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Nickel (C.A.S. 7440-02-0) is a naturally occurring silvery metal found in the earth's crust in the form of various nickel minerals. Nickel and its compounds can be detected in all parts of the environment, including plants, animals and soil.
Primary nickel is recovered from mined ore and nickel matte, and secondary nickel is recovered from scrap metal. Industry uses nickel to make steels and alloys, permanent magnet materials, and nickel- cadmium batteries, and in electroplating and ceramics. A large resource of yet-untapped nickel lies in the seabed.
Fuel oil combustion leads to releases of nickel to the atmosphere. Other sources include emissions from mining and refining operations, municipal waste incineration, and windblown dust. Minor sources of atmospheric nickel are volcanoes, steel production, gasoline and diesel fuel combustion, vegetation, nickel alloy production, and coal combustion. Sources of nickel in water and soil include stormwater runoff, soil contaminated with municipal sewage sludge, wastewater from municipal sewage treatment plants, and groundwater near landfill sites.
Chemical and physical properties:
The nickel compounds include: nickel oxide, green; nickel oxide, black; nickel acetate; nickel carbonyl; nickel hydroxide; nickel sulfide; nickel subsulfide; nickel powder; nickel chloride; nickel chloride hexahydrate; nickel sulfate hexahydrate; and nickel nitrate hexahydrate. Soluble compounds include: nickel acetate, nickel sulfate hexahydrate, nickel nitrate hexahydrate, and nickel chloride.
Several forms of nickel oxide have commercial and/or environmental significance. The various nickel oxide species have markedly different physicochemical characteristics and biological effects; as a result, it is important to distinguish between various nickel oxide species, particularly nickel oxide black, which is chemically reactive, and nickel oxide green, which is inert and refractory.
Synonyms & Trade Names: Nickel metal: Elemental nickel, Nickel catalyst
Synonyms of other nickel compounds vary depending upon the specific compound.
- Chemical Name: Metal Catalyst, Dry
- Regulatory Name: Nickel
- Formula: Ni
- DOT Label: Spontaneously combustible
- CAS: 7440-02-0
- STCC: 4916159
- UN Number: 2881
Workers' inhalation of nickel refinery dust, which contains nickel subsulfide, has resulted in increased numbers of deaths from lung and nasal cavity cancers, and possibly cancer of the voice box. The nickel compounds implicated as potential carcinogens are insoluble dusts of nickel subsulfide and nickel oxides, the vapor of nickel carbonyl, and soluble aerosols of nickel sulfate, nitrate, or chloride. Evidence for the carcinogenicity of nickel metal and other compounds is relatively weak or inconclusive.
The most common adverse effects of nickel exposure are skin allergies, specifically dermatitis. Rhinitis, nasal sinusitis, and nasal mucosal injury are among the effects reported in workers chronically exposed to nickel compounds. Asthma has been reported in nickel platers exposed to nickel sulfate, and in welders exposed to nickel oxides.
Because there are no nickel refineries in the U.S., there is very little exposure to nickel refinery dust and nickel subsulfide. Occupational exposure to nickel metal has not been associated with cancer.
The lung is the target organ for nickel toxicity in humans. After comparing ambient air nickel levels with nickel levels in work places associated with adverse effects, EPA has concluded that "human health effects other than cancer appear to be limited to the occupational environment."
Very small amounts of nickel have been shown to be essential for normal growth and reproduction in some species of animals; therefore, small amounts of nickel may also be essential to humans.
- IDLH: 10mg/m3; Not applicable for Nickel metal and other compounds (as Ni), a potential human carcinogen. (NIOSH, 1997)
- TLV TWA: 0.5 MG/M3, Confirmed human carcinogen (©ACHIH, 1999)
- NIOSH REL: Ca TWA 0.015 mg/m3 [The REL does not apply to Nickel carbonyl.]
- OSHA PEL: TWA 1 mg/m3 [The PEL does not apply to Nickel carbonyl.]
The last nickel mine and smelter in the U.S., Hanna Mining Co. in Riddle, Oregon, closed in 1987. The U.S. then was producing less than 1 percent of all the nickel mined in the world. Currently, more nickel is recovered from metal scrap than is obtained from domestic and imported ore combined.
U. S. manufacturers of nickel are: Alfa Products, Danvers, MA; Alloychem Inc, NY, NY; Atlantic Equip Engrs, Bergenfield, NJ; Belmont Metals Inc, Brooklyn, NY; Noah Chemical Div, Farmingdale, NY; Pfizer Minerals, New York, NY; Philipp Brothers Chemicals Inc, New York, NY; Tafa Inc, Bow, NH; Technic Inc, Cranston, RI; United Mineral & Chem Corp, New York, NY; McGean-Rohco, Inc, Cleveland, OH; Ney Products, Brooklyn, NY; A D Mackay, Inc, Darien, CT; Novamet Specialty Procucts Inc, Wychoff, NJ; Hall Chemical Co, Wickliffe, OH SCM Specialty Chemicals, Gainsville, FL; Var-Lac-Oid Chem Co, Inc, Bergenfield, NJ.
OSHA issues permissible exposure limits for nickel and soluble nickel compounds. Under the Emergency Planning and Community Right-to-Know Act, release of more than one pound of nickel and nickel compounds into the air, water, and land must be reported annually and entered into the national Toxic Release Inventory.
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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