Mtbe Methyl Tertiary Butyl Ether

This book evaluates the risks to human health and the environment posed by exposure to methyl tertiary-butyl ether (MTBE). Used almost exclusively as a fuel additive, MTBE is blended with gasoline to provide both octane enhancement and an increase in oxygen content. MTBE currently numbers among the 50 chemicals produced in the highest volume worldwide. Production and use are expected to increase, particularly in countries where oxygenated or reformulated gasolines are required in national programs aimed at reducing ambient air levels of carbon monoxide and ozone or benzene and other volatile hydrocarbons. A summary of sources of human and environmental exposure is followed by an assessment of what is known about the chemical's environmental behavior and fate. Studies demonstrate that, after discharge into air, MTBE largely remains in the air, with smaller amounts entering soil and water. Although atmospheric MTBE can partition into rain, data indicate that atmospheric transformation by hydroxyl radicals is a more important pathway of removal.