Lexikon

methyl tert-butyl ether, also known as methyl tertiary butyl ether and MTBE, is a chemical compound with molecular formula C₅H₁₂O. MTBE is a volatile, flammable and colorless liquid that is immiscible with water. MTBE is a gasoline additive (1-2%), used as an oxygenate to reduce carbon monoxide emission and to raise the octane number. MTBE quickly evaporates from open containers and surface water, so it is commonly found as a vapor in the air. It is much more soluble in water (5-7%) than the hydrocarbons. It has been found to easily pollute large quantities of groundwater e.g. around gas stations. MTBE may stick to particles in water, which will cause it to eventually settle to the bottom sediment. MTBE may be broken down quickly in the air by sunlight. It does not accumulates significantly in plants and animals. Breathing small amounts of MTBE for short periods may cause nose and throat irritation. Some people exposed to MTBE while pumping gasoline, driving their cars, or working in gas stations may have headaches, nausea, dizziness, and mental confusion. There is no evidence that MTBE causes cancer in humans. The EPA has issued guidelines recommending that drinking water levels of MTBE not exceed 3 mg/L. The American Conference of Governmental Industrial Hygienists (ACGIH) has recommended an exposure limit of 40 parts of MTBE per million parts of air (40 ppm) for an 8-hour workday, 40-hour workweek. (Source: Agency for Toxic Substances and Deseas Registry, ATSDR, www.atsdr.cdc.gov).