Maleinsäureanhydrid [MAK Value Documentation in German language, 2018]

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated maleic anhydride [ 108‐31‐6 ], considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. Maleic anhydride is an irritant to the upper respiratory tract. A LOAEC of 0.27 ml/m 3 for nasal and ocular irritation was obtained from a 6‐month inhalation study in rats, hamsters and monkeys. Since 2014 the Commission uses an empirical approach to set the maximum concentration at the workplace (MAK value) for substances with critical effects on the upper respiratory tract or the eyes. Based on this, the MAK value for maleic anhydride is set at 0.02 ml/m 3 (0.081 mg/m 3 ). Since the critical effect of maleic anhydride is local, Peak Limitation Category I with an excursion factor of 1 is confirmed and a momentary value of 0.05 ml/m 3 is set. Damage to the embryo or foetus is unlikely when the MAK value is not exceeded and maleic anhydride remains assigned to Pregnancy Risk Group C. Maleic anhydride is not genotoxic in vitro and in vivo. No increased tumour incidence was observed in a chronic feeding study in rats. Skin contact is not expected to contribute significantly to systemic toxicity. In humans airway sensitization is observed. There are positive results of contact sensitization in mice and guinea pigs. Maleic anhydride continues to be designated with “Sah”.