United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-94/144 September 1994
<&EPA Project Summary
Waste Reduction Evaluation of
Soy-Based Ink at a Sheet-Fed
Offset Printer
Beth Simpson, Pamela Tazik, Gary Miller, and Paul Randall
This Waste Reduction and Innova-
tive Technology Evaluation project fo-
cused on the use of soy-based inks as
a substitute for petroleum-based inks
in sheet-fed offset printing. The goal of
the study was to evaluate the waste
reduction and economic effects of us-
ing soy-based inks in place of the pe-
troleum-based inks traditionally used
in sheet-fed offset printing. The main
potential environmental benefits
claimed for soy-based inks are that they
are a renewable resource and emit less
amounts of volatile hydrocarbons dur-
ing the printing process. No published
studies verify the claim of reduced air
emissions or quantify other environ-
mental aspects of using soy-based inks
such as the amount of liquid wastes
generated and cleaners required. Other
reported benefits of soy-based inks are
that they are biodegradable in landfills
and are more conducive to cleanup with
degradable and less toxic cleaners than
are petroleum-based inks.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the program demon-
stration that is fully documented in a
separate report (see ordering informa-
tion at back).
Introduction
The impetus for developing soy-based
inks initially came from the oil shortages
of the 1970's that threatened the supply
of petroleum-based chemicals. Now, in-
creased emphasis on improving worker
safety and reducing environmental emis-
sions is motivating the printing industry to
seek cleaner technologies. In the 1980s,
soy-based inks were first used in offset
web presses for printing newspapers,
mainly for presumed environmental ben-
efits. In the late 1980s, soy-ink formula-
tions were marketed for sheet-fed offset
presses.
Sheet-fed soy inks are defined as those
that have a minimum of 20% soy oil by
volume. The soy oil replaces petroleum
oils in the ink vehicle and varnish compo-
nents. Use of the soy oil affects color,
drying, and other operating characteristics
of the inks. Soy-based inks used in sheet-
fed presses still contain at least 10% pe-
troleum oils. Research is continuing to
increase the proportion of soy and other
vegetable-based oils in these ink formula-
tions while maintaining satisfactory print-
ing characteristics.
The Office of Printing Services (OPS)
at the University of Illinois is the operating
partner in this study. They are considered
a medium size, in-plant printer and gross
about $4.5 million annually. They agreed
to enter into this cooperative project be-
cause of their commitment to active re-
search participation and out of a desire to
be a model environmentally aware print
shop. They were one of the first sheet-fed
offset presses in the United States to use
soy-based inks.
Approach
Data for this study was collected during
a full-scale print run on a Miller TP104
Plus' six-color press in July 1992 at the
OPS. The print job evaluated was a 4400
sheet, six-color, work-and-turn. Only four
Printed on Recycled Paper
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of the six colors were included in the study
because the type of ink used for two col-
ors was not changed between the runs.
All inks included in the study were manu-
factured by the same company, Handschy,
Inc. of Bellwood, IL* In-plant measure-
ments consisted of weighing the contain-
ers of inks, blanket cleaners, and roller
cleaners used during makeready and print-
ing at each press unit before and after
each print run. Cleanup rags were weighed
before and after each print run. Wastes in
the wash-up trays were weighed at each
press unit at the end of each run. Samples
of each type and color of ink and each
cleaner used were analyzed at the same
temperature as the press for total solids
and volatile content at the Hazardous
Waste Research and Information Center's
(HWRIC) Hazardous Materials Laboratory.
The operators at OPS use the same
cleaners for both petroleum-based and
soy-based inks. They had previously tried
aqueous and less volatile organic clean-
ers and had not found any satisfactory
substitutes. Problems identified with some
of the cleaners they tested were that they
required more labor, dried much slower,
and sometimes left a film on the presses
that had to be removed in an additional
step.
Results
Ink Use
During the two print runs studied,
makeready for the petroleum-based ink
run was considerably more involved than
that for the soy-based run. This was
caused by excess moisture in the original
batch of paper and not by differences in
the inks. This difference in the two runs
affected ink and blanket cleaner usage
and waste paper generated. The excess
moisture in the paper caused it to curl and
wrinkle during feeding into the press. This
problem was not a result of the type of ink
being used for that run but because the
paper had been stored in high humidity
conditions before the first run. Because of
this, about 25% more pages were printed
using petroleum-based inks, which makes
a comparison of inks and cleaners used
and waste generated between the two
runs difficult. These differences were com-
pensated for to the extent possible in
evaluating results of in-plant measure-
ments.
The study results showed that the pe-
troleum-based ink run required larger
quantities of three of the four colors of ink
than did the soy-based ink print run (Table
1). The amount shown in the g/100 sheets
printed column compensate for the differ-
ence in the number of sheets printed dur-
ing makeready. The % difference column
compares the amount of petroleum-based
ink used with the amount of soy-based ink
used. For these specific print jobs, in to-
tal, approximately 17% more petroleum-
based inks were used on a per sheet
printed basis.
Cleaner Use
The amount of blanket cleaners used is
shown in Table 2. Almost 46% more blan-
ket cleaners were used during the petro-
leum ink run (3,455.4g compared with
2,368.0g). Some of this difference can be
attributed to the larger amount of blanket
cleaners used during the longer makeready
that occurred during this run. The amount
of blanket cleaner used during makeready
was not recorded separately from that used
during press cleaning at the end of the
print run. The amount of additional clean-
ers used for that purpose during the print-
ing run could not be directly measured; it
Table 1. Quantity Inks Used
would not necessarily be directly propor-
tional to the amount of paper printed.
Therefore, an equivalent comparison can
not be made between the amount of blan-
ket cleaners used for each print run.
At the end of each printing run, roller
cleaners were used to clean up the
presses. Their use was not affected by
differences in makeready, but there was a
difference in the way the presses were
cleaned at the end of the two runs. At the
end of the petroleum ink run, the ink in
two of the stations was not changed. Also,
since the same colors were used in the
next run, each ink station was not cleaned
as thoroughly as it was at the end of the
second run with soy inks. The amounts of
each roller cleaner used for each color
and type of ink are shown in Table 3.
Overall, about 30% more roller cleaners
were used for the soy inks. This was ex-
pected since the stations were cleaned
more thoroughly at the end of the soy-
based ink run. Both inks appeared to re-
quire approximately the same amount of
cleaners and effort to remove from the
presses. On average in typical practice,
Ink Color
Black
Blue
Red
Yellow
Ink Type
Petroleum
Soy
Petroleum
Soy
Petroleum
Soy
Petroleum
Soy
Ink Used
(9)
241.8
162.7
124.8
79.5
109.7
87.1
85.8
53.6
Ink Used
(9)/100
Sheets
3.8
3.2
2.0
1.6
1.7
1.7
1.4
1.1
%
Difference
19
25
0
27
Table 2. Quantity (g) of Blanket Cleaners Used
Ink Type
Cleaner Name
Cleaner Used (g)
' Mention of irada names or commercial products does
nol constitute endorsement or recommendation for
use.
Petroleum
Soy
V120
Clean Quick
V120
Clean Quick
1768.7
1686.7
1141.2
1226.8
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Table 3. Quantity of Roller Cleaners Used at Each Color Station
Ink Color
Black
Blue
Red
Yellow
Ink Type
Petroleum
Soy
Petroleum
Soy
Petroleum
Soy
Petroleum
Soy
RBP#1(g)
40.1
78.8
44.8
75.7
29.5
97.9
35.1
40.3
RBP#2(g)
31.0
43.5
34.5
56.2
75.8
19.7
96.6
84.9
MIX(g)
12.4
27.9
33.8
52.1
19.5
24.9
61.5
71.5
the amount of cleaner used for the two
inks would be expected to be about the
same.
At the end of the petroleum-based ink
run, 663.8 g of ink and cleaner mixed
waste was in the washup trays. By com-
parison, there was 604.5 g at the end of
the soy-based ink run. This approximately
10% difference can be attributed to the
extended makeready at the beginning of
the petroleum-based ink run. On average
in typical practice, the amount of cleaner
usage for the two inks would be expected
to be the same.
Volatile Components
All inks had less than 6% volatile com-
ponents, and there were significantly less
volatile components in the soy-based inks
than in the petroleum-based inks. The pe-
troleum-based inks had an average of
about 4.6% volatile components compared
with an average of about 0.8% for the
soy-based inks. Thus, on average, the
soy-based inks only had about 17% of the
amount of volatiles as the petroleum-based
inks. The cleaners contained more than
97% volatile components except for one
roller cleaner that contained about 88%.
Based on these laboratory results and
on the amount of inks and cleaners used
(Tables 1 and 2), the amounts of solids
and volatiles in the inks and cleaners were
calculated (Table 4). The amounts of
volatiles were used to estimate the total
mass of air emissions. Over 90% of the
liquid wastes originated from the inks. As
for the volatiles, over 99% originated from
the cleaners in both cases.
Because of the difficulty of directly mea-
suring the amount of emissions from the
many sources on the press, the printed
papers, and the waste containers, a worst
case assumption was made that air emis-
sions were equal to the volatile content of
the materials used. Thus, for the petro-
leum-based ink run, 3,930.15 g were cal-
culated to be evaporated compared with
3,004.30 g for the soy-based ink run. This
was about 31% more emissions. As de-
scribed above, even after adjusting for
differences in makeready, about 17% more
petroleum-based ink was used. In addi-
tion, the petroleum-based inks had a higher
volatile content (4.6% compared with
0.77%). Just in terms of ink used, there
were 0.39 g/sheets of volatile emissions
from the petroleum inks compared to 0.23
g/100 sheets for the soy inks. This is
about 70% more emissions to the air for
an equivalent amount of printing with pe-
troleum inks.
As shown in Table 4, the mass of
volatiles estimated to be emitted from the
inks is less than 1.0% of the total mass
estimated to be emitted from the inks and
cleaners. Since most of the air emissions
were from the cleaners, less than 1% over-
all reduction in air emissions resulted from
using the soy-based inks. The longer the
print run the greater the reduction in vola-
tile emissions from using soy inks..
Liquid Components
The two main liquid wastes from the
printing press were from washup trays
and inks and cleaners on used rags. None
of these materials were spilled during the
two runs. To clean the various rollers and
blankets, several rags were saturated with
each cleaner and were used to wipe down
the press. As a result, the rags contained
some highly volatile inks and cleaners. An
undeterminable portion of these cleaners
and inks ended up in the washup trays.
Rather than determining the rapidly chang-
ing amount of liquids on the rags immedi-
ately at the end of the print run, the rags
were dried and the amount of dried solids
on the rags was weighed. About 60%
more solids were on the rags used to
clean the presses after the petroleum ink
run. Since more inks and cleaners were
used in that run, apparently much of these
materials ended up on the cleanup rags.
The amount of liquids in the washup
trays from this study was measured di-
rectly at the end of the print runs. Almost
10% more liquids were generated in the
washup trays after the petroleum ink run.
This liquid was a mixture of inks and vari-
ous cleaners. The amount of each ink and
each cleaner that ended up in these trays
and the rags (less the amount evaporated
and on printed product) could not be di-
rectly measured.
The amount of each cleaner used to
saturate the rags was not metered out
precisely by the press operators so that
differences between the two runs in the
amounts used were mostly the result of
operator variability when they poured
cleaners on the rags and not the results
of the type of ink being cleaned. We ob-
served no reason for there to be a consis-
tent difference in the amount of liquid
wastes generated by the two types of inks
studied. Differences resulted from opera-
tor variability, extended makeready during
the petroleum ink run, and more thorough
cleaning conducted at the end of the soy
ink run. It can not be concluded that one
ink generated more liquid wastes than the
other.
Table 4. Solid and Volatile Contents of Inks and Cleaners Used (g)
Parameter
Petroleum Print Run
Soy Print Run
Ink Solids
Cleaner Solids
Total Solids
Ink Volatiles
Cleaner Volatiles
Total Volatiles
537.17
64.78
601.95
24.93
3905.22
3930,15
371.36
48.64
420.00
11.54
2992.76
3004.30
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Solid Waste
During makeready for the petroleum-
based ink run, 1375 waste sheets were
generated. The reverse side of 100 waste
sheets were reused during makeready for
the soy-based ink print run. This is the
amount of solid waste generated directly
during these print runs. No other contain-
ers of solid wastes were observed. Addi-
tional solid waste that may be generated
in printing include trimmings and excess
number of pages printed to compensate
for losses that may occur during folding,
binding and any other final preparation
steps. Because the soy inks generally
spread further (by an average of about
17%), less used ink containers may be
generated with those inks. The amount of
the other solid wastes would be unaf-
fected by the type of ink used. In this
case, the difference in makeready waste
resulted from moisture in the paper at the
beginning of the print run and not from
difficulty with using the inks.
Press alignment and ink metering was
automated for the press used in this study.
Based on observations of manually oper-
ated presses at this and other facilities,
automation or efficient press set-up, rather
than the choice of ink, results in less solid
waste being generated during printing.
Once operators are familiar with the use
of either the petroleum or soy inks, then
the amount of solid waste generated dur-
ing makeready will not be noticeably dif-
ferent. In both cases, more waste paper
might be generated on some jobs be-
cause of difficulties in obtaining accept-
able colors or other print quality factors. In
this regard, neither ink appears to have a
clear advantage over the other.
Costs
The main cost factor considered was
that of raw materials. No equipment ex-
penditures were required by OPS to switch
from using petroleum to soy inks. There
was a difference in the amount of labor
involved in the two print runs but that was
due to the problems with paper at the
beginning of the first run and the fact that
cleanup was more rigorous at the end of
the second run. Neither of these differ-
ences was due to the type of ink being
used. The operating conditions of the
press, such as temperature and speed,
were the same for each ink so there was
no difference in overall rate of production
or utilities used because of the type of ink
used. Insurance, monitoring requirements,
reporting and recordkeeping, and permit
requirements are the same for each type
of ink. Any differences in future costs for
remediation or property damage would be
minimal. Employee health costs would
slightly favor the use of soy-based inks
because of reduced employee exposure
to breathing released chemicals. All the
quantified cost factors are for the Miller
TP 104 press only and not for the entire
facility at OPS.
The purchase prices of raw materials
(inks, cleaners, and paper) for this print
job are approximately the same for both
types of ink. Generally soy inks cost about
10% more. The average purchase price
for both the soy inks and petroleum inks
is about $8.00/lb (or $0.018g). Actual costs,
depending on the color, range from about
$4.00 to $12.00/lb. Costs do vary, how-
ever, when the amount of materials used
for petroleum inks is compared with the
amount of materials for soy inks. On an
equivalent basis of ink used during print-
ing and typical makeready, the overall cost
savings in ink used for the soy-based ink
print run was estimated to be $1.17. This
cost difference is not a major factor in ink
selection. Higher costs are involved in
printing including labor, materials such as
paper, equipment amortization, and utili-
ties. The portion of total printing costs
allocated to inks is usually very small.
When adjusted to the amount of accept-
able product printed, the difference be-
tween cleaner costs for the petroleum and
soy-based ink runs for this print job was
only 5 cents. This difference would be
greater if the cleaning after the petroleum-
based ink run had been more thorough.
Because the same cleaners were used
for both inks and on average there would
be no difference between the two inks in
the amount of cleaner needed, costs for
cleaning would not be expected to differ.
Discussion
Overall, about 17% less soy ink com-
pared with petroleum ink was used for the
print job studied. Because less amounts
of volatile hydrocarbons are emitted from
the soy-based inks, air emissions were
less. Since the inks and cleaners continu-
ously evaporate during use and the waste
inks and cleaners end up mixed together
in washup trays and on the cleanup rags,
it was difficult to determine the proportion
that evaporated during the actual printing
process. Ultimately, most if not all of the
volatiles in the inks and cleaners will ei-
ther evaporate, be discharged to the wa-
ter (such as from a commercial laundry)
or be containerized and sent to a landfill.
Some of these emissions will occur at the
print shop, some perhaps after shipment
of the printed product, and some at waste
management facilities. The proportion of
volatilization that will occur in any one
place will vary depending on how the waste
materials are managed. For comparison
purposes, it was assumed in this study
that all the air emissions occurred at the
print shop.
An important factor that influences the
amount of waste generated per unit of
production is the length of the print run.
Some uses of ink (and resulting wastes
generated) in the printing process are fairly
consistent among print jobs. For instance,
the amount of ink required to coat the
rollers and plates for each revolution is
relatively consistent. A certain amount of
waste is expected for every print job, but
a higher proportion of waste is produced
per raw material input on shorter print
jobs, such as the one monitored here.
With longer print jobs, a greater percent-
age of the ink used would be applied to
acceptable product.
To most printers, there are little or no
perceived differences in the cost of using
soy-based inks because the raw material
cost is slightly higher or equivalent to pe-
troleum-based inks. The cost difference is
more than offset by the fact that the soy
inks spread almost 20% further and do
not release as much volatile organic chemi-
cals. Less tangible benefits of using soy
inks (company image as being environ-
mentally friendly, improved employee re-
lations due to a perceived healthier working
environment, and customer preference for
products) are major factors considered by
printers. If customer response to product
quality is negative, printers will not adopt
a new ink. At OPS, their experience has
been that customers find the quality of the
product to be acceptable, and many pre-
fer to have their job printed with soy-based
inks.
A company also must consider the will-
ingness of its workers to switch to and
use soy inks and the time it takes for
operators to become skilled in using these
inks. Understandably there may be some
excess waste generated during such a
change. At OPS, there was some initial
resistance to the new inks. Formulations
of soy inks in sheet-fed offset presses
were new. In the past few years, these
formulations have improved and the press
operators at OPS have gained the experi-
ence necessary to produce high quality
images. Presently, the employees prefer
to use soy-based inks on this particular
press. A major reason for this is that the
soy inks are very similar to petroleum-
based inks to work with and clean from
presses. If an alternative cleaner was used
that took the operators longer or required
more effort for the soy inks then there
would be considerable resistance and cost.
-------
In addition to using soy-based inks, there
are other strategies printers can use to
reduce wastes from the sheet-fed offset
printing. Since most emissions were from
use of the cleaners, these emissions could
be reduced if aqueous or less volatile
cleaners were used. The press operators
at OPS have not found any of the alterna-
tive products they tried to be acceptable.
It should be kept in mind that the use of
less volatile cleaners may increase liquid
wastes.
Another strategy to reduce waste would
be to reduce the use of cleaners and inks.
This can be done in two ways; both may
involve additional capital for equipment.
One way is to recover or reuse waste inks
and cleaners. Installing a solvent still to
recover chemicals from the washup tray
wastes and possibly reusing those chemi-
cals in formulating cleaners might be fea-
sible. Some large printers have reportedly
adopted this approach.
A second way to reduce cleaner and
ink usage would be to purchase auto-
matic blanket washers and ink roller train
systems. Literature from one manufacturer
of this equipment claims that as little as
220 to 275 ml of cleaning solvent can be
used during a print run when the auto-
mated systems are in use. Although this
would not eliminate the need for hand
cleaning, it could greatly reduce the
amount of cleaner used and, thus, the
emissions from the cleaners. It could also
reduce employee exposure to potentially
harmful substances. An automatic blanket
washer could reduce cleaner use by up to
90%. It should be noted that on some
presses where these systems have been
installed the operators actually increased
use of the cleaners because, even during
a print run, the blankets can be cleaned
without stopping the press. Automatic ink
handling systems allow this type of press
to be operated with about 80% less ink in
the fountain.
The automatic blanket washer and ink
handling systems also reduce makeready
and cleanup times, saving the press crew
time and exposure to volatile compounds.
At OPS, it was estimated that such a
system would have a payback of about 3
yr. Most cost savings would be expected
in the cost of cleaners and in reduced
cleanup time.
Overall, soy inks have some environ-
mental and other advantages for sheet-
fed offset printers. The main environmental
advantage with soy inks is that they re-
lease less than 20% of the mass of vola-
tile organic chemicals compared to
petroleum inks. The soy inks also spread
about 15% further, which offsets the small
difference in cost that currently exists. Re-
portedly, recycling of soy ink printed pa-
per also has some advantages. In this
study all other factors including makeready
time, appearance of printed product, and
cleanup effort were essentially equivalent
between the two types of inks.
The full report was submitted in fulfill-
ment of Contract No. CR-815829 by the
Hazardous Waste Research and Informa-
tion Center, University of Illinois at Urbana-
Champaign under the sponsorship of the
U.S. Environmental Protection Agency.
5
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Beth Simpson. Pamela Tazik and Gary Miller are with the Hazardous Waste
Research and Information Center, Champaign, IL 61820.
Paul Randall is the EPA Project Officer (see below).
The complete report, entitled "Waste Reduction Evaluation of Soy-Based Inks
at a Sheet-Fed Offset Printer," (Order No. PB95-100046/AS; Cost: $17.50,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-94/144
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