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Methanol
Description: Methanol (C.A.S. 67-56-1), also known as methyl alcohol, is a clear, colorless liquid with a pungent odor at ambient temperatures. First discovered in the late 1600s, methanol has been called wood alcohol because it was obtained commercially from the destructive distillation of wood for more than a century. True wood alcohol contained more contaminants, including acetone and acetic acid, than the chemical-grade methanol available today. For many years the largest use for methanol (about 50 percent of all produced) was as a feedstock in the production of formaldehyde. It is now also used in the production of acetic acid; methyl tert-butyl ether (MTBE) and oxinol, which are used to improve gasoline octane; and other chemical intermediates. Methanol is also used as a solvent and in the production of single-cell protein, which is used as animal feed additives replacing such supplements as powdered milk, soybean meal, and fish meal. Chemical properties: Methanol is a fire hazard, exploding or flaming when exposed to heat, flame, or oxidizers. It produces poisonous gases, including formaldehyde, in fire. It is incompatible with beryllium dihydride, chloroform, cyanuric chloride, metals, oxidants, and potassium tert-butoxide. It has a slight alcoholic odor when pure; crude material may have a repulsive pungent odor. Methanol is highly soluble in water. Synonyms for methanol are methyl alcohol, carbinol, wood alcohol, wood spirits, columbian spirits, colonial spirit, methyl hydroxide, monohydroxymethane, pyroxylic spirit, and wood naphtha. Identification: Health effects: Methanol can cause permanent blindness when breathed, ingested, or passed through the skin. Exposure to high concentrations can cause death. A coma resulting from massive exposures may last as long as two to four days. Because of the slowness with which it is eliminated by the human body, methanol should be regarded as a cumulative poison. Exposure can damage the liver and cause headaches, cardiac depression, nausea, vomiting, blurred vision, dizziness, a feeling of intoxication, and irritations of the eyes, nose, mouth, and throat. Repeated or prolonged contact can cause dryness and cracking of the skin. Exposure Values: Economics: U.S. manufacturers of methanol are Air Products and Chemicals, Inc, Pensacola, FL; Ashland Oil, Inc, Plaquemine, LA; Atlantic Richfield Co, Channelview, TX; Borden Chemicals and Plastics Partnership, Geismar, LAE I du Pont de Nemours and Company, Inc, Beaumont, TX; Eastman Kodak Co, Kingsport, TN; Georgia Gulf Corporation, Plaquemine, LA; Hoechst Celanese Corp, Bishop, TX ; Quantum Chemical Corp, Deer Park, TX; Tenneco Inc, Hq, Pasadena, TX; and Texaco Inc, Delaware City, DE. Regulation: OSHA has issued permissible exposure limits for methanol. Methanol is regulated by the EPA as a water priority pollutant, an air toxic on the Hazardous Air Pollutant List, and a volatile organic compound. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of methanol 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 |