Low concentrations dissociate completely to hydrogen and bromate while high concentrations decompose to form bromine. Ozone can form the suspected carcinogen bromate in source water with high bromide concentrations. Sodium bromate is produced by passing bromine into a solution of sodium carbonate. Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking. Potassium bromate is produced when bromine is passed through a hot solution of potassium hydroxide. EPA has issued standards for bromate, chlorite, haloacetic acids and trihalomethanes. In theory, electrolysis of calcium bromide solution will also yield calcium bromate. Photoactivation (sunlight exposure) will encourage liquid or gaseous bromine to generate bromate in bromide-containing water. IBX is prepared from 2-iodobenzoic acid, potassium bromate, and sulfuric acid. Potassium bromate acts more directly or with fewer chemical conversion steps than ascorbic acid. Diperiodatonickelate anions in alkaline solution can oxidise bromate to perbromate. Adding carbon black also prevents the formation of bromate, a suspected human carcinogen. The bromate anion, BrO, is a bromine-based oxoanion. Bromic acid is the product of a reaction of barium bromate and sulfuric acid. Today, perbromates are produced by the oxidation of alkaline bromate solutions by fluorine gas.