MAK Value Documentation for Phosphorus trichloride
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of phosphorus trichloride of 0.5 ml/m3, considering the endpoints local and systemic toxicity as well as developmental toxicity. Available publications are described in detail. As described in the previous evaluation of 2006, phosphorus trichloride is corrosive to eyes and skin and in a 28‐day‐inhalation‐study irritative to the respiratory tract of rats with a NOAEC of 3 ml/m3. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. According to this approach, a concentration of 0.17 ml/m3 for the work place air can be calculated from this study. Therefore, the MAK value is lowered to 0.1 ml/m3. The assignment to Peak Limitation Category I, because local effects are critical, and the excursion factor of 1 are confirmed. A developmental toxicity study with phosphorus trichloride in rats shows that damage for the embryo or foetus is unlikely if the MAK‐value is observed, and the assignment to Pregnancy Risk Group C is retained.