Reproductive and developmental toxicity studies of toluene. I. Teratogenicity study of inhalation exposure in pregnant rats.

Toluene is a widely used solvent in industry which is the subject of abuse among the younger generation. A teratogenicity study of toluene by inhalation exposure was carried out in Sprague-Dawley rats and the effects on dams, fetuses and offspring were assessed. Pregnant females were exposed to 600 or 2000 ppm toluene for 6 h/day from day 7 to day 17 of pregnancy. The control group inhaled conditioned clean air under the same exposure conditions. Maternal exposure to 2000 ppm toluene caused significant toxic effects such as body weight suppression of dams and offspring, high fetal mortality and embryonic growth retardation, but no external, internal or skeletal anomalies were observed in the fetuses of any treated group. In addition, there were no differences in the results of pre- and postweaning behavioral tests of the offspring. However, no toxic or teratogenic changes which could be related to toluene exposure were apparent in the 600 ppm group. Further studies are warranted with toluene at higher concentrations applied during the period of organogenesis.