 |
Also see:
|
Carbon Disulfide
Description: Pure carbon disulfide (C.A.S. 75-15-0) is a colorless liquid with a pleasant odor that is like the smell of chloroform. The impure carbon disulfide that is usually used in most industry processes is a yellowish liquid with an unpleasant odor. In nature, very small amounts of carbon disulfide are found in gases from volcanic eruptions and in marshy areas. Carbon disulfide is made for commercial use by combining carbon and sulfur at very high temperatures. It has been an important industrial chemical since the 1800s because of its many useful properties, including its ability to solubilize fats, rubbers, phosphorus, sulfur, and other elements. Its fat-solvent properties also make it indispensable in preparing fats, lacquers, and camphor; in refining petroleum jelly and paraffin; and in extracting oil from bones, palmstones, olives, and rags. It was also used in processing India rubber sap from tropical trees. In all these extraction processes, it has now been replaced by other solvents. Carbon disulfide's most important industrial use has been in the manufacture of regenerated cellulose rayon, by the viscose process, and cellophane. Another principal industrial use for carbon disulfide has been as a feedstock for carbon tetrachloride production. It has also been used to protect fresh fruit from insects and fungus during shipping, in adhesives for food packaging, and in the solvent extraction of growth inhibitors. Carbon disulfide has been highly suitable for other industrial applications including the vulcanization and manufacture of rubber and rubber accessories; the production of resins, xanthanates, thiocyanates, plywood adhesives, and flotation agents; solvent and spinning-solution applications, primarily in the manufacture of rayon and polymerization inhibition of vinyl chloride; conversion and processing of hydrocarbons; petroleum-well cleaning; brightening of precious metals in electroplating; rust removal from metals; and removal and recovery of metals and other elements from waste water and other media. In agriculture, carbon disulfide has been widely used as a fumigant to control insects in stored grain, and to remove botfly larva infestations from the stomachs of horses and ectoparasites from swine. Use of carbon disulfide as a grain fumigant was voluntarily cancelled after 1985. Chemical properties: Carbon disulfide evaporates at room temperature, and the gas is more than twice as heavy as air. Carbon disulfide easily forms explosive mixtures with air and catches fire very easily; it is dangerous when exposed to heat, flame, sparks, or friction. Vapors can be ignited by contact with an ordinary light bulb. It is incompatible or reactive with strong oxidizers; chemically active metals such as sodium, potassium and zinc; azides; rust; halogens; and amines. When exposed to heat or flame, carbon disulfide reacts violently with chlorine, azides, ethylamine diamine, ethylene imine, fluorine, nitric oxide, and zinc. When heated to decomposition, it emits highly toxic fumes of sulfur oxide; it can react vigorously with oxidizing materials. It is miscible with anhydrous methanol, ethanol, ether, benzene, chloroform, carbon tetrachloride, and oils. Synonyms are carbon bisulphide, carbon disulphide, carbon sulfide, carbon sulphide, sulphocarbonic anhydride, dithiocarbonic anhydride, carbon bisulfide, bisulfuro de carbono (DOT Spanish), carbon disulphide, carbon disulfide, carbon sulfide (CS2), disulfure de carbone (DOT French), disulfuro de carbono (DOT Spanish), NCI-C04591, RCRA Waste Number P022, sulphuret of carbon, UN 1131, and Weeviltox. Identification: Health effects: At very high levels, carbon disulfide may be life-threatening because of its effects on the nervous system or heart. Exposure can be through inhalation, absorption through the skin, ingestion, or skin or eye contact. In acute poisoning, early excitation of the central nervous system resembling alcoholic intoxication occurs, followed by depression, stupor, restlessness, unconsciousness, and possible death. If recovery occurs, narcosis, nausea, vomiting, and headache can occur. In chronic poisoning, there are sensory changes such as a crawling sensation in the skin, sensations of heaviness and coldness, and "veiling" of objects so that they appear indistinct. Exposure can cause changes in breathing, chest pains, muscle pain, weakness, loss of feeling in the hands or feet, eye problems, skin blisters, chronic fatigue, loss of memory, personality changes, irritability, dizziness, anorexia, weight loss, psychosis, polyneuropathy, gastritis, kidney and liver damage, dermatitis, mental deterioration, Parkinsonian paralysis, and insanity. Exposure Values: Economics: U.S. manufacturers of carbon disulfide Akzo America, Inc. ,Delaware City, DE; Elf Atochem North America, Inc., Houston, TX; and PPG Industries, Inc, Natrium, WV. Regulation: Carbon disulfide is regulated by the Occupational Safety and Health Administration (OSHA), which sets permissible exposure limits for air (20 ppm C 30 ppm 100 ppm (30-minute maximum peak) of 4 ppm) for time-weighted average; and 12 ppm (36 mg/m3) for short-term exposure limit. The Department of Transportation regulates carbon disulfide, defining it as a DOT hazard/flammable liquid, and as a DOT/International Maritime Organization hazard/flammable liquid and poison. Carbon disulfide is regulated by EPA under the Clean Air Act, which has requirements to prevent equipment leaks of volatile organic compounds in the synthetic organic chemical manufacturing industry. EPA also sets tolerances and exemptions from tolerances for pesticide chemicals in or on raw agricultural commodities, with an exemption from the requirement of a tolerance on barley, corn, oats, popcorn, rice, rye, sorghum, and wheat. Other EPA offices which regulate carbon disulfide are Water Regulations and Standards, Emergency and Remedial Response, Solid Wastes, and Toxic Substances. Under Section 302 of the Emergency Planning and Community Right to Know Act of 1986, carbon disulfide is listed as an Extremely Hazardous Substance and has a threshold planning quantity of 10,000 lbs. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of carbon disulfide into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI). Facilities having a threshold quantity of 20,000 lbs of carbon disulfide are subject to the Risk Management Program Rule (RMP), Section 112r of the 1990 amendments to the Clean Air Act. The RMP toxic endpoint for carbon disulfide is 0.16 mg/L. 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 |