Potassium bromate is typically used in the United States as a flour improver (E number E924). It acts to strengthen the dough and to allow higher rising. However, if too much is added, or if the bread is not baked long enough or not at a high enough temperature, then a residual amount will remain, which may be harmful if consumed.
In the United States of America, it has not been banned. The FDA sanctioned the use of bromate before the Delaney clause of the Food, Drug, and Cosmetic Act—which bans potentially carcinogenic substances— went into effect in 1958. But since 1991 the FDA has urged bakers to voluntarily stop using it. In California a warning label is required when bromated flour is used.[9] - https://en.wikipedia.org/wiki/Potassium_bromate
Flour sold by the King Arthur Flour company has never contained bromate for all of the reasons listed above. If you are a baker who has never used bromated flour then you have nothing to worry about. If you are a baker currently using bromated flours and would like to switch you will have to make some slight adjustments to your mixing process, but in our view the effort is worth it as you will be able to provide your employees a safer working environment, and your customers with a healthier product.
https://www.kingarthurflour.com/professional/bromate.html
I just wrote to Pillsbury as I couldn’t find the answer on their website. Will advise their response.