Last May NaturalNews.com published an article on soy and how it's produced.
(NaturalNews) Virtually all "protein bars" on the market today are made with soy protein. Many infant formula products are also made with soy protein, and thousands of vegetarian products (veggie burgers, veggie cheese, "natural" food bars, etc.) are made with soy protein. That soy protein is almost always described as safe and "natural" by the companies using it. But there's a dirty little secret the soy product industry doesn't want you to know: Much of the "natural" soy protein used in foods today is bathed in a toxic, explosive chemical solvent known as hexane.Hexane is a neurotoxin.
In the industry, hexanes are used in the formulation of glues for shoes, leather products, and roofing. They are also used to extract cooking oils from seeds, for cleansing and degreasing all sorts of items, and in textile manufacturing.
Full article by Mike Adams: http://www.naturalnews.com/026303_hexane_soy_food.html