IARC group 3 substances,
chemical mixtures and exposure circumstances are those that can not be classified in regard to their carcinogenicity to humans by the
International Agency for Research on Cancer (IARC). This category is used most commonly for agents, mixtures and exposure circumstances for which the
level of evidence of carcinogenicity is inadequate in humans and inadequate or limited in
experimental animals. Exceptionally, agents (mixtures) for which the evidence of carcinogenicity is inadequate in humans, but sufficient in experimental animals may be placed in this category when there is strong evidence that the mechanism of carcinogenicity in experimental animals does not operate in humans. Agents, mixtures and exposure circumstances that do not fall into any other group are also placed in this category.
This list is focusing on the
hazard linked to the agents. This means that the carcinogenic agents are capable of causing cancer, but this does not take their
risk into account, which is the probability of causing a cancer given the level of exposure to this carcinogenic agent.[1] The list is uptodate as of January 2024.[2]
^"IARC monographs preamble (as amended in 2019)"(PDF). International Agency for Research on Cancer. Retrieved August 18, 2023. A cancer hazard is an agent that is capable of causing cancer, whereas a cancer risk is an estimate of the probability that cancer will occur given some level of exposure to a cancer hazard.