Methyl Tert-Butyl Ether (MTBE) was introduced as an oxygen enhancer for gasoline in 1973. MTBE has many advantages over methyl alcohol as an octane enhancer for gasoline. MTBE is especially important for refiners with limited reforming capacity, or for those who wish to replace toluene in gasoline outlets so that it can be used for petrochemicals. MTBE can be obtained as a by-product from the manufacture of propylene oxide by the Halcon process, whereby the tertiary butanol produced is dehydrated to isobutylene and used as the feedstock source. MTBE vapour is irritating to eyes, nose and throat, and at high concentrations rapidly leads to unconsciousness. MTBE should be stored in closed air-tight stainless steel or aluminium tanks under a nitrogen atmosphere in a well ventilated, cool area away from strong oxidizing materials. Clean-up staff and all workers handling MTBE should wear protective clothing, eye protection and a respirator.