Teratologic evaluation of styrene given to rats and rabbits by inhalation or by gavage.

Pregnant Sprague-Dawley rats and New Zealand white rabbits inhaled 0, 300 or 600 ppm of styrene 7 h/day from days 6 through 15 (rats) and 6 through 18 (rabbits) of gestation. Additional groups of rats were given styrene by gavage at dose levels of 0, 90 or 150 mg/kg twice daily (0, 180 or 300 mg/kg, respectively) from days 6 through 15 of gestation. Embryotoxicity and fetotoxicity were not evident in rats or rabbits inhaling styrene or in rats given the compound orally. Maternal effects (decreased body weight gain and decreased food consumption) were noted in all groups of rats given styrene but none were observed in rabbits. No teratogenic effect was detected in either species inhaling styrene or in rats given styrene by gavage.