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Is Azodicarbonamide in bread at Subway, McDonalds and other foods safe?


Azodicarbonamide, or azobisformamide, is a chemical compound being used as a food additive to bleach and increase the shelf life of breads, among other uses.  In 2014, it  appeared in the news when a consumer food blogger brought to attention that Subway, McDonald's and others were using it in their breads. The concern is with regard to the safety and effects of the compound on human health.  See this news from NBC News. On February 10, 2014, Senator Charles Schumer proposed that its use in food be banned.  Azodicarbonamide, is also used as a blowing agent in the rubber and plastics industries. The compound is used in the expansion of a wide range of polymers, including polyvinyl chloride, polyolefins, and natural and synthetic rubbers.

Is this compound allowed in food?

The Food and Drug Administration's guidelines on food and health safety for corporations permit the use of azodicarbonamide. Since the compound is allowed by the FDA as GRAS ("Generally Recognized as Safe"), any business can use it in their food and need not report its usage. In the United States, azodicarbonamide is allowed to be added to flour at levels up to 45 ppm. The United States ("21CFR172.806" Code of Federal Regulations. April 1, 2012.) and Canada permit the use of azodicarbonamide at levels up to 45 ppm.  In Australia and Europe the use of azodicarbonamide as a food additive is banned.

Are there health issues associated with Azodicarbonamide

In the UK, the Health and Safety Executive has identified azodicarbonamide as a respiratory sensitizer (a possible cause of asthma) in workplace settings and determined that containers of it should be labeled with "May cause sensitisation by inhalation.". The World Health Organization has linked azodicarbonamide to "respiratory issues, allergies and asthma" for individuals at workplaces where azodicarbonamide is manufactured or handled in raw form. The available data are restricted to these occupational environments. Exposure of the general public to azodicarbonamide could not be evaluated because of the lack of available data.

The World Health Organization says "No data on exposure of the general population could be identified. Concerning kinetics and metabolism, limited animal studies of exposures via inhalation and ingestion indicate that substantial quantities remain unabsorbed and are rapidly eliminated in the faeces. Studies further suggest that most systemic exposure is to the breakdown product, biurea, and not to the parent compound. Toxicity studies conducted in experimental mammals demonstrate low acute toxicity and no irritation of skin, eye, or respiratory tract. Although azodicarbonamide was found to be a mutagen in bacterial systems, the report found no evidence that this effect would occur in vivo. No adequate studies of carcinogenicity and reproductive toxicity, in animals or in humans, could be identified. Case reports and epidemiological studies in humans have produced abundant evidence that azodicarbonamide can induce asthma, other respiratory symptoms, and skin sensitization in exposed workers. Adverse effects on other systems have not been studied."

A Huffington Post article here presents more details on the studied and health effects.

Which restaurants are using this chemical in their foods?

In foods, it is used as a bleaching agent; it makes the bread whiter by reacting with the cartonene that occurs naturally in the flour. It also improves flour strength, which improves the dough’s ability to retain gas and makes the bread more elastic. It is also used in baked goods, rice, chewing gum, flour and grains. According to Huffington Post, Subway, McDonald's, Burger King, Kentucky Fried Chicken, Starbucks, Arby’s and Dunkin’ Donuts, and others use the substance as an ingredient.

NBC News reports the following specific uses:

What is being done about Azodicarbonamide?

Both Subway and McDonalds both announced that they planned to eliminate the use of the compound. Given the attention the press is giving the subject in February 2014, we can expect that the FDA or possibly Senate or House will move on this.

Details: What is Azodicarbonamide?

 Azodicarbonamide is a chemical compound with the molecular formula C2H4O2N4. It is a yellow to orange red, odorless, crystalline powder. As a food additive, it is known by the E number E927.

Azodicarbonamide is used as a food additive, a flour bleaching agent and improving agent. It reacts with moist flour as an oxidizing agent. Wikipedia tells us that the main reaction product is biurea, a derivative of urea, which is stable during baking. Secondary reaction products include semicarbazide and ethyl carbamate.

The principal use of azodicarbonamide is in the production of foamed plastics as an additive. The thermal decomposition of azodicarbonamide 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 article. Azodicarbonamide as used in plastics, synthetic leather and other uses can be pure or modified. This is important because modification affects the reaction temperatures. Pure azodicarbonamide generally reacts around 200 °C. In the plastic, leather and other industries, modified azodicarbonamide (average decomposition temperature 170 °C) contains additives that accelerate the reaction or react at lower temperatures. Azodicarbonamide as a blowing agent in plastics has been banned in Europe since August 2005 for the manufacture of plastic articles that are intended to come into direct contact with food. 


Do we really need this compound in bread? No!  Does it really even make much of a difference?  Probably not.

The CPSI (Center for Science in the Public Interest) says the FDA Should Ban Azodicarbonamide, saying "Two suspicious chemicals form when bread with azodicarbonamide is baked. One of the breakdown products is semicarbazide, which caused cancers of the lung and blood vessels in mice, but poses a negligible risk to humans. A second breakdown product, urethane, is a recognized carcinogen. When azodicarbonamide is used at its maximum allowable level, it leads to slightly increased levels of urethane in bread that pose a small risk to humans."

So what can you do to avoid aflatoxins?  

Avoid processed breads; stick to breads that are made with natural ingredients. Read the label!  Fast foods are usually not a good choice regardless.

References and external links

Most references are presented as links embedded in the text above.

1. Smith, Jim (2011-06-20). Food Additives Databook. Wiley-Blackwell. p. 548. ISBN 978-1405195430.

2. CNN, Subway

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This page was updated on 1-Apr-2016