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Hydrochloric Acid
Description: Hydrochloric acid (C.A.S. 7647-01-0), or hydrogen chloride, is either a colorless liquid with a pungent odor, or a colorless to slightly yellow gas which can be shipped as a liquefied compressed gas. It is used in the manufacture of phosphoric acid, chlorine dioxide, ammonium chloride, fertilizers, dyes, and artificial silk and pigments for paints. It is used as a refining ore in the production of tin and tantalum, as a lab reagent, and as a metal treating agent. It is used to remove scale and dust from boilers and heat exchange equipment, to clean membranes in desalination plants, to increase oil well output, to prepare synthetic rubber products by treating isoprene, and to clean and prepare other metals for coatings. It is used in the neutralization of waste streams, the recovery of zinc from galvanized iron scrap, the production of chloride chemicals, the production of vinyl chloride from acetylene and alkyl chlorides from olefins, the manufacture of sodium glutamate and gelatin, the conversion of cornstarch to syrup, sugar refining, electroplating, soap refining, leather tanning, and the photographic, textile, brewing, and rubber industries. It is used as an antiseptic in toilet bowls against animal pathogenic bacteria, and in food processing as a starch modifier. Chemical Properties: Hydrochloric acid is one of the most corrosive of the nonoxidizing acids in contact with copper alloys, and is handled in dilute solutions. It is soluble in benzene, alcohol, and ether; it is insoluble in hydrocarbons, and incompatible or reactive with metals, hydroxides, amines, and alkalis. Hydrochloric acid’s fumes have an acid, penetrating odor. Aqueous solutions of hydrochloric acid attack and corrode nearly all metals, except mercury, silver, gold, platinum, tantalum, and certain alloys. It may be colored yellow by traces of iron, chlorine, and organic matter. Synonyms for hydrochloric acid are hydrogen chloride, anhydrous hydrogen chloride, aqueous hydrogen chloride, chlorohydric acid, spirit of salts, and muriatic acid. Identification: Health effects: Exposure to hydrochloric acid can cause circulatory collapse which may lead to death; it can also cause asphyxial death due to glottic edema. It can also cause conjunctivitis and corneal burns, inflammation and ulceration of the respiratory tract, dermatitis, skin burns, rhinitis, laryngitis, tracheitis, bronchitis, pulmonary edema, dental erosion, hoarseness, a feeling of suffocation, nausea, vomiting, abdominal pain, diarrhea, dehydration, convulsions, oliguria, hypotension, chills, shock, lethargy, stupor, permanent visual damage, cough, and choking. Ingestion or skin contact with hydrochloric acid can cause corrosion of mucous membranes of the mouth, throat, and esophagus, with immediate pain and dysphagia; it can also cause gastric hemorrhage and intense thirst. Exposure Values: Economics: U.S. manufacturers of hydrochloric acid are Akzo Nobel Chemicals Inc., Gallipolis Ferry, WV; Allied-Signal Inc., Baton Rouge, LA; ARCO Chemical Co., Lake Charles, LA ; Ausimont USA, Inc., Thorofare, NJ; BASF Corp., Geismar, LA; Bayer USA, Inc., Pittsburgh, PA; Borden Chemicals and Plastics Operating Limited Partnership, Geismar, LA; Cabot Corp, Tuscola, IL; Callaway Chemical Co., Smyrna, GA; Ciba Specialty Chemicals Corp., McIntosh, AL; CONDEA Vista Company, Lake Charles, LA; Degussa Corporation, Theodore, AL ; Detrex Corporation, Ashtabula, OH; DLD Resources, Inc., Monument, NM; Dover Chemical Corporation, Dover, OH; DOW Chemical USA, Freeport, TX; Midland, MI ; Oyster Creek, TX ; Pittsburgh, CA ; Plaquemine, LA ; Polymer Chemical Division, La Porte, TX; DOW Corning Corporation, Carrollton, KY ; Midland, MI; DuPont, DuPont Fluoroproducts: Corpus Christi, TX; Louisville, KY; Ponca City, OK; Deepwater, NJ; DuPont Dow Elastomers LLC; La Place, LA; Elf Atochem North America Inc., Portland, OR; Fluorine Chemicals Division: Calvert City, KY; Wichita, KS; Organic Chemicals Division: Riverview, MI; Ferro Corp, Cleveland, OH; FMC Corp., Baltimore, MD; Formosa Plastics Corp USA, Baton Rouge, LA; Point Comfort, TX; GB Biosciences Corp., Greens Bayou, TX; General Electric Company, Waterford, NY; The Geon Company, La Porte, TX; Georgia Gulf Corp, Plaquemine, LA; HoltraChem Manufacturing Company, Acme, NC; ICI Americas Inc, St. Gabriel, LA; Jones-Hamilton Co; Walbridge, OH; Magnesium Corporation of America, Rowely, UT; MDA Manufacturing, Inc., Decatur, AL; Millenium Inorganic Chemicals, Inc., Ashtabula, OH; Niacet Corp., Niagara Falls, NY; Niachlor Inc., Niagara Falls, NY; Novartis Crop Protection, Inc., St. Gabriel, LA; Occidental Chemical Corp, Deer Park, TX; Olin Corporation, Augusta, GA 30913; Charleston, TN; Oxymar, Ingleside, TX; Pioneer Chlor Alkali Company, Inc., Henderson, NV; PPG Industries, Inc., La Porte, TX; Rhone-Poulenc Ag Company, Institute, WV; Shell Chemical Co, Norco, LA; Solutia, Inc., Bridgeport, NJ; Standard Chlorine of Delaware, Inc., Delaware City, DE; Velsicol Chemical Corp, Memphis, TN; Vulcan Materials Company, Geismar, LA; Westlake Monomers Corporation, Calvert City, KY; Weyerhaeuser Company, Longview, WA; Witco Corp, Phillipsburg, NJ; and Zeneca Inc., Cold Creek, AL. Regulation: The Occupational Safety and Health Administration (OSHA) sets permissible exposure limits for hydrochloric acid. Hydrochloric acid is regulated under the Emergency Planning and Community Right-to-Know Act; the Clean Air Act/National Emission Standards for Hazardous Air Pollutants; the Comprehensive Environmental Response, Compensation, and Liability Act; and the Federal Insecticide, Fungicide, and Rodenticide Act. It is designated as a hazardous substance under the Clean Water Act. Under the Section 313 of the Emergency Planning and Community Right-to-Know Act, releases of more than one pound of hydrochloric acid must be reported annually and entered into the national Toxic Release Inventory (TRI). Under Section 302 of the Emergency Planning and Community Right to Know Act of 1986, hydrochloric acid is listed as an Extremely Hazardous Substance and has a threshold planning quantity of 100 lbs. OSHA lists hydrochloric acid as a Highly Hazardous Chemical under the Process Safety Management Standard at a threshold quantity of 5,000 pounds. Facilities having a threshold quantity of 1,000 lbs of hyrdochloric acid are subject to the Risk Management Program Rule (RMP), Section 112r of the Clean Air Act. Hydrochloric acid's toxic endpoint is 0.011mg/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 |