IARC

IARC publishes its findings in a series called the Monographs. Expert working groups review the published studies on people, laboratory animals, and mechanisms, then assign each agent to a group. The monograph process is about whether an agent can cause cancer, not how likely it is under any particular exposure.

Group 1 means the agent is carcinogenic to humans. Group 2A means probably carcinogenic, Group 2B means possibly carcinogenic, and Group 3 means not classifiable as to carcinogenicity to humans. Group placement reflects the strength of the evidence, not the potency or size of the risk, which is why very different agents can share a group.

IARC is a hazard identification body, not a regulator. Its classifications inform other bodies. OSHA's HazCom rule requires Section 11 of the SDS to say whether a carcinogen is listed by IARC, the NTP Report on Carcinogens or OSHA, and a non-mandatory appendix explains how IARC and NTP findings relate to the GHS carcinogen categories.

On a safety data sheet, you may see IARC groupings in the toxicological section. Mixtures may carry a listing if an ingredient is listed. An IARC listing is not the same as a ban, and it does not tell you whether your exposure is meaningful.

Read the listing along with exposure information and the controls on the sheet.