The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the developmental toxicity of acetone. Available unpublished study reports and publications are described in detail. The maximum concentration at the work place (MAK value) of acetone is 500 ml/m3, based on the irritant effect and the state of health of volunteers.
In a development toxicity study after inhalation exposure no teratogenic effects were found in the mouse up to 6600 ml/m3. The diversity of malformations was increased at 11 000 ml/m3 in the rat, and there was a linear trend for variations of asymmetric sternebrae and delayed ossifications of the sternum. Reduced foetal weights were found in both rats and mice. The NOAEC for developmental toxicity in rats and mice is 2200 ml/m3; the NAEC (no adverse effect concentration) could be even higher than 2200 ml/m3. As a greater diversity of malformations was observed in rat pups at concentrations that caused only slight maternal toxicity, and only a four‐fold margin lies between the NOAEC for developmental toxicity and the MAK value of 500 ml/m3, damage to the embryo or foetus cannot be excluded after exposure to concentrations at the level of 500 ml/m3 and acetone is assigned to Pregnancy Risk Group B.
In view of the NOAEC for developmental toxicity of 2200 ml/m3, prenatal toxicity is not to be expected at acetone concentrations of about 200 ml/m3 or below, corresponding to the definition of Pregnancy Risk Group C.