The F.D.A. continues to state azodicarbonamide may be used in dough conditioners at a level of less than 45 parts per million.

Consider the setting

Blogger Vani Hari, also known as “The Food Babe,” in February 2014 began a petition to get the Subway restaurant chain to remove azodicarbonamide (ADA), a dough conditioner, from its bread. She pointed out that ADA is used to make yoga mats and that the World Health Organization has linked ADA to respiratory issues, allergies and asthma.

The W.H.O., however, did not examine the use of ADA in food in a Concise International Chemical Assessment Document released in 1999. Instead, it detailed the issue of ADA and human health in the working environment, such as places where ADA was used in the manufacture of products.

“On the basis that azodicarbonamide is a human asthmagen and that the concentrations required to induce asthma in a non-sensitive individual are unknown, it is concluded that there is a risk to human health under present occupational exposure conditions,” the W.H.O. said in the 1999 report.

The F.D.A. continues to state ADA may be used in dough conditioners at a level of less than 45 parts per million.

A study appearing in the Sept. 4, 2011, issue of the Journal of Agricultural Food Chemistry did address ADA’s use in food. Researchers from the University of Hebei in China found ADA partially degrades in the heat of processing to form trace amounts of semicarbazide, which shows carcinogenicity and has been shown to cause tumors. The researchers found semicarbazide in flour treated with ADA.