What Is Azodicarbonamide?
Azodicarbonamide, or ADA, is used in flour. The FDA's regulation, 21 CFR 172.806, permits it as an aging and bleaching ingredient in cereal flour at no more than 2.05 grams per 100 pounds of flour, which is 45 parts per million.
It does not survive baking intact. The FDA says ADA completely breaks down during bread making to form other chemicals, one of which is semicarbazide, or SEM, and that at high levels SEM has been shown to increase tumors when fed to female mice but not male mice or rats of either sex, at levels far above estimated human exposure from ADA-treated flour or bread. On a page last updated in 2018, the FDA says it is not recommending that consumers change their diets because of ADA or SEM and considers ADA a safe food additive at the levels its regulations specify. A 1999 WHO assessment noted data showing ethyl carbamate forms in bread and beer after azodicarbonamide is added, and said general public exposure could not be evaluated for lack of data.
The FDA is taking another look. In a May 13, 2026 Federal Register request for information, it said it is conducting a post-market assessment of the safety of ADA in food and will use what it receives to determine whether ADA remains safe under its current conditions of use in food and as a food contact substance.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Regulatory filingUnder 21 CFR 172.806, azodicarbonamide may be used as an aging and bleaching ingredient in cereal flour at no more than 2.05 grams per 100 pounds of flour, or 45 parts per million. US FDA, 21 CFR 172.806 (eCFR) ↗
- Government sourceThe FDA says it conducted a comprehensive exposure assessment in 2016 of semicarbazide, a breakdown chemical that forms from azodicarbonamide during bread making. US FDA ↗
- Government sourceThe FDA says at high levels semicarbazide has been shown to increase tumors in female mice but not male mice or either sex of rat, at levels far exceeding estimated human exposure from ADA-treated flour or bread. US FDA ↗
- Government sourceThe FDA says it is not recommending that consumers change their diets because of ADA or SEM, and considers ADA a safe food additive at the purposes and levels its regulations specify. US FDA ↗
- Regulatory filingIn a May 13, 2026 Federal Register request for information, the FDA said it is conducting a post-market assessment of ADA's safety to determine if it remains safe under current conditions of use in food and food contact. US FDA, Federal Register ↗
- Government sourceA 1999 WHO assessment says data indicate ethyl carbamate forms in bread and beer after azodicarbonamide is added, and that general public exposure to azodicarbonamide could not be evaluated for lack of data. World Health Organization, IPCS INCHEM ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.