what is methyl tertiary butyl ether (mtbe)
Methyl tert-butyl ether Methyl tert-butyl ether (also known as MTBE and 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[1] in water. It has a minty odor vaguely reminiscent of diethyl ether, leading to unpleasant taste and odor in water. MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial because of its contamination of groundwater and legislation favoring ethanol. However, worldwide production of MTBE has been constant owing to growth in Asian markets.[2]
Tetraethyllead In most industrialized countries, a phaseout of TEL from road vehicle fuels was completed by the early 2000s because of concerns over air and soil lead levels and the accumulative neurotoxicity of lead. The use of catalytic converters, mandated in the US for 1975 and newer model-year cars to meet tighter emissions regulations, started a gradual phase-out of leaded gasoline in the US.[5] The need for TEL was lessened by several advances in automotive engineering and petroleum chemistry. Safer methods for making higher octane blending stocks such as reformate and iso-octane reduced the need to rely on TEL, as did other antiknock additives of varying toxicity including metallic compounds such as MMT as well as oxygenates including MTBE, TAME, and ETBE.