Methyl-Tertiary Butyl Ether, or MTBE, is a gasoline additive produced from isobutylene and methanol. It has been used in gasoline since 1973 to help boost octane levels as lead was phased-out of gasoline. Today, gasoline sold in many parts of the world contains MTBE to help achieve cleaner air and to provide higher octane as aromatics and lead continue to be eliminated from gasoline.

When fuel oxygenates, such as MTBE, are added to gasoline they help improve the combustion of gasoline thus reducing harmful smog and toxic air emissions. MTBE also enables refiners to reduce the use of other harmful gasoline compounds, such as benzene and other aromatics, while maintaining octane levels and fuel performance and extending the life of a barrel of oil.

Asia:
With a growing population and concern over air pollution in urban areas from increased vehicle traffic, Asian countries are increasingly examining cleaner gasoline as a way to improve air quality. As a result, because MTBE provides cost-effective pollution reduction while maintaining existing crude oil supply, overall demand for MTBE throughout the region is growing.

Europe:
According to the European Fuel Oxygenate Association, the MTBE demand in Europe today is approximately equal to the production capacity, i.e. around 3 million tonnes. In the last few years Europe was a net exporter of MTBE (either as a straight component or blended into gasoline), but the implementation of stricter gasoline quality requirements has recently increased the demand for alternative high octane blending components. The consumption of MTBE is expected to remain fairly stable in Europe over the next few years.

United States:
In 1995, the use of MTBE grew in the United States after the U.S. Congress passed the 1990 Clean Air Act Amendments (CAAA). Under the CAAA, Congress started the Reformulated Gasoline (RFG) program in January 1995 for those areas of the country that had the highest levels of air pollution. Among its cleaner-burning fuel specifications, refiners producing RFG were required to blend a minimum of 2% oxygen by weight. Refiners quickly found that the oxygenate MTBE provided more environmental benefits such as reductions of volatile organic compounds (VOCs) and nitrogen oxide (NOx) and other benefits including lower production costs than other oxygenates (i.e., ethanol). Today, use of MTBE in the United States is declining due to regulatory changes.