Substances, mixtures and exposure circumstances in this list have been classified by the IARC as Group<unk> : The agent (mixture or exposure circumstance) is not classifiable as to its carcinogenicity to humans. This category is used most commonly for agents, mixtures and exposure circumstances for which the 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.
Further details can be found in the IARC Monographs.
List of IARC Group 3 carcinogens
List of IARC Group 4 carcinogens
List of IARC Group 2B carcinogens
List of IARC Group 2A carcinogens
List of IARC Group 1 carcinogens
List of cancer mortality rates
List of cancer clusters
Farmer's lung epidemiology and demographics