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 triethanolamine [102‐71‐6], considering the endpoints respiratory tract irritation and developmental toxicity.
Critical effect of triethanolamine is respiratory tract irritation (focal larynx inflammation). The previous MAK value of 5 mg/m3 is based on 5‐day and 28‐day aerosol studies in rats with a LOAEC of 20 mg/m3. A benchmark calculation gives a BMDL05 of 14,1 mg/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. Based on this approach, a concentration of 4,7 mg/m3 for the work place air can be calculated from this BMDL05. Therefore the MAK value of 5 mg/m3 is retained.
As local effects are critical, Peak Limitation Category I is retained. At an excursion factor of 2, the allowable maximum concentration is still below the BMDL05.
NOAEL for fetotoxicity are 300 mg/kg bw and day in rats and 1125 mg/kg body weight and day in mice . Teratogenicity was not tested. Nevertheless, because the calculated margins between NOAEL and MAK value are very high, and alkylamines lack teratogenicity, there is no reason to fear damage to the embryo or foetus when the MAK value is observed. Therefore, triethanolamine is assigned to Pregnancy Risk Group C.