Verification on the Developmental Toxicity of Short-term Exposure to Phenol in Rats

Objective To verify the health advisory for short-term exposure to phenol.Methods The method of this validation experiment was the same as the US Environmental Protection Agency(EPA) methodology for toxicology experiments used to determine phenol drinking water equivalent level(DWEL). Pregnant female Sprague-Dawley rats were administered phenol in distilled water by gavage at daily doses of 15, 30, 60, 120, and 240 mg/kg body weight(b.w.)from implantation(the 6 th day post-mating) to the day prior to the scheduled caesarean section(the20 th day of pregnancy). The following information was recorded: general behavior; body weight;number of corpus luteum, live birth, fetus, stillbirth, and implantation; fetal gender; body weight; body length; tail length; and abnormalities and pathomorphological changes in the dams.Results In the 60 mg/kg b.w. dose group, the mortality of pregnant rats increased with increasing doses, suggesting maternal toxicity. Fetal and placental weights decreased as phenol dose increased from30 mg/kg b.w., and were significantly different compared those in the vehicle control group, which suggested developmental toxicity in the fetuses. However, the phenol-exposed groups showed no significant change in other parameters compared with the vehicle control group(P > 0.05).Conclusion Despite using the same method as the US EPA, a different NOEAL of 15 mg/(kg·d) was obtained in this study.