Di‐n‐butylphthalat
MAK-Begründung, Nachtrag
Andrea Hartwig1 (Vorsitz der Ständigen Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxikologie, Karlsruher Institut für Technologie (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Deutschland
2 Ständige Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Deutschland
Abstract
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 52 mg/kg body weight and day, the lowest dose, could be derived for foetotoxicity and decreased birth weight in the male animals. 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 1410 mg/kg body weight and day could be derived for foetotoxicity and decreased number of live pups. The NOAEL/LOAEL for developmental toxicity and foetotoxicity can be scaled to concentrations of 32/107 and 84/252 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 observed, and the classification in Pregnancy Risk Group C is confirmed.
