Potency of Chemical Carcinogens

The objective of this Note is to provide guidance to RSC members that may have to conduct COSHH and other risk assessments involving carcinogens.

Cancer is a disorder in which the mechanisms which control proliferation of cells no longer function adequately. Cancer is considered to be an all-or-none effect, i.e. a tumour is or is not present. Because most cancers are considered as e motive irreversible life -threatening changes, chemical carcinogenesis (chemically induced cancer development) has hitherto been perceived by many to be different from other forms of chemical toxicity.

The overall proportion of cancer which may be occupationally related is uncertain but has been suggested to be in the range of 2-6%. Largely because of their observed effects on defined working populations a small number of specific chemicals have been identified as human carcinogens. Some chemical processes have also been associated with cancer in those operating them although the causative agents have not been identified. A few pharmaceuticals are also carcinogenic.