The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings may not have been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009. For more information, see the Explanation of Levels of Evidence for Developmental Toxicity. The findings and conclusions for this study should not be construed to represent the views of NTP or the U.S. Government.
Phenol, a widely used industrial chemical and antimicrobial agent, was evaluated for toxic and teratogenic effects in timed-pregnant CD rats. Phenol (0, 30, 60, or 120 mg/kg/day, po) in distilled water was administered in a volume of 5 ml/kg of body weight on gestational days 6-15. Females were weighed daily during treatment and observed for clinical signs of toxicity. A total of 20-22 females/group were confirmed to be pregnant at sacrifice on gd 20. The gravid uterus of each dam was weighed and the uterine contents examined for implantation sites and fetuses (live, dead or resorbed). Each live fetus was weighed and examined for external, visceral and skeletal malformations.
Dams failed to exhibit any statistically significant signs of maternal toxicity, nor were any clinical symptoms clearly related to phenol treatment. Examination of gravid uteri at term (gd 20) revealed a significant increase in the proportion of litters with resorption sites for the low- and mid-dose groups, but not for the high-dose group. Average live fetal body weight per litter was decreased in a dose-related manner, with high-dose fetuses significantly below controls. No evidence for a teratogenic effect of phenol in CD rats was observed under the conditions of the present study.