'Dough strengthener' to be removed from Subway sandwiches

The word azodicarbonamide does not provide much comfort when reading the ingredients of Subway's bread.

The chemical, used for strengthening dough by bakers, also adds elasticity to products like yoga mats and shoe soles. After much controversy, Subway is removing it from their sandwiches.

"We are already in the process of removing azodicarbonamide as part of our bread improvement efforts despite the fact that it is (a) USDA and FDA approved ingredient," Subway said in a statement. "The complete conversion to have this product out of the bread will be done soon."

The additive is approved by the FDA, but only in accordance with levels below 0.0045 percent by weight of the flour when used as a "dough conditioner."

Its breakdown products are known carcinogens, and cause some concern. The byproduct semicarbazide can cause cancer in the lungs and blood vessels in mice, but the Center for Science in the Public Interest also publicized that it and other breakdowns like it "pose a small risk to humans."

The American Bakers Association told CNN: "Past FDA sampling results have indicated appropriate low level use in products. As a dough conditioner it has a volume/texture effect on the finished loaf. It is a functional ingredient that improves the quality of bread and any substitutes are likely not to work as well as ADA (azodicarbonamide)."

Public debate over the chemical began with food blogger Vani Hari of Food Babe. The Subway critic had written about Subway ingredients before on the popular website, and drew public attention to this ingredient in particular, CSPI said. A petition was signed by over 67,000 people to remove azodicarbonamide.

The World Health Organization published a report in 1999 stating that past studies suggest the chemical can cause asthma. This belief is based off of the display of asthma-related symptoms in employees who work at facilities where azodicarbonamide is manufactured .

"The level of risk is uncertain; hence, exposure levels should be reduced as much as possible," WHO said.