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Formic Acid
Description: Formic acid (C.A.S. 64-18-6) is a colorless liquid that is used in the manufacturing of fumigants, animal feed additives, and commercial paint strippers. The largest single use of formic acid is as a silage additive in Europe, but this market hardly exists in the United States. Formic acid is used in textile dyeing and finishing, leather tanning, nickel plating baths, electroplating, coagulating rubber latex, regenerating old rubber, and dehairing and plumping hides. It is used to make metal salts, including nickel, cadmium, and potassium formates. It is used as a solvent for perfumes, and in the manufacturing of lacquers, glass, vinyl resin plasticizers, and formate esters for flavor and fragrance. It is used in the synthesis of aspartame. Chemical properties: Formic acid has a pungent, penetrating odor. It is miscible with alcohol ether, glycerol, ethyl acetate, methanol, and water. It is very soluble in acetone. It is incompatible or reactive with strong oxidizers, strong caustics, and concentrated sulfuric acid. It is corrosive to metals. It is a strong reducing agent, and may act both as an acid and as an aldehyde because the carboxyl is bound to a hydrogen rather than an alkyl group. Synonyms for formic acid are hydrogencarboxylic acid, and methanoic acid. Identification: Health effects: Exposure to formic acid targets the respiratory system, skin, kidneys, liver, and eyes. Ingesting formic acid can cause severe poisoning and death, with symptoms of salivation, bloody vomiting, burning sensation in the mouth, diarrhea, pain, and shock. Exposure can cause asphyxial death because of glottic edema, circulatory collapse, or renal failure. Exposure can cause severe primary damage to skin, mucosal surface, and eye, including permanent scarring of the cornea. Chronic absorption has been reported to cause albuminuria and hematuria. Exposure can cause lacrimation, increased nasal discharge, cough, throat discomfort, erythema, skin burns, dermatitis, and blistering. Prolonged exposure can cause depressive effects to the central nervous system, such as visual and mental disturbances. Formic acid is produced by bees, wasps, and ants, which can cause acute irritation. Exposure Values: Economics: The only U.S. manufacturer of formic acid is Hoechst Celanese Corporation, Pampa, TX. Regulation: The Occupational Safety and Health Administration (OSHA) sets permissible exposure limits, time-weighted average, for formic acid of 5 ppm (9 mg/m 3 ). Formic acid is regulated under the Comprehensive Environmental Response, Compensation, and Liability Act; the Resource Conservation and Recovery Act; the Clean Water Act; and the Emergency Planning and Community Right-to-Know Act. It is designated as a hazardous substance under the Federal Water Pollution Control Act. Under section 313 of the Emergency Planning and Community Right-to-Know Act, releases of more than one pound of formic acid into the air, water, or land must be reported annually and entered into the national 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 |