E AP Project Summary

United States

Environmental Protection

Agency

Waste Reduction Evaluation of

Soy-Based Ink at a Sheet-Fed

Offset Printer

Beth Simpson, Pamela Tazik, Gary Miller, and Paul Randall

Risk Reduction

Engineering Laboratory

Cincinnati, OH 45268

Research and Development

This Waste Reduction and Innovative Technology Evaluation project focused 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 using soy-based inks in place of the petroleum-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 during the printing process. No published

studies verify the claim of reduced air

emissions or quantify other environmental 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 demonstration that is fully documented in a

separate report (see ordering information 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, increased emphasis on improving worker

safety and reducing environmental emissions 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 benefits. In the late 1980s, soy-ink formulations 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 components. Use of the soy oil affects color,

drying, and other operating characteristics

of the inks. Soy-based inks used in sheetfed presses still contain at least 10% petroleum oils. Research is continuing to

increase the proportion of soy and other

vegetable-based oils in these ink formulations while maintaining satisfactory printing 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 because of their commitment to active research 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

EPA/600/SR-94/144 September 1994
2

of the six colors were included in the study

because the type of ink used for two colors was not changed between the runs.

All inks included in the study were manufactured by the same company, Handschy,

Inc. of Bellwood, IL.* In-plant measurements consisted of weighing the containers of inks, blanket cleaners, and roller

cleaners used during makeready and printing 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 cleaners 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 compensated for to the extent possible in

evaluating results of in-plant measurements.

The study results showed that the petroleum-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 difference in the number of sheets printed during 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 total, approximately 17% more petroleumbased 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 blanket cleaners were used during the petroleum 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 cleaners used for that purpose during the printing run could not be directly measured; it

would not necessarily be directly proportional to the amount of paper printed.

Therefore, an equivalent comparison can

not be made between the amount of blanket 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 expected since the stations were cleaned

more thoroughly at the end of the soybased ink run. Both inks appeared to require approximately the same amount of

cleaners and effort to remove from the

presses. On average in typical practice,

* Mention of trade names or commercial products does

not constitute endorsement or recommendation for

use.

Ink Color Ink Type Ink Used Ink Used %

(g) (g)/100 Difference

Sheets

Black Petroleum 241.8 3.8 19

Soy 162.7 3.2

Blue Petroleum 124.8 2.0 25

Soy 79.5 1.6

Red Petroleum 109.7 1.7 0

Soy 87.1 1.7

Yellow Petroleum

Soy 85.8 1.4 27

53.6 1.1

Table 1. Quantity Inks Used

Table 2. Quantity (g) of Blanket Cleaners Used

Ink Type Cleaner Name Cleaner Used (g)

Petroleum V120 1768.7

Clean Quick 1686.7

Soy V120 1141.2

Clean Quick 1226.8
3

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 changing amount of liquids on the rags immediately 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 directly 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 various 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 directly 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 observed no reason for there to be a consistent difference in the amount of liquid

wastes generated by the two types of inks

studied. Differences resulted from operator 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 3. Quantity of Roller Cleaners Used at Each Color Station

Ink Color Ink Type RBP #1(g) RBP #2(g) MIX(g)

Black Petroleum 40.1 31.0 12.4

Soy 78.8 43.5 27.9

Blue Petroleum 44.8 34.5 33.8

Soy 75.7 56.2 52.1

Red Petroleum 29.5 75.8 19.5

Soy 97.9 19.7 24.9

Yellow Petroleum 35.1 96.6 61.5

Soy 40.3 84.9 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 comparison, 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 components, and there were significantly less

volatile components in the soy-based inks

than in the petroleum-based inks. The petroleum-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 measuring 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 emissions were equal to the volatile content of

the materials used. Thus, for the petroleum-based ink run, 3,930.15 g were calculated to be evaporated compared with

3,004.30 g for the soy-based ink run. This

was about 31% more emissions. As described above, even after adjusting for

differences in makeready, about 17% more

petroleum-based ink was used. In addition, 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 petroleum 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% overall reduction in air emissions resulted from

using the soy-based inks. The longer the

print run the greater the reduction in volatile 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

Parameter Petroleum Print Run Soy Print Run

Ink Solids 537.17 371.36

Cleaner Solids 64.78 48.64

 Total Solids 601.95 420.00

Ink Volatiles 24.93 11.54

Cleaner Volatiles 3905.22 2992.76

 Total Volatiles 3930.15 3004.30

Table 4. Solid and Volatile Contents of Inks and Cleaners Used (g)
4

Solid Waste

During makeready for the petroleumbased 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 containers of solid wastes were observed. Additional 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 unaffected 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 operated 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 during makeready will not be noticeably different. In both cases, more waste paper

might be generated on some jobs because of difficulties in obtaining acceptable 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 expenditures 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 differences 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, however, 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 printing 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 utilities. The portion of total printing costs

allocated to inks is usually very small.

When adjusted to the amount of acceptable product printed, the difference between 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 petroleumbased 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 compared 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 continuously 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 either evaporate, be discharged to the water (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 percentage 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 petroleum-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 chemicals. Less tangible benefits of using soy

inks (company image as being environmentally friendly, improved employee relations 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 prefer to have their job printed with soy-based

inks.

A company also must consider the willingness 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 experience 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 petroleumbased 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.
5

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 alternative 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 chemicals in formulating cleaners might be feasible. Some large printers have reportedly

adopted this approach.

A second way to reduce cleaner and

ink usage would be to purchase automatic 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 automated 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 environmental and other advantages for sheetfed offset printers. The main environmental

advantage with soy inks is that they release less than 20% of the mass of volatile organic chemicals compared to

petroleum inks. The soy inks also spread

about 15% further, which offsets the small

difference in cost that currently exists. Reportedly, recycling of soy ink printed paper 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 fulfillment of Contract No. CR-815829 by the

Hazardous Waste Research and Information Center, University of Illinois at UrbanaChampaign under the sponsorship of the

U.S. Environmental Protection Agency.
6

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

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35

United States

Environmental Protection Agency

Center for Environmental Research Information

Cincinnati, OH 45268

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Penalty for Private Use

$300

EPA/600/SR-94/144