Potassium Bromate
Also known as: E924, E924a
Potassium bromate is classified by IARC as Group 2B (possibly carcinogenic to humans) based on animal studies showing renal, thyroid, and peritoneal tumors. It is banned as a food additive in the EU, UK, Canada, China, India, Brazil, and many other jurisdictions; the U.S.
What it is
Potassium bromate (E924), an inorganic oxidizing agent (KBrO3) added to flour to strengthen dough and improve loaf volume.
Flour treatment / dough conditioner / oxidizing agent.
Why it's flagged
- possible human carcinogen (IARC 2B)
- renal tumors in animal studies
- thyroid follicular tumors
What regulators actually say
"Potassium bromate is possibly carcinogenic to humans (Group 2B). Potassium bromate produced renal cell tumours, mesotheliomas of the peritoneum and follicular cell tumours of the thyroid in rats."
Regulatory status
United States — FDA
Permitted as a flour-treating agent under 21 CFR 136.110 with use limits, but listed as 'reasonably anticipated to be a human carcinogen'; banned in California (effective 2027 under AB 2316/Prop 65).
European Union — EFSA
Banned in the EU; not authorized as a food additive (Regulation (EC) No 1333/2008 Annex II).
Scan it before you buy it
Get Ube on iOS or Android — point at any barcode, see what's actually in there.
Get the app