periodate
Ethoxylated nonylphenol
Water
Haze Remover Ethoxylated nonylphenol
Phosphate surfactant
Alkali/Caustic
Water
Occupational Exposure
Table V-161
Occupational Exposure Estimates for Alternative System Omicron-AF
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Diethylene glycol butyl ether
0
0
0
0
984
4590
Propylene glycol
17
0.1
0
0.4
576
2690
Omicron Emulsion Remover)
Sodium periodate
0
0
0
0
47
218
Ethoxylated nonylphenol
0
0
0
0
31
146
Water
0
0
0
0
1480
6920
Haze Remover
Ethoxylated nonphenol
0
0
0
0
16
73
Alkali/Caustic
0
0
0
0
156
728
Phosphate surfactant
0
0
0
0
78
364
Other
0
0
0
0
109
510
Water
0
0
0
0
1200
5610
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
DRAFT—September 1994
V-219
-------
Table V-162
Occupational Risk Estimates for Alternative System Omicron AF
I
Margin Of Exposure'
Hazard Quotient1'
Dermal
Dermal
Inhalation
Routine
Immersion
| Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Diethyiene glycol butyl ether
NA
NA
NA
NA
NA
142
3.6
30
0.8
Propylene glycol
0.01
0.4
1.9
NA
NA
NA
NA
NA
NA
Emulsion Remover
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Ethoxytated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
ethoxytated nonylphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
AkaWCaustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
Phosphate surfactant
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
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.
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.
•tOAEL means Lowest Observed Adverse Effect Level.
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to
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B
2
i
n
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haza Remover Product System Qmlcren-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 removed.
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 veiy low.
o Risks from other components could not be quantified because of limitations in
hazard data, although denned 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 perlodate 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-221
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omlcron-AP
Environmental Releases
Table V-163
Environmental Release Estimates in Screen Cleaning Operations
Method 2, Alternative System Omicron-AF
Release Under Each Scenario
(g/day)
I
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol butyl ether
0
0
440
0
0
0
852
Propylene glycol
35
0
222
0.2
0.1
0.7
497
Emulsion Remover
Sodium periodate
0
19
0
0
0
0
0
Ethoxylated nonylphenol
0
13
0
0
0
0
0
Water
0
603
0
0
0
0
0
Haze Remover
Ethoxylated nonphenol
0
5.6
0
0
0
0
0
Alkali/Caustic
0
56
0
0
0
0
0
Phosphate surfactant
0
28
0
0
0
0
0
Other
0
43
0
0
0
0
0
Water
0
428
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 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-222
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product Svatam Omlcron-AF
Environmental Release Estimates from Screen Reclamation Processes
Screen Reclamation Method 2, Alternative System Omlcron 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:
To Air:
To Water:
To Landfill:
Diethylene glycol butyl ether
852 g/day at laundry
440 g/day
Propylene glycol
36 g/day
497 g/day at laundry
222 g/day
Sodium periodate
19 g/day
Ethoxylated nonylphenol
18.6 g/day
Alkali/caustic
56 g/day
Other
39 g/day
Phosphate surfactant
28 g/day
DRAFT—September 1994
V-223
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omlcmn-Ap
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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ugfl."
for 1000 MLD
Receiving Water
Diethylene glycol butyl
ether
852 g/day at
laundry
83%
145 g/day
1 x 10'1
Propylene glycol
497 g/day at
laundry
97%
14.9 g/day
1 x 10'2
Ethoxylated nonylphenol
18.6 g/day
100 %
0
0
Sodium Periodate
19 g/day
100%
0
0
Other
39 g/day
100%
0
0
Phosphate surfactant
28 g/day
100%
0
0
Alkali/caustic
56 g/day
100%
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
Amount of Releases per
Highest Average
Annual Potential
Substance
day
Concentration 100 M away
Dose, mg/year*
Propylene glycol
36 g/day
7.3 x 10"2 ug/m3
5 x 10"1
''This 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-224
-------
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. At Facility 18, the haze remover left too much haze under all conditions
DRAFT—September 1994
V-225
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omicron-Af
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-226
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Qmlffrw-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
DRAFT—September 1994
V-227
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Omlcron-ftp
system. The facility's standard procedure for these inks is to apply haze remover twice after
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 tor 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-228
-------
Table V-167
On-Site Performance Summary for Alternative System Omicron-AF
""
System
Component
Performance
Demonstration Conditions
Avg Drying Time
Before Using
Product
Average
Quantity
Applied
Average
Cleaning Time
Average Effort
Required
Performance for
Each System
Component
Overall System
Performance
Ink
type(s)
Emulsion
type
Mesh type;
Thread count
Average
Screen
Size
In-fletd Demonstrations at Vo
1
f
FacMty
4
Wt remover
46.1 ± 49.3 hrs
(n=22)
1.6 ±0.7
oz.(n=22)
5.1 ± 0.6 mins
(n=12)
Moderate
ink residue in stencH
area.
< Most screens
could not be reused
due to a haze.
¦ A ghost image
appeared when the
screens were
reused.
¦ Thefacffity
discontinued use
after 2 weeks.
uv-
curable
Direct
photo
stencil
Monofilament
Polyester,
calandered;
390
threads/inch
1577 in2
Emission
Remover
5.5 ±10.2 hrs (n=22)
1.4±0.5oz.
(n=22)
4.9 ± 0.3 mins
(n=12)
Low
EasSy removed
stencil.
Haze
Rammer
4.1 ± 2.0 mins (n=22)
2.1 ± 0.7 oz.
(n=12)
5.0 ± 0.2 mins
(n=12)
High
Did not remove
ghost image from
most screens.
r. ¦|H|I i
racMiy
18
Ink Remover
28.5 ±28.0 his
(n=47)
25 ± 05 oz.
(n=46)
2.7 ± 0.9 mins
(n=46)
Low
Removed ink well.
• Facility was
pleased with the ink
and emulsion
removers.
• They switched
back to their own
haze remover after
one week.
Solvent-
based
Direct
photo
stencil and
capillary
flm
Mono-
filament
polyester; 110
-460
threads/inch
1150 in2
Emulsion
Rammer
15 ±1.1 mins (n=47)
3.6±1.2oz.
(n=47)
4.0 ±1.1 mins
{"=47)
Low
Easily removed
stencil.
Haze
Ramom
0.8 ± 2.7 mins (rt=47)
1.9 ±0.7 oz.
(n=11)
4.1 ±1.4 mins
(n=11)
Low
Did not reduce haze.
l=
I
£
IS)
to
&
a?
o
3
22.
3D
a>
3
o
3
§
5
x
»
8
3D
9
3
0
1
3
¦u
I
5?
0
3
B-
1
-------
Table V-168
Laboratory Performance Summary for Alternative System Omicron-AF
Performance
System
Component
Avg Drying Time
Before Using
Product
Average
Quantity
AooKed
Avenge
Cleaning
Time
Average
Effort
Required
Performance for
Each Syatam
Component
Overal System
Performance
lnktypa(8)
cnumon
type
Meah type;
Thread count
Average
Screen
Size
SPTF
NtMra*
baeedtt
Ink Rhiiow
15 mins
1.5 oz.
5.7 mins
Moderate
Ink dssotod we*.
Solvent-
based
Dual cure
direct
Polyester; 260
threads/inch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
4.1 mins
Moderate
Stand (fcsotved easiy. Moderate ink
stain remaining.
Hue Remover
Omins
1.0 oz.
4.0 mins
Low
Lightened the ink stein.
SPTF
UV-curabie
Ink
Ink Remover
15mins
1.5 oz.
6.5 mins
Low
Ink dissolved wed
UV-curable
Dual cure
direct
Polyester; 390
threads/inch
360 in2
Emulsion
Amow
24 hours
1.0 oz.
4.1 mins
Low
Standi dtesotod easly. Light ink stein
remaining.
Haze Remover
Omins
0.5 oz.
4.5 mins
Low
Lightened he ink stain.
SPTF
Water-
btMd Ink
Ink Remover
15mins
2.5 oz.
7.8 mins
Moderate
Ink dissolved with extra effort and product
Water-
based
Dual cure
direct
Polyester; 260
threads/inch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
4.4 mins
Moderate
Stencil dissolved easily Some ink residue
remaining.
Haze Remover
Omins
1.0 oz.
42 mins
Low
Removed residue; lightened stain.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System QmiCfOft-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 Eire 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 filters are disposed of as hazardous waste along with the used shop rags. Waste water
DRAFT—September 1994
V-231
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product Svitam Qmieran-ftp
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-232
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: TradHlonal Reclamation With Haze Remover Product System Qmlcron-AF
Cost
Table V-169
Method 2: Summary of Cost Analysis for Alternative System Omicron-AF
Baseline
Alternative System Omicron-AF
Cost Element Description
(Traditional
System 4)
Facility 4
Facility 18
Facility Characteristics
Average screen size (in2)
2,127
1,210
1,150
Average # screens/day
6
6
13
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
15.0
3.28
10.8
2.37
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
1.3
0.20
1.3
0.20
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
1.6
0.12
2.2
0.17
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
1.4
0.10
3.6
0.27
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
2.1
0.15
1.9
0.14
Hazardous
Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0
0
0
Totals
Total Cost ($/screen)
6.27
3.86
3.14
Normalized8
6.27
4.45
3.89
Total Cost ($/year)
9,399
5,784
9,823
Normalized"
9,399
6,675
5,836
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-233
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
Product System Zeta
Formulation
Ink Remover Propylene glycol series ethers
Emulsion Remover Sodium periodate
Water
Haze Remover Alkali/Caustic
Propylene glycol
Water
Occupational Exposure
Table V-170
Occupational Exposure Estimates for Alternative System Zeta
Inhalation (mg/day
Dermal (mg/day)
System
1
II
III
IV
Routine
Immersion
Ink Remover
Propylene glycol series ethers
139
0.6
0
2.8
1560
7280
Emulsion Remover (diluted 1:4)
Sodium periodate
0
0
0
0
16
73
Water
0
0
0
0
1540
7210
Haze Remover
Alkali/Caustic
0
0
0
0
234
1090
Propylene glycol
0
0.1
0
0
62
291
Water
0
0
0
0
1260
5900
Scenario I = reclaiming 6 screens per day; each screen is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario Hi =
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-234
-------
Table V-171
Occupational Risk Estimates for Alternative System Zeta
Margin Of Exposure*
Hazard Quotient1'
Dermal
Dermal
Inhalation
Routine
Immersion
| Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Propylene glycol series ethers
32
18
87
NA
100
NA
NA
NA
NA
Emulsion Remover (diluted 1:4)
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
Akali/Caustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
I Propylene glycol
0.1
0.04
0.2
NA
NA
NA
NA
NA
NA
I Water
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.
^LOAEL means Lowest Observed Adverse Effect Level.
-------
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
Release Under Each Scenario
(g/day)
1
ii
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Propylene glycol series ethers
290
0
375
1.4
0.8
5.8
1345
Emulsion Remover (diluted 1:4)
Sodium periodate
0
6
0
0
0
0
0
Water
0
615
0
0
0
0
0
Haze Remover
Alkali/Caustic
0
80
0
0
0
0
0
Propylene glycol
0.7
21
0
0.2
0.1
0
0
Water
™Jn
r
o
n
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 paH; Scenario IV - storing waste rags in a drum and transferring them to a laundry
DRAFT—September 1994 V-236
-------
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:
To Air:
To Water:
To Landfill:
Propylene glycol series ethers
297.6 g/day
1345 g/day at laundry
375 g/day
Sodium periodate
6 g/day
Alkali/caustic
80 g/day
Propylene glycol
1 g/day
21 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
Amount Released
to Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Propylene glycol series
ethers
1375 g/day
83-97%
222 g/day
2 x 10"1
Sodium periodate
6 g/day
100%
0
0
Alkali/caustic
80 g/day
100%
0
0
Propylene glycol
21 g/day
97%
0.6 g/day
6x 10"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-237
-------
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
Amount of Releases
per day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year"
Propylene glycol series ethers
297.6 g/day
6.1 x 10"1 ug/M3
4
Propylene glycol
21 g/day
4.3 x 10"2 ug/m3
3 X 10"1
"This 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 Eire 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 lOOO 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. 'Hie 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-238
-------
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-239
-------
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. 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-241
-------
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 aire 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
-------
Table V-176
On-Site Performance Summary For Alternative System Zeta
System
Component
Performance
PemomliaUon Conditions
Avg Drying
Time Baton
Using Product
Average
Quantity
ftnnfcul
Average
Cleaning
Time
Average
Effort
Required
Per ft* mine fof Each
System Component
Overal System
Feitainance
lnktype(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
FacMy6
Ink remover
24.0 ± 15.2 his
M)
8.3 ±82
oz.
M)
2.8 ±1.3
mins (n=6)
Moderate
Ink residue in screen.
¦ Only 7 screens were
reclaimed at Ihis faafity.
• They did not use the
products because of poor
performance.
Solvent-
based, UV
ink, and
water-
based inks
Direct photo
standi
Polyester, no
treatment;
280 - 420
Ihreads/inch
3926 in2
Emulsion
remover
12.0113.8 hrs
M)
65 ±25
oz.
M)
4.8 ±3.8
mins (rv=4)
Moderate/
High
Worked wel sometimes,
but inconsistent results.
HazB remover
11.5 ±2.5 mins
(n=4)
2.8 ± 1.0
oz.
-------
Table V-177
Laboratory Performance Summary For Alternative System Zeta
System
Component
Performance
Demonstration Conditions
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning
Time
Average
Effort
Required
Performance for Each
System Component
Overall
System
Performance
Ink
type(s)
Emulsion
type
Mesh type;
Thread
count
Average
Screen
Size
SPTF
Solvent-
Ink
Ink Remover
15 mins
2.5 oz.
6.0 mins
High
2 applications required to r
stencil deteriorated in area
amove ink;
5.
Solvent-
based
Dual cure
direct
Polyester;
260
threads/inch
360 in2
Emulsion
Remover
24 hours
1.0 oz.
4.3 mins
Moderate
Stencil dissolved easily; some ink stain left.
Haze
Remover
Omins
1.0 or
16.6 mins
Low
Did not appear to lighten haze at all; strong
odor.
SPTF
UV-
curable
Ink
Ink Remover
15 mins
1.0 oz.
4.6 mins
High
2 applications required to remove ink; stains
in some spots.
UV-
curable
Dual cure
direct
Polyester;
390
threads/inch
360 in2
Emulsion
Remover
24 hours
1.5 oz.
4.5 mins
Moderate
Stencil dissolved easily; some ink stain left.
Haze
Remover
Omins
1.0 oz.
17.3 mins
Low
Did not appear to lighten haze at all; strong
odor.
SPTF
Wator-
Ink
Ink Remover
15 mins
1.5 oz.
5.7 mins
High
2 applications required to remove ink;
stencil deteriorated in areas.
Water-
based
Dual cure
direct
Polyester;
260
threads/inch
360 in2
Emulsion
Remover
24 hours
1.5 oz.
4.5 mins
Moderate
Stencil dissolved easily; some ink stain left
Haze
Remover
Omins
1.0 oz.
16.9 mins
Low
Did not appear to lighten haze at aH; strong
odor.
-------
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
laundry service. Used ink removal solvents are recycled on-site and the recycled product is
DRAFT—September 1994
V-245
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover
Product System Zeta
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 dally.
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
laundry service. Waste water from the high-pressure wash of the emulsion remover and haze
remover is not filtered at this facility.
DRAFT—September 1994
V-246
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 2: Traditional Reclamation With Haze Remover Product System Zeta
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-247
-------
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
Baseline
Alternative System Zeta
Cost Element Description
(Traditional '
System 4)
Facility 6
Facility 7
Facility 15
Facility Characteristics
Average screen size (in )
2,127
3,926
3,060
2,084
Averaoe # screens/day
6
13
11
5
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
17.6
3.85
21.0
4.59
32.8
7.18
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
0.0
0.00
3.8
0.56
0.0
0.00
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
8.3
1.50
8.5
1.53
3.0
0.54
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
6.5
0.23
1.3
0.04
4.1
0.15
Haze Remover
Average Volume (oz.)
Cost($)
3.0
0.12
2.8
0.64
2.0
0.47
2.3
0.55
Hazardous
Waste
Disposal
Amount (g)
Cost ($)
34
0.02
115
0.08
90
0.07
61
0.04
Totals
Total Cost ($/screen)
6.27
6,31
7.26
8.46
| Normalized®
6.27
5.39
6.51
8.99
Total Cost ($/year)
9,399
19,704
19,973
9,521
I Normalized®
9,399
8,080
9,772
13,479
"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-248
-------
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 find 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-249
-------
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/
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 I
Wash
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
DRAFT-September 1994
V-250
-------
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:
Ink Degradant:
Screen Degreaser:
Emulsion Remover:
Diethylene glycol butyl ether
Propylene glycol
Diethylene glycol butyl ether
Propylene glycol
Isopropanol
Ethoxylated nonylphenol
Water
Sodium periodate
Ethoxylated nonylphenol
Water
DRAFT—September 1994
V-251
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Mathod 3: SPAI Workshop Process , —Occupational Risk Conclusions and Oh»»rv«ttonft
Occupational Exposure
Table V-179
Occupational Exposure Estimates for Method 3, Alternative System Omlcron
'
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Ink Remover
Diethylene glycol butyl ether
0
0
0
0
984
4590
Propylene glycol
17
0.1
0
0.4
576
2690
Ink Dearadant
Diethylene glycol butyl ether
0
0
0
0
984
4590
Propylene glycol
17
0.1
0
0
576
2690
Deareaser
Isopropanol
2
2
1
0
16
73
Ethoxylated nonylphenol
0
0
0
0
47
218
Water
0
0
0
0
1500
6990
Emulsion Remover
Sodium periodate
0
0
0
0
47
218
Ethoxylated nonylphenol
0
0
0
0
31
146
Water
0
0
0
0
1480
6920
Scenario I = reclaiming 6 screens per day; each screen Is approximately 2100 in2; Scenario II = pouring 1 ounce of fluid for sampling; Scenario (II *
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
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.
DRAFT—September 1994
V-252
-------
Table V-180
Occupational Risk Estimates for Method 3, Alternative System
Margin Of Exposure8
Hazard Quotient13
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAEL0
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Diethyiene glycol butyl ether
NA
NA
NA
NA
NA
140
3.6
30
0.8
Propylene glycol
0.01
0.4
1.9
NA
NA
NA
NA
NA
NA
Ink Dearadant
Diethyiene glycol butyl ether
NA
NA
NA
NA
NA
140
3.6
30
0.8
Propylene glycol
0.01
0.4
1.9
NA
NA
NA
NA
NA
NA
Deareaser
Isopropanol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Ethoxyterted nonytphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Ethoxylated nonyiphenol
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
s.
7
8.
in
-u
0
D
¦o
1
s
9L
3
S-
o
o
3
a.
O
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.
°NOAEL means No Observed Adverse Effect Level.
"iLOAEL means Lowest Observed Adverse Effect Level.
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAl Workshop Process Occupational Risk Conclusions and Observing
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 veiy 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-254
-------
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
3D
•
1
Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Ink Remover
Diethylene glycol butyl ether
0
0
440
0
0
0
852
Propylene glycol
35
0
222
0.2
0.1
0.7
497
Ink Dearadant
Diethylene glycol butyl ether
0
330
0
0
0
0
0
Propylene glycol
35
158
0
0.2
0.1
0
0
Screen Deareaser
Isopropanol
4.2
1
0
4.1
2
0
0
Ethoxylated nonylphenol
0
16
0
0
0
0
0
Water
0
510
0
0
0
0
0
Emulsion Remover
Sodium periodate
0
19
0
0
0
0
0
Ethoxylated nonylphenol
0
13
0
0
0
0
0
Water
0
603
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 pad; 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-255
-------
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 Dally Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 3, Alternative System Omlcron
Substance:
To Air:
To Water:
To Landfill:
Diethylene glycol butyl ether
330 g/day
852 g/day at laundry
440 g/day
Propylene glycol
71.3 g/day
158 g/day
497 g/day at laundry
222 g/day
Isopropanol
10.3 g/day
1 g/day
Ethoxylated nonylphenol
29 g/day
Sodium periodate
19 g/day
DRAFT—September 1994
V-256
-------
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
Amount Released
to Water from
Facility
Wastewater
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Diethylene glycol butyl
ether
330g/day
852 g/day at
laundry
83%
56.1 g/day
145 g/day
6 x 10-2
1 x 10"1
Propylene glycol
158 g/day
497 g/day at
laundry
97%
4.7 g/day
14.9 g/day
5 X 10"3
1 X 10"2
Isopropanoi
1 g/day
83%
0.2 g/day
2x 10"*
Ethoxylated nonylphenol
29 g/day
100%
0
0
Sodium periodate
19 g/day
100%
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-257
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process Ecological Risks From Water Releases Of Screen Reclamation Ch«>r,|Tfl|g
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
Amount of Releases per
Highest Average
Annual Potential
Substance
day
Concentration 100 M away
Dose, mg/year*
Propylene glycol
71.3g/day
1.5 x10"1 ug/m3
1
Isopropanol
10.3 g/day
2 x 10"2 ug/m3
1 x 10"1
This 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 veiy 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 lOOO for a LOAEL indicate very low
risk.
Ecological Risks From Water Releases Of Screen Reclamation Chemicals
° 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-258
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 3: SPAI Workshop Process Coal
Cost
Table V-185
Summary of Cost Analysis for Method 3, Alternative System Omicron
Description
Baseline
(Traditional
System 4)
Alternative System
Omicron"
Facility Characteristics
Average screen size (in2)
2,127
2,127
Average # screens/day
6
6
Cost Elements per Screen
Labor
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
24.4
5.33
17.9
3.92
Materials and Equipment
# of rags used
Cost ($)
3
0.45
2.25
0.34
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
4.87
0.37
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
4.33
0.33
Haze Remover
Average Volume (oz.)
Cost($)
3.0
0.12
—
Degreaser
Average Volume (oz.)
Cost($)
...
3.0
0.21
Degradant
Average Volume (oz.)
Cost($)
—
3.0
0.23
Hazardous Waste
Disposal
Amount (g)
Cost ($)
34
0.02
0
0.00
Totals
Total Cost ($/screen)
6.27
5.57
Total Cost ($/year)
9,399
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-259
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Technology u»lng High-Pressure Water Blatter 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 o{ 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 psl
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-260
-------
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 1
No Chemicals
Emulsion
Removal
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
High Pressurel
Water Blast I
(3000 psi) I
Haze Removal/
High Pressure
Rinse
Product Groups
Include:
• OXIDIZERS
• NON-OXIDIZERS
• SOLVENTS
• SURFACTANTS
DRAFT—September 1994
V-261
-------
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
Furfuiyl alcohol
Alkali/caustic
Occupational Exposure
Table V-186
Occupational Exposure Estimates for Method 4, Alternative System Theta
Inhalation (mg/day
Dermal (mg/day)
System
I
II
III
IV
Routine
Immersion
Emulsion Remover®
Sodium periodate
0
0
0
0
1250
5820
Water
0
0
0
0
312
1460
Emulsion Remover (diluted 1:3)
Sodium periodate
0
0
0
0
312
1460
Water
o
0
0
0
1250
5820
Haze Remover
Alkali/Caustic
0
0
0
0
515
2400
Cyclohexanone
25
0.3
0
0
515
2400
Fufural alcohol
0
0
0
0
530
2480
"This 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 paH; 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-262
-------
0
3D
>
1
•p.
3
£
Table V-187
Occupational Risk Estimates for Method 4, Alternative System Theta
Margin Of Exposure*
Hazard Quotient11
Dermal
Dermal
Inhalation
Routine
Immersion
Name
Inhalation
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Emulsion Remover
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Emulsion Remover (diluted 1:3)
Sodium periodate
NA
NA
NA
NA
NA
NA
NA
NA
NA
Water
NA
NA
NA
NA
NA
NA
NA
NA
NA
Haze Remover
AkaWCaustic
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cyclohexanone
0.07
1.5
6.8
196
NA
NA
NA
NA
NA
Furfuryl alcohol
NA
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.
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.
"LOAEL means Lowest Observed Adverse Effect Level.
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-------
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, Omlcron, 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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
Emulsion Remover
Sodium periodate
0
177
0
0
0
0
0
Water
0
44
0
0
0
0
0
Emulsion Remover (diluted 1:3)
Sodium periodate
0
44
0
0
0
0
0
Water
0
177
0
0
0
0
0
Haze Remover
Alkali/Caustic
0
291
0
0
0
0
0
Cyclohexanone
53
239
0
0.7
0.4
0
0
Fufural alcohol
0
300
0
0
0
0
0
DRAFT—September 1994
V-264
-------
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
Release Under Each Scenario
(g/day)
1
II
III
IV
System
air
water
land
air
air
air
water
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.
Table V-189
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Using Screen Reclamation Method 4, Alternative System Theta
Substance:
To Air:
To Water:
To Landfill:
Sodium periodate
44 g/day
Alkali/caustic
291 g/day
Cyclohexanone
54.1 g/day
239 g/day
Furfural alcohol
300 g/day
DRAFT—September 1994
V-265
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster General Population Risk Conclusions And Ohservatim
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
Amount Released
to Water from
Facility
Waste water
Treatment
Removal
Efficiency
Amount to Water
After Waste water
Treatment
Daily Stream
Concentration, ug/La
for 1000 MLD
Receiving Water
Sodium periodate
44 g/day
100 %
0
0
Alkali/caustic
291 g/day
100 %
0
0
Cyclohexanone
239 g/day
83%
41 g/day
4 x 10"2
Furfural alcohol
300 g/day
97%
9 g/day
9 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 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
Amount of Releases per
day
Highest Average
Concentration 100 M
away
Annual Potential Dose,
mg/year8
Cyclohexanone
54.1 g/day
1.1 x10'1
8x10'1
"This 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-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
Although air releases were evaluated for only a single facility, it is very unlikely that em
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-267
-------
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
quantity of chemicals needed for screen reclamation by eliminating the ink remover and by
DRAFT—September 1994
V-268
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Bleeter 0<3St
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-269
-------
0
3D
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1
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3
w
sr
Perfoi imuco
System
Component
Avg Drying
Time Before
Using Product
Average
Quantity
Applied
Average
Cleaning Time
Average
Effort
Required
Overall System Performance
Demonstration Conditions
ink type
Emulsion
type
type;
Thread
count
»
M 3
C fit
Average
Screen
Size
ID
€
n
3
DD
§
CO
A
SPTF Testing at Volunteer Facility 1
A
8
a>
3
a>
o.
o
«a
«<
Solvent-
based Ink
Inkerd
Emulsion
Removal
Haze
Remover
18 hours
0.5 oz-
0 mins
1.5 oz.
2.7 mins
1.7 mins
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; virtualy no stain
remaining.
Solvent-
based
Dual-cure
direct
245
threads/rc
h
360 in2
UV-
curabie
M
Ink and
Emulsion
Remover
18 hours
1.0 oz.
5.5 mins
Low
Removed most of the stencil easily
without scrubbing; where ink was
scraped onto print side of screen,
stencil residue remaned.
UV-
cured
Dual-cure
drsct
Polyester,
390
threads/inc
h
360 in2
Haze
Remover
0 mins
1.5 oz.
1.5 mins
Low
No ink residue, and very light slain.
Parts of emulsion remained; a second
application of emulsion remover was
needed.
Ink
Ink and
Emulsion
Remover
18 hours
1.0 oz.
3.3 mins
Low
Removed stencil completely without
scrubbing; where ink was put on print
side of stencil, ink was mora difficult to
remove.
Water-
based
Dual-cure
direct
Polyester;
245
threads/inc
h
360 in2
Haze
Remover
Omins
1.5 oz.
1.5 mins
Low
Screen very clean; virtually no stain
remaining.
I
O
3
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 4: Alternative Screen Reclamation Technology
using High-Pressure Water Blaster Qs&t
Table V-193
Method 4: Summary of Cost Analysis for Alternative Technology Theta
Baseline
(Traditional
System 4)
Alternative
System Theta
Cost Element Description
Cost Element Description
Facility 1
Facility Characteristics
Average screen size (in2)
2,127
Average screen size (in2)
360
Average # screens/day
6
Average # screens/day
13
Cost Elements per Screen
Labor
Time spent applying,
scrubbing, and removing
reclamation products (min)
Cost ($)
24.4
5.33
Time spent pressure washing,
applying and removing removing
reclamation products (min)
Cost ($)
5.4
1.18
Materials and
Equipment
# of rags used
Cost ($)
3
0.45
Pressure Wash Equipment
Cost ($)
0.25
Reclamation
Product
Use
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
Water Use (gal.)
Electricity Use (kWhr)
Utility Cost($)
10.7
0.65
0.11
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
Emulsion Prep Product
Average Volume (oz.)
Cost($)
0.8
0.11
Haze Remover
Average Volume (oz.)
3.0
Haze Remover
Average Volume (oz.)
1.5
Cost ($)
0.12
Cost ($)
0.36
Hazardous
Waste Disposal
Amount (g)
Cost ($)
34
0.02
Amount (g)
Cost($)
0
0
Totals
Total Cost ($/screen)
6.27
Total Cost ($/screen)
2.02
Normalized®
6.27
Normalized*
4.53
Total Cost ($/year)
9,399
Total Cost (Styear)
6,315
Normalized®
9,399
Normalized*
6,797
"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.
bNo nitration system costs were included in this calculation.
Note: For additional information regarding product performance see performance demonstration summaries.
DRAFT—September 1994
V-271
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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 sure
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 veiy short period of time; most systems can clean a
DRAFT—September 1994
V-272
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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
screen 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-273
-------
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. Hie 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-274
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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 removed. 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
Releases to Air (g/day)
Ink remover solvent
555
Table V-195
Occupational Exposure from Automatic Screen Washer
| Solvent System
Inhalation (mg/day)
Dermal (mg/day)
1 Ink remover solvent
266
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.
Hie mass of solvent in this released vapor is (assuming complete saturation of the vapor
space):
DRAFT—September 1994
V-275
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Exposure and Environmental Releases
v p
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(—)(-5L)
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:
0.48x555xAA
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-276
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method S: 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 Removed 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 - Lacouer 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-277
-------
Table V-196
Occupational Risk Estimates for Auto Screen Washers Using Lacquer Thinner as the Ink Remover
8.
CJl
I yimn
¦ name
Hazard Quotient13
Margin Of Exposure*
Inhalation
Dermal
Inhalation
Dermal
Routine
Immersion
Routine
Immersion
NOAELc
LOAELd
NOAEL
LOAEL
NOAEL
LOAEL
Ink Remover
Methyl ethyl ketone (2-butanone)
7.7
56
NA
NA
NA
NA
NA
NA
Butyl acetate normal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Methanol
1.2
5.6
NA
NA
NA
NA
NA
NA
Naphtha, light aliphatic
NA
NA
NA
NA
NA
NA
NA
NA
NA
1 Toluene
5.6
111
NA
NA
NA
NA
NA
NA
| Isobutyl isobutyrate
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.
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.
cNOAEL means No Observed Adverse Effect Level.
dLOAEL means Lowest Observed Adverse Effect Level.
5
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6
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5?
i
3
3D
s
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£
o
8
3
£
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o"
2
0»
JT
n
0
1
c
-------
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
wt%
Molecular
Weight
Mole
fraction
Vapor
pressure
(mm Hg)
Partial
pressure
(mm Hg)
Emission
Inhalation
Dermal
Methyl ethyl
ketone
30
72.11
0.34
77.50
26.43
335.23
160.91
1,170
Butyl acetate
15
116.2
0.11
12.80
1.35
27.68
13.29
585
Methanol
5
32.04
0.13
126.88
16.23
91.47
43.91
195
Naphtha, light
aliphatic
20
86
0.19
20.00
3.81
57.67
27.68
780
Toluene
20
92.14
0.18
28.00
4.98
80.74
38.76
780
Isobutyl
isobutyrate
10
144.21
0.06
3.20
0.18
4.61
2.21
390
o Hazard quotient calculations indicate clear concerns for chronic dermal exposures
to toluene and methyl ethyl ketone and margined 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:
To Air:
To Water:
To Landfill:
Mineral Spirits
15.1 g/day
DRAFT—September 1994 V-279
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5- Automatic Screen Reclamation Technology Occupational Risk Conciu*^
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
Amount of Releases per
day
Highest Average
Concentration 100 M
away
Annual Potential Dose,
mg/year"
Mineral Spirits
15.1 g/day
3 x 10"2
2 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.
Table V-200
Summary of Estimated Daily Environmental Releases from a Hypothetical Facility
Automatic Screen Washer, Lacquer Thinner
Substance:
To Air:
To Water:
To Landfill:
Methyl ethyl ketone
335 g/day
n-butyl Acetate
27.7 g/day
Methanol
91.5 g/day
Aromatic solvent naphtha
57.7 g/day
Toluene
80.7 g/day
Isobutyl isobutyrate
4.6 g/day
DRAFT—September 1994
V-280
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Mathod S: Automatic Screen Reclamation Technology
Table V-201
Air Release, Concentration and Potential Dose Estimates from
a Single Model Facility
Automatic Screen Washer, Lacquer Thinner
Substance
Amount of Releases per
day
Highest Average
Concentration 100 M away
Annual Potential
Dose, mg/year*
Methyl Ethyl Ketone
335 g/day
7 x 10'1 ug/m3
5
n-butyl acetate
27.7 g/day
5 x 10'2 ug/m3
4 X 10"1
Methanol
91.5 g/day
2 x 10"1 ug/im3
1
Naphtha, light aliphatic
57.7 g/day
1 x 10"1 ug/m3
8 x 10"1 [
Toluene
80.7 g/day
2 x 10"1 ug/m3
1 |
Isobutyl isobutyrate
4.6
9 x 10"3 ug/m3
7 x 10"2 |
"This estimates closes 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 veiy 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 ecotoxlcity 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
ecotoxlcity concern concentration.
DRAFT—September 1994
V-281
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V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Cn«q
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 ($4.00/gallon) was taken from the Workplace Practices
Questionnaire. Emulsion removal and haze removal costs were assumed to be similar to those
of the baseline system.
Automatic Screen Washer #2 is a smaller unit on which some minimal information was
gathered. Screens must be loaded and unloaded by hand. Because it uses a solvent with
lower volatile fraction than #1. more solvent remains on the screen and must be washed off
following ink removal. Time spent loading and unloading the washers was taken from
manufacturer's documentation of the equipment. Two pumps operate using compressed air
which is reportedly available from other sources at the facility; the cost of a generator was not
included in the cost analysis. The price of the ink remover was provided by the equipment
supplier. Emulsion removal costs were assumed to be similar to those of the baseline system.
The manufacturer indicated that a haze remover was not required given the formulation of the
ink remover.
DRAFT—September 1994
V-282
-------
V. Substitute Comparative Assessment, Screen Reclamation Methods
Method 5: Automatic Screen Reclamation Technology Cast
Table V-202
Summary of Cost Analysis for Automatic Screen Washer Alternative
Baseline (Traditional System 4)
Automatic Screen Washer
Description
Quantity
and Cost
Description
Washer #1
Washer #2
Facility Characteristics
Average screen size (in2)
2,127
Average screen size (in2)
2,127
2,127
Average # screens/day
6
Average # screens/day
6
6
Cost Elements per Screen
Labor
Time spent applying,
scrubbing, and
removing reclamation
products (min)
Cost ($)
24.4
5.33
Time spent loading and rinsing
with automatic screen washer,
applying and removing
reclamation products (min)
Cost ($)
17.5
3.84
7.8
1.70
Materials
and
Equipment
# of rags used
Cost ($)
3
0.45
Automatic Screen Washer
Equip.
Cost ($)
5.95
1.73
Ink Remover
Average Volume (oz.)
Cost ($)
8.0
0.22
Ink Remover
Average Volume (oz.)
Cost ($)
2.0
0.06
2.8
0.44
Emulsion Remover
Average Volume (oz.)
Cost ($)
3.5
0.13
Emulsion Remover
Average Volume (oz.)
Cost($)
3.5
0.13
3.5
0.13
Haze Remover
Average Volume (oz.)
Cost ($)
3.0
0.12
Haze Remover
Average Volume (oz.)
Cost($)
3.0
0.12
...
Hazardous
Waste
Disposal
Amount (g)
Cost ($)
34
0.02
Amount (g)
Cost($)
43
0.04
0
0
Totals
Total Cost ($/screen)
6.27
Total Cost ($/screen)
10.14
4.13
Total Cost ($/year)
9,399
Total Cost ($/year)
15,213
6,198 |
Automatic screen washer #1 is large enclosed system with automated movement of screens through the cleaning process.
It is assumed to use mineral spirits as a solvent.
Automatic screen washer #2 is smaller piece of equipment requiring manual loading and unloading as well as water rinsing
of residual ink remover. It uses a less volatile 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 die baseline facility's operations and size;
It is profiled In Table VI-1. It should be noted that screen disposal is moat 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 ($6.87), which is slightly higher than for
screen reclaimers, was used to calculate labor costs for this method.
DRAFT—September 1994
VM
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Screen Disposal as a Method of Pollution Prevention
Table VI-1
Summary of Cost Analysis for Screen Disposal Alternative
Description
Baseline
(Traditional
System 4)
Description
Facility Characteristics
Average screen size (irr
Average # screens/day
2,127
Average screen size (in )
Average # screens/day
Cost Elements per Screen
Labor
Materials and
Equipment
Reclamation
Product
Use
Waste Disposal
Time spent applying, scrubbing, and
removing reclamation products (min)
Cost ($)
# of rags used
Cost ($)
Ink Remover
Average Volume (oz.)
Cost ($)
Emulsion Remover
Average Volume (oz.)
Cost ($)
Haze Remover
Average Volume (oz.)
Cost ($)
24.4
5.33
0.45
8.0
0.22
3.5
0.13
3.0
Amount, Hazardous (g)
Cost ($)
0.12
34
0.02
Time spent stretching,
degreasing, and removing screen
(min)
Cost ($)
Screen Mesh (in2)
Cost ($)
Prep Degreasing
Volume (oz.)
Cost ($)
Amount, Nonhazardous (g)
Cost ($)
Total*
Total Cost ($yscreen
6.27
Total Cost ($Vyear
9,399
Total Cost/Screenb
Total Cost/year1'
Note: Screen disposal is cost effective only wilh smaller screen sizes and/or long production runs, where the number nt im» . —
nears (he expected We of the screen. 01 ""pwsaons
"Not applicable. Screen disposal does not require this cost element.
The replacement of screens (after the end of the useful life of the mesh) was not considered in the baseline or other alternate
reclamation methods evaluated. A value of $0.60 per screen was therefore deducted from the total cost of this method.
DRAFT-September 1994
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention
through Improved Workpractlces 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 Workpractlces
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 co. *
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
VK3
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention
through Improved Workpractlces 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 no misunderstanding about proper chemical handling, and to minimize the potential
DRAFT-September 1994
VI-4
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Improved Workpractices Framework for Pollution Prevention
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 disposed. 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
Benefits
Prepare a written environmental policy
Establishes environmental management goals; illustrates
management commitment to pollution prevention and
environmental goals
Prepare written procedures on equipment operation and
maintenance, materials handling and disposal
Better informs employees of the proper procedures for
using and disposing of materials
Provide employee training on health and safety issues,
materials handling and disposal
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
Seek employee input on pollution prevention activities
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
Make employees accountable for waste generation and
provide incentives for reduction
Encourages employees to be aware of ways they can
prevent pollution; rewards active involvement in pollution
prevention activities
Provide feedback to employees on materials handling and
disposal and pollution prevention performance
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
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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
Benefits
Manage inventories on a first-in, first-out basis
Reduces materials and disposal costs of expired materials
Maintain accurate logs of chemical and materials stock,
chemicals and materials use, and waste generation rates
Understanding materials flow and how it relates to waste
generation rates provides insights into pollution prevention
opportunities
Minimize the amount of chemicals kept on the floor at any
time
Gives employees an incentive to use less materials
Centralize responsibility for storing and distributing
chemicals
Gives employees an incentive to use less materials
Segregate waste by waste stream and keep in marked,
easily accessible, closed containers
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
Keep spent solvents in marked, easily accessible, closed
containers
Promotes waste segregation, recovery and reuse; minimizes
evaporation of VOCs; reduces worker exposure
that can be adopted to prevent pollution at the source. Table Vl-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
flammabllity 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
DRAFT—September 1994
VI-6
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Improved Workpractices Framework for Pollution Prevention
remover, 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
Benefits
Keep chemicals in safety cans or covered containers
between uses
Reduces materials loss; increases worker safety; reduces
worker exposure
Use plunger cans, squeeze bottles or specialized spraying
equipment to apply chemicals to the screen
Reduces potential for accidental spills; reduces materials
use; reduces worker exposure
Consider manual, spot-application of chemicals, where
applicable
Reduces materials use; reduces worker exposure if
aerosol mists are avoided
Use a pump to transfer cleaning solutions from large
containers to the smaller containers used at the work
station
Reduces potential for accidental spills; reduces worker
exposure
Reduce the size of the towel or wipe used during clean-up
More efficient use of the towel; reduces solvent use;
reduces worker exposure
Reuse shop towels on the first pass with ink remover
Reduces material (shop towel and ink remover) use;
reduces worker exposure
Evaluate alternative chemical: water dilution ratios
(increase the amount of water)
Reduces chemical usage with no loss of efficiency;
reduced worker exposure
Only apply chemicals where necessary
Reduces chemical usage; reduces worker exposure
Avoid delays in cleaning and reclaiming the screen
Simplify ink and emulsion removal; less potential for haze
on the screen
Gravity-drain, wring, or centrifuge excess solvent from rags
Recovers solvent for reuse
Place catch basins around the screen during the screen
cleaning/reclamation process
Captures chemical overspray for recovery and reuse
Use appropriate personal protective equipment (gloves,
barrier cream, respirator, etc.)
Reduces worker exposure
DRAFT—September 1994
VI-7
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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 removed, 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 material^
(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.
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
DRAFT-September 1994
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Improved Workpractices Framework for Pollution Prevention
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
Cleaning/Reclamation Step
Ink
Emulsion
Haze
pour from container onto screen
9.3%
4.7%
5.6%
dip rag or brush into container and wipe screen
31.8
28.0
65.4
spray on w/ nozzle from tank
31.8
24.3
0.9
spray on w/ spray bottle
29.9
31.8
12.1
use specialized spraying equipment
12.1
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
Cleaning/Reclamation Step
ink
Emulsion
Haze
brush
40.2%
41.1%
3.7%
low-Dressure water spray
NA
11.2
10.3
high-pressure water spray
NA
73.8
65.4
water blaster
NA
13.1
8.4
squeegee
1.9
NA
NA
disposable rags
16.8
5.6
0.9
reusable rags
28.0
7.5
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
Waste
Ink Removal
Screen
Reclamation
Rags
in closed container
71.0%
31.8%
77.6%
in open container
4.7
3.7
11.2
no specified container
2.8
15.9
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 thro.mv,
improved workplace practices is intended to be a guide or starting-point for individual pS
DRAFT-September 1994
VI-10
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Sprayer/Application Systems
to develop pollution prevention practices within their own facility. The specific examples given
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)
Brush
Head
Air-Operated
Pump
Chemical
Resistant
Hose
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.
Tnnverselv while the pressurized spray applicator and recirculation system products
„ rL.the time effort, and waste associated with reclaiming screens, cost can be a
m hihmve factor Since the cost for many of these technologies stretches into the thousands
Pf dnlWs one should weigh the benefits obtained by such products against the total amount
spent reclaiming screens. Additionally, there have been concerns about the
DRAFT—September 1994
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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
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 reclamaUon. 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
remover within a specific area will minimize the quantity of solvent necessary for reclamation,
DRAFT—September 1994
VI-13
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Washout Booths
Figure VI-3
A Variation of the Sprayer/Applicator with Trigger Control
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
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VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Washout Booths
Figure VI-4
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
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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
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. 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
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
-------
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
-------
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
sGeankoplis, Christie J., Transport Processes and Unit Operations. (New YorkiAllyn and Bacon Inc.), 1983.
4If the media had a polar configuration, then the filter would exhibit a propensity towards the water t""'—iilfa
which are also polar. The result would be retention of the entire effluent as the filter nwHta would act as a giant
sponge.
DRAFT—September 1994
VM9
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Filtration Systems
Figure VI-?
Basic Filtration System
(Includes Both Filters)
Effluent
Screen
Classifiers
to Separate Particulates
Filtered
Water
Bag Filter Media
Bag Filter Holder
Power Drain to
Remove Filtered Water
id :.| In addition, tbrs#- systems require an. annual upkeep cost of approximately $501)
to k i ,< >0
-------
VI. Overall Poilihion Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Filtration Systems
Figure ¥1-8
Variation of Filtrate - 1 ,v- tem
(Effluent Pass* i!,rough Screen and Reaches Setting Tank Below)
Effluent Waste
Filter Media Stretches
Arrosr, How 1 «- .Helton. 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 not5* < jh..» Ileal 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 nitration 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 wouhl perioral best Uv km wing
the specific contaminants which can be filtered by these two typ<-s <v Mentis and by
considering the components of print r. a, .tud reclaiming chemicals, the printer can better
determine whether an adsorption separation system is warranted. A printer may And that,
after examination of the chemicals used in the system, only physical separatist is utvt>*,h.uy»
DRAFT-September 1994
Vl-21
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prswrtion through Equipment Modifications
Filtration Systams
Figure Vi-9
/a need Filtration System
systems include an "activated" filter media to further clean the effluent)
Wash Water
Collection Tank
Wm
—
maEfajrar^
Activated Carbon
Filter
Connections to
Filtration Unit
Cartoon-Filtered
Water to Sewer
Clean Water for Re
in Reclaiming
Pressurized Water
Supply Tank
Pump
For many aqueous-based ebr-r^-l rr»riamatlon systems. -i » separation
system may be sufficient After u» filtration to rent..,«• n«- >mi *«< m„jm. i the
effluent In an aqueous-based cheim .• matlon system ii„«v o» mi «% «.«.» • • >
that require advanced filtration. Unless these solutions have hydrocarbon wiiiiptmiiti* or
metals In solution, filtering through an "activated" media probably would not provide
additional benefits. For example, etie'*>,< .1 . " u u. Mi.--.! ,.ic piedominantly composed of
surfactants or ionic salts would probs-'t „ ., ,. s is. .ugh physical separation ant! then
recirculation. However, printers shouiu Know thni m -m* 4%,u*mcrcially available aqueous
chemical systems may benefit from the use of a-K«ij»
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Filriien Systems
DRAFT-Saptwnbtr 1994
Vi-23
-------
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
con.tariiiiiat.eci 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, arid local
envirorainen llations.
Recirculation Systems
regulation system, though a. coiribl.iia.tJon of several techiiologl.es, 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, ai .nip 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 reclaim!} <: reen, 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, to 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 tf-circulated 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 ,-000 to $3,000 for the complete system. Tills 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 frt to 50 gallons). Lastly, printers should'
keep in mind that these systems only remove ink. and the emulsion/stencil must noved
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 tr.itllvldti.al.
components that are linked together and may provide satisfactory screen reclamation at an
economically conipetltn f jkim* II nme Individual components are essential when attempting to
DRAFT—September 1994
¥i#§
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modification*
Recirculation Systems
Flgura VI-11
Solvent Recirculating System
I
Ummtt
Solvent
Filtration Unit
recirculate both Ink remover and emulsi-.n m mover 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 m r«-< n i> clamation products.
Such a water-based system might include a washout booth. ,i pressure sprayer, a
filtration unit, a 11 circulating pump, and an aqueous-based chemical reclaiming system, as
shown to Figure VI-12. The chemical reclamation system in combination with the pressure
sprayer will !><- i . sponsible for removing the ink and emulsion from the sateen. Depending on
the chemical formulations «,i the cleaning products, a combined solution, of water, cleaning
solution. Ink, and emulsion part it Ivs if, Hint carried to the filtration system where the
contaminants are removed through physical separation and possibly adsorption by an
"activated" media. As not.-.! <\u lier, this process must be carried out separately for both ink
systems and emulfrlori .systems; however, the end product of each filtration it; a solution that
could be pumped by the recirculation pump back through the pressure sprayer to clean
subsequent screens.
This example is only our ut 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, oilier printers, and relevant environmental regulations to obtain more
information.
DRAFT—September 1994
Vi-21
-------
VI. Overall Pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Recirculation Systems
Flgum VI-12
Advanced Reclamation Sy»t»in
(W'hlto thlm clomm d«pict may options, tt could mlmo Incorporate a rf»circul«tlon ayntam)
Depeiidtag on the printer's requirements, the hybrid system could cost as little as $3,000
or as much <»u0. The cost varies greatly because of the various kinds of equipment
that couiil h< meJu«i«-ti 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 toe an important
consideration. A small number of screen n « 'aimed dally or a small quantity of solvent used
annually are good indicators thai ,i icnrculatlon system may not be the most cost-effective
method for minimizing pollution.
However, for slightly larger operations, the ink remover reclreulators 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 $ I 1j < »o0), but, for those printers that use large quantities of
chemical* - and n-i iaim 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 facili inter 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. Overall Pollution Preventon Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modification* Distillation Equipment
For those printers that do choose to a Irculatioii system, one key Issue
concerning pollution must be addressed. Printers should, realize that although solvent use
may be redo- • ^ -!. rough 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 reelreuiator to a system thai 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, lie/she should carefully consider the vast array of options In order to
properly match th» to their facility. Further, printers should keep in iriind that
recirculation syst e not closed systems and that they are not designed to eliminate
pollution from a p. n ''<-1 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, 111¦ ~ • ,1 (deration and recirculation system, these solvent distillers
provide an opportunity to reduce solvent use and operating costs.
Features
After a solvent, h seel 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 boImUoii. 'i In* t.ipmim* j«»i!n»ii <
-------
VI. Overall Pollution Prevention OppofmrnmES for Screen Reclamation
Pollution Prevention through Equipment Modifications _ _ DSstillition Equipment
Figure ¥1-13
, Differential Pisi'^fi nip-ojc of\ distilling Up t;> 110 Oallons of Used Solvent per Cycle
(Note tha distillation unit (far left) and the drum for recovered solvent (far right))
Used
Solvent
Temperature/
Pressure Controls
Distillation
Tank
/
Recovered
Solvent Drum
=T
8 I
¦ i
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 in 'Hi )»>'>< mi nt i|h- i< ntaining 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 ami t < mat- n-.er 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 tin same In function and
composition. The main container i*. '•¦"ed with a heat-transfer liquid (usually water, or
polyethylene glycol, and the dram containing the used solvent Is placed Into this media. An
air tight He! 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 inenrporair- a « olleetloii chamber for the recycled solvent and an Internal
recirculating cooling system.
DRAFT—September 1994
VI-28
-------
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
< ndenser
Distillation
Distilled
Solvent
Solvent
Input
Power
Supply
Distillation units can vary as much in < w.t a.*» riiey do In size, A small distiller (2 to !>
gallons) Is available for several thousand dollars. As the capacity of the distiller Increases, the
price also begins to Increase, For a distillation unit Willi a 15 gallon capacity, a printer should
expect to pay approximateiv ^ i 0 000, ,»ni for the larger units {more than 100 gallons), prices
can rise into the $20,OOO it > $ 1 < >0,000 range.
Issues to Consider
The main Issue for printers to address Is the question of need. Giu-n a pi Inter's
individual operation. Is a distillation unit the best method for reducing solvent use while
maintaining compliance with relevant environmental regulations? Distillation units cam
provide an effective method for reclaiming used solvent for future use (these units frequently
yield 90 percent recovery of available solvent). Given this effective m-nv<*ry potential and the
resultant decrease in new solvent use. these units may provide an extremely practical method
of pollution prevention for those print* is tliat spend significant time, money, and effort in
DRAFT-Septomber 1994
-------
VI. Overall pollution Prevention Opportunities for Screen Reclamation
Pollution Prevention through Equipment Modifications Distillation Equipment
screen 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 Are
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
-------
Chapter VII
Cost/Benefit, Energy & Trade Issues
Internationa! 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.
Fairfax, VA. pi04.
DRAFT—September 1994
Screen Printing Association International,
VIM
-------
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
Screen Reclamation Method
1
2
3
4
Ink Removal Chemical
~
~
~
X
Degreaser/Degradant Chemical
X
X
~
X
Water Wash
Optional
Optional
Optional
/
Emulsion Removal Chemical
/
~
~
~
Water Wash
/
/
~
~
Haze Removal Chemical
X
~
X
~
Water Wash
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 removed 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
DRAFT—September 1994
VIM
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VII. Macroeconomic Issues
Energy and Natural Resource Issues Energy Impacts
taking 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
VIM
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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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Vll. macroeconomic Issues
Cost/Benefit Analysis of Alternative Screen Reclamation Processes
Table VII-2
Costs and Risk Trade-offs of Screen Reclamation Substitutes
System Evaluated
Cost/Screen Cost/Facility Risk Trade-offs
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
$3.63
$1.95-2.83
$7.97
$2,918-4,245 j Moderate concern for worker
dermal risks and very low
concern for inhalation risks
$5,446 | Clear concern for worker dermal
risks and worker inhalation risks
$11,958
Baseline for All Other Methods (Traditional System 4)
$6.27
$9,399 | Clear concern for worker dermal
risks and worker inhalation risks
Method 2: Chemical substitutes
for ink removal, emulsion
removal and haze removal.
Alpha
Chi
$5.92-9.37
$8,886-
14,062
$3.25-3.89
$4,879-5,829
Moderate concern for worker
dermal risks and low concern for
inhalation risks
Delta
$3.28-7.66
$4,917-
11,489
Epsilon
$3.08-5.29
$4,624-7,930
Gamma
$5.06-5.61
$7,590-8,417
Mu
$4.79-9.33
$7,185-
13,997
Phi
$6.10-7.82
$9,233-
11,728
Omicron-AE
$5.49-10.85
$8,240-
16,278
Omicron-AF
$3.89-4.45
$5,836-6,675
Zeta
$5.39-8.99
$8,080-
13,479
Method 3: Chemical substitutes
for ink removal, degreasing and
emulsion removal. No haze
removal required.
Omicron
$5.57
$8,358 J Moderate concern for worker
, dermal risks and very low
concern for inhalation risks
Method 4: Technology
substitute of screen disposal in
lieu of reclamation.
Theta
$4.53
Technology Substitute
Automatic Screen
Washer
Work Practice Substitute
Screen Disposal
$6,797 | Marginal concerns for worker
dermal risks and very low
concerns for worker inhalation
risks
$4.13-10.14
6,198-15,213 | Moderate concern for worker
dermal risks and very low
concern for inhalation risks
$49.43
$74,141 | No risks associated with screen
reclamation products
Note: Costs presented are normalized costs. Ranges
method and system in the performance demonstration.
are presented when there was more than one facility using the
DRAFT—September 1994
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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
Worker Population Exposed to
Traditional Products
Worker Population Exposed to
alternative products
Ink Remover
13,120 - 39,360
6,880 - 20,640
Emulsion Remover
20,000
60,000
Haze Remover
5,400 - 48,000
0
Total Exposed Worker Population
20,000
o>
o
o
s
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
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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. EFA's risk assessment indicates, however,
that health impacts to the general population from screen reclamation products are veiy 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 V1I-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
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
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VII. Macroeconomic Issues
Cost/Benefit Analysis of Alternative Screen Reclamation Processes
Costs and Benefits by Method
demonstrations range from as little 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 $0.80/screen ($l,201/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 veiy 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 ($3,201/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
DRAFT-September 1994
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VII. Macroeconomic Issues
Cost/Benefit Analysis of Alternative Screen Reclamation Processes Additional and Societal Benefits
on 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
DRAFT—September 1994
VII-11
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VII. Macroeconomic Issues
Cost/Benefit Analysts of Alternative Screen Reclamation Processes Additional and Societal Benefits
$1.8 million/year 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 VIM 2
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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 bioconcentration factor (BCF)
O biodegradation
primary degradation
ultimate degradation
O biochemical oxygen demand (BOD)
O gravitational settling
O Henry's Law constant (Hc)
O hydrolysis
O hydrophile/hydrophobe
O hydroxyl radical
O leaching
O mobility
O octanol/water partition coefficient (KoJ
O persistence
O photolysis
direct photolysis
indirect photolysis
O photooxidation
O screening test
O soil sorption constant (K^)
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
material 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 biodegradation of the alkyl
group
DRAFT—September 1994
A-1
-------
Appendix A. Glossary of Terms Used in the Environmental Fate Summaries
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
Primafy degradation: any biologically induced structural transformation of the parent
compound that changes its molecular identity
Ultimate degradation: any biologically mediated conversion of an organic compound to
inorganic compounds (e.g., C02 and H20) 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 (Hc): the air/water partition coefficient, usually estimated by dividing
the vapor pressure of a sparingly water soluble chemical substance by its water
solubility. Hc 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)
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 (Kow): 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. is an important parameter because it provides an indication
DRAFT-September 1994
A-2
-------
Appendix A. Glossary of Terms Used in the Environmental Fate Summaries
of a chemical's water solubility and its propensity to bioconcentrate 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 (K^): 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
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 25° C
DRAFT—September 1994
A-3
-------
Appendix A, Glossary of Terms used in the Environmental Fate Summaries
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
A-4
-------
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
'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 A.
DRAFT—September 1994
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
WORKPLACE PRACTICES QUESTIONNAIRE
FOR
SCREEN PRINTERS
Prepared by
Screen Printing Association International
in cooperation with
Univemty of Tennessee
Center for Clem Products and Clean Technologies,
and EPA Design for the Environment Staff
This questionnaire is to chancteriw typical screen printing facilities and workplace
practical associated with the screen printngfrsHntiou process. The results of the
questionnaire will be used to estimate exposure snd characterize risk from this process and to
help identify pollution prevention opportunities. Pollution Prevention is the use of materials,
prowea, practices or products that avoid, reduce or eliminate wastss or toxic releases,
through activities such ss material substitution, source reduction and closed loop recycling.
This information is being developed for industry us*r to help printers matt 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 Street
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 615/974-1838).
Respondents to this questionnsire 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
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
The purpose oi ihis questionnaire u to ctunctemt typical screen priming facilities and workplace practices usocuiea
with the sci«ea printing/ reclamation process. The busmen profile ami general facility inlormation requested beiow
illowi us to understand your workplace practice! wittun lA* context of your overall pruning business.
1) Bum** Profile
Appmaimauiy what pnreunga oi
your products ax pruned on die
following tvbttmai Tlmt fhfltk th*
N?ita 'Ian wAr,)
< 50%
50-95*
95-100%
Plana (ngid/flexible)
~
a
a
Paper (coated or uncoated)
Q
a
~
Metal
a
~
~
Ceramic
a
~
~
Glass
a
a
~
Other ^acrif Maw)
a
a
~
2) Pleaen liit the mator product*
produced at your facility.
i) General Facility Infonnatiaa
How many naif do you employ? How many hours per day doe* your naif spend removing ink and
cleaning/reclaiming screens? Ink removal it the removal of the bulk of the ink from the tcnen prior to further
cleaning/ reclamation. Screen 'cleaning/reclamation activities include residual ink removal, emulswo removal, and haze
removal. Question! about ink removal do not pertain to presfrside operations, unlen this is the only siu used tor ink
removal. Please assume a 5-day work week with one 8-hour shift each day. (Please check the bqtq Iflj"
Number of Employees
it this Location
Number of
Employees Involved
in Ink Removal
Number ot Employees
Involved in Screen
C leaning/Reclamation
Average time
(hr/day) a (ingle
individual is
involved w/ ink
removal
Average ume ^hr/day) a 1
single individual it involved
w/ cleaning/rerlaiming
M C
1-3 C
1-3 C
<1 C
<1 c
6-10 C
4-6 C
+-6 C
1-2 C
t-2 C
11-15 C
7-10 C
M0 C
2-4 C
2-4 C
16-30 C
>11 C
>11 C
4-6 C
4-6 C
31-50 C
specify
sp«a»y
6-8 C
M C
>50 a
other C
otbsr C
DRAFT—September 1994
B-3
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
A)
Wkaiypaat i
ram um wwii a
a. 115
/¦mM WhM ¦ l
Tjrpaotlafc
VotMdU
pil«l
t n-«
Pr—y ?*¦¦¦¦
Tndnaaii
(*1-1*1
NA - » (!J*|
See Table 2A
Ptwac »<77.«%)
«) 07.4%)
Ma* )} (2L7%)
O" 5 (4J%)
Camm * (!M|
Oftetpaifr) ttQUV)
¦niM«yy W
«i«Tidak
•ooi
StL-C
UV Canhb
NA - M (19 JIM)
Sea Table 2B
P*>«r }| (JIM)
Mai 15 (UM)
Oai 2(U%|
Od»||iii<») 17 (14 J*)
nayi(MM).
*m4.*ik
NK-JOtV)
(U0*)
NA • 100 (17.0%)
See Table 2C
Wmm »(7.1%)
Satna 1 (O.M)
lafjtlm
II.1IPI 1(7.0%)
(¦fiMrmiiMH
N^WKC
bunlaihiAhv
Plw 10(17%)
P«P" 7 (4.1%)
Mari t (0J%)
Glaa 0
Comic 0
Otka (qMcifr) 4 OJ*)
vifITi
MR-110**)
Otiwr ttp«arv)'
It inpnmkiMi
(U.MH
NA - W (77.4%)
See Table 20
Pluuc 9 (7 |%J
P«P« olS.2%)
M«ul 10 (17%)
cu» i io.v%)
Cmc 1 (0.9%)
Odar (>p*aff) I (70%)
iiiiiIm
NK-I (0 «%)
" Oik* type «< i»k iedwU ewulliE tie. ec.
' U TM do M • typ* «< ak. MM'0*
See Table 2E - Total Ink Use
DRAFT—September 1994
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
The manning questions ate omv in reierence io solvent- or l_TV-bas«a inks printed on plastic/vtnvi substrata. If your iaalitv
Joat not primarily uic ine» tvpes ol sutxtraies or mu, picas* do not complete (he rat ol the questionnaire.
B) '7h«l is ih« avenge numocr ol screens cleaned/reclaimed each day tor future user -I J - 5
Pleas* cQeck the appropriate box) 1 5 -10
~ 10 -IS
~ > -is Specify.
C) Please specify (he average IIX* oi fnme uieo at your facility? _____
(Please specify units; t-%, it z ft or in x in, ect.)
D) Do you have icpama ami tor ink removal and scnea reclamation taxntimi ~ ya ~ no
li yes, please check ail thai apply in trie toUowim ubi*.
Si
V
mi ami for ink ream
ai ad km dm
¦a arti vines'
Size of Ink
Removal Area
(ft1)
Type of
Ventilation
Siaeof
Sena
Aim Oft
<20
~
local (mechanical)
~
<20
~
local (mirt—il)
~
20-30
~
plant (fatality-wide)
~
20-30
~
plan (fatality-wide)
j—t
30-100
~
aanml
~
30-100
~
ami
~
100-200
~
other (specify below)
~
100-200
~
odw («peafy)
~
>200
~
>200
~
Specify size
Specify tixe
' Screen cleaninf/ieclamanoa activities include residual ink removal, rroutmni removal, and haae removal.
E) Do you have a combined area for uik removal and screen reclamation? Z yes Z no
If ves, please check all that apply in the following table.
Combined area for ink removal and screen reclamation activities
Size of Combuied Area (ft2)
Type of Venulauoo
<20
~
local (mechanical)
~
20-50
~
plant (facility-wide)
~
30-100
~
natural
U
100-200
~
other (specify)
a
>200
~
Specify Size
4
DRAFT—September 1994
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
1
3
-I
8
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t
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*;
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5
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It
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£-s
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So-. •« •> « 1
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jiilli I'Jliillii !
li>
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-£ o
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w% »-> OR
2 e Ci.
S " c "S
1 4 M
* v I
i > 4 *
3 3 ui Je
fjii
irv
w
1
c
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
J* ~ ~ ~
*
s
•§
0
3
8
1
E
w
~ ~
S ~ ~ ~
o
s c ~ ~
11
tt M
" o
i t
s 1
5 1
£
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!
>»
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= 9
y> *
ft. V
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at a. Z
DRAFT—September 1994
B-7
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
I
J
T5
1
>
9
zj 1 ?
•if1*!
I
- ^ c
»r C. X — ~ SL
© n *r o x 0 £
Equipment or
Materials Used to
Remove Haze
~ ~ z - - 3 no
u "-o
5 >» 3 ^ - -J
^1 b "7
4j&yc.-7 —
" ? o. i 5 IE J?
i II i! i £ i* i li i
Method of Applying tlaze
Removal Product
Pour from container onto ~
screen surface
Dip rag or brush intu ~
container and wipe screen
Spray on with nozzle ~
from tank
Spray on with .--pray a
bottle
Use spa lalized spra> »ig (i
equipment (specify)
Other (specify) LI
Personal
Protective
Equipment
Used
Gloves Q
Eye a
protection
Apions D
Respiratory ~
protection
Bariier n
Cteam
None Use J ~
Oilier ~
(specify)
Percent of
Time Haze
Keinover Used
~ ~ ~ = ~
j
>v
>~». 0s. 9 u
* ~ * 5r
2 wn "J —
Cost of Haze
Removal Product
({/gallon)
Annual Volume
orilue
Removal
Product Uaed
(gallons)
II arc Removal Product
t Trade Name)
3
a
I
i
i
u
¦t
e
1
3
I
v
u
1
C
a
V
£
DRAFT—September 1994
B<8
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
u
3)
> Alternatives
Do you uu a icno degicaier?
Trade Nat of Product.
. .a _ no
DoymiMi itfmwt ink before applying emulsion remover/ (Answer yes only if (he ink degndM u
dilfm *aa ibe pnmarr tak naval produco? 3 yes ~ no
Trade Name of Product
»)
A)
Where do you sun ink removal and term redamauoa ptoduas and in what quantity?
Ink Reasoral and Sanaa Cleaning
Aieafs)
Ink/Cfcemscai Storage Room
30- or 35-gslloa dram with bung
30- or 35-galkm dram with buag bole kapi open
~
bole kepi open
~
30- or 55-iallou dram wiib bunt bole kepi closed
LJ
30- or 33-gaUoa dram with bung
bole kepi closed
~
30- or 33-galloa dram with top removed
n
30- or 33-galloo dram with top
Open pail
o.
itBpvad
~
Closed pail
~
Opaepail
~
~
Quart or smaller squirt bottle
Oosadpasl
~
Safety can
—
Qosn or smaller squin bottle
~
Safety cabinet
—
Safey can
~
No separate storage area
~
Safely cabinet
Other (specify below)
Not kepi in the press room
-
Other (specify below)
3
Size of storage room f« *
—
B) How do you retrieve ink removal and screen reclamation products from ink/dwmical storage? If you Imp boll large add small
mm si am la (be ink removal sod semen cleaning/reclamation areas, how do you transfer the products from large cootsmenio
small comaintn for use?
Retrieval from Storage Room
Transfer from Large to Small Container for Use
Eatin cowamar moved to press room ~
Pumped iaMsaaaUer container ~
Ladled Iho G
Other (specify below) ~
Pumped into small cotaainer used at work stauoa ~
Poured into smaller container ~
1 jmft mmIW MUMiMf ~
Other (specify below) Q
DRAFT—S«ptemb«r 1994
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
VmmDi
?'rMf iMMM tor quiMitv 01 *uu *og cuoom oi unuiiiv u rujn
n«l07 )Q mppMMU u4 1%I
¦m NuntirotK n.4Aimil OR
-Jik
vNw*v at 55 pi. 4naat OR _
. CM i > i W » pi dnmi OR
flaWkl
ipl in Mifc)
, (Pi--MM
o-i07 n
im TaUa M
IHhmi
Ink M Va
MaW ai Swop Pnar tm
MaMrf fcmpPMri*
SaTakbllA
No
5 (4.7*)
j ai*»i
Filar or trm pact ta
So T«Ut
lap ¦ ill m iwtm «(5.*%) I1A
Sadlo racrabr 22 (2LM)
iQAHi 11
:i
ata
** (4J.0%)|
h
¦l"l 34(1LM||
U(u.nl
Vaa
NR-20(17I%)
Du^hh
Duooat m bo»
It (MlM|
*> («**!
7(1M|
13 (ai«i
¦
It (17JV)
Odtff liptoiTI ! (47*11
towai wmct
VR-I* (1S.0%)
NR«JJ (2».**)
NA-t (4.4%)
NA.«(SM)
im TaUt UB- Ink m4 Scm C/R Wm Gmnud
im Takla 1IC • PrcMaa Pn Ilium tmi Ww Oupotad
DRAFT—September 1994 ~—
B-10
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
C) How are waste rags contaminated wiiii ink removal and screen cleaning/reel amnion products stoned, treated or disposed
01? (Pleese check al|| |f|H >
Method of Storage Prior to
Premamor Dispoeal
Method of Premnmat
Method of Recycle or Disposal
In opea ooouam ~
Caotfbgt ~
Ob sua water lauadry ~
In closed containers ~
Allow liquid to dram out a
On-site dry cleaner ~
No specified mm sawn ~
Other (specify) ~
Off-site water laundry a
None ~
Off-site dry ctaoer a
HarinwM ~
Tim fin ii w» a
DoaMOMiap ~
Other (speetfy) ~
DRAFT—September 1994
10
B-11
-------
Appendix B. Workplace Practices Questionnaire for Screen Printers
DRAFT—September 1994 B-12
-------
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 Product* 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
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
Presentation of Results
The Workplace Practices Questionnaire for Screen Printers included check-off
type questions where respondents could cheek 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 with 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.
The total sample size (n) for the questionnaire was 1 IS respondents. This sample
size was used to calculate the percentages shown on pages two, three and 11. Of the US
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 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 «p»ndi
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 (j.2
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
WORKPLACE PRACTICES QUESTIONNAIRE
FOR
SCREEN PRINTERS
Prepared by
Screen Printing Association International
in cooperation with
University of Tram—wh
Center tor Clean Products and Clean Technologies,
and EPA Design for the Environment Staff
This questionnaire is daajgaed to channsrhn typical an— printing fiacalHi— and workplace
practices associated with the screen printin^rerianiarton proceaa. The results of the
questionnaire will be used to rsrimate cxpoewa and < hsrsrtnrii» risk from this praceas and to
help identify pollution prcveution opportunities. Pollution Preveutioo is the uae of materials,
processes, practices or piuduus that avoid, redaoe or rliminats wastes or toxic retaaaea,
through activities such as material substitution, source reduction and closed loop recycling.
This information is being developed for industry use to help printers make Unarmed choices
about the environmental attributes of alternative cleaning and reclamation products and
technologies.
Please mail completed questionnaires to: Marcia Y. Kinter
Director of Government AfiEurs
Screen Printing Asaociatioo International
10015 Main Street
Fiirta, 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 613/974.1838).
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 requeated 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 01 ihi« questionnaire is to cmractenze tvpical screen printing facilities and workplace practical associated
•Vitn (he screen printing/reclamation orocest. ."he Ousuxas proliU and general facility loiomuuoa requenea below
Jlovs us to understand vour vorxoiice orjaices within the context of your overall printing custom.
:) Business Profile
Approximately what
percentage of your products
are primad on the following
substrates? ri"rk 'h*
bOTa dat tgpir.)
n-115
114 respondents (99.1%)
NR-1 (0.9%)
<50%
»«%
»VW0%"
Plan
31(Z7.2%)
M(4)M)
27(73.$%)
Piper (coaaaa «r iinrn«arfl
54(47.0%)
13(11.3%)
:•«.«»
M «»¦* A'» ""iHT fIt-1! thf b°"»
n-115 114 respondents (99.1%)
Nnaabar o( Fmplnyeaa
«tkn Location
Number e< Eefleyie
Invetal ia Ink
Removal.
Nake ol Imphr—
liiiglml ¦ Sew
A««m|i ana (kr/d«f)
• Moata mdmdual ia
involved */ ink
monl
Amp one (ha/day)*
na* admM ii
umtvadv/
scraam
OS 21 (11.)%)
1-3
62 (93.9%)
1-3
102 (U7%)
<1
44 (31.9%)
< 1 14 (13.9%)
4-10 10 (1.7%)
44
22 (111%)
44
7(4.1%)
1-2
44 (31.9%)
1-2 24 (30.9%)
HIS 10(1.7%)
7-10
15 mm
7-10
3(2.4%)
2-4
11(9.7%)
2-4 24 (20l9%)
16-10 21 (IS.3%)
>11 19(13.0%)
>11
1 (0.*%)
44
6 (5.3%)
44 20 (17.4%)
31-50 II (157%)
ipta
ivcn
<7
IK 0 to 35
ifr. I2.S
ipmat
1WI
*r
12
12
4-1
7(4.2%)
M 26 (214%)
>50 33 (21.7%)
other
0)
"hat I (0.9%)
NR-2 (1.7%)
NR-1(0.9%)
NR •
NA -
l(0.»%)
1(0.9%)
NR
NA
- 2 (1.1%)
- 1 (0.9%)
NK - 4 (3.S%)
DRAFT—September 1994
C-4
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
t) Cnuifumt and MimimIi Use
A) That types of and how mucn ink do vow km in vow printing processes? What do you use as a reducer/reorder?
Vhit is the primary subetnte you use with each ink type# Or lilt ill thll MTlT^
Tvpe ot Ink
Volume ot Ink
o'sed/Yeei*
'jailoes)
Type of
Reducer/Retaider
Primary
Stibium
Traditional solvent-based
Piaeoc ~
Paper ~
Maui ~
Glta ~
Ceramic ~
Other (specify) ~
UV Curable
Plasbc ~
Paper ~
Metal ~
Glaa ~
Ceramic ~
Other (specify) ~
Waur-btscd
Water ~
Solvent 0
Water/Solvent
~ Mixture
(specify trade
name)
~~~~~~
mi
Other (specify)*
Plastic ~
Paper ~
Metal ~
Glass ~
Ceramic ~
Other (specify) ~
' Other type* of ink include metallic inks, etc.
k If you do not um a type of ink, nut *0*
DRAFT—September 1994
C-5
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
art omv in mmntt la worm- or >/.' ham mi oninw on pumtwnml iuwnui. It ^ n rrMM„ m, t(—g
i or inlu. ptdM «e not cmidmw tn* rm ei irw imninmifi
i ot tht qvammmmmn. Thtwiow. im aau om inponM ir« o*mo on n*» iw'
¦ (M »»wm numorr ot tttmm (MMti/muM ftu aav ror nnwrv u**f
i th» i^nrtprw oo«) i*l07
1 %nm « »« riwmm, %rm
'¦ 1 -<> (M.3%)
>S - I21.S%|
19 15
- '5 «S (».«
nap.jn
Q PI«M*aafrifcmni>*«<Ut)
FUaa. *-07 *¦» n > R or ui i ji, aa.) M37X»
3) Jo yon b»w urn »u M i—ni mm tcnm ncummtam tatrwmt m Jl (t/J%) NR.; ((.)%) M Jl (24J%)
li ym. phm -**»
1—tfcifci |
51OIN)
:&so
y<20.«)
plaKdaaalar^lat U (J*J%)
iN
13 (MM)
50-100
ml ilVM)
J0-I00
13 (Ul«l
ami
IOMOO
IOfM«)
lOOJOO
aObM)
•atorfrpaiM
*«.*»
>100
1I(I0J%)
¦
>ao
U(UJ1)
dirar ««¦, taa
—
sp«*r«
•aa
NK-»«.«%)
N*«7 (4J%)
nVJOUXO
NA-M (2fc2%)
n^.2J0M400
NA-U (HJ%|
avangi
-1370
arcnp-JIO
NR-10 (».!*) 1
NJU7(*J%)
NA-21 (U.2%) |
NA-2J QU%)
' ScnmdMnia^iadaauaM inimiai wdmit nmtml iab nawni, wIm wii mm) tei naavd.
E) Do jut Kiv® 1 cambiaM am tot im lamoaal and ma mriwmn) ym 41 (31.1%) NR-7(*.S%) no J»fti.1%)
U vm, pi«aat cJwck ail dial appijr in iht loUowing UOk. 0* |07
SiM 200 11 (I0J%)
SpMtrSuK raa«i-Jlt w M0
mn|a>W
NR.; i*.5*l
NA-» i a i H 32 (».0%)
pitm tfariirr « (|>M)
"««¦»» i on)
atkMbr—tri 2(i.m)
NR-I (7.5%)
NA-5* (».!«)
Tlumca rapondeaa uuwmd yes to both quotiom 4-0) and 4-E).
4
DRAFT—September 1994
C-6
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
R-
3
1
£
T3
5
6
i
«
&
"8
o
Ink Removal Product
(Trade Name)
Annual Volume
of Ink Removal
Product
Purchased
(gallons)
Cost of Ink
Removal
Product
($/gallon)
Solvent- ~
based
UV ~
Curable
Either' ~
Solvent- ~
based
UV ~
Curable
Eithei* ~
Solvent- ~
based
UV D
Curable
Either* O
Type of Ink with
which Product
Works Best
Gloves ~
Eye ~
protection
Aprons ~
Respiratoiy ~
protection
Barrier ~
Cream
None Used ~
Other a
(specify)
Personal
Protective
Equipment
Used
Iff ! If f
t H 1lJ li if
sl! 1 1 li 8|
31 i Mi 5
* 1 I *
~ ~~~~~
Method of Applying Ink
Removal Product
fi*Pf f I
w (» g H
K
~ D ~ D ~
Equipment or
Materials Used
to Loosen Ink
02 ~
2 4 ~
4 6 ~
68 U
8 10 ~
Other U
(tpcci/y numbci )
Ave. No of Rags Used
Per Screen to Remove
Ink
08 > *5
DRAFT—September 1994 ^
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
r»
g
7T
a*
*
w
i
£
II
:• *
e
1 <9
3 5
1 I
s =
i£ £
£
i f! if ^ if
*« ! « I? r
i. c.
«
s
7*
§
8-
i £
2* 2 2
$
*3
1
£
S
i
3i
J
¦a
&
w
(A R
X-
«
K
«
1
41
!?
¦s 5
4 I
a
3
•sj
JS g.
Wi
¦»
n
2
?*"
t«
i E
•»
£22
T
¦x
i
2£
*
z
3
PS
Iff
Z o
* <
3 fc.
•a. -o
£
a
ttf[5
iir
3-3 E.
<=¦! E"
M 8
3 -
Lf
P~
Si1
E.
X* >
s s
i z
o &
? ft.
II
m
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
o
»«•
»*
¦5
i-
;
?
2
i
IT
=»
or
ST
•a
I 111 * S 5 *
?
*• 0 W A M
» i i i i
£[?
i p [»if * r *
I - s 5 | 5 1
£ -St « S f 8 ?
2 o 2 2 2 2 2
4
i
I nnnnn
1 i M
- - * - || -j
i i i i H I
i
K
i
rr
[
! IHUifl}'
2 $ * S "8 =
^ *
9 9 9 & o O
o 2 2 o 2 i 2 2
1
n
Z ffo ^
JL f- E " * 1"
1 w .. *
2 ~4 ^ I »
rll
55-
p!»
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9 > N
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r
s
1
s
i
DRAFT—September 1994
-------
Soma CI—im/1 iiti—i— AlMrMUW
Do i
I KM I KNM ^Rwr'
Trada Nana oi Product.
.n ISf7*4%»
S- Tibh l-A
-o 12 C0*%)
Domini
«k bdm* wmIum rnowMAaw r« «Wf •< Um ink
l^O itm prmtrf «* i—D"«l pn±m» rm ltlP.1 %> at ft (71.9%)
Tmk N« W Pro*«
it po« ¦
II-107 102 (
i(MJ%)
Ink
Anatf
»o» VI |rito«inmvkiof
30- or S) pUoo 4nm w*k bua| kok kap
opm » l»-4%)
MX or 51 ptl— in— wt bw«t koh
40(17.*%)
1(0.9%)
~P-7%)
J2(21M)
20 (117*)
30(21.0%)
It (15.0%)
' (14%)
Opapaii
daa^H
Qiun or Hsaliar aqtan book
Saky can
Saiay abiMt
No« k«pt«(lit (*»» room
(MmivobbJoM 15 (14.%fl)
ipind 1 pi.»t—« pourmo*
racfck hit oak, dapomr 30 |*1.
racus, uak, oauada
NK-5 (4.7%)
bk/Owal Swiy IU*e
30- or Mylli 4raa w*k k«a( hob kapt opm
3ft or Si nB— »«k hi Mi !¦>» domt
»or 35 pBndwimk««»i
Op-l-J
OoMrfpad
Quan or i
Ut*T<
SAt^i
No i
OdwCnwcif Ww)
ouuk. plwic pi jup, draa* W pump*
Su> et mertft root* SaUbl
NR-I4 (l).l%)
5 (2.1%)
»(4*J%)
0
I (<>.»%»
21 (21 J%)
10(»J%)
17 (1S.«%)
li(llM)
IS (14.0%)
?M%)
fcl
If ya« knp Mi bifi m1 mII cm
IMtWak
Rmianl fiwo Stongi Aoon
TriMhf lw U«y lo S—U Cn««i— far U»
Earn in»iMir ami w prat room IS (14.0%)
PM^Mttmibr tioluMwr' :i (24.2%)
LaM km wafer coauiim 3 (2.1%)
Otkardpacrfrbdow) <(37%)
ptaaparf 4umatf fro* «o»t roan, trun
cammm to ink ma.
NX-* (1.4%)
Puf4 —o MB mmiiaii —«d ¦ work«MBoo 43 (40J%)
Pound o
-------
Appendix^Sumary of Responses to Workplace Practices Questionnaire for Screen Printers
10) W«M Plajaaal
A) Please indicate the quantity of wane you dispose of annually as to
spent solvent waste ______ Number of 53 gal. drums) OR (gal. in bulk)
ink warn (Nuabar of 55 gal. dim) OR _______ (gat. »• boik)
used shop tag warn ______ (Ntmbar of 35 gat. drama) OR _______ CjaJ. ia balk)
an tbcM waatt maianili irimwl tu ditpo—it of? (QggiB.stKlUlLtlHUBBtX-)
Ink JlMMfal VMM
-lull 1
QMBttqr
nvwn oi nni
!
i
*
QmtHsr
MMoliM«
Gmaraert
to Traaoaaai and/or
Diipoaal
Gcaaraaad
Prior toTraaamor
aMfUpai
Anally
Dtapoaai
Anoaally
Disposal
(galloai)
In doead ooatataan a
Piheror mei ~
In opea coauian a
Piker or tna a
prior to diipoiai or
prior •* disposal
racycki
or recycle
In open coautaera a
Saodtotacydar ~
Inclaeed a
Dbchaptt 0
No tptdIM ~
conrtinrr
Recycle oo site ~
No specified a
Diactapio a
containers
septic tank
Other (specify) ~
Discharge to sewer a
Other (specify) O
Haaarttw 0
Want
Dispoae at
Noa-Haurdom ~
hazardous warn a
wme
Dupoea u noo-
baavdeu* wane Q
Other (specify)
~
DRAFT—September 1994
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
CJ How arc wui raga condmnuud ink icmovai ino w iren cleaning/ reclamation produeu florid, irMud of dmpoimd oft
n»lQ7 10) ropomtau
Mofcod oi Stony Pnor to
PraMBMH «r 0«fwl
Method of Pmranm
Mehed «< Keeyds w Di^eel
laapMCMUM
n 12(IU%)
Comhp <(37%)
Omh «MI iMdqp
0
In €h—i catuu
an 13 (77.6%)
Allow liquid to drain out 29 (27.1%)
Omu dry cUmmt
Q
No i>in»fnil ton
man & (5 4*)
Other (ipcaiy) 1 (7.5%)
0f« n* Inadtr
*0 (37.4%)
Now 53 (41.5%)
Otf-ou dry dmu
23 (215%)
evaporation
ruaf out
Hawdoamau
14 (11.1%)
Mm In—rtfim mw
Doaotuaiiit
2 (1.1%)
OA-<^dM
i2(nj%)
¦ma
NR.S (4.7*)
Nfc-12 (11.2%)
N*-S (47%)
10
DRAFT—September 1994 q.12
-------
Appendix C. Summary of Responses to Workplace Practices Questionnaire for Screen Printers
- rs-'8
1
;n<
rrh
k
1«{ irrr
l» Jia:
i iif
I 1
s
I:
8-
* S* 8 St
mi
iitmji
p"!il
li1
ill
-9 «
! i
; i
•3 *
n
U
I
}
s
j
i
t
n
i
at
1
3
T
r
8-
1
r i
i1
1
i
9
1
!ii
I
4
f.
ir
1
DRAFT—September 1994
C-13
-------
-------
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.cc"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,:
M,
' 1 w
where M, is the molecular weight of the component. The partial molar volume Is defined by:
K-(^>
' dnt"t
n, being the number of moles of 1 and V the volume of one mole of the mixture. V and V, are
also related by:
V=2xtVt
which allows us to determine the amount of component i in the mixture once V, is known.
Now, it is shown in standard texts on thermodynamics (e.g., J.M. Smith and H.C. Van
Ness, Introduction to Chemical Engineering Thermodynamics) that the partial molar volume V, is
related to the chemical potential m:
and the chemical potential can be divided Into two parts, one part representing the
potential of i In an ideal mixture (JM), and the other part representing the access (E) 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
Substituting into eq. (4) gives:
The first term on the right is simply the molar volume of pure liquid L The second term
can be related to the activity coefficient yt of i 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 (is small. In this case, we can replace the activity coefficient with the Henry's
constant:
where P"' is the saturation vapor pressure of (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:
the Oy 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
V^xiJtP)=Vl0ci=UTiF)+RTX?~i)T
VfaJJ3)=Vi(xi=lJtPr) +RTC
ainiHJP?)
where
DRAFT—September 1994
D*
-------
Appendix D. Densities of Solutes in Aqueous Mixtures
a-lsm
VSP
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):
kT V 6kT V Jo ar
where u(r) 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 Modern 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 t is the work associated with bringing a molecule
of i 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 jlJ\^r)g^x)4nr3drdk
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 nonldeal 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
aqueous 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
-------
Appendix D. Densities of Solutes in Aqueous Mixtures
to know the molar volume of pure liquid NaCl (V^l.T.P)). However, sodium chloride is a
solid below 804 °C and the properties of the hypothetical liquid state are not available.
DRAFT—September 1994
-------
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 Handprlnters 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 0,-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 ftmin"1
through a screen cleaning room 8 ft wide x 10 ft long x 10 ft high would imply Q » 8,000
ft3.min'\ The actual flowrate would be lower than this, since the maximum velocity would not
be reached in the corners of the room nor lmmedlatefy adjacent to the walls. However, CEB
uses a typical air flow rate of Q » 3,000 ft.min"1, which may be too low. Changing Q to 8,000
ft3.min1 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
p ™=-v.Vc+Djflc
dt *
where
c = Concentration, mol.m"3
t = Time, s
v = Velocity vector, m.s'1
Dab = Dlffuslvity in air, m2.s '
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:
dc n &C
v,—=D.
dx ^dx2
where
vz = 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
Re. = Reynolds number, dimenslonless
o = Air density, kg.m"3
z = Length along surface from leading edge, m
^ a Air viscosity, kg.m'.s"1
, „ . than about 10s, the flow in the layer will be laminar. Above this
IfJ:he/ lf^Lturb^ntFor the case of a 100 ftmln" air stream flowing over a
value, the flow will bee number Is about 4.000 and the flow regime Is laminar. If a
2127 In silk screen, the yn liquid pool, a concentration profile will develop
chemical is pS*'^Wnthe boundary layer. However, the
that has the same shape ^ velocity boundary layer, meaning that. If one
teTache^frt%~rn^ and
DRAFT-September 1994 E.2
-------
Appendix E. Review of Air Release Models
Sc=-H-
P Dab
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 Sc"1/3. The rate of mass transfer
can be expressed in terms of another dlmensionless group, the Sherwood number:
SA=- Fz
cDab
where:
Sh = Sherwood number, dlmensionless
F = Mass flux, mol.m'3.s'1
c = Concentration at the pool surface, mol.m"3
Both experimentally and theoretically, these three dlmensionless 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, voll, 3rd ed., p.332):
Sh _0.332
ReJSc113 fRex
This equation is analogous to the following equation for heat transfer:
N _ 0.332
Refr113" y/S
where:
Nu = Nusselt number, dlmensionless 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
ReJPr1*' sfRi
In deriving Eq. (1), the author states that an analogy may be drawn to a derivation in
§17.5 of Bird, Stewart, and Ughtfoot's Transport Phenomena. However, in that example, the
DRAFT—September 1994
E-3
-------
Appendix E. Review of Air Release Models
chemical is being absorbed from the air into the boundary layer. The velocity at the outside
edge of the boundary layer, where most of the absorption occurs, is practically the same as the
free stream velocity. In the present case, most of the concentration gradient lies within a thin
layer right next to the surface 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 during removal of ink
from a printing screen using 100% toluene. The worker cleans screens for 1 hour each day in a
room with a ventilation rate of3,000ff.miri'. The screen area is 2,217 in3. Assume a mixing
factor of k = 0.5.
Toluene has the following physical properties:
Molecular weight: 92.14 g.mol'1
Vapor pressure: 28 mmHg at 25 °C
Diffusion coefficient: 0.076 cm2.sec'1
Using these values in eq. (1) gives:
Generation rate G: 0.28 g.s'.m'2
Airborne concentration: 141 ppm (GJ
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 Jc = 0.1 and a
ventilation rate of 500 ft^.min1, then the estimated airborne concentration is Cv = 4,216 ppm.
Exposures and volatilization rates are calculated by multiplying the pure-component values
from Table 1 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. Recalculate the vapor generation rate and worker exposure for Example 1 using
the laminar boundary-layer model
The results are:
Rex = 3662
Sc = 21.35
Sh = 111.5
The concentration at the pool surface can be estimated from the vapor pressure of toluene
which is 28 mmHg:
c=-—-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 '.m 2
Using this vapor generation rate and an air flow rate of 8,000 ft'.min'1 gives:
DRAFT—September 1994 e-4
-------
Appendix E. Review of Air Release Models
Cv
cm
19 ppm
71 mg.m3
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 ft3.min"1, the results are:
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.
Q,
Cm
379 ppm
1428 mg.m'3
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 gin 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.
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
DRAFT—September 1994
F
-------
Appendix F. Screen Printers Technical Foundation (SPTF) Testing Methodology
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: 390/34 LE for UV ink
260/40 LE for solvent- and water-based ink
Supplier/Manufacturer:
Brand Name of Fabric:
Mesh Opening:
Fabric Thickness:
Twill or Plain Weave:
Suggested Tension:
Frame Type:
Frame Size:
Tensioning System:
Adhesive:
Tensioning Procedure:
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
18" x 20" Outside Dimensions
Tetko SST Pneumatic Clamp System
KIWO Klwobond 1000 HMT
DRAFT—September 1994
F
-------
Appendix F. Screen Printers Technical Foundation (SPTF) Testing Methodology
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
O
o
Solvent-based Ink:
UV Ink:
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 W 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 9724
Black
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
0-1
-------
Appendix G. Facility Background Questionnaire
FACILITY BACKGROUND QUESTIONNAIRE
Design for the Environment Scrun Printing Project
1. Business Profile
a. Products
Approximately what percentage of your product* are printed on the following nibttiM? (Pleaae -h—1>
all boxes that apply).
<50*
50 - 95*
95 - 100%
Plastics (rigid/flexible)
~
~
~
Paper (coated or uncoated)
~
~
~
Metal
~
~
Cetamic
~
~
~
Glass
~
~
~
Other (specify)
~
~
~ 1
b. Pleaae 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
a. Screen Size: Specify the average size frame used at your facility: (ft or in1)
b. Tracking: Describe how your screens are tracked or numbered in the facility:
DRAFT-September 1994
-------
Appendix G. Facility Background Questionnaire
c. Volume:
What is tbe average number ot screens cleaned/reclaimed each day for future use?
(Please check the appropriate box)
0-5 H 5-10 ~ 10-15 ~ >15 Z (specify J
d. Employees
Please All in the table below. For the purposes of this quetfnanaire, "Ink Removal" is not defined
as press-side operations, unless this is the only site used for ink removal. Assume a 5-day woric
week with one 8-hour shift each day. Please check all boxes that apply.
Number of Employee*
at tUa L notion
Number of
EmployMi Involved
in Ink Rnooval
Number of Eaopksyeae
Involved in Senea
Average time (hr/dty)
imMw/ iik
Avwifli dm* (fac/dqr) 1
iavoMw/semn
0-5 ~
1-3 I
1-3 ~
<1 ~
<1 "
o,
O
~
4-6 ~
4-6 a
1-2 ~
1-2 ~
u-u ~
~
©
1
r*
—I
»
o
~
3-4 ~
u
1
~
16-30 ~
>u ~
loactftr
>n ~
Kwcify
J-6 ~
S - 6 O
31-50 ~
7-« ~
7-8 ~
>50 ~
attar, veeiiy
altar, ipwify !
e. Ink Removal and Screen Reclamation Aran
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 ~
- 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.
Stptntt vmi ftr Mt nmaml mi tenm
clmMiHg/rttlamatiOM idMto
Ink
RamoraJ
Ana (If)
Type of Vcadlatloa
Cmh
jutn
Ana (ff)
Type of V«odMea
Stasef
Ana Aft
VwtifeMtai
<20 ~
local (mrhniml) ~
<20 ~
Iocs! (minhwinil) ~
<20 ~
local ~
20 - 50 ~
pleat (facility-wide) ~
20 - 50 ~
pla* (hcibty-wide) ~
20-50 ~
plan a
50-100 ~
yilfOTtl G
50- 100 ~
natwal ~
*
s
8
~
tmm1 ~
100-200 ~
other ~
100 - 200 ~
other ~
(^eeiiy):
100 • 200 ~
ater ~
>200 ~
(ipeeify):
(•pecify):
>200 ~
(ipeeiiy):
>100 ~
(qpatfy):
2
DRAFT—September 1994
-------
Appendix G. Facility Background Questionnaire
J. Rates
a. Record tije electric rue:
b. Record the w«ter rate:
c. Record the sewer rate:
d. Record the screen reclamation employee's wage rate:
e. Record the printer's wage rate: (Use the rate for the primer who would
determine if the prim image quality is acceptable).
4. Current Ink Remover Procedures (NOT process cleaning)
a. What type of ink(s) do you use?
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 namepiate):
- Specify the pressure (psi) and flow rate (gpm):
- What are the equipment energy use specifications (from namepiate):
- 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.
3
DRAFT—September 1994
Q-4
-------
Appendix G. Facility Background Questionnaire
iU
C *
ill
s i
! :
u
f* ^ O 30 i A
6 ^ + O AO 0
Materials
Used to
Looms
Ink
~ hd a
1 f L L ji
a J!* £ S pc? 5 1
I
II
3D „~ ~ ~ -Z j
» I 1 „
2 8 « 3 ••
f i J i 1.
I ! 1 | is
I Is 8 1 lit s
js il'' u *
II si 1 1 11 1
m
Gloves ~
Eye
Protection ~
Aprons ~
Respiratory
protection ~
Barrier CreaiQ
None Used ~
Type of Ink
with which
Product
Works Best
~ ~ ~' ~
JJ ^
| -h 3 g
il s s !
Cost of Ink
Removal Product
($/fallou)
jlll
iiii
w
¦3
*
•s
DRAFT—September 1994
-------
Appendix G. Facility Background Questionnaire
n
i
i
i
o
8.
>*
A
8
&
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J
*
>
ll*
m
.9
I
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ii
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ll
li 1
~ ~ ~ ~ ~
1 i
E J> 3"
a I I
! 11
S fl 1 f
• » I?4
ll I! i i I! I
~ ~~ ~~~~~
I &
-------
Appendix G. Facility Background Questionnaire
13
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>>
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1 1
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ii it i i if i
~ ~ ~ ~ ~ ~ ~
t !i 1 i I
DRAFT—September 1994
G-7
-------
Appendix G. Facility Background Questionnaire
I
O
'J
3
X
i
I
>>
I
"3
!9
e
©
M
*«^
1
Hi
ill!
a t
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13
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>>
&
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4
£
J*
8,|l
B;h
i
•a S ft
li!
'it
I
llll
.a
,s 1%
ill!
•a 3
jijf
1 ill
•8
i
~
~
II
**> £ *
•2 S f
~
» *fl
111
ill
~
~
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f1
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ill
~
~
i
~
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1 li
~
~
~
If
~
I
~
II
DRAFT-September 1994
G-8
-------
Appendix G. Facility Background Questionnaire
S. Wasu Dispotal
a. Pleue indicate the quantity of watt you dispose of annually as watt for
spent solvent waste: (gal. in bulk) OR (# of 55 gaL drama)
ink waste: _______ (gaL in bulk) OR _______ (# of 55 gaL drama)
used shop rag waste _______ (gal. in bulk) OR (# of 55 gaL drams)
b. Ink RmotiI nod Screen Cleaning Waetse
Pill in the table below to describe the treatment and disposal methods used for wasle (not only
hazardous wastes) generated by the ink removal and screen rlraning/rcrlamstinn opeiatinw
Ink Im»wI Aim WmIm
Quaatkjr
l3T,,y
Stonga Prior to
TrntMri/
Dhposal
*
il!
fill
to TraMMBt/
MHtV
Incloeed
containeri ~
Filler or trial prior to
dijpoeal or recycle ~
Incloeed
mieiiwi ~
Filler or Mat
prior to dapoaai
or fatyeia ~
In open oomaimii
Send to recycier ~
IaopM
cootaiaen ~
Send to recycled
No «p*cified
container ~
Recycle on lite ~
No opacified
container ~
Recycle on «»eO
Other ~
(ipecify):
Diicherje to aewer ~
Other ~
(specify):
Diaefcargato
wwer ~
Diipeee aa bazardou*
wute ~
Diapoaaaa
haartowa waw£1
Diipoaa aa ooa-
hazaidaua waata ~
DiapoaaaB^iwj-^
Other.(¦peeity) ~
Other (ipaeify) ~
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, healer, etc.)
- If drying equipment is used, note:
- Duiation of drying step:
- Manufacturer and model of the
- Energy use
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, healer, etc.)
- If drying equipment is used, note:
- Duration of drying step:
- Manufacturer and model of the equipment:
- Energy use specifications:
s
DRAFT—September 1994
0-9
-------
-------
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-1
-------
Appendix H. Observers' Evaluation Sheet
Observer's Evaluation Sheet
Screen Reclamation Products Performance Demonstrations
Facility namo: Location: _
Date: Time: Facility contact name/phone:
Screen reclamation employeesCs): ——
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
09l9RIMIf'*
Screen identification and
history
• Enter the identification marking code that is on the screen:
• Estimate the number of impressions printed over the life of this screen:
• Estimate how much ink was left on the screen?
Screen size
x (specify units; in2 or ft2)
Number of impressions of
the screen's last run
Screen degreaser
• Specify manufacturer and series # or name:
Ink type
• Circle one:
Solvent-based, UV, or water-based
• Specify manufacturer and series 0 or name:
Ink color
• Circle one:
Blue, Black, Other (specify):
Emulsion type
• Circle one:
Capillaiy film, Direct photo stencil, Dual cured, Other:
• Specify manufacturer and series 0 or name:
1
DRAFT-September 1994
-------
Appendix H. Observers' Evaluation Sheet
Observer's Evaluation Sheet
Screen Reclamation Products Performance Demonstrations
Ink coverage
• Check one:
0 - 25%...~ 25 - 50%...D 50 - 75%...D 75-
10096...D
Screen condition
Note any rips, holes, corrosion
Screen mounting
Is a retensionable frame used? 1
Is the screen glued to the frame? |
Thread count
Thread diameter
threads/inch
(specify units)
Tension level (measure both
major axes; specify units)
maior axis: N/cm
minor axis: N/cm
Mesh type (record type of
mesh material)
Mesh treatment (has the
mesh been abraded?
calendared? or treated?)
Calibration of
measurements
scoop(s) of haze remover * ounces
Temperature (in the work
area)
• Ink removal area: °F
• Emulsion/Haze removal area: °F
Humidity (in the work
area)
• Ink removal area: %
• Emulsion/Haze removal area: %
DRAFT—September 1994
-------
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
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 control, in the ink removal or reclamation area.
4. Performance
Complete the performance evaluation table on the next page for alternative products and for currently uaed
products.
3
-------
Appendix H. Observers' Evaluation Sheet
Performance Evaluation
Enter quantity, comments, and nous \
Drying Time
(specify units; hours or mins.)
• Time from end of Dress ran to start of ink removal with nroduct: I
• Time from ink removal comoleted to start of emulsion removal:
• Time from emulsion removal comoleted to start of haw removal:
Dilution
(record dilution ratio or enter
"None")
• Ink Remover (enter ratio) or "none"
• Emulsion Remover (enter ratio) or 'none'
• Han Remover (enter ratio) or "none"
Quantity of Product Used
• Ink Remover (enter # of ounces)
• Emulsion Remover (enter f of ounces)
• Haze Remover (enter # of ounces)
Time to clean
(do not include screen
positioning or equipment dean
up time)
• Ink Remover minutes
• Emulsion Remover minutes
• Haze Remover 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:
• 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 Yea fsoecifv lenxth of time used
mins.)
• For Emulsion Removal:
No Yes (specify leuth of tiaae used
mins.)
• For Haze Removal:
No Yes (specify length of time used
mins.)
DRAFT—September 1994
-------
Appendix H. Observers' Evaluation Sheet
Was tap water (NOT
pressure wash) used in any
part of screen
cleaning/reclamation?
Was (non-pressurized) water used in (check all that apply): 1
Ink Removal... ~ or Emulsion Removal... ~ or Haze Removal... ~ |
Flowrate: (gallons/minute)
Length of time used: fsoecifv aecond* or
minutes)
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:
• 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: H
(e.g., Is there is a ghost image? Can the screen be used for reverse I
printing? For dose tolerance work? Can transparent inks be used?) Q
Remeasurv the screen tension
of both major axes and record
(specify units)
• major axis: N/cm 1
• minor axis: N/cm |
Examine the substrate image
after the screen is reused.
Comment on the print image
quality.
1
Comments or suggestions - Use the bade of this sheet to note anything unusual about this 1
(e.g., did you have to reapply any of the products? was this screen more difficult to clean others?) fl
5
DRAFT-Stptember 1994
-------
Appendix H. Observers' Evaluation Sheet
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(i) better, the same, or worse than your old product?
- If you have not tried a different chemical product, please check the box that best 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: ~
Coat is prohibitive: ~
Other: (please explain): (3
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 die time, effort or water
required to use those products? Yes D No ~
• If yes, please describe:
c. Does this facility have a pollution prevention, waste minimization, or source reduction program?
- If yes, please describe:
6
DRAFT—September 1994
H-7
-------
-------
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
M
-------
Appendix I. Ink Remover Evaluation Sheet for Printers
INK REMOVER EVALUATION SHUT
Facility name and locanoo:
Dale: T**:
• Enter the identification maridng (trading) cade for the,
• Estimate how much ink was left on the screen?
Scnm aiao
inches x
inchei
Screen condition
threads per inch
Note screen condition including any rips, holes, corrosUm:
• Record the screen mesh sue:
thraada/tncfa
Ma*
(Record mesh material type
and type of mesh treatment,
(e.g., abraded, calendared,
etc.) if any)
• Mesh type:
• Mesh treatment:
Number of huiii'Mrim* of
the ktmo'i la* rnn
Ink typo
• Circle one:
Solvent-baaed, UV, Watefbeaed
• Specify manufacturer and series #/
• arcleone:
Ink color
Blue. Black, Otter Opacify):
DRAFT—September 1994
1-2
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Appendix I. Ink Remover Evaluation Sheet for Printers
INK REMOVER EVALUATION SHBT
EmoWntypa
• Circle one:
Capilliryfilm. Direct ptalo, Dal am, Ottar
(specify):
• Specify manufacturer and series #.-
% Ink Coverage
• Check one:
0-25H...D 23 - 50*...~ 50 - 73*...D 75 - 10M...O
Drying Tinw
Time between end of pros ran and stait of Ink removal sgfegntaa
(hours or mint.; specify mitt)
r*
jftim-f iiwi. v. <¦ «¦ -i.
& * 1
Ink Remover Dilution
(enter ratio) or 'none*
Quantity of Ink Remover
Used
oz.
Time (enter time from
application of ink remover
product until screen is ready
for the next step)
Note: Do not include screen portioning or clean up time,
mint.
Physical effort required
(circle rating and comment)
Low, Moderate, High
How many wipce did you
use?
Was a preeeure washsr
used?
(check one) Yes No
Examine screen after ink
removal.
Did the ink remover tftalvefy and aaMlj remom tketnkJ (Mm mam
any side effects of the product on the screen)
J f minimal ni mmilinni Trrrnf my " n "i Ti-rtf nrtr ngHiing munal «hiM ths ml—iw tm ¦ 1
| separate sheet of peper. (e.g.,didyouhavetoreappiy tbeptodncrtwhy wastteicmahMdloclMlI) |
DRAFT—September 1994
W
-------
-------
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
demonstration.
DRAFT—September 1904
J-1
-------
Appendix J. Emulsion Remover and Haze Remover Evaluation Sheet
**"*l,^JfULsro^SJovraAN?HAS^55rovS^vALUA?l8RTBBfr^ISSISr57
Facility name and location: —
naui4 -J-,,*-- Screen Reclamation employee's name:
Sctmb IdMlUlattDB
Drying Tta»
(Specify units; hours or
mitts.)
FlU in the blank or circle the appropriate characteristic. Mate any nam or 1
comments in the space to the right. |
• Enter the identification marking (tracking) code for the screen:
• Tim from iak mbowI cooaptottd to nut of mnMob rami:
• Tim frw* Luufilatad to MX of ho* nmoval:
Dilution
• Cmiiitifw Brmnvnr (ratio) or none
. «i.t. Remover (ratio) or none
Quantity of Product
Used
Enter If of ounces used:
• Rmnisinn Remover ounces
Enter $ of ounces used:
• Ham Remover ouncea
Product Uae Time (enter
time from application of
product until screen is
ready for the next step)
• Fnuilakm Remover mini.
• H>«e Remover miM.
Wm a |ii lira wMher
uaad?
• For emulsion removal? (check one) Yet No
• flflf Ifflm removal? (check one! Ye» No
DRAFT—September 1994
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Appendix J. Emulsion Remover and Haze Remover Evaluation Sheet
mmm umuviw m umil am STflFirsoxiiDinnnriiHHnT
jatUl
Physical effort required
(circle one for each step
and describe the level of
efforti
¦ ffmnleiaa litr 1
circle one: Lam, Med., High; Describe if the stencil dissolved easily or 1
slowtf, and if a great deal or very Uakt scrubbing took place: 1
• Haaa Remorer:
circle one: Low, Med., High; Describe the effort reqind for haze
removal:
Examine acraan altar
emulsion removal.
• la there any ink haze or itencil Main on the tneeh? If so, deecribe1
• If any emulsion is still present, describe the residue left on the screen in
detail:
Rwmliw icrwn after
reclamation la complete*
• Can the screen be reueed for all lobs? duck one: Yes No
If "No", describe why the screen cannot be reused: (e.g., Is then is a
ghost image? Can the screen be mod far reverse printing? Can it be used
for close tolerance work? Can transparent Ms be used with it?)
Examine the subatrato
image altar the acraan i»
reueed. Comment on the
print Image quality.
Commanta - Record any comments and note anything unmal about the rerlaaisrine on a separata
sheet, (e.g., did you have to reapply the product? why was this acraan mora 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 the observers to record
their weekly calls to the printers participating in the on-site performace demonstration.
DRAFT—September 1994
K-1
-------
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 fonn is to guide the conversation,
but let the printer discuss any problems, changes or concerns. Rmt*d thm to sttul in Uu mmJojm
with this wttk't form.
1. In your opinion, is the performance of the alternative products belter, 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 conditions).
3. Have you found any conditions (ink type, emulsion type, etc.) where the products work particularly
well? If so, please describe the conditions).
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 soooer?
• do you let the product sit/soak on the screen longer?
• have you used a different type of brash? or scrubber? or wipe?
DRAFT—September 1994
K-2
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Appendix K. Weekly Follow-up Call Guidance
5. Have you tried any different application technique* that did not improve performance?
• What did you changed
• Why did you make the change?
• Was product performance worae after the change? How?
6. Have you changed the quantity of product you uae? Why?
H
7. How are you timing bow 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 sprey bottle and the
scoop provided?
9. Do you think the screen failure rate has increased, decreased or ramainri the same as a rasnk of
using the new product? What signs have you seen that suggetf the fUhira nte may differ?
10. Do you have any other comments, concerns or problems regarding the alsentive protects?
DRAFT—Stptembar 1994
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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 nwrhanipal 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 (ft?).
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
DRAFT—September 1994
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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
Fvamples-. 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-contact 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.
The chemical components of each product system must be submitted by each
manufacturer participating in the demonstration project. The physical characteristics of each
systetn 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
, , crrpens at the facility. They will examine the screen after the reclamation
PTOMS1S romplete and answer two questions: (1) Can this screen be reused for general
Draft—September 1994
L
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Appendix L. Screen Printing Performance Demonstration Methodology
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 Mc/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 ft3 each. The manufacturer will also
ship to SPAI a quantity of product necessary to reclaim 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 L). 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 ln-field demonstrations will only include screens
DRAFT—September 1994
L
-------
Appendix L. Screen Printing Performance Demonstration Methodology
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 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 operation*. 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 operation*. 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
emplpyee(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 product*. 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
DRAFT—September 1994
L
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Appendix L Screen Printing Performance Demonstration Methodology
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 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-appllcatlon 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 fined 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 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
DRAFT—September 1994
L
-------
Appendix L Screen Printing Performance Demonstration Methodology
¦
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.
DRAFT—September 1994
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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. An 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 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 Nabholz, 1991. The most frequently
used Hazard Profile for the aquatic environment consists of six effective concentrations as reported
by Nabholz, et al., (1993a). These are:
o A Fish Acute Value (Usually a Fish 96-hour LC^ value)
o An Aquatic Invertebrate acute value (Usually a Daphnid 48-hour LC^ value)
o A Green Algal Toxicity value (Usually an Algal 96-hour ECso value)
o A Fish Chronic value (Usually a 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 a Algal 96-hour NEC value for biomass)
For the acute values, the LCU (mortality) (ECjJ (effects) refers to the concentration that
results in 50 percent of the test organisms 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 exposure.
The Hazard Profile can be constructed using effective concentrations based on toxicity test
data (measured) or 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
predicted values, or a combination of both. Also, the amount of data in the hazard profile may
range from a minimum of one acute or chronic value to the full compliment of three acute values
and three chronic values.
In the absence of measured toxicity values, estimates of these values can be made using
Structure Activity Relationships (SARs). SAR methods include Quantitative Structure Activity
Relationships (QSARs), qualitative SARs or use of the best analog. The use of SARs by OPPT has
been described (Clements, 1988; Clements, et al., 1994 in press). The use and application of
QSARs for the hazard assessment of new chemicals has been presented (Clements, et al., 1993a).
DRAFT—September 1994
M*1
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Appendix M. Ecological hazard Profile Methodology
The development, validation and application of SARs in OPPT have been presented by OPPT staff
(Zeeman, etal., 1993b; Boethling, 1993; Clements, etal., 1993b; Nabholz, etal., 1993b; Newsome.
et al., 1993 and Lipnlck, 1993).
The predictive 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 measured data, the confidence interval
associated with the equation are not used to provide a range of toxicity values. Even with
measured test data, the use of the confidence limits to determine the range of values is not used.
Determination of Concern Concentration
Uoon completion of a hazard profile, a concern concentration (CC) is determined. A
concern concentration is that concentration of a chemical in the aquatic environment which, if
exceeded may cause a significant risk. Conversely, if the CC is not exceeded, the assumption is
made that probability of a significant risk occurring is low and no regulatory action is required,
^e CC for each chemical is determined by applying Assessment Factors (AsF) (USEPA 1984) 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 data and (2) species
sensitivity For example, if only a single LC^ value for a single species, is available, 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, would the value differ? Second, there are differences
in sensitity (toxicity) among and between species that have to be considered. Is the species tested
the most or the least sensitive? In general, if only a single toxicity value is available, there is a
laree uncertainty about the applicability of this value to other organisms in the environment and
large assessment factor, i.e.. 1000, is applied to cover the breadth of sensitivity known to exist
among and between organisms in the environment. Conversely, the more information that 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 1 is used.
Four AsFs are used by OPPT to set a CC for chronic risk: 1, 10. 100, and 1000. The AsF
used is dependent on the amount and type of toxicity data contained in the hazard profile and
reflects theamount of uncertainty about the potential effects associated with a toricity value In
general, the more complete the hazard profile and the greater the quality of the toxicity data, a
smaller factor is used. The following discussion describes the use and 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.
DRAFT—September 1994
M-2
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Appendix M. Ecological Hazard Profile Methodology
3. If the hazard profile contains one chronic value, the concern concentration Is set
at 1/10 of the chronic value If 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 measured chronic value from a field study, then an
assessment factor of 1 is used.
Hazard Ranking
Chemicals can be 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) £ 1
Moderate Concern (M) > 1 and < 100
Low Concern (L) > 100
This ranking can also be expressed In terms of chronic values as follows:
High Concern (H) S 0.1
Moderate Concern (M) > 0.1 and < 10.0
Low Concern (L) 2 10.0
Chronic toxicity ranking takes precedent over the acute ranking.
DRAFT—September 1994
M4
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Appendix M. Ecological Hazard Profile Methodology
References
Boethling R S. 1993. Structure Activity Relationships for Evaluation of Biodegradability in the
Epa's Office of Pollution Prevention and Toxics. Environmental Toxicology and Risk Assessment,
2nd Volume ASTM STP 1216. J.W. Gorsuch, F. James Dwyer. Christopher G. Ingersoll. and
Thomas W. La Point. Eds.. American Society for Testing and Materials. Philadelphia, 1993, pp.
540-554.
Clements R G (Ed) 1988. "Estimating Toxicity of Industrial Chemicals to Aquatic Organisms
Using Structure Activity Relationships." EPA-748-R-93-001. Environmental Effects Branch, Health
and Environmental Review Division (7403). Office of PoUution Prevention and Toxics. U.S.
Environmental Protection Agency. Washington. DC. PB94-108206. National Technical Information
Services (NTIS), U.S. Department of Commerce. Springfield, Va. 22161.
Clements R G (Ed ) 1994. "Estimating Toxicity of Industrial Chemicals to Aquatic Organisms
Using Structure Activity Relationships," EPA-560/6-88-001, Environmental Effects Branch. Health
and Environmental Review Division (7403). Office of Toxic Substances. U.S. Environmental
Protection Agency, Washington. DC. PB89-117592. National Technical Information Services
(NTIS), U.S. Department of Commerce, Springfield, Va. 22161. In Press.
Clements R G J.V. Nabholz, D.W. Johnson and M. Zeeman. 1993a. "The Use and Application
of QSAR's in the Office ofToxic Substances for Ecological Hazard Assessment of New Chemicals".
Environmental Tnvtrnlogy and Risk Assessment. ASTM STP 1179. Wayne G. Landis. Jane S.
Hughes, and Michael A. Lewis, Eds., American Society for Testing and Materials, Philadelphia,
1993. pp. 56-64.
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Structure-Activity Relationships (QSARs) as Screening Tools in Environmental Assessment".
Tnvirnlntfv and Risk Assessment. 2nd Volume. ASTM STP 1216, J.W. Gorsuch. F.
James Dwyer. Christopher G. Ingersoll, and Thomas W. La Point. Eds., American Society for
Testing and Materials. Philadelphia. 1993. pp. 555-570.
Lipnick R L "Baseline Toxicity QSAR Models: A Means to Assess Mechanism of Toxicity for
Aquatic Organisms and Mammals. Environmental Toxicologv and Risk Assessment, 2nd Volume.
ASTM STP 1216 J W Gorsuch. F. James Dwyer. Christopher G. Ingersoll. and Thomas W. La
Point. Eds.. American Society for Testing and Materials. Philadelphia. 1993. pp. 610-619.
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Substances Control Act.: The Science of the Total Environment. Vol. 109/110. pp. 649-665.
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Chemicals Under the Toxic Substances Control Act fTSCA) Section Five." Environmental
Toxicologv and Risk Assessment. ASTM STP 1179, Wayne G. Landis, Jane S. Hughes, and Michael
A. Lewis, Eds.. American Society for Testing and Materials, Philadelphia. 1993. pp. 40-55.
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Appendix M. Ecological Hazard Profile Methodology
Nabholz, J.V., Clements, R.G., Zeeman, M.G., Osbom, K.C. and R. Wedge. 1993b "Validation of
Structure Activity Relationships Used by the USEPA's Office of Pollution Prevention and Toxics for
the Environmental Hazard Assessment of Industrial Chemicals. Environmental Toxicology and
Risk Assessment. 2nd Volume. ASTM STP 1216, J.W. Gorsuch, F. James Dwyer, Christopher G.
Ingersoll, and Thomas W. La Point, Eds., American Society for Testing and Materials. Philadelphia.
1993, pp. 571-590.
Newsome, L.D., Johnson, D.E. and J.V. Nabholz. "Quantitative Structure-Activity Predictions for
Amine Toxicity Algae and Daphnids". Environmental Toxicology and Risk Assessment. 2nd
Volume. ASTM STP 1216, J.W. Gorsuch, F. James Dwyer, Christopher G. Ingersoll. and Thomas
W. La Point, Eds., American Society for Testing and Materials, Philadelphia, 1993, pp. 591-609.
U.S. Environmental Protection Agency (USEPA), 1984. "Estimating Concern Levels for
Concentrations of Chemical Substances in the Environment," Environmental Effects Branch,
Health and Environmental Review Division (7403) Office of Pollution Prevention and Toxics. U. S.
Environmental Protection Agency, Washington, DC.
Zeeman, M.G. and James Gilford. 1993a. "Ecological Hazard Evaluation and Risk Assessment
Under EPA's Toxic Substances Control Act fTSCA): An Introduction". Environmental Toxicology
and Risk Assessment. ASTM STP 1179, Wayne G. Landis, Jane S. Hughes, and Michael A. Lewis.
Eds., American Society for Testing and Materials, Philadelphia. 1993, pp. 7-21
Zeeman. M.G. Nabholz, J.V., and R.G. Clements. 1993b. "The Development of SAR/QSAR for Use
Under EPA's Toxic Substances Control Act fTSCA): An Introduction. Environmental Toxicology
and Risk Assessment. 2nd Volume. ASTM STP 1216. J.W. Gorsuch. F. James Dwyer. Christopher
G. Ingersoll, and Thomas W. La Point, Eds., American Society for Testing and Materials,
Philadelphia, 1993, pp. 523-539.
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