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Manganese (C.A.S. 7439-96-5) is an abundant element and naturally occurring substance found in many types of rock. Pure manganese is a silver-colored metal, similar to iron in its physical and chemical properties. Manganese does not occur in the environment as a pure metal, but is a component of more than 100 minerals, including sulfides, oxides, carbonates, silicates, phosphates, and borates. It is combined with other elements or chemicals such as oxygen, sulfur, and chlorine to make compounds that do not evaporate. The most important manganese compounds are manganous chloride (MnCl2); manganous sulfate (MnSO4); manganese tetroxide (Mn3O4); manganese dioxide (MnO2); and potassium permanganate (KMnO4).
Rocks containing high levels of manganese compounds are mined and used to produce manganese metal, which is mixed with iron to make various types of steel. Most manganese is used to produce ferromanganese, or metallic manganese, which is used in the production of steel to improve hardness, stiffness, and strength. It is used in carbon steel, stainless steel, high- temperature steel, and tool steel, along with cast iron and superalloys.
Manganese dioxide is commonly used in production of dry-cell batteries, matches, fireworks, porcelain and glass-bonding materials, amethyst glass, and as the starting material for production of other manganese compounds. Manganese chloride is used as a precursor for other manganese compounds, as a catalyst in the chlorination of organic compounds, in animal feed to supply essential trace minerals, and in dry-cell batteries.
Manganese sulfate is used in glazes, varnishes, ceramics, and fertilizers; as a fungicide; and as a nutritional supplement. Potassium permanganate is used as an oxidizing agent, a disinfectant, and an anti-algal agent; for metal cleaning, tan- ning, and bleaching; and as a preservative for fresh flowers and fruits. The organomanganese compound MMT is used as an antiknock additive in unleaded gasoline in some countries, but is currently banned for that purpose in the United States.
Manganese can change from one compound to another, either by natural or human processes, but it does not break down or disappear in the environment. Some manganese compounds can dissolve in water, and low levels of these compounds are normally present in lakes, streams, and the ocean.
Manganese decomposes in water and dissolves in dilute mineral acids. Manganese tetroxide and manganese dioxide are insoluble in water, and soluble in hydrochloric acid. Manganous chloride is soluble in alcohol, and insoluble in ether. Manganous sulfate is insoluble in alcohol. Potassium permanganate is soluble in sulfuric acid and acetone.
When exposed to flame, manganese dust or powder is a moderate fire hazard. It will react with water or steam to produce hydrogen; it is incompatible with oxidizers.
Synonyms for manganese are colloidal manganese, elemental manganese, and cutaval.
- Chemical Name: Manganese
- Regulatory Name: Manganese
- CAS: 7439-96-5
The amount of manganese in a normal diet is enough to meet daily needs with no ill health effects. Exposure to too much manganese can cause mental and emotional disturbances, and slow and clumsy body movements; this combination of symptoms is a disease called manganism. Manganism occurs because too much manganese injures a part of the brain that helps control body movements.
Some of the symptoms of manganese can be reduced by medical treatment, but the brain injury is permanent.
Breathing too much manganese dust can cause irritation of the lungs. Sometimes this makes breathing difficult and increases the chances of getting a lung infection, such as pneumonia. Inhalation or ingestion of manganese dust or fumes can cause Parkinson's, asthenia, insomnia, mental confusion, metal fume fever, weakness, spastic gait, paralysis, dry throat, cough, tight chest, dyspnea, rales, flu-like fever, low back pain, vomiting, malaise, and fatigue.
A common effect in men who are exposed to high levels of manganese dust in air is impotence.
- IDLH: 500 mg/m3 (NIOSH, 1997)
- NIOSH REL: TWA 1 mg/m3 ST 3 mg/m3
- OSHA PEL: C 5 mg/m3 [*Note: Also see specific listings for Manganese cyclopentadienyl tricarbonyl and Methyl cyclopentadienyl manganese tricarbonyl.]
U.S. manufacturers of manganese are Atlantic Equipment Engineers Division Micron Metals, Inc, Bergenfield, NJ; Cerac, Inc, Milwaukee, WI; Chemetals, Inc, Glen Burnie, MD; Consolidated Astronautics, Smithtown, NY; GFS Chemicals, Columbus, OH; Kerr-McGee Chemical Corp, Oklahoma City, OK; SCM Metal Products, Cleveland, OH; Agromex, Inc, Mobile, AL; Alfa Products, Morton Thiokol, Inc, 152 Andover St, Danvers, MA; Atomergic Chemetals Corp, Farmingdale, NY; Belmont Metals, Inc, Brooklyn, NY; Elkem Metals Co, Pittsburgh, PA; Noah Technologies Corp, Noah Chemical Division, San Antonio, TX; Reade Metals & Minerals Corp, Rumson, NJ; and Witco Corp, New York, NY.
The Occupational Safety and Health Administration (OSHA) issues permissible exposure limits (time weighted average) for manganese fume, as manganese, of 1 mg/m3; manganese cyclopentadienyl tricarbonyl, as manganese, of .1 mg/m3; and manganese tetroxide of 1 mg/m3.
Offices within the Environmental Protection Agency that issue regulations for manganese are Air Quality Planning and Standards, Water Regulation and Standards, Emergency and Remedial Response, Solid Waste, and Toxic Substances.
The Food and Drug Administration regulates manganese concentrations in bottled water. The Department of Justice's Drug Enforcement Agency ranks potassium permanganate as an essential chemical in illegal drug production; records of sales and uses are required for amounts over 500 kg.
Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of maganese into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI).
National Overview of 1998 Toxics Release Inventory
See EPA's Toxic Release Inventory.
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.
- CAMEO®, U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, www.epa.gov/ceppo.
- Chemical Manufacturers Association, 1300 Wilson Blvd., Arlington, VA 22209: (703) 741-5000 or Chemical Referral Library, (800) 262-8200.
- National Institute of Environmental Health Sciences, Clearinghouse on Environmental Health Effects, 100 Capitola Drive, #108, Durham, NC 27713; (800) 643-4794; fax (919) 361-9408.
- TOXNET, National Library of Medicine, National Institutes of Health;
- U.S. Environmental Protection Agency, 401 M St., SW, Washington, DC 20460; Right to Know Hotline (800) 535-0202.
- U.S. Department of Labor, Occupational Health and Safety Administration, Washington, DC,
- OSHA PEL: Z-1 Table:
- OSHA PEL: Z-2 Table:
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Originally published in Environment Writer by the National Safety Council. Reprinted with permission.
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