Clearing the air: Using scientific information to regulate reformulated fuels

The gasoline oxygenate MTBE (methyl tert-butyl ether) was widely adopted across the United States in the 1990s as a key component of federally mandated oxygenated and reformulated fuels. The regulations implementing statutory mandates for oxygenated fuels were promulgated without a comprehensive evaluation of the environmental or health consequences of using MTBE or other oxygenates in such large quantities. Policymakers only belatedly realized the environmental ramifications of increased levels of MTBE in gasoline, especially groundwater contamination resulting from leaking fuel tanks. The policy process that led to MTBE's predominance was flawed, since no systematic attempt was made a priori to evaluate multimedia implications of MTBE's widespread use. The history of MTBE in the United States illustrates several typical, but problematic, features of environmental policymaking. It reveals how the scale of chemical usage directly impacts actual and perceived environmental effects. It highlights how institutional factors constrain policymakers through statutory mandates, regulatory agency organizational structures, and the strong influence exerted by political-economic actors even in supposedly technical debates. Finally, the MTBE case reveals barriers to effective scientific and technical communications among policymakers, regulated industries, special-interest groups, and the public.