Soy Ink: Myth vs. Reality

By Anne Michelsen

“Green” is rarely black and white. More often, it comes in multiple shades of gray. And in the case of one “green” product, those shades of gray come in every color of the rainbow.

The demand for soy-based ink is rising as corporate sustainability moves into the mainstream. First developed by the newspaper industry in the 1970s in response to rising petroleum prices, soy and other vegetable-based inks offer a healthier, environmentally friendly alternative to conventional ink.

Or do they?

There are many popular notions surrounding soy ink. Some may be true. Some are blatant misconceptions. And most fall somewhere in between.

Is soy ink really a good environmental choice? If so, could it be better? This article is an attempt to shed some light on the matter by exploring four common myths about soy ink.

Myth #1: “Everything in soy ink comes from soy.”

In Reality: “The biggest misconception people have is that all of the components of soy ink are made from soy,” says Gary Jones, Vice President EHS of the Printing Industries of America.

 

Oil is just one component of ink.  Other ingredients include pigments, resins and film formers, and various additives to lend desired characteristics to different kinds of ink.

Some of those other components may come from renewable resources, but many do not. Pigments, especially, are generally mineral in origin and it’s not uncommon for them to be toxic. For instance, carbon black is widely used as the pigment for black ink and is classified as a Group 2B carcinogen.

What may come as a surprise to many people is that most veggie inks contain substantial amounts of petroleum.

“In order for an ink to use the American Soy Association’s Soy Seal logo, it only needs to contain the specified amount of soy oil or soy oil derivatives. No other specifications regarding the other components of the ink are identified,” explains Jones.

“For example, in order for a heatset web offset lithographic paste ink to be considered a ‘soy ink,’ it must have 7 percent soy oil content. Therefore, a heatset litho ink that contains 7 percent soy oil and 93 percent of other ingredients such as methyl ethyl death would be considered a ‘soy ink’ and can carry the Soy Seal logo.”

Depending on the type of ink and its intended use, an ink’s oil content must be a minimum of 6 percent to 40 percent soy in order to qualify for the Soy Seal logo. The most common use of soy oil in ink occurs in offset lithographic ink – the kind most commonly used in commercial printing. Black offset litho ink must have at least 40 percent soy oil content to qualify as a soy ink.

Mark Nelson, Web Press Advisor and Director of Manufacturing at the John Roberts Company, a commercial print shop in Minneapolis, explains why: “If you don’t get the percentage correct it won’t dry properly. It’s a lot like adding ethanol to gasoline – too much and it won’t work well.”

Myth #2: “Soy ink emits fewer VOC’s (volatile organic compounds) than conventional ink.”

In Reality: “It’s important to realize that VOC content and VOC emissions are two different things,” says Jones. “The EPA has a specific test method (Method 24) that is required to be used to determine VOC content. Using that method, there’s less VOC in soy ink.

 

“However, vegetable oils will absorb oxygen from the air, which cross links in the vegetable oil to cause it to dry. When the vegetable oils cross link, they produce and emit VOCs. So even though the actual measured VOC content may be lower, it’s not uncommon to see a higher veggie oil content resulting in more VOC’s actually being emitted.”

While this may be true in the lab, those who use the inks on a daily basis have a different perspective.

“One of the wonderful side effects of (switching to vegetable inks) is that (our shop) doesn’t smell like a print shop anymore,” reports Dee Bisel, owner of Minuteman Press in Overland Park, KS, who has switched exclusively to using vegetable based inks in her commercial printing franchise. “We have reduced our VOC’s 22 percent and HAP’s (hazardous air pollutants) by 93 percent by switching from petroleum-based ink to soy and vegetable ink.”

Bisel adds, “Once you switch to the soy inks, you have to go to new cleaners and solvents – they all have to change.” She believes the switch to less volatile solvents is a major contributor to the improved air quality.

Nelson agrees. He also notes that John Roberts (which, like Bisel’s shop, is certified as a Green Printer through the Sustainable Green Printing Partnership) has reduced the total volume of solvents used on a daily basis. “We recycle our solvents through a distilling process. We don’t order in nearly as much fresh solvent as we used to. I can guarantee it’s half as much.”

Myth #3: “Soy ink facilitates paper recycling.”

In Reality: “That’s a case of “Don’t believe everything you read online,” says Jones.

 

You may have read that soy ink is easier to remove from paper pulp than conventional ink. This observation is based on a 1991 laboratory study done at a major Midwestern university.

There is no reason to doubt the validity of the study; however, it was conducted using ink that had been aged for only 4 weeks. Industry experience reveals a different truth. It turns out that once veggie ink is truly aged in the field it can be much harder to remove from paper pulp than conventional ink, due to the increased oxidation and crosslinking that occurs when vegetable oils dry.

Myth #4: “Soy ink is good for the environment.”

In Reality: If only it were so simple! The fact is, no ink is good for the environment. The question is: Is soy ink truly a better choice?

 

Soy is one of the major crops used in conventional agriculture’s monoculture system, which severely limits biodiversity and inhibits ecosystem resiliency. Over 90 percent of U.S. soy fields are planted in genetically modified soy; GMO’s present a range of environmental concerns. And, the increase in global demand for soy products contributes to large scale deforestation in the Amazon rainforest and elsewhere.

Soy may be a renewable resource. But it does take diesel to grow soy, so thinking that each drop of soy ink used is a drop of petroleum saved is a fallacy. (For comparison, one reliable estimate for biodiesel production is about 2.5 gallons of soy biodiesel per gallon input of standard diesel fuel.)

On the other hand, soy beans require minimal chemical input compared to many other crops. There’s no denying that even vegetable inks containing mineral components are usually far less toxic than conventional inks. And, veggie inks are proving to be more biodegradable as well.

So are soy and other veggie based inks really better for the environment?

Nearly all sustainability experts say, “Yes!”

But perhaps Jones puts it best: “From a global sustainability aspect, the more (renewable content) that’s incorporated the better, because that way you’re at least moving in the right direction.”

What do you think? Has your company made the switch to veggie ink? What drove the change, and what’s been your experience?

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A freelance copywriter and principal of Green Ink Copywriting, Anne Michelsen helps companies  promote their sustainable products and services while remaining compliant with green marketing guidelines.  She also enjoys writing about environmental issues. Anne publishes a monthly newsletter of green marketing and compliance insights.

Image credit: Pixabay