[Studies on the teratogenic potential of 2,2'-methylenebis (4-ethyl-6-tert-buthylphenol) in rats]

2,2'-Methylenebis (4-ethyl-6-tert-buthylphenol), an antioxidant, was given orally to pregnant Wistar rats by stomach intubation at the dose levels of 187, 375 or 750 mg/kg body weight during days 7 to 17 of gestation, and the effects of the compound on dams and fetal development were examined. In dams at the two higher doses of 375 and 750 mg/kg, toxic signs such as hair fluffing and diarrhoea were observed, and their body weight gain and food consumption were suppressed. Two dams which showed marked diarrhoea in the highest dose group of 750 mg/kg died. However, there was no evidence of fetal malformations attributable to the treatment of the compound in any of the dose group tested, though a slight increase in fetal death was found in the highest dose group. It is concluded that 2,2'-methylenebis (4-ethyl-6-tert-buthylphenol) has a weak lethal effect on fetal development but not a teratogenic effect in the rat.