ALSOFOUNDINPotassium Bromate (Bromated flour)
Banned AbroadBanned in the EU, UK, Canada, and China. Still in US flour. Also listed on labels as E924, Bromated flour, Bromate.
E-number: E924
What it is
A flour 'improver' — an oxidizing agent added to bread flour to strengthen dough, boost the rise, and whiten the crumb. On labels it hides behind one word: 'bromated.'
Why it's in food
It makes industrial baking forgiving: stronger gluten, taller loaves, consistent texture on fast production lines. The theory is that it converts to harmless bromide when bread is fully baked — the fight is over the word 'fully.'
US vs EU status
United States
Never banned federally. The FDA asked bakers to stop voluntarily back in 1991 — and left it at that. California requires a Prop 65 warning and, in its 2023 food safety law, banned potassium bromate outright statewide starting January 2027. Many big bakers dropped it years ago; it survives in some flours, breads, and dough from smaller operations. The label tell is 'bromated flour.'
European Union
Gone since 1990, after the WHO's cancer agency track led to a Group 2B 'possible carcinogen' listing based on kidney and thyroid tumors in rats. The UK, Canada, China, India, Brazil, and Nigeria followed — a ban that now spans five continents. The rest of the world strengthens dough with alternatives like ascorbic acid: vitamin C.
Common products
- Some commercial breads, rolls, and buns
- Bagged flour labeled 'bromated'
- Pizza dough and bagels from shops using bromated flour
- Some flour tortillas
- Anything from a bakery supply chain that hasn't switched
Cleaner swaps
- Unbromated flour — most major US brands now are
- Breads made with ascorbic acid (vitamin C) as the improver
- Malted barley flour formulas
Case note
The rest of the world strengthens bread with vitamin C. America still allows the additive that gave rats tumors, on the theory that it bakes away if everything goes right. When the fix costs pennies and five continents already switched, the open question in this file isn't scientific — it's what exactly is being defended.
FAQ
Why is potassium bromate banned in so many countries?
Because feeding it to rats produced kidney and thyroid tumors, earning it a 'possibly carcinogenic to humans' classification in 1999. Most regulators applied a simple test: when a bread additive has that file and a vitamin-C substitute costs pennies, why permit any of it? The EU, UK, Canada, China, India, Brazil, and Nigeria all reached that answer. The US didn't.
Doesn't it bake out of the bread?
That's the official theory — properly baked, bromate converts to harmless bromide. In practice, testing has found bromate residues in finished bread, especially when loaves are underbaked, rushed, or overdosed. The ban countries decided a safety story that depends on every industrial oven doing everything right isn't a safety story.
How do I avoid it in the US?
Read the flour line: 'bromated flour' or 'potassium bromate' is the tell, and its absence usually means you're clear — most major brands quietly reformulated after 1991. The blind spots are unlabeled settings: pizza shops, bagel shops, and bakeries, where you'd have to ask what flour they buy.
Is the US doing anything about it?
Slowly. The FDA's 1991 voluntary request was the last federal move. Since then: California listed it under Prop 65, then banned it statewide effective 2027, and advocacy petitions for a federal ban are pending. As with Red 3, the states are moving first and daring the FDA to catch up.
How the FDA decides what reaches your table and your medicine cabinet — and how it learned to decide.
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