Azodicarbonamide vs Mineral Oil: which is worse?

What is Azodicarbonamide?

Azodicarbonamide (ADA) is a synthetic chemical used in the food industry as a flour bleaching agent and dough conditioner, and industrially as a blowing agent in foam rubber and plastic production. Its chemical formula is C2H4N4O2. When it reacts with water or heat, it breaks down into biurea (primary product) and semicarbazide (SEM).

What is Mineral Oil?

Mineral oil (E905) is a refined petroleum product used as a food-grade lubricant, coating agent, and glazing agent in food processing and production. Food-grade mineral oil is a highly refined grade of petroleum distillate with specifications limiting impurities. It differs from pharmaceutical-grade (Vaseline) and cosmetic-grade mineral oils in refinement level.

Documented risks

Azodicarbonamide: ADA's primary food safety concern is its breakdown to semicarbazide (SEM) during baking. In a 2002 study, SEM was found to increase the incidence of vascular tumors in female mice at high doses. This single animal finding was sufficient under the EU's precautionary principle to ban ADA in food use in 2005. The FDA conducted a comprehensive SEM exposure assessment in 2016, concluding that US population exposure to SEM from ADA-treated bread is many orders of magnitude below doses showing tumor effects in rodents and does not warrant regulatory change. This reflects the FDA's risk-based approach. Urethane (ethyl carbamate) is another potentially harmful breakdown product of ADA. Urethane is classified as an IARC Group 2A probable human carcinogen. Small amounts of urethane can form from SEM in fermented or alcohol-containing environments. The 2014 'yoga mat chemical' controversy highlighted ADA's dual use: it is the same chemical used as a blowing agent in foam rubber and plastic manufacturing — including yoga mats. Consumer advocacy blogger Vani Hari's 'Food Babe' campaign led over 50,000 people to petition Subway, which voluntarily removed ADA from its bread in 2014. The dual industrial-food use raised public concern even though ADA's behavior in each context is chemically different. From occupational health: workers exposed to ADA powder in bakery or plastic manufacturing settings can develop occupational asthma. WHO recognizes ADA as a respiratory sensitizer in occupational settings, though dietary exposure through bread is fundamentally different from inhalation exposure.

Mineral Oil: EFSA has raised significant concerns about mineral oil hydrocarbons (MOH) contamination in food through two pathways: (1) deliberate food-grade mineral oil use in coatings and processing, and (2) migration from recycled paper and cardboard food packaging into food. MOH comprises two types: mineral oil saturated hydrocarbons (MOSH), which accumulate in human adipose tissue, liver, and spleen, and mineral oil aromatic hydrocarbons (MOAH), which include polycyclic aromatic hydrocarbons (PAHs) that are potentially carcinogenic. A 2011 Swiss study found mineral oil hydrocarbons in human liver and spleen samples from autopsy, demonstrating real bioaccumulation. EFSA's 2023 preliminary opinion identified MOAH contamination in food as a safety concern that cannot be dismissed, recommending ALARA (as low as reasonably achievable) minimization. Untreated and mildly treated mineral oils are IARC Group 1 human carcinogens for occupational inhalation. Highly refined food-grade mineral oil (E905) is not classified as a direct carcinogen, but MOAH contamination in even food-grade mineral oil is an ongoing concern.