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Chemical Sampling Information (CSI)
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General Description

Synonyms: Cobalt metal dust; Cobalt metal fume

OSHA IMIS Code Number: 0720

Chemical Abstracts Service (CAS) Registry Number: 7440-48-4

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: GF8750000

 NIOSH Pocket Guide to Chemical Hazards, Cobalt metal dust and fume (as Co): chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):
General Industry: 29 CFR 1910.1000 Z-1 Table -- 0.1 mg/m3 TWA

Construction Industry: 29 CFR 1926.55 Appendix A -- 0.1 mg/m3 TWA

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 0.1 mg/m3 TWA
American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 0.02 mg/m3 TWA; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans; BEI®

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 0.05 mg/m3 TWA

Health Factors

Carcinogenic Classification:
International Agency for Research on Cancer (IARC): Group 2B, possibly carcinogenic to humans [85 KB PDF, 35 pages]
NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 20 mg/m3

Potential Symptoms: Cough, dyspnea (breathing difficulty), wheezing, decreased pulmonary function, pulmonary edema; weight-loss; skin sensitization; dermatitis; diffuse nodular fibrosis; respiratory hypersensitivity, asthma; INGES. ACUTE: Abdominal pain, vomiting; sensation of hotness; INGES. CHRONIC: Cardiomyopathy.

Health Effects: Asthma (HE9); Cumulative lung damage (HE10); Dermatitis, Heart failure (HE3)

Affected Organs: Skin, respiratory system, heart

Notes:
  1. Cobalt is an OSHA Select carcinogen. NTP's Report on Carcinogens (latest edition) lists only cobalt sulfate as "Reasonably anticipated to be a human carcinogen".
  2. Cobalt is a constituent of vitamin B12 (cyanocobalamin), an essential nutrient found in eggs, meat, poultry, shellfish, milk and milk products.
  3. One study estimated that an 8-hr TWA exposure to 20 or 50 µg/m3 will result in urinary cobalt levels of about 18 and 32 µg per gram of creatinine, respectively, at the end of the workweek. Another study reported an estimated concentration of about 40 µg/liter of urine for an airborne concentration of 50 µg/m3.
  4. Cobalt may display cross-sensitivity to nickel for causing allergic dermatitis.
  5. Although cobaltous salts may be added to animal feed to avoid trace element deficiency, the FDA prohibits the direct addition of these salts to human food (21 CFR 189.120).
Date Last Revised: 02/07/2006

Literature Basis:
  • NIOSH Pocket Guide to Chemical Hazards: Cobalt metal dust and fume (as Co).
  • International Chemical Safety Cards (WHO/IPCS/ILO): Cobalt.
  • Centeno, J.A., Pestaner, J.P., Mullick, F.G. and Virmani, R.: An analytical comparison of cobalt cardiomyopathy and idiopathic dilated cardiomyopathy. Biol. Trace Elem. Res. 55(1-2): 21-30, 1996.
  • Jarvis, J.Q., Hammond, E., Meier, R. and Robinson, C.: Cobalt cardiomyopathy. A report of two cases from mineral assay laboratories and a review of the literature. J. Occup. Med. 34(6): 620-626, 1992.
  • Linnainmaa, M. and Kiilunen, M.: Urinary cobalt as a measure of exposure in the wet sharpening of hard metal and stellite blades. Int. Arch. Occup. Environ. Health 69(3): 193-200, 1997.
  • Lauwerys, R. and Lison, D.: Health risks associated with cobalt exposure – an overview. Sci. Total Environ. 150(1-3): 1-6, 1994.
  • Lison, D., Bucher, J.-P., Swennen, B., Molders, J. and Lauwerys, R.: Biological monitoring of workers exposed to cobalt metal, salt, oxides, and hard metal dust. Occup. Environ. Med. 51(7): 447-450, 1994.
  • Pohanish, R.P. (editor): Cobalt and Oxides. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 643-646.
  • Ratcliffe, J. and English, J.S.: Allergic contact dermatitis from cobalt in animal feed. Contact Dermatitis 39(4): 201-202, 1998.

Monitoring Methods used by OSHA

Laboratory Sampling/Analytical Method:
  • sampling media: Mixed Cellulose Ester Filter (MCEF) 0.8 microns
    maximum volume: 960 Liters   
    minimum volume: 480 Liters   
    maximum flow rate: 2.0 L/min
    current analytical method: Atomic Absorption Spectroscopy; AAS
    method reference: OSHA Analytical Method (OSHA ID-121)
    method classification: Fully Validated
    alternate analytical method: Inductively Coupled Argon Plasma; ICP-AES/MS
    method reference: OSHA Analytical Method (OSHA ID-125G, OSHA 1006)
    method classification: Fully Validated
    alternate analytical method: Inductively Coupled Argon Plasma; ICP-AES
    method reference: OSHA Analytical Method (OSHA ID-213, for cobalt in cemented tungsten carbide or tungsten alloy matrices)
    method classification: Fully Validated
    note: If the filter is not overloaded, samples may be collected up to an 8-hour period.
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Page last updated: 03/09/2007

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