Chlorobutanol hemihydrate (Chlorbutol hemihydrate) is an orally toxic preservative with antimicrobial activity that inhibits Gram-positive and Gram-negative bacteria and fungi, inhibits the aggregation and release of human platelets in vitro, and is commonly used in cosmetics.

The high dose was set at 100 mg/kg/day and the medium, medium-low, and low doses were set at 50 mg/kg/day, 25 mg/kg/day, and 12.5 mg/kg/day, respectively, in a 28-day repeated-dose toxicity study by gavage.There was no significant change in body weight in the repeated-dose toxicity study.100 mg/kg/day The relative weights of liver and kidney were significantly increased in both sexes in the dose group.[1]