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Glycol Ether
Description: Glycol ethers are general solvents, also known as cellosolves, which are used in the semiconductor industry. They are also used in surface coatings, such as lacquers, paints, and varnishes; fingernail polishes and removers; dyes; writing inks; cleaners; and degreasers. Three important glycol ethers are ethylene glycol monoethyl ether (CAS #110-80-5), ethylene glycol monobutyl ether (CAS #111-76-2), and propylene glycol monomethyl ether (CAS #107-98-2).
Ethylene glycol monoethyl ether is used in varnish removers, lacquers, and as a solvent for printing inks, duplicating fluids, and epoxy. Ethylene glycol monobutyl ether is used in hydraulic fluids, as a coupling agent for water-based coatings, in vinyl and acrylic paints and varnishes, and as a solvent for varnishes, enamels, spray lacquers, dry cleaning compounds, textiles, and cosmetics.
Propylene glycol monomethyl ether is primarily used in the manufacture of lacquers and paints, as an anti-freeze in industrial engines, a tailing agent for inks used on very high-speed presses, a coupling agent for resins and dyes in
water-based inks, and a solvent for celluloses, acrylics, dyes, inks, and stains. It is also used in cleaning products such as glass and rug cleaners, carbon and grease removers, and paint and varnish removers; and in pesticide formulations as a solvent for applications to crops and animals.
Chemical properties: All glycol ethers have a low vapor pressure and a high potential for dermal absorption. They are nonflammable.
Ethylene glycol monoethyl ether is a colorless liquid with a sweet, mild odor and slightly bitter taste. It is miscible in all proportions of acetone, benzene, carbon tetrachloride, ethyl ether, methanol, and water. It dissolves many oils, resins, and waxes.
Ethylene glycol monobutyl ether is a colorless liquid with a mild, rancid, ether-like odor. It is soluble in most organic solvents and mineral oil. It mixes with acetone, benzene, carbon tetrachloride, ethyl ether, n-heptane and water; it is miscible with many ketones, ethers, alcohols, aromatic paraffin, and halogenated hydrocarbons. A synonym for ethylene glycol monobutyl ether is ethylene glycol mono-n-butyl ether.
Propylene glycol monomethyl ether is a colorless liquid with a sweet ether-like odor and bitter taste. It is soluble in water, ether, acetone, and benzene. A synonym for propylene glycol monomethyl ether is 1-methyl-2-hydroxypropane.
Identification: Identification: Identification: Health effects: Inhaling glycol ethers can result in dermatitis with erythema, edema, and weeping; hyperpigmentation; and photosensitization.
Exposure to ethylene glycol monoethyl ether can cause depression of the central nervous system, resulting in headaches, drowsiness, weakness, slurred speech, tremor, and blurred vision. Ethylene glycol monobutyl ether is regarded as the most toxic glycol ether used as a solvent. Exposure can result in bone marrow damage, headaches, drowsiness, weakness, slurred speech, tremor, and blurred vision. Exposure to vapors can result in respiratory, nose, throat, and eye irritation.
Exposure to propylene glycol monomethyl ether can cause eye, nose, and throat irritation. High levels become objectionable because of the chemical's odor.
Exposure Values Propylene Glycol Methyl Ether:
Exposure Values Ethylene Glycol Monobutyl Ether:
Exposure Values 2-Ethoxyethanol:
Economics: U.S. manufacturers of ethylene glycol monoethyl ether are Occidental Petroleum Corporation, Bayport, TX; and Union Carbide Corporation, Seadrift, TX.
U.S. manufacturers of ethylene glycol monobutyl ether are Dow Chemical USA, Hq, Midland, MI; Eastman Chemical Co, Kingsport, ; Longview, TX; Occidental Petroleum Corporation, Bayport, TX; Shell Chemical Co, Geismar, LA; and Union Carbide Corporation, Seadrift, TX.
U.S. manufacturers of propylene glycol monomethyl ether are Dow Chemical USA; Midland, MI; Atlantic Richfield Co, Hq, ARCO Chemical Co, the production site was not reported; and Olin Corp, the production site was not reported.
Regulation: Glycol ethers are regulated under the Emergency Planning and Community Right-to-Know Act, the Clean Air Act, and the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund).
The Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit for ethylene glycol monoethyl ether, eight-hour time-weighted average, of 200 ppm (740 mg/m3) for skin exposure. It is also regulated under the Toxic Substances Control Act and the Resource Conservation and Recovery Act.
OSHA has set a permissible exposure limit for ethylene glycol monobutyl ether, eight-hour time-weighted average, of 50 ppm (240 mg/m3) for skin exposure. It is also regulated under the Toxic Substances Control Act.
OSHA has not set a permissible exposure limit for propylene glycol monomethyl ether. The National Institute for Occupational Safety and Health has set a 10-hour time-weighted average of 100 ppm (360 mg/m3), and a 15-minute short-term exposure limit of 100 ppm (540 mg/m3). It is also regulated under the Toxic Substances Control Act.
Under the Emergency Planning and Community Right-to-Know Act, releases of more than one pound of glycol ethers 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 |