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 Prio rity Substances to be assessed under the Canadian Environmental Protec tion Act (CEPA). Based on the lack of identified relevant data, MTBE i s considered ''unclassifiable with respect to carcinogenicity in human s''. Although few data on concentrations in environmental media were i dentified, based upon levels of MTBE in ambient air and water predicte d by fugacity modelling and limited information on concentrations in s hellfish, the estimated average intake of MTBE for the most exposed ag e group in the general population in Canada is much less (by approxima tely 45 000 times) than the tolerable daily intake derived on the basi s of data from bioassays in animal species.