Extract from article:

"Think you’re being healthy by choosing a veggie burger instead of red meat? Think again.

...In an effort to make their products as low-fat as possible, many veggie burger manufacturers are turning to a potentially harmful chemical, according to an investigation by the non-profit Cornucopia Institute. It revealed in a recent report that most non-organic veggie burger brands contain a chemical called hexane, which is an EPA-registered air pollutant and neurotoxin.

This lovely chemical is traditionally reserved for shoe glue, leather products and roofing. ...
...So, they soak soybeans in hexane so they can separate the fat from the protein.

According to the Cornucopia Institute’s report, “if a non-organic product contains a soy protein isolate, soy protein concentrate, or texturized vegetable protein, you can be pretty sure it was made using soy beans that were made with hexane.”
...The Cornucopia Institute also revealed some popular veggie burger brands that absolutely do use hexane: Amy’s Kitchen, Boca Burger, Franklin Farms, Garden Burger, It’s All Good, Lightlife, Morningstar Farms, President’s Choice, Soy Boy, Taste Above, Trader Joe’s and Yves Veggie Cuisine.

Brands that do not use any hexane in their veggie burgers are: Helen’s Kitchen, Superburgers by Turtle Island, Tofurky, Wildwood and Morningstar “Made with organic”...+Sunshine Burger"

http://yourorganicgardeningblog.com/health-warningneurotoxin-in-veggie-burgers/