(Ethylendioxy)dimethanol
MAK-Begründung
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 Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) summarized and evaluated the data for (ethylenedioxy)dimethanol [3586-55-8] to derive an occupational exposure limit value (maximum concentration at the workplace, MAK value) considering all toxicological end points. Relevant studies were identified from a literature search and also unpublished study reports were used. (Ethylenedioxy)dimethanol is used as a biocide. It releases formaldehyde in aqueous solution. (Ethylenedioxy)dimethanol is not expected to occur in aerosol form because of its high vapour pressure. The substance is irritating to the skin and corrosive to the eyes of rabbits. At a pH of 7.0 and 20 °C, a 1% (ethylenedioxy)dimethanol solution has a hydrolysis half-life of 6 minutes. It can therefore be assumed that (ethylenedioxy)dimethanol hydrolyses to formaldehyde upon impaction in the respiratory tract. Based on the worst-case, the release of two formaldehyde molecules per molecule of (ethylenedioxy)dimethanol in the respiratory tract, a MAK value of 0.15 ml/m3 has been derived for (ethylenedioxy)dimethanol in analogy to the MAK value of formaldehyde of 0.3 ml/m3. Peak Limitation Category I has been assigned with an excursion factor of 2 in analogy to the classifications made for formaldehyde. Formaldehyde is classified in Carcinogen Category 4 because it causes nasal tumours at concentrations that exceed the detoxification capacity of that tissue. Studies investigating the carcinogenicity and germ cell mutagenicity of (ethylenedioxy)dimethanol are not available. Thus, in analogy to the classifications made for formaldehyde, the substance has been assigned to Carcinogen Category 4 and Germ Cell Mutagenicity Category 5. In rats, the NOAEC for the developmental toxicity of formaldehyde is 10 mg/m3 and the NOAEL of ethylene glycol, a hydrolysis product of (ethylenedioxy)dimethanol, is 200 mg/kg body weight. As no teratogenicity was observed and the margins between the NOAELs and the MAK value are sufficiently large, (ethylenedioxy)dimethanol has been assigned to Pregnancy Risk Group C. Skin contact is expected to make a relatively minor contribution to systemic toxicity. The available data show no evidence of sensitization.
