Di‐ n ‐butyl phthalate [MAK value documentation, 2017]

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the developmental toxicity of di‐n‐butyl phthalate. Available publications are described in detail. In prenatal developmental toxicity studies in rats, the most sensitive endpoint was altered morphometry (size and organization) of the seminiferous cords, the precursor of the seminiferous tubules, at 50 mg/kg body weight and day and above; the NOAEL was 30 mg/kg body weight and day. In rats, teratogenic effects like hypospadia and underdeveloped or absent epididymides were observed at 250 mg/kg KG body weight and day and above; the NOAEL was 100 mg/kg body weight and day. In a two‐generation reproduction toxicity study in rats, a LOAEL of 80 mg/kg body weight and day, the lowest dose, could be derived for foetotoxicity and decreased live pup weight at birth. In rats, the NOAEL for behavioural toxicity is 291 mg/kg body weight and day in male pups. From a one‐generation reproduction toxicity study in mice, a NOAEL of 420 mg/kg body weight and day could be derived for foetotoxicity and decreased number of live pups. The NOAELs and the LOAEL for developmental toxicity and foetotoxicity can be scaled to concentrations of 32, 107, 84 (LOAEL) and 252 mg/m3, respectively, at the workplace. Thus, damage to the embryo or foetus is unlikely when the MAK value of 0.58 mg/m3 is not exceeded, and the classification in Pregnancy Risk Group C is confirmed