, 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
£
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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
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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.
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