e MAK Collection for Occupational Health and Safety 2018, Vol 3, No 1 295 1-Chloro-2,3-epoxypropane (Epichlorohydrin) BAT Value Documentation T. Göen 1 , M. Bader 2 , H. Drexler 3, * , A. Hartwig 4, * , MAK Commission 5, * DOI: 10.1002/3527600418.bb10689e2318 Abstract e German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated EKA (exposure equivalents for carcinogenic substances) for epichlorohydrin (CAS-No 106-89-8) in 2017. Available publications are described in detail. In rodents, epichlorohydrin induces malignant lymphomas, hyperplasias, forestomach papillomas and carci- nomas, subcutaneous fibromas and lung and pituitary tumours. Epichlorohydrin was classified in category 2 for carcinogenic substances. e substance can easily pass through the skin, so biological monitoring is indi- cated for a valid individual risk assessment. In several biomonitoring studies the mercapturic acids derivatives N-acetyl-S-(3-chloro-2-hydroxypropyl)-L- cysteine (CHPMA) and N-acetyl-S-(2,3-dihydroxypropyl)-L-cysteine (DHPMA) in urine as well as the hemo- globin adducts N-(3-chloro-2-hydroxypropyl)valine and N-(2,3-dihydroxypropyl)valine are suggested as bio- markers after epichlorohydrin exposure. Validated analytical procedures for their quantification are available. Data of a correlation of epichlorohydrin in the air and the CHPMA-excretion in urine were considered for the evaluation of exposure equivalents for carcinogenic substances. Sampling time is at the end of exposure or end of shift and after long term exposure at the end of the shift after several shifts. Keywords epichlorohydrin; 1-chloro-2,3-epoxypropane; 2-(chloromethyl)oxirane; gamma-chloropropylene oxide; (D,L)-alpha-epichlorohydrin; BAT value; EKA (exposure equivalents for carcinogenic substances); occupa- tional exposure; biological tolerance value; toxicity Author Information 1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, 91054, Erlangen, Schillerstraße 25 and 29, Germany 2 BASF SE, Corporate Health Management, FEH/CB, 67056 Ludwigshafen, Germany 3 Chair of the Working Group “Setting of reshold Limit Values in Biological Materials”, Deutsche For- schungsgemeinschaft, Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schillerstr. 25 and 29, 91054 Erlangen, Germany 4 Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Com- pounds in the Work Area, Deutsche Forschungsgemeinschaft, Department of Food Chemistry and Toxicol- ogy, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Germany 5 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany * Email: H. Drexler (hans.drexler@fau.de), A. Hartwig (andrea.hartwig@kit.edu), MAK Commission (arbeitsstoffkommission@dfg.de)