Methyl tert-butyl ether (MTBE) (IUPAC: 2-methoxy-2-methylpropane; CAS No. 1634‑04‑4) is a colorless, volatile, flammable liquid (bp ~55 °C, mp ~–109 °C). Slightly soluble in water (~26 g/L at 20 °C), miscible with organic solvents, used primarily as a fuel oxygenate and industrial solvent