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Methyl Tert Butyl Ether
Description: Methyl t-butyl ether (C.A.S. 1634-04-4), or methyl tert-butyl ether, is a synthetic chemical commonly known as MTBE which is mixed with gasoline for use in reformulated gasoline. It is a liquid made from combinations of such chemicals as isobutylene and methanol. It was first introduced as an additive for unleaded gasoline in the 1980s. In areas where there is concern about pollutants such as carbon monoxide, the EPA may require the use of either MTBE or ethanol as a cleaner burning oxygenating agent during the winter months. It is also used as a laboratory reagent to extract semi-volatile organic compounds from such sample types as leachates or solid wastes, and as a pharmaceutical agent to dissolve gallstones.
Chemical properties: MTBE is a colorless, flammable liquid with a distinctive odor that many people find unpleasant. It is soluble in alcohol and ether. It is unstable in acidic solutions. Synonyms for MTBE are methyl tert-butyl ether, tert-butyl methyl ether, and
2-methoxy-2-methylpropane.
Identification: Health effects: Exposure to MTBE can cause headaches, nausea, dizziness, irritation of the nose or throat, and sense of confusion. If MTBE is used to treat gallstones and leaks from the gall bladder to other areas of the body, it can cause minor liver damage, a lowering of the amount of white blood cells, nausea, vomiting, sleepiness, dizziness, and confusion. Populations most at risk to high exposures of MTBE are workers at facilities that manufacture, store, or transport MTBE. Workers in automobile repair shops, truck terminals, gasoline truck terminals or gasoline filling stations may also experience higher exposures if ventilation is not adequate.
Exposure Values: Economics: U.S. manufacturers of methyl tert butyl ether are Amerada Hess Corporation, Port Reading, NJ; Amoco Corporation, Whiting, IN; Yorktown, VA; ARCO Chemical Company, Channelview, TX; ARCO Products Co., Carson, CA; Ashland Petroleum Company, Catlettsburg, KY; Paul Park, MN; Belvieu Environmental Fuels, Mont Belvieu, TX; Chevron Products Co., El Segundo, CA; Pascagoula, MS; Richmond, CA; CITGO Petroleum Corporation, Corpus Christi, TX; Lakes Charles, LA; Coastal Chem, Inc., Cheyenne, WY; Coastal Refining and Marketing, Inc., Corpus Christi, TX; Conoco Inc., Lake Charles, LA; Ponca City, OK; EGP Fuels Company, Laporte, TX; Exxon Chemical Company, Houston, TX; Exxon Chemical Americas, Baton Rouge, LA; Baytown, TX; Exxon Company, U.S.A., Benicia, CA; Fina Oil and Chemical Company, Big Spring, TX; Global Octanes Corporation, Deer Park, TX; Hess Oil Virgin Islands Corp., St. Croix, Virgin Islands; Huntsman Corp., Port Neches, TX; Koch Refining Company, L.P., Corpus Christi, TX; Rosemount, MN; Lyondell Petrochemical Company, Channelview, TX; Marathon Oil Company, Detroit, MI; Robinson, IL; Mobil Chemical Company, Beaumont, TX; Occidental Chemical Corporation, Chocolate Bayou, TX; Philips Petroleum Company, Sweeny, TX; Shell Chemical Company, Deer Park, TX; Norco, LA; Star Enterprise, Convent, LA; Delaware City, DE; and Sun Company, Inc., Marcus Hook, PA; Texas Petrochemicals Corporation, Houston, TX; Tosco Corporation, Martinez, CA; Ultramar Diamond Shamrock Corp., Dumas, TX ; Valero Refining Co., Corpus Christi, TX; Houston, TX; Krotz Springs, LA; Texas City, TX.
Regulation: Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of methyl tert butyl ether into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI).
National Overview of 1998 Toxics Release Inventory See EPA's Toxic Release Inventory. Notations: The NIOSH recommended exposure limits (RELs) are time-weighted average (TWA) concentrations for up to a 10-hour workday during a 40-hour workweek. A short-term exposure limit (STEL) is designated by "ST" preceding the value; unless noted otherwise, the STEL is a 15-minute TWA exposure that should not be exceeded at any time during a workday. A ceiling REL is designated by "C" preceding the value. Any substance that NIOSH considers to be a potential occupational carcinogen is designated by the notation "Ca." The OSHA permissible exposure limits (PEL) are found in Tables Z-1, Z-2, and Z-3 of the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000). Unless noted otherwise, PEL are TWA concentrations that must not be exceeded during any 8-hour workshift of a 40-hour workweek. A STEL is designated by "ST" preceding the value and is measured over a 15-minute period unless noted otherwise. OSHA ceiling concentrations (designated by "C" preceding the value) must not be exceeded during any part of the workday; if instantaneous monitoring is not feasible, the ceiling must be assessed as a 15-minute TWA exposure. In addition, there are a number of substances from Table Z-2 (e.g., beryllium, ethylene dibromide, etc.) that have PEL ceiling values that must not be exceeded except for specified excursions. For example, a "5-minute maximum peak in any 2 hours" means that a 5-minute exposure above the ceiling value, but never above the maximum peak, is allowed in any 2 hours during an 8-hour workday. Information Sources:
Originally published in Environment Writer by the National Safety Council. Reprinted with permission. Environment Writer Metcalf Institute for Marine and Environmental Reporting University of Rhode Island Graduate School of Oceanography Office of Marine Programs Narragansett, RI 02882 Tel: 401-874-6211; Fax: 401-874-6485 Disclaimer * Copyright 2002-2006 * All rights reserved. * University of Rhode Island |