Reproduction study of dimethylacetamide following inhalation in the rat

Groups of 10 male and 20 female Crl:CD(SD)BR rats were exposed to vapors of dimethylacetamide (DMAC) at concentrations of 0 (control), 30, 100, or 300 ppm. Exposures were conducted for 6 hr/day, 5 days/week for 10 weeks (prebreeding), then 7 days/week for 7 to 8 weeks (through breeding, gestation, and lactation). The exposure period was interrupted for female rats between gestation Day 21 and postpartum Day 4. No compound-related effects on body weight, survival, or clinical signs were detected in parental rats. Liver weight to body weight ratios were increased in groups where both males and females were exposed to 300 ppm but not in groups where only males or only females were exposed to 300 ppm. No significant differences were observed between control and test rats with respect to mating performance, fertility, length of gestation, progeny numbers, structure, and viability. At 21 days postpartum, pups derived from matings involving exposure of both sexes to 300 ppm or exposure of parental females to 300 ppm had lower body weights than did the controls. Gross pathologic examination of representative pups and evaluation of liver and gonad weight data did not reveal any DMAC-related changes. It is concluded that reproduction in rats was not altered by repeated inhalation exposure to up to 300 ppm DMAC.