Dr. Edward F. Group III gives several good reasons to avoid bread that includes azodicarbonamide in a well referenced article published at Global Healing Center. He also lists several fast food chains that use this ‘foamy’, industrial chemical additive in their baked goods, including Subway, McDonalds, Wendy’s, Arbys and Chick-fil-A and others. Dr. Group writes about this additive, banned in Europe and Australia:
1. Azodicarbonamide is an Industrial Chemical
The primary function of azodicarbonamide is centered on the way it breaks down during processing — it creates tiny bubbles that make things “foamy.” Somewhere in the testing procedures, scientists discovered it whitened flour and acted as an oxidizing agent. Bakers, or rather “food scientists” soon concluded that it should be a standard inclusion in bread.
2. Azodicarbonamide Increases Gluten Content in Bread
Oxidizing agents like azodicarbonamide are used to increase gluten content. This is “desirable” because higher levels of gluten create stronger, more durable dough. The added convenience to processing isn’t without other risks though. Gluten has been linked to a host of gastro-intestinal, immunologic and neurologic diseases.  
3. Azodicarbonamide Can Cause Respiratory Problems
Research has established a direct link between exposure to azodicarbonamide and the onset of asthma.  According to a World Health Organization (WHO) follow-up report, regular occupational exposure to azodicarbonamide can lead to asthma and allergies. The WHO report notes many of those who developed asthma and other respiratory complications experienced symptoms within just three months of exposure. 
4. Azodicarbonamide is a Skin Irritant
The WHO report also noted physical exposure to azodicarbonamide caused recurring dermatitis.  Fortunately for those suffering, eliminating exposure caused the indications of the dermatitis to go away. While this is good news, these results show how quickly industrial chemicals can initiate an autoimmune response. Unfortunately, skin irritation seems to be the least of concerns…
5. Azodicarbonamide Disrupts the Immune System
In 2001, lab tests found that direct exposure to azodicarbonamide inhibited human immune cell formation and function.  Although “direct exposure” may be less of a common problem, the bigger problem happens when azodicarbonamide is heated up, as when it’s a bread ingredient…
6. Azodicarbonamide Creates Toxic By-Products When Heated
While azodicarbonamide is used to condition bread dough, when it’s baked, the heat causes it to break down. Two by-products can result: semicarbazide and ethyl carbamate. Semicarbazide belongs to a family of chemicals known as hydrazines that are especially carcinogenic. A 2003 study using animal models found that it caused free radical damage to DNA.  Other studies have found that semicarbazide damages human immune cells and the DNA of animals. 
The other half of the gruesome twosome is no better. The National Institute of Health’s Hazardous Substances Data Bank states that ethyl carbamate is a carcinogen to animals; in fact this is backed by over 200 studies.   Research from 17 years ago confirmed that adding azodicarbonamide to bread increased ethyl carbamate levels.  The awful truth is that industry has known for nearly two decades that this is toxic trash and fed it to us anyway.
7. Harmful to Hormone Function
Exposure to semicarbazide can present another health risk. Animal studies have found it has a toxic impact on hormone function and the hormone-regulating organs, including the thyroid, thymus, spleen, testes, ovaries, and uterus.   As is the case with all endocrine disrupting compounds, this stuff is poison!
8. Europe and Australia Have Banned It
While US Officials continue to claim the amount of azodicarbonamide found in most baked products poses no serious health threat, European and Australian officials have banned its use in bread. Baby food jars were another source of exposure and officials were left without answers concerning the “safe levels” for infants.  Consequently, European officials disallowed its use in sealing glass jars.
Click here for the full report by Dr. Group, including references.