Methyl tert-butyl ether

Methyl tert-butyl ether (MTBE), also known as tert-butyl methyl ether, is an organic compound with a structural formula (CH₃)₃COCH₃. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. Primarily used as a fuel additive, MTBE is blended into gasoline to increase knock resistance and reduce unwanted emissions. However, due to groundwater contamination concerns and its offensive taste and smell, MTBE was banned in several U.S. states and gradually phased out of the country. Other countries that have banned MTBE include Japan and Canada, but its use has continued unhindered in much of the rest of the world, with China being its largest market.