Methyl tert-butyl ether

MTBE(methyl tert-butyl ether)Methyl tert-butyl ether (also known as MTBE, tert-butyl methyl ether, tertiary butyl methyl ether and tBME) is anorganic compound with molecular 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 in the US and declining in use in part because of its occurrence in groundwater and legislation favoring ethanol. However, worldwide production of MTBE has been constant at about 18 million tons/y (2005) owing to growth in Asian markets which are less subject to ethanol subsidies

Methyl tert-butyl ether
Skeletal formula of MTBE
Ball-and-stick model of the MTBE molecule
IUPAC name

Other names

Methyl tertiary-butyl ether; Methyltert-butyl ether; Methyl t-butyl ether; MTBE; tert-Butyl methyl ether; tBME;tert-BuOMe
CAS Registry Number
1634-04-4 Yes
ChEBI CHEBI:27642 Yes
ChemSpider 14672 Yes
Jmol-3D images Image
KEGG C11344 Yes
PubChem 15413
Chemical formula
Molar mass 88.15 g·mol−1
Density 0.7404 g/cm³
Melting point −109 °C (−164 °F; 164 K)
Boiling point 55.2 °C (131.4 °F; 328.3 K)
Solubility in water
26 g/L (20 °C)[1]
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity (yellow): no hazard code Special hazards (white): no code

NFPA 704 four-colored diamond

Flash point −10 °C (14 °F; 263 K)
Except where otherwise noted, data are given for materials in their standard state(at 25 °C [77 °F], 100 kPa).