International Agency for Research on Cancer

The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations.

Its main offices are in Lyon, France. Its role is to conduct and coordinate research into the causes of cancer. It also conducts epidemiological studies into the occurrence of cancer worldwide. It maintains a series of monographs on the carcinogenic risks to humans posed by a variety of agents, mixtures and exposures.

IARC Categories
The IARC categorizes agents, mixtures and exposures into five categories.
 * Category 1: carcinogenic to humans.
 * Category 2A: probably carcinogenic to humans.
 * Category 2B: possibly carcinogenic to humans.
 * Category 3: not classifiable as to carcinogenicity in humans.
 * Category 4: probably not carcinogenic to humans.