Beyond MTBE: Applying the Precautionary Principle to Gasoline Additives

Printed 1/2/2001 2 Based on an evaluation of the physicochemical and toxicological properties of Methyl tert-Butyl Ether (MTBE), as well as an ex post-facto cost and benefit analysis, it has become clear that there are less expensive and disruptive approaches to achieving the goals of the 1990 Clean Air Act Amendments with regards to gasoline-powered mobile sources. However, before jumping to the next blending component to improve combustion efficiency and reduce air emissions, we propose a thorough investigation of the properties of alternatives to MTBE, such as ethanol, toluene or alkylates. We conducted a preliminary cost/benefit analysis of the various alternative formulations based on the information available in California. We conclude that non-oxygenated reformulated gasoline presents the least cost for the same benefits. However, we should apply the Precautionary Principle and conduct an exhaustive research program to ensure that such widely used gasoline components are not persistent and that the toxicological or organoleptic properties are within acceptable bounds.