“Which Veggie Burgers Were Made With a Neurotoxin?” asked Mother Jones this week, in an article detailing the findings of a Cornucopia Institute study on the use of hexane, a harsh pollutant, in non-organic soy production.

After Mother Jones published the article on Monday, CBS News, New York Daily News, and dozens of blogs picked up the story. “Soy Vey! Non-Organic Veggie Burgers Contain Neurotoxin,” “One Soy Burger, Hold the Hexane,” “Soy Burger With a Side of Toxin?” were among the headlines swirling around the web this week.

The Cornucopia report calls the use of hexane–which the Environmental Protection Agency (EPA) lists as a “hazardous air pollutant”–a widespread “dirty little secret” in the natural foods business. According to the report, the chemical is used in the manufacturing of many “natural” soy foods like veggie burgers, nutrition bars, and protein shakes–and to this reporter’s dismay, that list includes Clif Bars.

Hexane, a byproduct of gasoline refining, is used in the food business as a solvent to separate the oil from the protein and fiber of grains, including soy beans.

“The effects on consumers of hexane residues in soy foods have not yet been thoroughly studied and are not regulated by the U.S. Food and Drug Administration (FDA),” according to the study, titled Behind the Bean.”Test results obtained by The Cornucopia Institute indicate that residues–ten times higher than what is considered normal by the FDA–do appear in common soy ingredients.”

There is no requirement for food companies to test for Hexane residues, so it is unclear how often the chemical shows up in food products at the grocery store.

According to Charlotte Vallaeys, a senior researcher for the group, the main concern with using the chemical in food processing is the environmental impact. Consumers may think they are buying a “green” vegetarian product, which is in fact contributing to significant hexane emissions. Consumers can avoid the issue by choosing certified organic soy, which bars the use of the chemical. 

“If you’re buying organic, you can be assured it’s not allowed,” Vallaeys told Food Safety News. “There are other ways to make a veggie burger. We just want to make sure people know there are alternatives.”

Vallaeys also cautioned that “made with organic ingredients” does not necessarily mean the soy is organic. She recommends looking for labeling that specifies “organic soy” or the USDA Organic symbol.

The report offers the following two lists to help consumers who wish to avoid products made with hexane:

Products with no hexane-extracted soy ingredients

Boca Burgers “Made with organic soy”
Helen’s Kitchen
Morningstar “Made with organic”
Superburgers by Turtle Island

Products with hexane-extracted soy ingredients

Amy’s Kitchen
Boca Burger, conventional
Franklin Farms
Garden Burger
It’s All Good
Morningstar Farms
President’s Choice
Soy Boy
Taste Above
Trader Joe’s
Yves Veggie Cuisine

The full report can be found here.