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Chlorine
Description: Chlorine is a greenish-yellow gas with a pungent, irritating odor. It is used to bleach fabrics, to purify water, to bleach woodpulp and paper, to disinfect, to clean dairy equipment, to control biofouling in cooling systems, to shrink-proof wool, and to detin and dezinc iron. It is used for sterilization for root canals, tooth extractions, irrigations, or wounds. It is also used in the manufacturing of pesticides, antifreeze, refrigerants, antiknock compounds, plastics, and resins. It is used in the manufacturing of synthetic rubber and plastics, chlorinated hydrocarbons, polyvinyl chloride, ethylene dichloride hypochlorous acid, chlorobenzene, chlorinated lime, carbon tetrachloride, ethylene and propylene oxides, glycols, trichloroethylene, perchloroethylene, chloroform, vinylidene chloride, polychloroproprene, hydrogen chloride, metal chlorides, chloracetic acid, chloral, synthetic glycerine, methyl chlorides, chlorinated benzenes, tetraethyl lead, fluorine compounds, titanium tetrachloride, monochloroacetic acid, phosgene, chloroisocyanuric acid, phosphorus chloride dichlorobutene, and chlorinate paraffins. Chemical properties: Chlorine is corrosive to some forms of plastics, rubber, and coatings. It is soluble in chlorides, alkali, and alcohols. It combines readily with all elements except the rare gases, excluding xenon, and nitrogen. It reacts explosively or forms explosive compounds with many common substances such as acetylene, ether, turpentine, ammonia, fuel gas, hydrogen, and finely divided metals. It is a noncombustible gas, and a strong oxidizer. Chlorine is heavier than air, and less water-soluble than ammonia. Water dissolves about twice its volume of chlorine gas, forming a mixture of hydrochloric and hypochlorous acids. Synonyms for chlorine are chlorine gas, chlorine water, molecular chlorine, javelle water, and NaOCl. Identification: Health effects: Chlorine exposure occurs through inhalation, or skin or eye contact. Exposure can cause burning of eyes, nose, and mouth; lacrimation and rhinorrhea; coughing, sneezing, choking, and substernal pain; nausea and vomiting; headaches and dizziness; syncope; fatal pulmonary edema; pneumonia; conjunctivitis; keratitis; pharyngitis; burning chest pain; dyspnea; hemoptysis; hypoxemia; dermatitis; and skin blisters. When inhaled in high concentrations, chlorine causes emphysema and damage to the pulmonary blood vessels. Chronic exposure can cause corrosion of the teeth. Cardiac arrest may occur secondary to hypoxia. Inhalation of small amounts of chlorine causes few or no symptoms. In larger amounts, it is a powerful irritant to the mucous membranes of the eyes, nose, and throat. Exposures of 1-3 ppm can cause mild mucous membrane irritation; 5-15 ppm, moderate irritation of upper respiratory tract; 30 ppm, immediate chest pain, vomiting, dyspnea, and cough; 40-60 ppm, toxic pneumonitis and pulmonary edema; 430 ppm, lethal over 30 minutes; and 1,000 ppm, death within a few minutes. Death is possible from asphyxia, shock, reflex spasm in the larynx, or massive pulmonary edema. Populations at special risk from chlorine exposure are individuals with pulmonary disease, breathing problems, bronchitis, or chronic lung conditions. Exposure Values: Economics: U.S. manufacturers of chlorine are ASHTA Chemicals Inc., Ashtabula, OH; Bayer Corporation, Baytown, TX; Cedar Chemical Corporation, Vicksburg, MI; DOW Chemical USA, Freeport, TX; Plaquemine, LA; DuPont, Niagra Falls, NY; Elf Atochem North America IncPhiladelphia, PA; Formosa Plastics Corp USA, Baton Rouge, LA; Point Comfort, TX; Fort Howard Corporation, Green Bay, WI; Muskogee, OK; Rincon, GA; General Electric Company, Burkville, AL; Mount Vernon, IN; Georgia Gulf Corp; Plaquemine, LA; Georgia-Pacific West Inc., Bellingham, WA; The BFGoodrich Company, Calvert City, KY; HoltraChem Manufacturing Company, Acme, NC; Orrington, ME; LaRoche Industries Inc, Gramercy, LA; Magnesium Corporation of America, Rowely, UT ; Niachlor Inc., Niagara Falls, NY; Occidental Chemical Corp, Convent, LA; Ingleside (Corpus Christi), TX; Deer Park, TX; Delaware City, DE; La Porte, TX; Mobile, AL; Muscle Shoals, AL; Niagara Falls, NY; Tacoma, WA; Taft, LA; Olin Corporation, Augusta, GA; Charleston, TN; McIntosh, AL; Oregon Metallurgical Corporation, Albany, OR; Pioneer Chlor Alkali Company, Inc., Henderson, NV; St. Gabriel, LAPPG Industries, Inc., Lake Charles, LA; New Martinsville(Natrium), WV; Titanium Metals Corporation of America, Henderson, NV; Vulcan Materials Company, Geismar, LA; Port Edwards, WI; Wichita, KS; and Weyerhaeuser Company, Longview, WA. Regulation: The Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit, time-weighted average, for chlorine of .5ppm (1.5 mg/m3); short-term exposure limit is 1 ppm (3 mg/m3). OSHA lists chlorine as a Highly Hazardous Chemical under the Process Safety Management Standard at a threshold quantity of 1,500 pounds. Chlorine is regulated under the Clean Water Act; Emergency Planning and Community Right-to-Know Act; Clean Air Act; Comprehensive Environmental Response, Compensation, and Liability Act; and Federal Insecticide, Fungicide, and Rodenticide Act. Under Section 302 of the Emergency Planning and Community Right to Know Act of 1986, chlorine is listed as an Extremely Hazardous Substance and has a threshold planning quantity of 100 lbs. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of chlorine into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI). Facilities having a threshold quantity of 2,500 lbs of chlorine are subject to the Risk Management Program Rule (RMP), Section 112r of the 1990 Clean Air Act with a toxic endpoint of .0087 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 |