Final Report on the Safety Assessment of Sodium Bromate and Potassium Bromate

Abstract

Sodium Bromate and Potassium Bromate are inorganic salts that act as oxidizing agents. Whereas there are currently no reported uses of Potassium Bromate, Sodium Bromate is used in permanent waves and related hair care products. No current data were available to indicate the concentrations at which this ingredient is used. Bromate was poorly absorbed, if at all, through the skin in several in vivo and in vitro studies. The oral median lethal dose of Potassium Bromate in rats was 200–400 mg/kg. A guinea pig sensitization study suggested at most a mild sensitizing potential for Sodium Bromate. Potassium Bromate was found to be mutagenic in a mammalian cell assay and in one of three bacterial strains tested. Potassium Bromate produced a dose-dependent increase in renal neoplasms in an oral feeding study in rats. A two-stage, 26-week carcinogenesis study in rats suggested that Potassium Bromate was both a tumor promoter and a tumor initiator. Renal cell tumors, of a type not seen in controls, were seen in male golden hamsters administered Potassium Bromate in drinking water. Potassium Bromate applied to the skin of mice or injected subcutaneously into newborn mice or rats, however, was noncarci-nogenic. The high reactivity/poor skin absorption of these oxidizing agents was considered a likely explanation for the difference between the results seen with different routes of exposure. Based on the test concentrations reported, it is concluded that Sodium Bromate and Potassium Bromate are safe in cosmetic permanent wave formulations at concentrations not to exceed 10.17%, measured as Sodium Bromate.