Developmental toxicity of inhaled ethylene oxide in rats following short-duration exposure

The developmental toxicity of ethylene oxide (EtO) was examined in Sprague-Dawley rats following inhalation exposure during Days 6 to 15 of gestation. Two different exposure regimens were used: (1) exposure for 0.5 hr once a day to 0, 400, 800, or 1200 ppm EtO; or (2) exposure for 0.5 hr three times a day to 0, 200, or 400 ppm EtO or 0, 800, or 1200 ppm EtO. Repeated brief exposures (3 x 0.5 hr/day) to EtO caused fetal toxicity indicated by reduced fetal weight at 800 and 1200 ppm, and overt maternal toxicity manifested as reduced body weight gain at 1200 ppm. Neither embryolethality nor teratogenicity occurred following any exposure regimen.