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Acrylonitrile
Description: Acrylonitrile (C.A.S. 107-13-1) is a colorless to pale yellow liquid with an unpleasant odor that is considered to be an important industrial chemical. It is used extensively in the manufacture of synthetic fibers, resins, plastics, elastomers, and rubber for a variety of consumer goods such as textiles, dinnerware, food containers, toys, luggage, automotive parts, small appliances, and telephones. It is also used in fumigants. In 1986, about 40% of the acrylonitrile produced was used to produce acrylic and modacrylic fibers, 28% to produce acrylonitrile-butadiene-styrene and styrene-acrylonitrile resins, and 15% to produce adiponitrile, an intermediate used in nylon production. The remainder was used in the production of acrylamide, nitrile elastomers, barrier resins, and miscellaneous specialty chemicals. Chemical properties: Acrylonitrile is a volatile liquid that is soluble in water and most common organic solvents such as acetone, benzene, carbon tetrachloride, ethyl acetate, and toluene. It melts at 84 degrees C and boils at 77 degrees C. Technical-grade acrylonitrile is more than 99% pure and always contains a polymerization inhibitor. Acrylonitrile is a reactive chemical that polymerizes spontaneously, when heated, or in the presence of a strong alkali unless it is inhibited, usually with ethylhydroquinone. It can explode when exposed to flame. It attacks copper. It is incompatible and reactive with strong oxidizers, acids and alkalis; bromine; and amines. Synonyms for acrylonitrile are AN, acrylonitrile monomer, cyanoethylene, propenenitrile, vinyl cyanide, and VCN. Health effects: Acrylonitrile may reasonably be anticipated to be a carcinogen, according to the Sixth Annual Report on Carcinogens, published by the National Toxicology Program of the U.S. Department of Health and Human Services. It is also classified by the U.S. Environmental Protection Agency as a carcinogen in the national Toxic Release Inventory (TRI). The primary routes of potential human exposure to acrylonitrile are inhalation and dermal contact; it can also expose humans through ingestion or skin absorption. Exposure can cause asphyxia, eye irritation, headaches, sneezing, nausea, vomiting, weakness, lightheadedness, skin vesiculation, and scaling dermatitis. The primary organs acrylonitrile affects are the central nervous system, peripheral nervous system, skin, and eyes. Exposure Values: Economics:
U.S. manufacturers of acrylonitrile American Cyanamid Company, Fortier Plant, Avondale, LA; BP America, Inc, Green Lake, TX, Lima, OH; Du Pont Company, Beaumont, TX; Monsanto Co, Alvin, TX; Sterling Chemicals, Inc, Texas City, TX. Regulation: OSHA has issued permissible exposure limits for acrylonitrile of 2 ppm; ceiling concentration, which must not be exceeded during any part of the workday, is 10 ppm. OSHA regulates acrylonitrile under the Hazard Communication Standard and as a chemical hazard in laboratories. EPA regulates acrylonitrile under the Clean Air Act; Clean Water Act; Comprehensive Environmental Response, Compensation, and Liability Act (Superfund); Federal Insecticide, Fungicide, and Rodenticide Act; Resource Conservation and Recovery Act; and Superfund Amendments and Reauthorization Act. According to EPA, acrylonitrile is classified by the EPA as a water priority pollutant, a hazardous air pollutant, and a volatile organic compound. Under Section 302 of the Emergency Planning and Community Right to Know Act of 1986, acrylonitrile is listed as an Extremely Hazardous Substance and has a threshold planning quantity of 10,000 lbs. 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 |