A Cooperative Project
between the
U.S. Environmental
Protection Agency
and the
Printing Trade
Associations
Nationwide
EPA 742-F-95-009
 FOR
'THE
                                                                             SCREEN PRINTING PROJECT BULLETIN 2
                      U.S.EPA
                                      SCREEN PRINTING
       Performance of the alternative screen recla-
      mation system as demonstrated In laboratory
      tests and at two volunteer printing facilities;
       The health and environmental risks of the
      alternative system;
       The cost of the alternative system.
                                                                           Background
                                   SMARTER, SAFER SCREEN
                                          RECLAMATION
                                  Alternative System Epsilon
                                     The chemicals used for screen reclama-
                                     tion can be some of the most
                                     hazardous products in a screen print-
                                ing facility. Highly volatile solvents are
                                typically used. These cleaners may contain
                                chemicals that are harmful to the health of
                                employees if inhaled, ingested, or absorbed
                                through the skin. If they are not disposed of
                                properly, these products may also harm to
                                the environment.
                                     To reduce the hazards of screen recla-
                                mation to workers and to the environment,
                                screen printers using solvents for screen recla-
                                mation should consider switching to one of
                                the safer substitute products currently on the
                                market. These substitutes often contain
                                less harmful chemicals and have a
                                lower volatile organic compound (VOC)  VI
                                content. With a lower VOC content, the
                                chemical is less likely to be inhaled by
                                employees or released to the air.
                                     This bulletin highlights the charac-
                                teristics of one type of substitute product
                                system and  compares it to a traditional
                                (solvent-based) screen reclamation system.
                                Specifically, this bulletin describes:
           Initiated by industry, this project was
      entirely voluntary and involved almost all sec-
      tors of the screen printing industry:
      manufacturers donated their products for eval-
      uation, staff from Screenprinting and Graphic
      Imaging Association International (SGIA) coor-
      dinated the field demonstrations, the Screen
      Printing Technical Foundation (SPTF) per-
      formed initial product testing, printers
      nationwide evaluated the products in their
      facilities, and EPA staff conducted a risk
      assessment of the products. One advantage of
      this coordinated effort is that all product sys-
      tems were evaluated using the same methods.
      The consistency of the evaluations allows you
      to compare the results to determine which of
      the alternatives may be a viable substitute for
      your current reclamation products.

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      This bulletin highlights one alternative system, referred
to as Alternative System "Epsilon." This system, as with all
systems demonstrated in this project, is a real, commercially
available screen reclamation system; however, "Epsilon" is a
masked name. The actual trade name for this alternative sys-
tem (or for any of the alternative systems demonstrated) is
not used in this bulletin 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
  concerns 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 reclama-
  tion products you purchase.
 Since every screen  printing shop  is different, manufacturers
  recognize that their product's performance may vary greatly
  depending on the operating conditions;  and,
  moreover, printers'  opinions of the products
  will vary. In order to get their full coopera-
  tion before the results were available, the DfE
  project complied with the requests of some
  manufacturers that  the product names be
  masked.
      To compare the cost and risk of Alterna-
tive System Epsilon to a known system, a
baseline was established  using a traditional
solvent-based screen reclamation system con-
sisting of: lacquer thinner as the ink remover,
a sodium periodate solution as the emulsion
remover, and a xylene/acetone/mineral spir-
its/cyclohexanone blend  as the haze remover.
These chemicals were selected because screen
printers indicated  they were commonly used
in screen reclamation. It should be noted  that
these technologies were evaluated using a
case study approach; rigorous scientific testing
was not  conducted. Instead, much of the
information presented here is based on print-
ers' experiences with these products as used
at their facilities.
           long demonstrations. Each product system was demonstrated
           in two or three facilities to get a more complete evaluation of
           performance under a variety of operating conditions.

           Laboratory Testing

                 During laboratory testing, three imaged screens were
           reclaimed using Alternative System Epsilon: one with a sol-
           vent-based ink, the second with an ultraviolet-curable (UV)
           ink, and the third with a water-based ink. During the labora-
           tory tests, the Epsilon ink remover dissolved the ink quickly,
           was easy to use, and removed residue from the screens with
           solvent-based and UV-curable inks. 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  rinsing. In the final step, the
           Alternative System Epsilon haze remover lightened the ink
           stains on all three screens.
                                       Chemical Composition
                     Ink Remover
   Alternative
   System
   Epsilon
Cyclohexanone
Methoxypropanol acetate
Diethylene glycol
Benzyl alcohol
Diacetone alcohol
Aromatic solvent naphtha
Derivatized plant oil
   Traditional
   System
Promising
Performance
      Performance was evaluated in two phas-
es: 1) performance demonstrations at SPTF's
laboratory under controlled conditions; and 2)
field demonstrations at volunteer printers' facili-
ties under the variable conditions of produc-
tion. Since conditions vary greatly,  printers felt
it would be  most valuable to evaluate perfor-
mance based on the experiences and opinions
of the experts: the printers who used the alter-
native products  in their facilities during month-
100% Lacquer thinner, consisting
of:
30% Methyl ethyl ketone
20% Naphtha light aliphatic
20% Toluene
15% n-butyl acetate
10%lsobutylisobutyrate
5% Methanol
                                       Emulsion Remover
Sodium periodate
Sulfate salt
Water
                                     1% Sodium periodate
                                     99% Water
                                                               Haze Remover
Alkyl benzene sulfonates
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. The information in this table is based on the September 1994 draft
document, Cleaner Technologies Substitutes Assessment: Screen Printing Technical Report

If the assumption is made that gloves are worn, dermal exposures are assumed to be negligible to none.

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                 V
           U.S.EFVX
        On-site Demonstrations

             Two different facilities used System Epsilon for a month
        to evaluate how well it performed in a production situation.
        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 as Facility A and Facility B) found the product system
        worked well, especially the emulsion remover.
             Ink Remover Performance: At  Facility A, the ink
        remover worked well, easily removing the solvent-based ink.
        However, when removing catalyzed inks, some of the work-
        ers thought that the ink remover acted more slowly and
        required extra effort. Facility B used the products on screens
        with both UV-curable and solvent-based inks. The Epsilon ink
        remover efficiently removed the inks; it worked especially
        well on the UV-curable ink. In addition, Facility B found they
        used significantly less alternative ink remover per screen than
Health Risks' ^^^H
1 Remover
I
	
 There are no clear concerns associated with any part of
the Epsilon system. There is a marginal concern for
developmental toxicity risk from inhalation exposures to
cyclohexanone in the ink remover.
 If you use the ink or haze remover on a daily basis
without wearing gloves, there is a marginal concern for
harmful effects from the chemicals (specifically
cyclohexanone, benzyl alcohol, and methoxypropanol
acetate) being absorbed through your skin. If gloves and
safety goggles are worn, the risk is negligible.
 There is a clear concern that regular, unprotected contact
with the emulsion remover will cause skin and eye irritation
and tissue damage. If gloves and safety goggles are worn,
the risk is negligible.
 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
(also from toluene, methyl ethyl ketone, and acetone). The
concern is marginal for contact with cyclohexanone in the
haze remover. If gloves and safety goggles are worn, the
risk is negligible.
 There is a clear concern that regular, unprotected contact
with the emulsion remover will cause skin and eye irritation
and tissue damage. If gloves and safety goggles are worn,
the risk is negligible.
In on-site
demonstrations,
removed ink well.
Worked ink well in lab
testing.







With solvent and UV
inks, it removed the
ink with moderate
scrubbing effort. A
gray haze remained
on the entire screen.
With water-based ink,
the ink solidified







Emulsion
Remover
Quickly and
easily
removed the
stencil during
facility demos
and lab tests.







Not
demonstrated2











Haze
Remover 1
Lightened the ink
stain and usually
removed the
haze during both
lab testing and
facility demon-
strations.







Not
demonstrated2











^^^^^^^^^^H
Facility A:
$3.08/screen
or $4,624/year
Facility B:
$5.29/screen
or $7,930/year







$6.27/screen
or
$9,399/year










The ink remover was demonstrated during laboratory tests as a component of a different recalma-
tion system.
their standard product, lacquer thinner.
      Emulsion Remover Performance:'The emulsion remover
worked very well at both facilities, dissolving the stencil
quickly and easily.
      Haze Remover Performance: Both facilities evaluated
the haze remover performance as similar in efficacy to then-
standard haze removers.
      Overall Evaluation: The performance of Alternative Sys-
tem Epsilon was good at both facilities, according to the
printers' evaluations. Because the two facilities have very dif-
ferent operations, the fact that System Epsilon performed well
at both print shops demonstrates that this system can work
well under different operating conditions. 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 solvent-based and UV-curable inks.
They use a direct photo  stencil and screens with a  mesh
            count of 355 threads/inch. Even with these differ-
            ences, Alternative System Epsilon was  successful
            in reclaiming screens at both facilities.  The final
^^"^^"1    proof for the participating printers was that all
        I    the reclaimed screens could be reused for future
            print jobs.


            Reduced Risk
                                                                                      Environmental releases and occupational
                                                                                 risks associated with both the Alternative System
                                                                                 Epsilon and the traditional screen reclamation
                                                                                 system were evaluated. Review the table for a
                                                                                 detailed description of the health risks.
                                                                                      Whether using traditional screen reclama-
                                                                                 tion techniques or an alternative system, chemi-
                                                                                 cals can get into your body either through your
                                                                                 skin when you contact the product or through
                                                                                 your lungs when you inhale chemical vapors.
                                                                                 Some chemicals have a lower tendency to evapo-
                                                                                 rate 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 inhalation of the chemi-
                                                                                 cals in Alternative System Epsilon are much
                                                                                 lower than those associated with the traditional
                                                                                 system. With the  traditional system, daily inhala-
                                                                                 tion of toluene and methyl ethyl ketone in the
                                                                                 ink remover, and acetone in the haze remover
                                                                                 could lead to eye, nose, and throat irritation,
                                                                                 headaches, or fatigue.
                                                                                      Applying either the Alternative System
                                                                                 Epsilon or the traditional system products regu-
                                                                                 larly without wearing gloves can be harmful to
                                                                                 your health. The  potential for these harmful
                                                                                 effects through skin contact are attributed to
                                                                                 chemicals in all the products of the traditional
                                                                                 system (ink remover, emulsion remover, and

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haze remover) and to chemicals in the alternative ink
remover and emulsion 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 traditional system or Alternative System Epsilon
were found to be hazardous to the environment in the quan-
tities used for screen reclamation. However, a reduction in
the use of traditional screen reclamation chemicals could cut
a facility's air releases. Traditional screen-cleaning solvents
often have a high volitile organic compound (VOC) content,
contain Hazardous Air Pollutants regulated under the Clean
Air Act, or contain a RCRA listed or  characteristic waste. Sub-
stituting an alternative product system for these traditional
screen reclamation chemicals could reduce your facility's reg-
ulatory burden. Contact your state and local environmental
regulatory authority for information  specific to  your location.
Cost Savings
     The demonstrations showed that both of the participat-
ing facilities could reduce their costs for screen reclamation
by switching from the traditional system to Alternative System
Epsilon. As with the risk comparisons, costs of Alternative
System Epsilon were compared to the costs of using the tradi-
tional system. The cost estimate is based on the assumption
that 6 screens were reclaimed daily and that all screens were
approximately 15 ft2 in size, for both the traditional and the
alternative systems. Included in the cost estimate were: 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  or characteristic (ignitable
                based on flashpoint) waste.  The RCRA-list-
               ing applies to the traditional  system ink
             remover, but does  not apply to any part of the
alternative system.
     For Facility A,  reclamation cost per screen would drop
51% from $6.27/screen to $3.08/screen for annual savings of
$4,775. At Facility B, the reclamation cost of $6.27/screen
using the traditional system would drop to 16% to
$5.29/screen for the alternative system. Over a year, the sav-
ings at Facility B would amount to $1,469. The difference in
costs between the facilities is due to differences in the quanti-
ty of product used and the labor time required per screen as
recorded by each facility's employees.
For More Information...
     Although the alternative system described in this case
study proved to be a viable alternative in the two printing
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 booklet, Designing Solutions for Screen Printers: An
Evaluation of Screen Reclamation Systems, which includes
information on all the alternative product systems and alterna-
tive technologies evaluated. When you identify a product sys-
tem that seems like a potential substitute, contact your
supplier, identify the alternative system by its chemical com-
position, and discuss the characteristics of the products you
are looking for.
       This bulletin is part of a series of bulletins and case
  studies that provide screen printers with information on
  products and techniques that can help them to prevent pol-
  lution in their facilities. Information in these bulletins is
  largely based on the work done by the Design for the
  Environment Screen Printing Project. For copies of this bul-
  letin, other DfE Screen Printing Project Materials, or more
  information about the project, contact :

    Pollution Prevention Information Clearinghouse (PPIC)
            U.S. Environmental Protection Agency
                  401 M Street,  SW (7409)
                  Washington,  DC 20460
                 Telephone: 202-260-1023
                     Fax: 202-260-4659
   Screenprinting and Graphic Imaging Association Interna-
                       tional (SGIA)
                     10015 Main Street
                     Fairfax, VA 22031
                 Telephone: 703-385-1335
                     Fax: 703-273-2870

  You may also contact the DfE Home Page at:
  http://www.epa.gov/dfe or the  SGIA
  Home Page at http://www.sgia.org/
                                                                              Recycled/Recyclable

                                                                     Printed with Soy/Canola Ink on paper containing at
                                                                     least 50% recycled fiber.

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