METHYL TERTIARY-BUTYL ETHER - EVALUATION OF RISKS TO HEALTH FROM ENVIRONMENTAL EXPOSURE IN CANADA

''Methyl tertiary-butyl ether'' (MTBE) is included on the List of Priority Substances to be assessed under the Canadian Environmental Protection Act (CEPA). Based on the lack of identified relevant data, MTBE is considered ''unclassifiable with respect to carcinogenicity in humans''. Although few data on concentrations in environmental media were identified, based upon levels of MTBE in ambient air and water predicted by fugacity modelling and limited information on concentrations in shellfish, the estimated average intake of MTBE for the most exposed age group in the general population in Canada is much less (by approximately 45 000 times) than the tolerable daily intake derived on the basis of data from bioassays in animal species.