Azodicarbonamide, when exposed to heat (as in bread baking) degrades into semicarbazide, a known carcinogen that has been shown to cause tumors in animal studies. It is not permitted for use as a food additive in Europe due to the carcinogenicity and genotoxicity caused by semicarbazide which is created. EFSA has also banned it as a blowing agent in food contact materials since August 2005. When inhaled, azodicarbonamide has been linked to asthma and respiratory issues in people as well.