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Acetonitrile
Description: Acetonitrile (C.A.S. 75-05-8) is a colorless liquid with an aromatic odor. It is used in organic synthesis as a starting material for acetophenone, alpha-naphthaleneacetic acid, thiamine, acetamidine, amides, amines, higher molecular weight mono- and dinitriles, halogenated nitriles, ketones, isocyanates, and heterocycles. It is used in the manufacturing of acrylic fibers, pharmaceuticals, perfumes, nitrile rubber, and pesticides. It is used to remove tars, phenols, and coloring matter from petroleum hydrocarbons; to extract fatty acids from fish liver, animal, and vegetable oils; and to recrystallize steroids. It is used wherever a polar solvent having a high dielectric constant is required; as a solvent in non-aqueous titrations; and as a non-aqueous solvent for inorganic salts. Chemical properties: Acetonitrile burns with a luminous flame. It may cause explosions when in contact with strong oxidizers; nitrogen-fluorine compounds are potentially explosive in contact with it. It can react violently with sulfuric acid, oleum, chlorosulfonic acid, and perchlorates. It forms explosive mixtures with air. When heated to decomposition, it emits highly toxic fumes of cyanides. It is incompatible and reactive with strong oxidizers, nitrating agents, indium, dinitrogen tetraoxide, nitric acid, and ulfite. It will react with water, steam or acids to produce toxic and flammable vapors and nitrogen oxides. It is miscible with water, methanol, benzene, methyl acetate, acetone, ethyl acetate, ether, acetamide solutions, chloroform, carbon tetrachloride, ethylene chloride, and with many unsaturated hydrocarbons. An equal weight of acetonitrile and these materials are miscible at room temperature: formic acid, acetic acid, levulinic acid, methanol, cellosolve solvent, formaldehyde, di-n-butyl amine, acetic anhydride, pyridine, nitrobenzene, aniline, xylene, phenol, acetyl chloride, dibutyl phthalate, diglycol stearate, n-butyl ether, dichloroethyl ether, methyl isobutyl ketone, nitromethane, nitroethane, and nitropropane. It is immiscible with many saturated hydrocarbons, and dissolves slightly in inorganic salts such as silver nitrate, lithium nitrate, and magnesium bromide. It is very soluble in ethyl alcohol. Liquid acetonitrile will attack some forms of plastics, rubber, and coatings. Synonyms for acetonitrile are cyanomethane, ethyl nitrile, ethanenitrile, methanecarbonitrile, methyl cyanide, acétonitrile (DOT French), acetronitrile cluster, acetonitrilo (DOT Spanish), cianuro de metilo (DOT Spanish), cynaure de méthyle (DOT French), methane, cyno-, methyl cyanide (MECN), NA 1648, NCI-C60822, RCRA Waste Number U003, UN 1648, USAF EK-488. Identification: Health effects: Acetonitrile is poisonous. Massive doses of acetonitrile can produce sudden loss of consciousness, violent convulsions, paralysis, and death from respiratory arrest. With smaller but still lethal doses, the illness may be prolonged for one or more hours. In the early phases of poisoning, an increase in vasoconstrictor tone causes a rise in blood pressure and reflex slowing of the heart rate. Exposure to acetonitrile can cause hyperpnea, dyspnea, headaches, anorexia, asphyxia, nausea, vomiting, chest pain, weakness, stupor, convulsions, anxiety, vertigo, stiffness in the lower jaw, and pink coloring of the skin. Its vapor can irritate eyes, nose and throat; liquid can irritate skin and eyes. Exposure Values: Economics: U.S. manufacturers of acetonitrile are BP America, Inc, Cleveland, OH; Du Pont Chemicals, Beaumont, TX; Texas City, TX; JT Baker Chemical Co, Phillipsburg, NJ; Sterling Chemicals, Inc, Texas City, TX; The Proctor & Gamble Co, Phillipsburg, NJ. Regulations: Acetonitrile is regulated under the Clean Air Act; Comprehensive Environmental Response, Compensation, and Liability Act; Resource Conservation and Recovery Act; and Emergency Planning and Community Right-to-Know Act. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of acetonitrile 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 |