, Cooperative Project between the U.S. Environmental Protection Agency and the Printing Trade Associations Nationwide FOR THE FNV SCREEN PRINTING CASE STUDY 3 DRAFT October 1994 FWT CHEMICAL ALTERNATIVES FOR SCREEN RECLAMATION /•"•""•{he Design for the Environment (DfE) I Screen Printing Project is a unique, J> cooperative effort between the screen printing industry and the U.S. Environmental Protection Agency (EPA) dedicated to helping screen printers improve their efforts to pro- tect the environment. Improving environmen- tal performance means using new procedures, products, and equipment to do the same job with less hazard to both work- ers and the environment. Industry partici- pants in the DfE Screen Printing Project stress that understanding the possible environmental benefits of alternative products should be an early step in evaluating any changes to current work practices. One goal of the pro- ject is to provide printers with chemi- cal risk and pollution prevention information, along with performance and cost information, so that they are better equipped to incorporate environ- mental concerns into day-to-day business decisions. Printers, EPA, product manufacturers, and the screen printing trade association are all concerned with minimizing the environmental and health hazards of screen reclamation chemicals currently used in printing shops. In response to these concerns, the DfE Screen Printing Project worked with printers and selected the screen reclamation process as the project's focus. Through DfE, these groups worked together to evaluate alternative screen reclamation products. A total of eleven alterna- tive chemical "systems" were evaluated. Most "systems" included an ink remover, an emul- sion remover, and a haze remover. This is the third in a series of case stud- ies developed by EPA to illustrate how indus- try and the EPA can work together to investigate ways to improve environmental performance in the screen printing indusm Specifically, this case stxidy is geared towy \\ K getting information to small- or medium-si/ < * 1 printers like you. As you think about changing to environmentally improved products in your shop, these case studies can help you sort through some of the different factors that can make OKI product a more aSi-active substitute than another. This case study highlights one of the alternative systems demonstrated in £ ------- DRAFT October 1994 the DfE project, describing: • Performance evaluations of the alternative system from laboratory tests and from two volunteer print- ing facilities; • The health and environmental risks of the alternative system compared to a traditional screen reclamation system; • The cost of the alternative system compared to the cost of a tradition- al system. Background Initiated by industry, this project was entirely voluntary and involved almost all sectors of the screen printing industry: manufacturers donated their products for evaluation, staff from Screenprinting and Graphic Imaging Association International (SGIA) coordi- nated the field demonstrations, the Screen Printing Technical Foundation (SPTF) performed initial product test- ing, printers nationwide evaluated the products in their facilities, and EPA staff conducted the risk assessment of the products. One advantage of this coordinated effort is that all product systems were evaluated using the same methods. The consistency of the evalu- ations allows you to compare the results to determine which of the alter- natives may be a viable substitute for your current reclamation products. This case study highlights one alternative system, referred to as Alter- native System "Epsilon." This system, as with all systems demonstrated in this project, is a real, commercially avail- able screen reclamation system; how- ever, "Epsilon" is a masked name. The actual trade name for this alternative system (or for any of the alternative systems demonstrated) is not used in this case study or in the final project report. Trade names were masked for several reasons: • One of the goals of the DfE project is to illustrate the process of searching for and evaluating cleaner alternatives. DfE hopes to encourage you to incorporate environmental con- cerns in your facility's decision-making processes and into your discussions with suppliers. By masking trade names, DfE encourages you to discuss the characteristics of the products you use, or are considering using, with your suppliers. This case study and the DfE project help you to know what characteristics to look for in the screen reclamation products you purchase. • Since every screen printing shop is different, manufacturers recog- nize that their product's performance may vary greatly depending on both the operating conditions and the vary- ing opinions of the different printers using the products. In order to get their full cooperation before the results were available, some manufacturers asked that the product names be masked. To compare the cost and risk of Alternative System Epsilon to a known system, a baseline was established using a traditional solvent-based screen reclamation system. The tradi- tional system used in the comparison consists of lacquer thinner as the ink remover, a sodium periodate solution as the emulsion remover, and a xylene/acetone/mineral spirits/cyclo- hexanone blend as the haze remover. These chemicals were selected because screen printers indicated they were commonly used in screen reclamation. In both the cost and risk comparisons, it was assumed that these chemicals were applied manually to 6 screens per day, each 2,127 in2 (approximately 15 ft2) in size. Promising Performance Performance,,was evaluated in two phiasesrl. performance demonstra- tions at SPTF's laboratory evaluated the products under controlled conditions; and 2. field demonstrations at volunteer printers' facilities provided performance information under the variable condi- tions of production. Since conditions vary greatly, printers felt it would be most valuable to evaluate performance based on the experiences and opinions Alternative System Epsilon | Cyclohexanone Methoxypropanol acetate Diethylene glycol Benzyl alcohol Diacetone alcohol | Aromatic solvent naphtha Derivatized plant oil Traditional System 100% Lacquer thinner, consisting of: 30% Methyl efhyl ketone 20% Naphtha light aliphatic 20% Toluene 15% n-butyl acetate 10%lsobutylisobutyrate 5% Methanol Sodium periodate Sulfate solt Water 1% Sodium periodate 99% Water Alkyl benzene sulfonafes Ethoxylated nonylphenol Phosphate salt Sodium hydroxide Derivatized plant oil Water Ink Remover 10%Xylene 30% Acetone 30% Mineral spirits 30% Cyclohexanone Clear concern> Marginal concern> Negligible concern. Concerns are identified because exact risk was not quantified. ------- EPA DRAFT October 1994 of the experts: the people who used the alternative products in their facili- ties during the month-long demonstra- tions. Each product system was demonstrated in two or three facilities to get a more complete evaluation of performance under a variety of operat- ing conditions. Laboratory Testing During laboratory testing three imaged screens were reclaimed using Alternative System Epsilon: one that had been inked with a solvent-based ink, the second with an ultraviolet-cur- able (UV) ink, and the third with a water-based ink. Following the ink application, screens were allowed to dry for 15 minutes to simulate a shop situation. After drying, the ink remover was applied according to the manufac- turer's instructions. Again the screen was allowed to sit, this time for 24 hours, before applying the emulsion and haze removers. In the lab, the Epsilon ink remover dissolved the ink quickly, was easy to use, and rinsed clean of residue on the screens with solvent-based ink and UV-curable ink. In both cases, a light to moderate ink stain remained on the screen. When the ink remover was used on the screen with water-based ink, more time and effort were needed, but the ink was removed except for a light stain. On all three screens, the emulsion remover dissolved the stencil, and there was no emulsion residue on any of the screens after pressure rins- ing. In the final step, the Alternative System Epsilon haze remover lightened the ink stains on all three screens. Health Risks' ••• ^^^^^^^^^^^^^^^^^^^^^^^^^^H Remover • If you use the ink or haze remover on a daily basis without wearing gloves, there is a marginal risk concern for harmful effects from the chemicals (specifically, cyclohexanone, benzyl alcohol, and methoxypropanol acetate) being absorbed through your skin. If gloves are worn, the risk is negligible. • There is a clear concern that regular, unprotected contact with the emulsion remover will couse skin ond eye irritation and tissue domage. If gloves and safety glasses are worn, the risk is negligible. • There is a marginal concern for reproductive toxicity risk from inhalation exposures to cyclohexanone in the ink remover. •If you use the ink or haze remover on a regular basis, there is a clear concern for harmful health effects from inhaling the chemicals (specifically, toluene, methyl ethyl ketone, and acetone). • There is also a clear concern for adverse health effects if your skin contacts the ink or haze remover on a daily basis (from toluene, methyl ethyl ketone, and acetone). The concern is marginal for contact with cyclohexanane in the tf-J^nover. If gloves are worn, the risk is IW^re is a clear concern that regular, unprotected contact with the emulsion remover will couse skin and eye irritation and tissue damage. If gloves and safety glasses are worn, the risk is negligible. In on-site demonstrations, removed ink well, but one of the facilities felt it took some extra time. Worked well in lab testing With solvent and UV Inks, removed the ink with moderate scrubbing effort. A grey haze remained on the entire screen. With wafer-based ink, the ink solidified. Emulsion Remover Quickly and easily removed the stencil during facility demos and lab tests. Not demonstrated2 Haze ^^^^H Remover ^^^^^^^^H Lightened the ink stain and usually removed the haze during both lab testing and facility demonstrations Not demonstrated2 Focilify A: $3.08/screen' or $4,624/yeor Fnrilitv R* ruuniy P. $5.29/screen $7,930/year $6.27/screen or $9,399/year The ink remover was demonstrated during laboratory tests as a component of a different reclama- tion system. On-site Demonstrations Two different facilities used Sys- tem Epsilon for a month to evaluate how well it performed in a production siuiation. The participating facilities recorded the amount of product used, the length of time needed, and their opinion of how well the product reclaimed the screen. Both facilities (referred to in this case study as Facility A and Facility B) found the product sys- tem worked well, especially the emul- sion remover. Ink Remover Performance: At Facility A, the ink remover worked well, although some of the workers who used it thought that it acted more slow- ly and required more effort on cat- alyzed inks than on other solvent-based inks. At Facility B, the ink remover removed both UV-curable and solvent-based inks efficiently, but the UV-curable ink was slightly easier to clean than the solvent-based ink. In addition, Facility B found they used sig- nificantly less alternative ink remover per screen than their standard product which was lacquer thinner. Emulsion Remover Performance: The emulsion remover worked well at both facilities, dissolving the stencil quickly and easily. Haze Remover Performance: Both facilities evaluated the haze remover performance as "acceptable," and similar in efficacy to their standard haze removers. Overall Evaluation: The perfor- mance of Alternative System Epsilon was similar at both facilities, according to the printers' evaluations. Because the two facilities have very different opera- tions, the fact that System Epsilon per- formed well at both plants demonstrates that this system can work well under a variety of operating condi- tions. Facility A prints banners and point-of-purchase displays on plastic using a variety of solvent-based inks, a dual cure emulsion, and mesh counts of 83 - 280 threads/inch. Facility B prints vinyl and mylar labels using both sol- vent-based and UV-curable inks. They use a direct photo stencil and screens with a mesh count of 355 threads/inch. Even with these differences, Alternative System Epsilon was successful in reclaiming screens at both facilities. The final proof for the participating ------- DRAFT October 1994 printers was that all the reclaimed screens could be reused for future print jobs. Reduced Risk Environmental releases and occupational risks associated with using Alternative System Epsilon for screen reclamation were evaluated. See the table for a detailed description of the health risks of both Alternative Sys- tem Epsilon and the traditional system. Whether using traditional screen reclamation chemicals or an alternative system, chemicals can get into your body either through your skin when you contact the product or through your lungs when you breathe in the chemical vapors. Some chemicals have a lower tendency to evaporate or to enter the body through the skin; and different chemicals have different effects, some more harmful than others, once in your body. The risks associated with inhaling the chemicals in Alterna- tive System Epsilon are much lower than those of the traditional system. With the traditional system, inhalation of toluene and methyl ethyl ketone in the ink remover, as well as acetone in the haze remover on a daily basis, could lead to harmful health effects because they evaporate readily. Applying either Alternative Sys- tem Epsilon or the traditional system products regularly without wearing gloves can be harmful to your health. These harmful effects through skin contact are attributed to chemicals in the alternative ink remover and emul- sion remover, as well as to chemicals in all the products of the traditional system (ink remover, emulsion remover, and haze remover). If you wear gloves regularly however, these risks are negligible. Minimal Environmental Releases Based on the EPA assessment, none of the chemicals in either the tra- ditional system or Alternative System Epsilon were found to be hazardous to the environment in the quantities used for screen reclamation, even when con- sidering the combined releases to water from several printers in one area. Air releases from facilities using traditional or alterative chemicals were also evalu- ated for their effects on the general population and were found to have no significant impact. Cost Savings The demonstrations showed that both of the participating facilities could reduce their costs for screen reclamation by switching from the tra- ditional system to Alternative System Epsilon. As with the risk comparisons, costs of Alternative System Epsilon were compared to the costs of using the traditional system. The cost esti- mate for each reclamation system included labor time spent to reclaim the screen, the cost of an average quantity of reclamation products, and the cost of hazardous waste disposal for RCRA-listed chemicals. For Facility A, their reclamation cost per screen would drop from $6.27/screen to $3.08/screen. This would lead to annual savings of $4,775. At Facility B, the reclamation cost of $6.27/screen using the tradition- al system would decrease to $5.29/screen for the alternative system. Over a year, the savings would amount to $1,469. The difference in costs between the facilities is due to differ- ences in the quantity of product used and the labor time required per screen as recorded by the employees. The Design for the Environment Approach The EPA's Design for the Envi- ronment Program encourages you to evaluate systematically your facility's technologies, practices, and procedures and how they might affect your employees' health and the environ- ment. Our goal in working with screen printers is to help you to make more informed choices, now and in the future, by catalyzing the search for and evaluation of cleaner alternatives. With this case study and others like it, we hope to illustrate the application of this goal and the pursuit of continuous environmental improvements. Although the alternative system described in this case study proved to be a viable alternative in the two print- ing facilities where performance demonstrations were conducted, it may not be the solution for all types of screen printing operations. If you find that Alternative System Epsilon does not seem like a feasible substitute for your facility, refer to the summary of the project's full technical report, called the Cleaner Technologies Substitutes Assessment (CTSA), which includes information on all the alternative prod- uct systems and alternative technolo- gies evaluated. When you identify a product system that seems like a possi- ble substitute for your facility, contact your supplier to discuss the characteris- tics of the products you are looking for. For trade association informa- tion, contact: Screenprinting and Graphic Imaging Association International 10015 Main Street . ' '- , • Fairfax, VA 22031 >,*' ' Phone:703-385-1335 %J To obtain other case studies, a /• •" summary of/the Screen Printing » CTSA, or forSfhore information--- "" ' about the DfE Program contact: EPA's Pol inghous Phone: Fax: 202^260-0178. ion Prevention ClearT "\o • >. '"^ Recycled/Recyclable ErimgcTwith Soy/Canoto Ink on paper that contains at least 50% recycled fiber. ------- |