Inhalation cobalt

The dust and powder of cobalt metal, ores, and some compounds, such as cobaltous nitrate [ColNOfljT bH O], are flammable and toxic if inhaled. Cobaltous acetate [ColCjHjOjlj dHjO], which is soluble in water, is not allowed to be used in food products because of its toxicity. 

In vitro, cobalt(II) may replace zinc, magnesium, and manganese in a variety of enzymes, without affecting enzymatic activity (Lindskog 1970) this effect is due to the similar ionic sizes of these cations. Whether similar displacement reactions also occur in vivo is not known. Inhaled cobalt particles are rapidly cleared from the lung and excreted. 

Toxicology Exposure is by inhalation. Cobalt causes skin allergies and irritation, and its dust causes occupational asthma. The lARC decided that cobalt metal powder and cobaltous oxide are A3 confirmed carcinogenics in animals, and they are possible human carcinogens [20]. 

Slauson et al. (119) have studied deposition, retention, and clearance of inhaled cobalt oxide particles from the lungs of calves with acute inflammatory... 

Kreyling WG, Perron GA, Haider, B. An interspecies comparison of the lung clearance of inhaled monodisperse cobalt oxide particles—part IV lung clearance of inhaled cobalt oxide particles in beagle dogs. J Aerosol Sci 1989 20 219-232. 

Inhalation of extremely fine carbide, cobalt, and nickel powders should be avoided. Efficient exhaust devices, dust filters, and protective masks are essential when handling these powders. 

Johansson, A., T. Curstedt, and P. Camner. 1991. Lung lesions after combined inhalation of cobalt and nickel. Environ. Res. 54 24-38. 

Rhabdomyosarcomas developed in rats injected intramuscularly with the powder of either pure cobalt metal or cobalt oxide. In other studies implantation of cobalt caused local fibrosarcomas in rabbits, but inhalation studies in hamsters did not reveal any increase in tumors from cobalt oxide. Lifetime exposure to cobalt sulfate by inhalation resulted in increased incidence of alveolar/bronchiolar neoplasms and a spectrum of inflammatory, flbrotic, and proliferative lesions in the respiratory tract of male and female rats and mice. ... 

National Toxicology Program Cobalt Sulfate Heptahydrate (CAS No. 10026-24-1) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). Technical Report Series No 5, NIH Pub No 91-3124. Research Triangle Park, NC, US Department of Health and Human Services, Public Health Service, National Institutes of Health, 1991... 

Inhalation toxicity and carcinogenicity studies of cobalt sulfate. Toxicol Sci 49 56-67, 1999... 

Palmes ED, Nelson N, Lasldn S, Kuschner M Inhalation toxicity of cobalt hydrocarbonyl. Am Ind Hyg Assoc J 20 453 68, 1959... 

Cobalt (Co) Inhalation exposure "hard metal" pneumoconiosis Alloy in metals - but also associated with vitamin Bq2... 

In finely powdered form, cobalt ignites spontaneously in air. Reactions with acetylene and bromine pentafluoride proceed to incandescence and can become violent. The metal is moderately toxic by ingestion. Inhalation of dusts can damage lungs. Skin contact with powdered material can cause dermatitis. 

Cobalt octacarbonyl is toxic by ingestion, inhalation, and other routes of... 

Inhalation vs. oral Americium-241 Californium-252 Cesium-137 Cobalt-60 Hydrogen-3 Iodine-125 Iodine-129 Iodine-131 Phosphoms-32 Plutonium-239 Polonium-210 Radium-226 Strontium-90 Thorium-232 Uranium-235... 

Toxicity. Coball, like most oilier metals, is not entirely harmless, although ii is not in any way comparable lo the known toxic metals, such as mercury, cadmium, and lead. Inhalation of fine cobalt dust over long periods can cause an irritation of Ihe respiratory organs, which may result in chronic bronchitis. Complete recovery is usually achieved upon removal from the contaminated atmosphere. Cobalt salts can cause benign dermatoses, either in people new to handling them, or aflci prolonged exposure, usually several years. 

Cobalt is an essential element that is part of vitamin B12, or cobalamin, a coenzyme that is essential in the formation of proteins, nucleic acids, and red blood cells. Although cobalt poisoning is not common, excessive levels can be harmful. Most cases of human exposure to toxic levels of cobalt have occurred through inhalation in the workplace. Many exposures have been suffered by workers working with hard metal alloys of cobalt and tungsten carbide, where very fine particles... 

How, you may ask, can the FDA be so irresponsible as to approve for use in food contact applications a substance that is a suspected carcinogen A bit of common sense, often a rarity in environmental matters, prevailed in this situation. The FDA recognized that the only way cobalt compounds are carcinogenic, if indeed they are at all, is via the respiratory route. Since it is not reasonable to anticipate that food contact plastics will be inhaled, and since there is no other discernible hazard, the FDA has approved the use of these colorants. 

CONSENSUS REPORTS lARC Cancer Review Group 2B IMEMDT 52,363,91 Human Inadequate Evidence IMEMDT 52,363,91. Reported in EPA TSCA Inventor). Cobalt and its compounds are on the Community Right-To-Know List. EPA Extremely Hazardous Substances List. OSHA PEL TWA 0.1 mg(Co)/m3 ACGIH TLV TWA 0.1 mg(Co)/m3 SAFETY PROFILE Poison by inhalation and intraperitoneal routes. Questionable carcinogen. Decomposes in air to form a product that ignites spontaneously in air. When heated to decomposition it emits acrid smoke and fumes. See also CARBONYLS and COBALT COMPOUNDS. 

DFG MAK DFG TRK 0.5 mg/m calculated as cobalt in that portion of dust that can possibly be inhaled in the production of cobalt powder and catalysts hard metal (mngsten carbide) and magnet production (processing of powder, machine pressing, and mechanical processing of unsintered articles) other cobalt alloys and compounds 0.1 mg/m calculated as cobalt in that portion of dust that can possibly be... 

SAFETY PROFILE Poison by ingesdon and inhalation. A skin and eye irritant. When heated to decomposition it emits very toxic fumes of F and NOx. See also COBALT COMPOUNDS. 

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