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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