Developmental toxicity study of piperonyl butoxide in CD rats.

Piperonyl butoxide was administered to pregnant rats by gavage at a level of 0 (control), 630, 1065, and 1800 mg/kg bw on days 11-12 of gestation. The animals were killed on day 20 of gestation. Average maternal body weight gain (gestational days 11-20) was significantly reduced in the 1065 and 1800 mg/kg bw groups. Total resorption rate was significantly increased in the 1800 mg/kg bw group and those effects were significantly dose-related. The average fetal body weight of each sex was significantly reduced in the 1065 and 1800 mg/kg bw groups. External limb deformity (oligodactyly, syndactyly, and polydactyly) was significantly increased in the 1065 and 1800 mg/kg bw groups in a dose-related manner. The dose levels of piperonyl butoxide in the present study produced limb deformities in rats.