The acute toxicity and metabolism of potassium bromate (KBrO3), used as a food additive and a neutralizer in permanent wave chemicals, were examined by oral administration (85, 159, 325 and 602 mg/kg) to male and female adult Wistar rats. The results obtained were as follows : 1. There was no death in the animal treated with KBrO3 in a dose of 85 mg/kg after 72 h of administration, but about 20% of the animals treated with KBrO3 in a dose of 159 mg/kg survived. The LD50 value of KBrO3 in rats was estimated to be 157 mg/kg. 2. After administration, KBrO3 was absorbed rapidly as bromate from the stomach and reduced partially in the gastric pouch, and about 95% of KBrO3 disappeared from the stomach in 30 min. 3. The trace amount of methemoglobin was detected in the blood of animals, but the presence of hemochromatosis were observed significantly on the kidney, spleen and liver. 4. Until 24 h after administration, about 13% of KBrO3 was excreted in the urine. Nevertheless, the residue of this bromate was not found in the kidney, spleen, liver and other organs. It was suggested that almost all KBrO3 disappeared in the target organ cells through metabolic reduction systems.
