IARC group 1

IARC group 1 Carcinogens are substances, chemical mixtures, and exposure circumstances which have been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). This category is used when there is sufficient evidence of carcinogenicity in humans. Exceptionally, an agent (chemical mixture) may be placed in this category when evidence of carcinogenicity in humans is less than sufficient, but when there is sufficient evidence of carcinogenicity in experimental animals and strong evidence in exposed humans that the agent (mixture) acts through a relevant mechanism of carcinogenicity.

This list focuses on the hazard linked to the agents. This means that while carcinogens are capable of causing cancer, it does not take their risk into account, which is the probability of causing a cancer, given the level of exposure to this carcinogen. The list is up to date as of January 2024.

Agents

Infectious conditions

Viruses

Human immunodeficiency virus type 1 (infection with)
Human T-cell lymphotropic virus type I
Human papillomavirus types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59
Hepatitis B virus (chronic infection with)
Hepatitis C virus (chronic infection with)
Kaposi's sarcoma-associated herpesvirus
Epstein–Barr virus
Merkel cell polyomavirus
Hepatitis D virus (chronic infection with)

Bacterium

Helicobacter pylori (infection with)

Worms

Clonorchis sinensis (infection with)
Opisthorchis viverrini (infection with)
Schistosoma haematobium (infection with)

Chemical substances

Acetaldehyde associated with consumption of alcohol
Acrylonitrile
Aflatoxins
4-Aminobiphenyl
Aristolochic acids, and plants containing them
Arsenic and inorganic arsenic compounds
Asbestos (all forms, including actinolite, amosite, anthophyllite, chrysotile, crocidolite, tremolite)
Azathioprine
Benzene
Benzidine, and dyes metabolized to
Benzo[a]pyrene
Beryllium and beryllium compounds
1,3-Butadiene
1,4-Butanediol dimethanesulfonate (Busulphan, Myleran)
Cadmium and cadmium compounds
Chlornapazine (N,N-Bis(2-chloroethyl)-2-naphthylamine)
Chlorambucil
Bis(chloromethyl)ether
Chloromethyl methyl ether
Chromium(VI) (Hexavalent chromium) compounds
Ciclosporin
Cyclophosphamide
1,2-Dichloropropane
Diethylstilboestrol
Erionite
Ethanol, a chemical known as alcohol as a drug
Ethylene oxide
Etoposide alone, and in combination with cisplatin and bleomycin
Fluoro-edenite fibrous amphibole
Formaldehyde
Gallium arsenide
Lindane
Melphalan
Methoxsalen (8-Methoxypsoralen) plus ultraviolet A radiation
4,4'-Methylenebis(2-chloroaniline) (MOCA)
MOPP and other combined chemotherapy including alkylating agents
Mustard gas (Sulfur mustard)
2-Naphthylamine
Nickel compounds
4-(N-Nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK)
N-Nitrosonornicotine (NNN)
2,3,4,7,8-Pentachlorodibenzofuran
3,4,5,3’,4’-Pentachlorobiphenyl (PCB-126)
Pentachlorophenol
Perfluorooctanoic acid (PFOA), evaluated 2023
Polychlorinated biphenyls
Semustine [1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea, Methyl-CCNU]
Silica dust, crystalline, in the form of quartz or cristobalite
Tamoxifen
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
Thiotepa (1,1',1"-Phosphinothioylidynetrisaziridine)
Treosulfan
Trichloroethylene
o-Toluidine
Vinyl chloride
hydrochlorothiazide
voriconazole
tacrolimus

Radiations and physical agents thereof

Ionizing radiation (all types)
Neutron radiation
Phosphorus-32, as phosphate
Plutonium
Radioiodines, including iodine-131
Nuclear fission products, including strontium-90
Radionuclides, α-particle-emitting, internally deposited
Radionuclides, β-particle-emitting, internally deposited
Radium-224 and its decay products
Radium-226 and its decay products
Radium-228 and its decay products
Radon-222 and its decay products
Solar radiation
Thorium-232 and its decay products
Ultraviolet radiation (wavelengths 100-400 nm, encompassing UVA, UVB, and UVC)
X-ray and gamma radiation

Complex mixtures/agents

Aflatoxins (naturally occurring mixtures of)
Outdoor air pollution
Outdoor air pollution, particulate matter in
Alcoholic beverages
Areca nut, also known as betel nut
Betel quid with or without tobacco
Coal-tar pitch
Coal-tars (see Coal-tar distillation)
Engine exhaust, diesel
Estrogen-progestogen menopausal therapy (combined)
Estrogen-progestogen oral contraceptives (combined)
Estrogen therapy, postmenopausal NB There is "evidence suggesting lack of carcinogenicity" for estrogen-only menopausal therapy in humans and colorectal cancer. An inverse association has been observed between estrogen-only menopausal therapy and cancer of the colorectum.
Leather dust
Mineral oils, untreated or mildly treated
Phenacetin, analgesic mixtures containing
Plants containing aristolochic acid
Polychlorinated biphenyls, dioxin-like, with a Toxic Equivalency Factor (TEF) according to WHO (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189)
Processed meat (consumption of)
Salted fish, Chinese-style
Shale-oils
Soot, as found in occupational exposure of chimney sweeps
Wood dust

Exposure circumstances

Acheson process, occupational exposure associated with
Acid mists, strong inorganic
Aluminium production
Auramine production
Boot and shoe manufacture and repair (see Leather dust, Benzene)
Chimney sweeping (see Soot)
Coal gasification
Coal, indoor emissions from household combustion of
Coal-tar distillation
Coke production
Firefighter (occupational exposure as a)
Furniture and cabinet making (see Wood dust)
Haematite mining (underground)
Iron and steel founding (occupational exposure during)
Isopropyl alcohol manufacture using strong acids
Magenta production
Opium consumption
Painter (occupational exposure as a)
Paving and roofing with coal-tar pitch (see Coal-tar pitch)
Rubber manufacturing industry
Tobacco, smokeless
Tobacco smoke, second-hand
Tobacco smoking
Ultraviolet-emitting tanning devices
Welding fumes and UV radiation

Notes

This evaluation applies to the group of compounds as a whole and not necessarily to all individual compounds within the group.
Evaluated as a group.
There is also conclusive evidence that this agent (tamoxifen) reduces the risk of contralateral breast cancer.
Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents.
There is also convincing evidence in humans that these agents confer a protective effect against cancer in the endometrium and ovary.
Overall evaluation upgraded to Group 1 with strong supporting evidence from other relevant data.

[compunds-6] This evaluation applies to the group of compounds as a whole and not necessarily to all individual compounds within the group.

[evaluated-7] Evaluated as a group.

[8] There is also conclusive evidence that this agent (tamoxifen) reduces the risk of contralateral breast cancer.

[nuclide-11] Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents.

[13] There is also convincing evidence in humans that these agents confer a protective effect against cancer in the endometrium and ovary.

[14] Overall evaluation upgraded to Group 1 with strong supporting evidence from other relevant data.