Di‐tert‐dodecyl pentasulfide / Di‐tert‐dodecyl polysulfide

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), the Pregnancy Risk Group and the absorption through the skin of di‐tert‐dodecyl pentasulfide [31565‐23‐8] and di‐tert‐dodecyl polysulfide [68583‐56‐2; 68425‐15‐0].The systemic toxicity is low and the substances are at most minimally irritating to skin and eye. Acidophilic globuli are present in the kidney of male rats in an oral 28‐day study at 50 mg/kg body weight and day, presumably resulting from an α2u‐globulin mediated kidney toxicity which, however, has not actually been proven. Based on this LOAEC the MAK value would be 10 mg/m3. However, the substances are poorly water‐soluble liquids and an accumulation in the lung is expected. Most of the di‐tert‐dodecyl pentasulfide and di‐tert‐dodecyl polysulfide molecule consists of hydrocarbon chains resulting in characteristics similar to severely refined mineral oil, for which a MAK value of 5 mg/m3 had been set as the respirable fraction (R) based on inhalation studies. Therefore, the MAK‐value for di‐tert‐dodecyl pentasulfide and di‐tert‐dodecyl polysulfide is also set at 5 mg/m3 R. Peak Limitation is designated as well by analogy with severely refined mineral oil with Category II and excursion factor of 4.New data on developmental toxicity are not available. As the MAK value is lowered, Pregnancy Risk Group C is retained. Skin contact is not expected to contribute significantly to systemic toxicity.