Super Categories



Known Synonyms


Cobalt is the constituent of hard metal responsible for hard metal disease (giant cell interstitial pneumonitis), identified by finding a similar  disease in workers using cobalt to mount industrial diamonds where there was no tungsten carbide (the main constituent of hard metal). Cobalt is also the cause of occupational asthma in hard metal workers. Asthma is more common than hard metal disease and probably needs lower levels of exposure. Users of hard metal tipped tools may also develop cobalt occupational asthma from dry grinding of hard metal tipped tools. Cobalt may also dissolve in some metal-working fluids and cause occupational asthma in exposed workers (there are many other agents in metal-working fluid which may also be implicated). Cobalt may be added to the surface of other metals to increase wear resistance (eg stellite). Other rarer cobalt toxicities include cardiomyopathy, thyroid disease and polycythaemia.

Agent Cobalt
Other Names
Hard metal, stellite
Sources of Exposure
Hard metal manufacture and grinding, metal working, metal-working fluid
Jobs Moulder, grinder, sinterer, machinist,
Epidemiological Studies
Sauni R, Linna A, Oksa P, Nordman H, Tuppurainen M, Uitti J, Cobalt asthma — a case series from a cobalt plant, Occup Med, 2010; 60 : 301-306
Air Measurements working within exposure limits does not prevent occupational asthma
Specific IgE/ Skin prick test

Have been described but not generally available. Shirakawa T, Kusaka Y, Morimoto K, Specific IgE antibodies to nickel in workers with known reactivity to cobalt, Clin Exp Allergy, 1992; 22: 213-218

Biological Monitoring Post shift urine cobalt identifies exposure
Specific Challenge Genenerally nebulised cobalt chloride 0.1-2mg/ml or cobalt dust 0.1-1 ml/l (Occup Med, 2010; 60 : 301-306)
Early References

Jobs H, Ballhausen C., Powder metallurgy as a source of dust from the medical and technical standpoint, Vertrauensartz Krankenkasse, 1940; 8 : 142-                                                              Bech AO, Kipling MD, Heather JC, Hard metal disease, Brit J Industr Dis, 1962; 19: 239- Demedts M, Gheysens B, Nagels J, Cobalt lung in diamond polishers, Am Rev Respir Dis, 1984; 130: 130-135

Metal-working fluids can be formulated to reduce cobalt solubility.


References for: Cobalt See published papers on "Cobalt" from this website.
Haz-Map information on: Cobalt See information on "Cobalt" from the HazMap (Information on Hazardous Chemicals and Occupational Diseases) website.

Oasys Notifications for Cobalt

The Oasys Audit scheme started midway through 2010 and collects agents typed in through the Oasys program. The years before 2010 show old data entered during 2010 or later and are likely to have many fewer notifications. We expect Oasys to become more widely adopted as time goes by so increasing notifications does not necessarily mean an increasing problem.

Occupational asthma notifications to the Oasys Audit Scheme for Cobalt

Comments for Cobalt

Please sign in or register to add your thoughts.

Oasys and occupational asthma smoke logo