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Formaldehyde
Description: Formaldehyde (C.A.S. 50-00-0) is a colorless gas with a pungent, suffocating odor. It is often used in an aqueous solution. The primary uses for formaldehyde are for the production of urea-formaldehyde resins (25% produced), phenol- formaldehyde resins (20%), plastics (15%), and intermediates (22%). Urea-formaldehyde resins and phenol-formaldehyde resins are used primarily as adhesives in the manufacture of particle board, fiberboard, and plywood, and for molding, paper treating and coating, textile treating, surface coating, and foams for insulation. Most of the formaldehyde used for the production of intermediates is in the manufacture of acetylenic chemicals; smaller quantities are used in the production of entaerythritol, hexamethylenetetramine, and urea-formaldehyde concentrates. Formaldehyde has miscellaneous uses in agriculture for seed treatment, soil disinfection, and as a insecticide and fungicide; as a reagent in analysis; to water- and grease-proof concrete and plaster; as a drying agent and preservative in cosmetics; in room fumigants; as a chemical intermediate for dyes, surface-active agents, and processing aids; in embalming as a preservative and hardener of tissues; in histopathology; as a biocide in drilling fluids; as a stabilizer in gasoline; in leather tanning; as a corrosion inhibitor in metal industries; in paper industries as a chemical intermediate for wet-strength and other paper treating resins; as a photographic film hardener; as a starch modifier; to modify fibers in textiles; and in wood preservatives. Formaldehyde is also used as a treatment for athlete's foot, in cough drops, skin disinfectants, mouthwashes, spermaticide creams, as a disinfectant for vasectomies and root canals, and formerly to sterilize certain cysts prior to surgical removal. In veterinary medicine, it is used as an antiseptic and fumigant in the treatment of tympany, diarrhea, mastitis, pneumonia, and internal bleeding; in association with iodine; it is used as a coccidiostat in chickens. Chemical properties: Formaldehyde is a highly flammable gas or a combustible liquid. Vapors may travel to a source of ignition and flash back. Poisonous gases are produced if it catches on fire; containers of formaldehyde may explode in fire. Formaldehyde is miscible with water, acetone, benzene, diethyl ether, chloroform, and ethanol. It is incompatible and reactive with strong oxidizers, alkalis and acids, phenols, and urea. Pure formaldehyde has a tendency to polymerize. Formaldehyde has a short half-life in air because photochemical processes degrade it; it is unstable in water, and highly soluble in water. Formaldehyde is available in the United Sates as its cycle trimer, trioxane, and as paraformaldehyde. Trioxane is a crystalline solid with a chloroform-like odor. It is easily soluble in water, alcohols, ketones, ether, acetone, chlorinated and aromatic hydrocarbons, and other organic solvents. It is slightly soluble in pentane, petroleum ether, and lower paraffins. In nonaqueous systems, trioxane readily converts to monomeric formaldehyde. Paraformaldehyde is available as a powdered or flaked product containing the equivalent of 90-93% formaldehyde, a maximum of 9% water, and a maximum of .03% acidity as formic acid. It is soluble in fixed alkali hydroxide solutions, slowly soluble in cold water, more readily soluble in hot water with evolution of formaldehyde vapors, and insoluble in alcohol and ether. Synonyms for gaseous formaldehyde are methanal, methyl aldehyde, and methylene oxide. A synonym for aqueous solution formaldehyde is formalin. Identification: Health effects: Formaldehyde gas is classified as a substance which may reasonably be anticipated to be a carcinogen, according to 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 classified as a carcinogen in the Environmental Protection Agency's Toxic Release Inventory (TRI). The evidence for a possible involvement of formaldehyde in cancers is strongest for nasal and nasopharyngeal cancer, since the nose and nasopharynx come into direct contact with formaldehyde through inhalation. Exposure to formaldehyde irritates the eyes, nose, and throat, and can cause skin and lung allergies. Higher levels can cause throat spasms and a build-up of fluid in the lungs, leading to death. Contact can cause severe eye and skin burns, leading to permanent damage. These may appear hours after exposure, even if no pain is felt. Formaldehyde can cause an asthma-like allergy. Future exposures can cause asthma attacks with shortness of breath, wheezing, cough, and/or chest tightness. Repeated exposures may cause bronchitis, with symptoms of cough and shortness of breath. Exposure Values: Economics: U.S. manufacturers of formaldehyde are: Borden Inc, Columbus, OH; BTL Specialty Resins Corp, Warren, NJ; Chembond Corp, Eugene, OR; D B Western, North Bend, OR; E I du Pont de Nemours & Co, Inc, Wilmington, DE; GAF Corp, Wayne, NJ; Georgia-Pacific Corp, Atlanta, GA; Hercules Incorporated, Wilmington, DE; Hoechst Celanese Corp, Somerville, NJ; International Minerals and Chemical Corp, Northbrook, IL; Monsanto Co, North St Louis, Mo.; RVP Corp, White City, OR ; Wright Chemical Corp, Riegelwood, NC. Regulation: Under the authority of the Federal Hazardous Substances Act, the Consumer Product Safety Commission requires warning labels on household products containing 1% or more of formaldehyde. It has also banned the use of urea-formaldehyde foam insulation in residences and schools. The Occupational Safety and Health Administration (OSHA) issues permissible exposure limits for formaldehyde and regulates formaldehyde under the Hazard Communication Standard and as a chemical hazard in laboratories. EPA regulates formaldehyde under the Clean Air Act; Clean Water Act; Comprehensive Environmental Response, Compensation, and Liability Act (Superfund); Food, Drug, and Cosmetic Act; Resource Conservation and Recovery Act; Superfund Amendments and Reauthorization Act; and Toxic Substances Control Act. EPA has designated formaldehyde as a hazardous air pollutant, water pollutant, waste constituent, and inert ingredient of pesticide products. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of formaldehyde into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI). Under Section 302 of the Emergency Planning and Community Right-to-Know Act of 1986, formaldehyde is listed as an Extremely Hazardous substance and has a threshold planning quantity of 500 pounds. Facilities having a threshold quantity of 15000 pounds of formaldehyde are subject to the Risk Management Program Rule (RMP), Section 112r of the Clean Air Act. The RMP toxic endpoint for formaldehyde is 0.012 mg/L - basis ERPG-2. OSHA lists formaldehyde as a highly hazardous chemical under the Process Safety Management Standard at a threshold quantity of 1000 pounds. 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 |