Chemicals in the news

Azodicarbonamide (also known as azo(bis)formimide) or ADA:

Azodicarbonamide molecule structural formula.

Azodicarbonamide has recently received a lot of attention when the sandwich chain, Subway®, announced its plans to remove this compound from its bread. The compound was used to improve dough and maintain bread texture.1,2 This came about because of an online petition claiming that the use of ADA is like eating a “yoga mat sandwich” and calling for the ban of the chemical from food products.3,4 ADA has two common uses: as a chemical foaming agent in the plastics industry and as a food additive (known as E927) for use as a whitening agent in cereal flour and as a dough conditioner in bread baking.

The principal use of ADA is in the production of foamed plastics as a blowing agent. The thermal decomposition of ADA results in the evolution of nitrogen, carbon monoxide, carbon dioxide, and ammonia gases, which are trapped in the polymer as bubbles to form a foamed product.5 This process creates materials that are strong, light, spongy and malleable. It is used in products such as yoga mats and shoe soles — hence the deleterious namesake for its use in food products.

The use of ADA in bread baking came about because in centuries past, flour fresh from the mill had to age several months before it could be kneaded into dough and baked in the oven. It was discovered that ADA caused flour to achieve maturing action without long storage. The result was commercial bread that renders large batches easier to handle and makes the finished products puffier and tough enough to withstand shipping and storage.

There is no scientific evidence to suggest ADA, as it is currently used, is a public health or safety concern. The FDA considers small amounts of ADA to be safe and the agency long ago set an allowable level of 45 parts per million in dough.6  Certain countries (mainly in Europe) have restricted or banned the use of ADA however due to the risk when it is used in an industrial setting. If inhaled, ADA can cause respiratory problems. Unfortunately, certain websites have extrapolated this information incorrectly and state respiratory problems can be caused by its use in bread.

There are a couple of interesting discussion areas that come to mind when talking about this chemical. It could be discussed that just because a chemical has an industrial use, does not automatically mean it is unsafe to use in food. There are plenty of examples: calcium pills contain calcium carbonate, the same chemical found in gravestones or sodium hydrogen sulfate found in both a cake mix and toilet bowl cleaner or calcium sulfate, used in sheet rock and in the making of tofu.

Another potential area of discussion is the misleading “spin” that can be created by the media making a chemical sound dangerous. It is important to look at all the information and then decide what is credible and what is based on scientific studies. Becoming “smart” consumers is a very important goal for our science students. It seems to me that there are probably more dangerous problems society should worry about than azodicarbonamide in their morning toast.

References (all references retrieved in September 2014)