MTBE, or methyl tertiary butyl ether, is an oxygenate commonly used in gasoline in America, Europe, and other countries throughout the world. It is a compound created by the chemical reaction of methanol and isobutylene that is added to gasoline because of its high octane level, allowing gasoline to reach the required octane levels and still include a gasoline component. In addition, because it is an oxygenate, MTBE helps gasoline more fully combust, which increases performance and reduces the amount of harmful pollutants such as CO, VOCs, NOx, and particulates released into the atmosphere from automobile exhaust [EFOA]. However, opposition has recently arisen against the use of MTBE in gasoline.
Every underground gas tank eventually leaks, and the gasoline is soaked up by the surrounding ground. MTBE is not soluble in water; therefore, when the gasoline leaks out of the tank, the MTBE pollutes the ground water (well water), and eventually the surface water also. In addition, though MTBE reduces the amount of most pollutants released from automobiles, it also produces a harmful pollutant, formaldehyde, when combusted [CECA]. Even worse, a study performed by a medical researcher from the University of Pennsylvania, shows that MTBE may be the cause of a seventeen percent increase in asthma among kindergarten students since it has been utilized in gasoline. The study also shows that MTBE has failed to improve smog levels in the years it has been in use [Jones].
Therefore, is MTBE good or bad? It is still early to give a definite answer, however the banning of MTBE in many states in the US in exchange for its most common alternative, ethanol, shows signs that MTBE is doing more harm than help. To be fair, if more strict legislation were to be passed to force gas stations to maintain leak free tanks, much of MTBE’s pollutant problems would be solved.