The Bread Additive Banned Almost Everywhere but Your Cafeteria: A Student's Guide to Potassium Bromate

The dinner roll next to your cafeteria chili, the bun around your Friday burger, the crust under Tuesday's pizza. A lot of that bread rises faster, bakes cheaper, and looks fluffier because of a chemical called potassium bromate. It has been in American flour since the early 1900s, and most students eat it without ever knowing the name.

Here is the strange part. Potassium bromate is banned in the European Union, the United Kingdom, Canada, China, India, and Brazil. Those countries pulled it for the same reason: their food-safety agencies decided a possible cancer risk was not worth a taller loaf. The United States never followed. This post covers what potassium bromate does, why so much of the world said no, and why a handful of states are finally getting it off school trays.

What Potassium Bromate Actually Does

Potassium bromate is a dough conditioner, an oxidizing agent bakers add to flour to make gluten stronger. Stronger gluten traps more gas, so the bread rises higher, bakes faster, and comes out with a springy, uniform crumb. For a company making thousands of buns a day, that means cheaper and more consistent bread.

The theory is that during baking the bromate fully converts into bromide, a harmless byproduct. In practice that conversion is not always complete. If a bakery uses too much, bakes at too low a temperature, or underbakes the loaf, residual potassium bromate stays in the finished bread. That is the exact bread a student picks up in line.

Why Most of the World Banned It

In 1999 the International Agency for Research on Cancer classified potassium bromate as Group 2B, possibly carcinogenic to humans. Animal studies had linked it to tumors of the kidney, thyroid, and other organs. That was enough for regulators around the world to act.

The UK banned it in 1990. Canada, the EU, China, India, and Brazil followed. In most of the world, bromated flour simply is not sold anymore. The US Food and Drug Administration still allows it under federal rule 21 CFR 136, a rule written before much of the cancer data existed. It was grandfathered in and never seriously revisited.

How It Ends Up on a School Tray

Schools rarely bake from scratch. Most cafeteria bread, the rolls, buns, pizza crust, and breadsticks, arrives frozen or par-baked from large commercial suppliers. Those suppliers are exactly the kind of high-volume bakeries that historically leaned on bromate to keep production fast and loaves uniform.

Because the additive is legal at the federal level, a district in a state without its own ban has no automatic reason to screen for it. Unless someone reads the ingredient spec sheets and asks vendors directly, bromated bread can move through the supply chain and onto trays completely unnoticed.

The States Finally Moving

California went first. The California Food Safety Act, known as AB 418 and signed in 2023, bans potassium bromate along with Red Dye 3, brominated vegetable oil, and propylparaben from all food sold in the state starting January 1, 2027. Because California is such a large market, national brands are expected to reformulate rather than run two separate recipes, so the effect reaches far past state lines.

A few states went straight at schools. Utah's HB 402 bars schools from serving food that contains potassium bromate, and Arizona's HB 2164 does the same starting in the 2026 to 2027 school year. These school-specific laws matter because they close the gap for the exact group eating the most cafeteria bread every week.

What You Can Do

You do not need a chemistry degree to catch this one. On an ingredient list it shows up as potassium bromate, or hidden inside the words bromated flour or enriched bromated flour. Unbromated flour already exists and plenty of bakeries use it, so switching is realistic, not radical.

If you want to check your own cafeteria, ask your food-service director one question: do any of our bread products contain potassium bromate or bromated flour? Ask to see the ingredient spec sheets. If the answer is yes, you have a clear and winnable ask, because suppliers that make unbromated versions are already out there.

Potassium bromate is one of the clearest examples of a gap students can actually close. The science was settled enough that most of the planet acted decades ago, the recipe fix is simple, and what is missing in a lot of districts is just someone willing to ask the question.

If you want to bring that question to your own school, we can help you do it. Join us at cleanlunchcoalition.org/join-us and we will get you the checklist, the vendor questions, and students who have already won this fight in their own districts.