The first report of cancer caused by occupational exposure was in 1775 by Percival Pott, a British surgeon who described scrotal cancer in boy chimney sweeps. A century later, in 1895, Rehn, a German surgeon working in Frankfurt, treated a cluster of three cases of bladder cancer in workers at a local factory producing aniline dyestuffs from coal tar.

Occupational cancer is any malignancy wholly or partly caused by exposures at the workplace or in occupation. Such exposure may be to a particular chemical (such as β-naphthylamine), a physical agent (such as ionising radiation or a fibre like asbestos), a biological agent (such as hepatitis B virus), or an industrial process in which the specific carcinogen may elude precise definition (such as coke production).

About 4% of all cancer deaths in people aged over 15 years may have an occupational cause. This translates into over 3000 male deaths in England and Wales from potentially preventable malignancies. The proportion occurring in women is probably less because of their lower potential for exposure.

The International Agency for Research on Cancer (IARC) was set up within the World Health Organisation in 1971 to assess whether individual agents, mixtures, and occupational exposures have carcinogenic potential for humans. Since 1972 the agency has published 63 monographs covering more than 700 such evaluations. Today, some 65 agents and occupational environments are regarded by IARC as established human carcinogens. Over 50 are listed as probably carcinogenic, and about 300 are thought to be possibly carcinogenic.