Developmental effects of inhalation exposure to 2-bromopropane in rats.

2-Bromopropane (2-BP), known as a reproductive and hematopoietic toxicant in humans, was assessed for developmental toxicity. Sprague-Dawley rats were exposed by inhalation to 2-BP at a concentration of 0 (control), 125, 250, 500, or 1000 ppm for 6 h per day, 7 days per week during 2 weeks of the pre-mating period, during the mating period until copulation and during the period of gestation days 0-19. After parturition, dams were allowed to breast feed their pups until postnatal day 4. 2-BP exposure resulted in no signs of maternal toxicity as assessed by clinical observations and body weight gain. On the other hand, the inhalation exposure to 1000 ppm markedly decreased the number of pups born, although the number of implantations did not decrease. No effect of 2-BP on pups weights or survival until postnatal day 4 was found. It was found that the repeated inhalation exposure of rats to 1000 ppm 2-BP induced fetal lethality during the post-implantation period.