Teratologic evaluations of N,N-diethyl-m-toluamide (DEET) in rats and rabbits.

The potential for DEET to produce developmental toxicity was evaluated in Charles River CD rats and New Zealand White rabbits. Rats were administered undiluted DEET by gavage on Gestational Days (gd) 6-15 at dosage levels of 0, 125, 250, and 750 mg/kg/day. Rabbits were administered undiluted DEET by gavage on gd 6-18 at dosage levels of 0, 30, 100, and 325 mg/kg/day. Group sizes were 25 females per group for rats and 16 females per group for rabbits. Control rats and rabbits were administered corn oil at the same dosage volumes administered in the high-dose DEET groups. In rats, maternal toxicity in the form of clinical signs including two deaths and depressed body weight and food consumption was observed at the high-dose level of 750 mg/kg/day. Rat fetal body weights per litter also were reduced at 750 mg/kg/day. In rabbits, maternal toxicity in the form of depressed body weight and food consumption was observed at the high-dose level of 325 mg/kg/day. No maternal toxicity was observed at the low- or mid-dose groups for rats or rabbits. With the exception of the reduced fetal weights in rats at 750 mg/kg, there was no evidence of fetal toxicity, no effects on any of the gestational parameters, nor were there any treatment-related increases in external, visceral, or skeletal variations or malformations in the offspring from the rats and rabbits from these studies.