Through a series of product trials, EPA's Design for the Environment
(DfE) Lithographic Printing Partnership evaluated 22 different commercially
available blanket washes. All of the washes were scrutinized for
their performance, cost, and environmental and health characteristics.
Then each wash was categorized based on its chemical make-up. This
bulletin highlights one category of these blanket washes: vegetable
esters. Vegetable esters are fatty acid derivatives produced from
agricultural sources, mainly soybean oil.
Use this bulletin to compare the performance, cost, and health
and environmental benefits of vegetable ester blanket washes with
your current wash. This information can help you get started in
finding the best substitute blanket wash for you.
| Lower VOCs: An Important Benefit
| One of the biggest advantages of vegetable ester blanket
washes is that they are lower in volatile organic compounds (VOCs)
than many standard blanket washes. VOCs are chem-icals that evaporate
very quickly. The faster a chemical evaporates, the faster it will
get into the air during use. While standard, solvent-based washes
can contain up to 100% VOCs, the VOC content of the vegetable ester
washes typically ranges from 12 to 30%. This range drops to 2% or
less for vegetable ester and water mixtures.
Worker Health Concerns
The higher the VOC content of a product, the greater the chances
that your workers are inhaling harmful chemicals. Vegetable ester
washes, with their low VOC content, evaporate more slowly. Worker
exposure is less, so potential health risks are decreased.
| The quick evaporation of VOCs can also harm the environment.
VOCs are a major contributor to smog, and are among the most persistent
emissions problems in the printing industry. High-VOC washes will
increase your shop's contribution to environmental problems.
Just as they can improve worker safety, low-VOC vegetable esters
can reduce the environmen-tal impact of your shop on your community.
A Less Flammable Substitute
| Compared to most of the other blanket washes, vegetable
esters are much less flammable. This is because they have a much higher
flash point (the temperature at which the wash can be ignited). A
less flammable blanket wash means a safer work environment.
| During the product trials, overall press operator opinion
of the performance of vegetable ester washes varied but was generally
favorable. The printers found that the vegetable ester blanket washes
handled quite differently from their traditional wash. Press operators
discovered that a little extra effort was required, but with changes
in the way the wash was used, the substitute performed as well as
the standard wash. Some problems associated with using vegetable ester
washes, and their solutions, include:
|There is an oily film left on the blanket.
||Use a wipe firmly wrung in water instead of a dry wipe to
remove the oily film from the blanket surface.
|It takes longer to dry.
||Dry the blanket with a clean dry wipe.
|The wash is thicker.
||Give the wash enough time to soak into the wipe by keeping
a supply of wipes and wash together in a covered container.
When ready to use the wash-soaked wipe, squeeze or wring the
excess wash back into the container.
| In general, vegetable ester washes cost more per gallon
than many of the other blanket washes tested. However, it is important
to remember that purchase price alone may not be the best indicator
of the true overall cost of using a blanket wash. Take into account
the following factors which may affect the actual cost of a blanket
COMPLIANCE COSTS. Washes high in VOC content may yield
waste - excess wash or used wipes - that has to be handled as regulated
hazardous waste. Low-VOC washes such as vegetable esters may eliminate
this potentially costly handling procedure. Also, with lower VOCs,
a facility's air emissions may drop to levels below the threshold
amounts that require costly permitting and reporting.
QUANTITY OF BLANKET WASH NEEDED. Some printers found that
once experienced in using a vegetable ester wash, they often needed
much less wash for a given job. This can mean cost savings.
INSURANCE COSTS. Switching to a low-flammability vegetable
ester wash may reduce your insurance costs. Check with your underwriter
to see if such benefits apply to your facility.
Where Do I Go From Here?
| 1. Get to know your current wash. Look at product
labels and material safety data sheets (MSDS) and ask your supplier
the questions listed to the left, so that you can learn:
2. Work with your supplier to evaluate substitute washes:
- The chemicals or chemical families
- The VOC content
- The health and environmental impacts
- The regulatory issues
3. Try out substitute blanket washes:
- Question your supplier about substitute washes (see left)
- Work with your supplier to optimize the wash performance
- Use the summary booklet, Evaluating Blanket Washes: A Guide
For Printers, for additional information (see below for ordering
4. Compare your traditional wash with your favorite substitute
- Follow supplier suggestions on how to use substitutes properly
- Try the substitute blanket wash with different ink types, ink
coverages, conditions of the blanket, and lengths of runs prior
to blanket cleaning
- Expect cost and performance to improve as you optimize the washing
- Use the "Substitute Blanket Washes: Making Them Work" bulletin
for information on different washing techniques (see below for
About the Design for the Environment Lithographic
- Compare cost, performance, and health and environmental impacts
of your traditional wash with the substitute wash
- Use the "A Worksheet To Help You Choose A Better Wash" bulletin
for additional information (see below for ordering information)
| The goal of the Design for the Environment (DfE) Lithographic
Printing Partnership is to provide lithographers with information
that can help them design an operation which is more environmentally
sound, safer for workers, and more cost effective.
Concentrating on the process of blanket washes, the partners of
the DfE Lithographic Printing Partnership, in a voluntary cooperative
effort, evaluated 37 different blanket wash products. Information
was gathered on the performance, cost, and health and environmental
risk trade-offs of the different types of substitute blanket wash.
For more details on the evaluations, please refer to the booklet,
Evaluating Blanket Washes: A Guide For Printers.
In addition to the Lithographic Printing Partnership, similar
DfE projects are currently underway with both the screen printing
and flexography industries.
To obtain additional copies of this or other bulletins and case
studies, or for more information about EPA's Design for the Environment
Pollution Prevention Information Clearinghouse (PPIC)
1200 Pennsylvania Ave. NW (7407-T)
Washington, DC 20460-0001