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Acrylamide
Description: Acrylamide (C.A.S. 79-06-1) is an odorless, free-flowing white crystalline used as a chemical intermediate in the production and synthesis of polyacrylamides. These high-molecular weight polymers can be modified to develop nonionic, anionic, or cationic properties for specific uses. The principle end use of acrylamide is in water-soluble polymers used as additives for water treatment, enhanced oil recovery, flocculants, papermaking aids, thickeners, soil conditioning agents, sewage and waste treatment, ore processing, and permanent press fabrics. Acrylamide is also used in the synthesis of dyes, in copolymers for contact lenses, and the construction of dam foundations, tunnels, and sewers. The largest use for polyacrylamide is in treating municipal drinking water and wastewater. The polymer is also used to remove suspended solids from industrial wastewater before discharge, reuse, or disposal. Acrylamides also find use in oil-drilling processes to control fluid losses. In the pulp and paper industry, polyacrylamides are used as binders and retention aids for fibers and to retain pigments on paper fibers. The paper industry uses approximately 20% of the annual U.S. production volume of polyacrylamides. Acrylamide is a soil stabilizer and also finds use in foundry operations to facilitate free sand flow into molds. Home appliances, building materials, and automotive parts are coated with acrylamide resins and thermosetting acrylics. Acrylamides are formulated in cosmetics and soap preparations as thickeners and in dental fixtures, hair grooming preparations, and preshave lotions. Minor uses of acrylamide are as latex thickeners, emulsion stabilizers for printing inks, gelling agents for explosives, binders in adhesives and adhesive tape, in the production of diazo compounds, and for gel chromatography and electrophoresis. Chemical properties: Acrylamide occurs in crystalline form and in aqueous solution. It is soluble in water, methanol, ethanol, dimethyl ether, and acetone; it is insoluble in benzene and heptane. The monomer readily polymerizes at the melting point or under ultraviolet light. Solid acrylamide is stable at room temperature, but may polymerize violently when melted or in contact with oxidizing agents such as chlorine dioxide and bromine. When heated to decomposition, acrylamide emits poisonous gas, acrid fumes, and NOx. If heating to high temperatures, acrylamide can explode. Synonyms for acrylamide are acrylamide monomer, acrylic amide, propenamide, 2-propenamide, acrilamida (DOT Spanish), acrylamide (DOT French), acrylamide solution, acrylic acid amide (50%), acrylic amide (50%), ethylene carboxamide, ethylenecarboxamide, propenamide (50%), propenoic acid, amide, RCRA Waste Number U007, UN 2074, vinyl amide. Identification: Health effects: Acrylamide is classified as a substance which may reasonably be anticipated to be a carcinogen in the Sixth Annual Report on Carcinogens, 1991, published by the National Toxicology Program of the U.S. Department of Health and Human Services. It is also classified as a carcinogen by EPA. There is limited evidence that acrylamide may damage the male reproductive glands. Acrylamide can damage the nervous system, causing numbness, "pins and needles," and/or weakness in the hands and feet. Acrylamide can affect human health through inhalation, absorption through skin, ingestion, and skin or eye contact. Exposure to acrylamide irritates the nose, throat, and skin, causing a rash or burning feeling on contact. It can also cause loss of balance, slurred speech, and heavy sweating. Contact may cause eye burns and a skin rash. Exposure Values Economics: U.S. manufacturers of acrylamide are American Cyanamid Company, Avondale, LA, Linden, NJ; Dow Chemical USA, Midland, MI; Nalco Chemical Co, Garyville, LA; BF Goodrich Co, Cleveland, OH; Cosan Chemical Corp, Carlstadt, NJ. Regulations: The Food and Drug Administration has regulated the use of acrylamide and polyacrylamide in foods; acrylamide should not exceed .2%, and up to 10 mg polyacrylamide/L water can be used to wash or peel fruits and vegetables. OSHA issues permissible exposure limits for acrylamide of .3 mg/m3 for an eight-hour time-weighted average for skin. EPA regulates acrylamide under the Clean Air Act; Comprehensive Environmental Response, Compensation, and Liability Act; Resource Conservation and Recovery Act; Safe Drinking Water Act; and Superfund Amendments and Reauthorization Act. Acrylamide is classified by EPA as a toxic pollutant of air and water, and a volatile organic compound. Under Section 302 of the Emergency Planning and Community Right to Know Act of 1986, acrylamide is listed as an Extremely Hazardous Substance and has a threshold planning quantity of 1000/10000 lbs. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of acrylamide 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 |