Developmental toxicity of 2-butin-1,4-diol following oral administration to the rat.

Developmental toxicity of 2-butin-1,4-diol was determined in groups of 18-22 pregnant Wistar rats at dose levels of 10, 40 and 80 mg/kg bw/day administered by gavage from days 6 to 15 pc. At 80 mg/kg bw/day food consumption and maternal body weight were reduced and one dam died during the treatment period. At this dose level the incidence of affected fetuses per litter with accessory 14th ribs was increased. This variation is assessed as an embryotoxic effect resulting from non-specific stress on the dams. No teratogenic effects were caused by 2-butin-1,4-diol. The NOAEL on the maternal and the developing organism was 40 mg/kg bw/day.