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Why is Soy Ink Considered Environmentally Responsible?

Print Sustainability

Soy Bean Field

Compiled from information from American Soybean Association, SoySeal User Agreement, International Paper, US Inks, and Gans Ink Co.

Many print buyers today are asking their printers if they use soy inks. These buyers are under the impression that by using soy ink they are being environmentally responsible. The truth is that even though soy inks are a part of environmental printing, or, "Printing Green," they are not the whole answer.

Responsible printers, like Casey Printing, have been working on removing hazardous chemicals in their pressrooms for years. Manufacturers of inks and solutions used in the printing process today have eliminated the use of lead, chromium, and silver and are working hard to reduce the harmful VOC (volatile organic content). They are also under close scrutiny to monitor and reduce their waste streams. All of these are as important as whether or not they are using soy inks.

Why is soy ink considered environmentally responsible?

The popularity of Soy oil-based inks actually began several years ago as a replacement for petrochemical oils. Soybeans are plentiful and are a popular crop among farmers, making it widely available.

The use of soy oil-based inks has gained in popularity recently to address the environmental issues and reduce our dependence on foreign petrochemical-based oil for inks. Other vegetable oils used in making ink include cottonseed, vernonia, sunflower, tung, linseed, and canola.

Printing inks today fall under several classes that include:

  • Sheet-fed ink (dried by oxidation or polymerization)
  • Newspaper inks (dried by absorption, oxidation)
  • Heat-set inks (dried by the action of heat)

The American Soybean Association (ASA) was very effective in the late 1980's at promoting the use of soy oils in printing inks. They established minimum percentages of soy oil content in order for the SoySeal to be displayed on an ink can or a printed piece. The minimum levels are:

  • 30% for colored news inks
  • 40% for black news inks
  • 20% for business forms inks
  • 20% for sheet-fed inks
  • 7% for heat-set inks

Heat-set ink manufacturers are substituting the soy oil today in place of linseed oil as the modifier for the heat-set varnish. It is ironic that the ink producers are replacing one vegetable oil for another. The advantage is that the ink manufacturer and printer can now claim the ink is "soy based" and be able to use the ASA SoySeal.

Sheet-fed inks have used linseed oil as the base oil in ink for many years. Linseed oil was used because it imparts good flow characteristics to ink and converts into a solid over a long period of time (drying). To accelerate this drying process additives are added, such as cobalt or manganese.

Press-related problems with soy oil inks have been related mostly to drying. Soy inks dry (due to the soy oil) at a slower rate. With print buyers demanding closer deadlines, these inks are not an option for many quick turnaround printers. Soybean and other vegetable oil are actually more expensive than petrochemical oils. Again, print buyers are demanding the lowest price possible. The lowest price may not be the best environmental choice.

Ink manufactures are experimenting with many new vehicles and other non-petroleum products to give their next generation of inks faster and harder drying properties. These inks may not contain enough soy oil to qualify for the ASA SoySeal logo, but they are low VOC, high vegetable oil (cottonseed, vernonia, sunflower, tung, linseed, and canola) renewable resource inks.

While there have been many claims of the ecological benefits to be gained, ink made with soybean oil contains waxes, pigments, and other additives. This makes it no easier to dispose of a soy oil-based Ink than a petro-based ink, printed or non-printed. This requires that the same considerations be taken for disposal in a landfill or incineration, as petro-based inks would need. While soy or vegetable containing inks may help reduce the measured VOC's (volatile organic compound content), the EPA (Environmental Protection Agency) has not exempted vegetable oils as a non-VOC. The EPA believes that while all vegetable oils are not VOC's, they are "precursors to precursors of ozone". When vegetable oils, including soy, dry by oxidation, there is evidence that minute amounts of VOC's are released, so says the Environmental Conservation Board. While the EPA and the ECB have made these statements, they do believe they (soy inks) are much more friendly to the air environment than petro-based oils. The same would hold true for any other vegetable oil based ink.

If print buyers are interested in doing business with printers who follow sustainable business practices, they should not just be concerned with the use of soy oil (unless you have a vested interest in growing soy beans). They should also, and perhaps more importantly, ask if their printer is doing their part in reducing VOCs, monitoring their waste streams, using vegetable based ink etc. or, in other words, are they really  "Printing Green."

If you want to learn more about environmental best practices in printing, or how Casey adheres to these standards, sound off in the comments below or hit that "Talk to an Expert" button.

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