© 1989 Oxford University Press
research-article |
Developmental Toxicity of 1,1,1-Trichloroethane in CD Rats1



*Chemistry and Life Sciences, Center for Life Sciences and Toxicology, Research Triangle Institute P.O. Box 12194, Research Triangle Park, North Carolina 27709-2194
National Toxicology Program, National Institute of Environmental Health Sciences Research Triangle Park, Norih Carolina 27709
Received September 16, 1988; accepted May 9, 1989
1,1,1 -Trichloroethane (TCEN), a major industrial and household solvent, was evaluated for pre- and postnatal developmental effects in SpragueDawley rats. This study was designed to assess the repeatability of a report (S. C. Dapson, D. E. Hutcheon, and D. Lehr, Teratology 29, 25 A, 1984) that indicated that 10 ppm TCEN in drinking water caused cardiac malformations in developing rats. In the present study, TCEN (97% pure) was administered in the drinking water at target concentrations of 3, 10, and 30 ppm, using 0.05% Tween 80 as an emulsifying agent Two control groups, one receiving deionized/filtered water and the other receiving a vehicle control solution containing 0.05% Tween 80 and 0.9 ppm 1,4-dioxane, a stabilizing agent found in the bulk chemical, were also included. Male and female breeders (more than 30 per group) were exposed to the control solutions or test compound for 14 consecutive days prior to cohabitation and for up to 13 days during the cohabitation phase. Sperm-positive females (2429 per group) continued to be exposed to these formulations during pregnancy and lactation to Postnatal Day (PND) 21. Parental animals exhibited a slight aversion to the 30-ppm drinking water during the premating exposure. No significant effect on reproductive competence of the parental animals or postnatal growth and development of the offspring to PND 21 was noted. A slight increase in mortality from implantation to PND 1, possibly due to high mortality in one litter, was observed in the 30-ppm dose group. There was no indication of an increase in the incidence of cardiac or other malformations in PND 21 pups. In summary, TCEN administered at 3, 10, and 30 ppm in the drinking water had no significant effect on the morphological development of CD rats,