Clearing the air: Using scientific information to regulate reformulated fuels

The gasoline oxygenate MTBE (methyl tert-butyl ether) was widely adopted ac ross the United States in the 1990s as a key component of federally mandate d oxygenated and reformulated fuels. The regulations implementing statutory mandates for oxygenated fuels were promulgated without a comprehensive eva luation of the environmental or health consequences of using MTBE or other oxygenates in such large quantities. Policymakers only belatedly realized t he environmental ramifications of increased levels of MTBE in gasoline, esp ecially groundwater contamination resulting from leaking fuel tanks. The po licy process that led to MTBE's predominance was flawed, since no systemati c attempt was made a priori to evaluate multimedia implications of MTBE's w idespread use. The history of MTBE in the United States illustrates several typical, but problematic, features of environmental policymaking. It revea ls how the scale of chemical usage directly impacts actual and perceived en vironmental effects. It highlights how institutional factors constrain poli cymakers through statutory mandates, regulatory agency organizational struc tures, and the strong influence exerted by political-economic actors even i n supposedly "technical" debates. Finally, the MTBE case reveals barriers t o effective scientific and technical communications among policymakers, reg ulated industries, special-interest groups, and the public.