Potassium bromate

Flour improver: White flour, bread and rolls.
This additive has long been used to increase the volume of bread and to produce bread with a fine crumb (the not-crust part of bread) structure. Most bromate rapidly breaks down to form innocuous bromide. However, bromate itself causes cancer in animals. The tiny amounts of bromate that may remain in bread pose a small risk to consumers. Bromate has been banned virtually worldwide except in Japan and the United States. It is rarely used in California because a cancer warning might be required on the label. In 1999, the Center for Science in the Public Interest petitioned the FDA to ban bromate. Since then, numerous millers and bakers have stopped using bromate. (Calcium bromate, which likely is toxicologically similar to potassium bromate, occasionally may be used.)