Methyl Tertiary Butyl Ether

Cas Number


Other Names

Methyl tertiary-butyl ether,

Methyl tert-butyl ether,

Methyl t-butyl ether,


tert-Butyl methyl ether,



The formula



Methyl Tertiary Butyl Ether (MTBE) is a gasoline additive. MTBE undergoes oxidative degradation in the presence of propane-oxidizing bacterial strains.

Physical and Chemical Properties
Physical state and appearance clear liquid
Odor Characteristic. (Strong.)
Molecular Weight 88.15 g/mole
Color Clear Colorless.
Boiling Point 55.2°C (131.4°F)
Melting Point -109°C (-164.2°F)
Specific Gravity 0.7405 (Water = 1)
Vapor Pressure 245 mm of Hg (@ 20°C)
Vapor Density 3.1 (Air = 1)
Volatility 100% (v/v).
Dispersion Properties See solubility in water, methanol, diethyl ether
Solubility Soluble in methanol, diethyl ether. Partially soluble in cold water
Assay (g.c) 98.0% min
Methanol 0.3% max
Diisobutylene 1.0% max
Triisobutylene 1.0% max
T-butyl alcohol 1.0% max
C4 C5 hydrocarbons 1.0% max
Water 500ppm max
Cu corrosion Pass

1. MTBE commonly known as oxygenates because they raise the oxygen content of gasoline is almost exclusively used as a fuel component in engine gasoline

2. It is also used: as an extraction solvent; in the manufacture of methyl amyl alcohol; and as a denaturant for ethyl alcohol