Assessment of the reproductive toxicology of bromochlorodifluoromethane (BCF, halon 1211) in the rat

The effect of bromochlorodifluoromethane (BCF) on reproduction in the rat has been investigated in two studies. Pregnant female rats were exposed by inhalation to 1000, 10,000, or 50,000 ppm BCF for six hours a day on days six to 15 of gestation (day of mating = day 0). Exposure to 50,000 ppm BCF caused a reduction in maternal weight gain over the exposure period but there was no evidence of either teratogenicity or embryo/fetotoxicity at any concentration. In a study designed to assess the potential effect of BCF during a complete reproductive cycle male and female rats were exposed to 5000 ppm or 25,000 ppm BCF for six hours a day for five days a week for 10 weeks (males) or three weeks (females) before mating. Exposure to BCF continued during mating and up to day 20 of gestation for half the females which were subsequently allowed to litter and the development of their offspring monitored. The remaining females were removed from exposure to BCF after mating and killed on day 20 of gestation for examination of their uterine contents. There were no effects on adult fertility, pup numbers, survival, or pup development. It was concluded that BCF had no reproductive toxicity potential in the rat.