Cancer Risk and Prevention

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Known and Probable Human Carcinogens

A carcinogen is something that can cause cancer. Carcinogens can be chemicals, infections, some kinds of radiation, smoke and air pollution, or other substances.

In general, the American Cancer Society does not determine whether something should be considered a carcinogen. Instead, we look to other respected organizations for help with this.

The International Agency for Research on Cancer (IARC) and the US National Toxicology Program (NTP) are the main sources of carcinogen information.

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Known vs. probable carcinogens

A known carcinogen is a substance or exposure with conclusive evidence showing it causes cancer.

A probable carcinogen is a substance or exposure that is strongly linked to cancer, but the evidence is not conclusive.

The substances and exposures listed here include only known and probable human carcinogens. Some agencies use other classifications, such as possible carcinogen, not classified, or probably not a carcinogen. These categories are used when the evidence is limited, unclear, or shows that a substance likely does not cause cancer.

Who creates carcinogen lists?

When something has been classified or labeled a carcinogen, it has been studied extensively. As a result, 1 or more agencies have evaluated the scientific evidence and determined it to be a cause of cancer.

The known and probable human carcinogens listed here are collected from the lists published by the International Agency for Research on Cancer (IARC) and the US National Toxicology Program (NTP). These agencies act independently to study what causes cancer and make the information available to the public.

To learn more about how carcinogens are studied and evaluated, see How Do We Know What Causes Cancer?

Tips for navigating the carcinogen lists

  • The lists are alphabetical, but many of the substances and exposures here can go by different names. This can make it hard to find a particular substance on one or both lists.
  • The lists include only those agents that have been evaluated by IARC and NTP. These agencies focus on substances and exposures most likely to cause cancer, but there are others that have not been fully studied yet.
  • The lists include only agents that have been classified as known or probable human carcinogens. The lists do not include substances that have been classified as possible carcinogens, for which the evidence is not as strong, or those evaluated as “not classifiable as to its carcinogenicity in humans.”
  • The lists describe the level of evidence that something can cause cancer, not how much it might raise your risk. For example, IARC considers there to be strong evidence that both tobacco smoking and eating processed meat can cause cancer, so both are listed as “carcinogenic to humans.” But smoking is much more likely to cause cancer than eating processed meat, even though both are in the same category.
  • Many known or suspected carcinogens appear on both organizations’ lists. But any differences in the lists do not mean there is disagreement between IARC and NTP. If a substance or exposure is only on 1 agency’s list, it’s possible that the other agency may not have evaluated it.
  • The lists contain many commonly used medicines, including some hormones and drugs used to treat cancer. For example, tamoxifen increases the risk of certain kinds of uterine cancer, but it can be very useful in treating some breast cancers, which may be more important for some women. If you have questions about a medicine that appears on one of these lists, be sure to ask your doctor.
  • Most of the agents on the IARC and NTP lists have been linked only with certain kinds of cancer, not all cancer types.

Lists of known human carcinogens

Learn more about the topics in this list in the IARC monographs.

  • Acetaldehyde from consuming alcoholic beverages
  • Acheson process, workplace exposure
  • Acid mists, strong inorganic
  • Acrylonitrile
  • Aflatoxins
  • Alcoholic beverages
  • Aluminum production
  • 4-Aminobiphenyl
  • Areca nut
  • Aristolochic acid and plants containing it
  • Arsenic and inorganic arsenic compounds
  • Asbestos in all forms and mineral substances that contain asbestos, such as talc or vermiculite
  • Auramine production
  • Automotive and aviation gasoline
  • Azathioprine
  • Benzene
  • Benzidine and dyes metabolized to benzidine
  • Benzo[a]pyrene
  • Beryllium and beryllium compounds
  • Betel quid, with or without tobacco
  • Bis(chloromethyl)ether and chloromethyl methyl ether, technical-grade
  • Busulfan
  • 1,3-Butadiene
  • Cadmium and cadmium compounds
  • Chlorambucil
  • Chlornaphazine
  • Chromium (VI) compounds
  • Clonorchis sinensis (infection with), also known as the Chinese liver fluke
  • Coal, indoor emissions from household combustion
  • Coal gasification
  • Coal, indoor emissions from household use
  • Coal-tar distillation
  • Coal-tar pitch
  • Coke production
  • Cyclophosphamide
  • Cyclosporine or ciclosporin
  • 1,2-Dichloropropane
  • Diethylstilbestrol (DES)
  • Engine exhaust, diesel
  • Epstein-Barr virus (EBV) infection
  • Erionite
  • Estrogen-only menopausal therapy
  • Estrogen-progestogen menopausal therapy combined
  • Estrogen-progestogen oral contraceptives combined (Note: There is also convincing evidence in humans that these agents could help protect against cancer in the endometrium and ovary.)
  • Ethanol in alcoholic beverages
  • Ethylene oxide
  • Etoposide
  • Etoposide in combination with cisplatin and bleomycin
  • Firefighter, workplace exposure
  • Fission products, including strontium-90
  • Fluoro-edenite fibrous amphibole
  • Formaldehyde
  • Haematite mining, underground
  • Helicobacter pylori infection
  • Hepatitis B virus chronic infection
  • Hepatitis C virus chronic infection
  • Hepatitis D virus infection
  • Human immunodeficiency virus type 1 (HIV-1) infection
  • Human papillomavirus (HPV) infection, types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59 (Note: HPV types classified as carcinogenic to humans can differ in how likely they are to cause cancer.)
  • Human T-cell lymphotropic virus infection, type I (HTLV-1)
  • Hydrochlorothiazide (HCTZ)
  • Ionizing radiation, all types
  • Iron and steel founding, workplace exposure
  • Isopropyl alcohol manufactured using strong acids
  • Kaposi sarcoma herpes virus (KSHV) infection, also known as human herpes virus 8 (HHV-8)
  • Leather dust
  • Lindane
  • Magenta production
  • Melphalan
  • Merkel cell polyomavirus (MCPyV) infection
  • Methoxsalen (8-methoxypsoralen) plus ultraviolet A radiation, also known as PUVA
  • Methyl-CCNU or semustine
  • 4,4'-Methylenebis chloroaniline (MOCA)
  • Mineral oils, untreated or mildly treated
  • MOPP and other combined chemotherapy including alkylating agents
  • 2-Naphthylamine
  • Neutron radiation
  • Nickel compounds
  • N’-Nitrosonornicotine (NNN) and 4-(N-Nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK)
  • Opisthorchis viverrini infection, also known as the Southeast Asian liver fluke
  • Opium consumption
  • ortho-Toluidine
  • Outdoor air pollution and particulate matter in it
  • Painter, workplace exposure
  • 3,4,5,3',4'-Pentachlorobiphenyl (PCB-126)
  • 2,3,4,7,8-Pentachlorodibenzofuran
  • Pentachlorophenol
  • Perfluorooctanoic acid (PFOA)
  • Phenacetin and mixtures containing it
  • Phosphorus-32, as phosphate
  • Plutonium
  • Polychlorinated biphenyls (PCBs)
  • Polychlorinated biphenyls (PCBs), dioxin-like, with a Toxicity Equivalency Factor according to WHO (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, and 189)
  • Processed meat, consumption of
  • Radioiodines, including iodine-131
  • Radionuclides, alpha-particle-emitting, internally deposited (Note: Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents.)
  • Radionuclides, beta-particle-emitting, internally deposited (Note: Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents.)
  • Radium-224 and its decay products
  • Radium-226 and its decay products
  • Radium-228 and its decay products
  • Radon-222 and its decay products
  • Rubber manufacturing industry
  • Salted fish, Chinese-style
  • Schistosoma haematobium infection
  • Shale oils
  • Silica dust, crystalline, in the form of quartz or cristobalite
  • Solar radiation
  • Soot, in workplace exposure of chimney sweeps
  • Sulfur mustard
  • Tacrolimus
  • Tamoxifen (Note: Evidence shows tamoxifen reduces the risk of contralateral breast cancer in people with breast cancer.)
  • 2,3,7,8-Tetrachlorodibenzo-para-dioxin (TCDD); "dioxin"
  • Thiotepa
  • Thorium-232 and its decay products
  • Tobacco, smokeless
  • Tobacco smoke, secondhand
  • Tobacco smoking
  • Treosulfan
  • Trichloroethylene
  • Ultraviolet (UV) radiation, including UVA, UVB, and UVC rays
  • Ultraviolet radiation from welding
  • Ultraviolet-emitting tanning devices
  • Vinyl chloride
  • Voriconazole
  • Welding fumes
  • Wood dust
  • X- and gamma radiation

Learn more about the topics in this list in the NTP’s Report on Carcinogens.

  • Aflatoxins
  • Alcoholic beverage consumption
  • 4-Aminobiphenyl
  • Analgesic mixtures containing phenacetin
  • Aristolochic acids
  • Arsenic and inorganic arsenic compounds
  • Asbestos
  • Azathioprine
  • Benzene
  • Benzidine
  • Beryllium and beryllium compounds
  • Bis(chloromethyl) ether and technical-grade chloromethyl methyl ether
  • 1,3-Butadiene
  • 1,4-Butanediol dimethylsulfonate or busulfan
  • Cadmium and cadmium compounds
  • Chlorambucil
  • 1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU)
  • Chromium hexavalent compounds
  • Coal tar pitches
  • Coal tars
  • Coke oven emissions
  • Cyclophosphamide
  • Cyclosporin A
  • Diethylstilbestrol (DES)
  • Dyes metabolized to benzidine
  • Epstein-Barr virus (EBV) infection
  • Erionite
  • Estrogens, steroidal
  • Ethylene oxide
  • Formaldehyde
  • Helicobacter pylori chronic infection
  • Hepatitis B virus infection
  • Hepatitis C virus infection
  • Human immunodeficiency virus type 1 (HIV-1) infection
  • Human papillomaviruses (HPVs) infection, some genital-mucosal types
  • Human T-cell lymphotropic virus type 1 (HTLV-1) infection
  • Kaposi sarcoma-associated herpesvirus (KSHV) infection, or human herpesvirus 8 (HHV-8)
  • Melphalan
  • Merkel cell polyomavirus (MCV) infection
  • Methoxsalen with ultraviolet A therapy (PUVA)
  • Mineral oils, untreated and mildly treated
  • Mustard gas
  • 2-Naphthylamine
  • Neutrons
  • Nickel compounds
  • Radon
  • Silica, crystalline, respirable size
  • Solar radiation
  • Soots
  • Strong inorganic acid mists containing sulfuric acid
  • Sunlamp or sunbed exposure
  • Tamoxifen
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
  • Thiotepa
  • Thorium dioxide
  • Tobacco smoke, environmental
  • Tobacco, smokeless
  • Tobacco smoking
  • o-Toluidine
  • Trichloroethylene (TCE)
  • Ultraviolet (UV) radiation, broad spectrum
  • Vinyl chloride
  • Wood dust
  • X-radiation and gamma radiation

Lists of probable human carcinogens

Learn more about the topics in this list in the IARC monographs.

  • Acrolein
  • Acrylamide
  • Adriamycin or doxorubicin
  • Alachlor
  • Androgenic or anabolic steroids
  • Aniline and aniline hydrochloride
  • ortho-Anisidine and ortho-anisidine hydrochloride
  • Art glass, glass containers, and press ware manufacturing
  • Atrazine
  • Azacitidine
  • Biomass fuel, primarily wood emissions from household combustion
  • Bischloroethyl nitrosourea (BCNU) or carmustine
  • Bitumens, occupational exposure to oxidized bitumens and their emissions during roofing
  • 2-Bromopropane
  • Captafol
  • Carbon electrode manufacture
  • Chloral
  • Chloral hydrate
  • Chloramphenicol
  • alpha-Chlorinated toluenes, including benzal chloride, benzotrichloride, benzyl chloride and benzoyl chloride, combined exposures
  • 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU)
  • 4-Chloro-ortho-toluidine
  • Chlorozotocin
  • Cisplatin
  • Cobalt metal without tungsten carbide or other metal alloys
  • Cobalt metal with tungsten carbide
  • Creosotes
  • Cyclopenta[cd]pyrene
  • DDT or 4,4'-Dichlorodiphenyltrichloroethane
  • Diazinon
  • Dibenz[a,j]acridine
  • Dibenz[a,h]anthracene
  • Dibenzo[a,l]pyrene
  • Dichloromethane or methylene chloride
  • Dieldrin, and aldrin metabolized to dieldrin
  • Diethyl sulfate
  • Dimethylcarbamoyl chloride
  • N,N-Dimethylformamide
  • 1,2-Dimethylhydrazine
  • Dimethyl sulfate
  • Epichlorohydrin
  • Ethyl carbamate or urethane
  • Ethylene dibromide
  • N-Ethyl-N-nitrosourea
  • Frying, emissions from high-temperature
  • Glycidol
  • Glycidyl methacrylate
  • Glyphosate
  • Hairdresser or barber, workplace exposure
  • Human papillomavirus (HPV) type 68 infection
  • Hydrazine
  • Indium phosphide
  • IQ (2-Amino-3-methylimidazo[4,5-f]quinoline)
  • Lead compounds, inorganic
  • Malaria caused by infection with Plasmodium falciparum
  • Malathion
  • 2-Mercaptobenzothiazole
  • 5-Methoxypsoralen
  • Methyl methanesulfonate
  • Methyleugenol
  • N-Ethyl-N-nitrosourea
  • N-Methyl-N-nitro-N-nitrosoguanidine (MNNG)
  • N-Methyl-N-nitrosourea
  • Night shift work
  • Nitrate or nitrite ingested under conditions that result in endogenous nitrosation
  • ortho-Nitroanisole
  • 6-Nitrochrysene
  • Nitrogen mustard
  • 1-Nitropyrene
  • N-Nitrosodiethylamine
  • N-Nitrosodimethylamine
  • 2-Nitrotoluene
  • Non-arsenical insecticides (workplace exposures in spraying and application of)
  • Petroleum refining, workplace exposure
  • Pioglitazone
  • Polybrominated biphenyls (PBBs)
  • Procarbazine hydrochloride
  • 1,3-Propane sultone
  • Red meat consumption
  • Silicon carbide whiskers
  • Soluble cobalt(II) salts
  • Styrene
  • Styrene-7,8-oxide
  • Talc
  • Teniposide
  • Tetrabromobisphenol A
  • 3,3′,4,4′-Tetrachloroazobenzene
  • Tetrachloroethylene or perchloroethylene
  • Tetrafluoroethylene
  • 1,1,1-Trichloroethane
  • 1,2,3-Trichloropropane
  • Tris(2,3-dibromopropyl) phosphate
  • Tris(chloropropyl) phosphate (TCPP)
  • Trivalent antimony
  • Very hot beverages above 65 degrees Celsius
  • Vinyl bromide (Note: Vinyl bromide acts similarly to the human carcinogen vinyl chloride.)

Vinyl fluoride (Note: Vinyl fluoride acts similarly to the human carcinogen vinyl chloride.)

Learn more about the topics in this list in the NTP’s Report on Carcinogens.

  • Acetaldehyde
  • 2-Acetylaminofluorene
  • Acrylamide
  • Acrylonitrile
  • Adriamycin (doxorubicin hydrochloride)
  • 2-Aminoanthraquinone
  • o-Aminoazotoluene
  • 1-Amino-2,4-dibromoanthraquinone
  • 1-Amino-2-methylanthraquinone
  • 2-Amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ)
  • 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)
  • 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ)
  • 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)
  • Amitrole
  • o-Anisidine and its hydrochloride
  • Antimony trioxide
  • Azacitidine (5-Azacytidine, 5-AzaC)
  • Basic Red 9 Monohydrochloride
  • Benz[a]anthracene
  • Benzo[b]fluoranthene
  • Benzo[j]fluoranthene
  • Benzo[k]fluoranthene
  • Benzo[a]pyrene
  • Benzotrichloride
  • 2, 2-bis-(bromoethyl)-1,3-propanediol (technical grade)
  • Bromochloroacetic acid (BCA)
  • Bromodichloroacetic acid (BDCA)
  • Bromodichloromethane
  • 1-Bromopropane
  • Butylated hydroxyanisole (BHA)
  • Captafol
  • Carbon tetrachloride
  • Ceramic fibers (respirable size)
  • Chloramphenicol
  • Chlorendic acid
  • Chlorinated paraffins (C12, 60% chlorine)
  • Chlorodibromoacetic acid (CDBA)
  • Chloroform
  • 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea
  • Bis(chloroethyl) nitrosourea
  • 3-Chloro-2-methylpropene
  • 4-Chloro-o-phenylenediamine
  • Chloroprene
  • p-Chloro-o-toluidine and p-chloro-o-toluidine hydrochloride
  • Chlorozotocin
  • Cisplatin
  • Cobalt and cobalt compounds that release cobalt ions in vivo
  • Cobalt-tungsten carbide: powders and hard metals
  • p-Cresidine
  • Cumene
  • Cupferron
  • Dacarbazine
  • Danthron (1,8-dihydroxyanthraquinone)
  • 2,4-Diaminoanisole sulfate
  • 2,4-Diaminotoluene
  • Diazoaminobenzene
  • Dibenz[a,h]acridine
  • Dibenz[a,j]acridine
  • Dibenz[a,h]anthracene
  • 7H-Dibenzo[c,g]carbazole
  • Dibenzo[a,e]pyrene
  • Dibenzo[a,h]pyrene
  • Dibenzo[a,i]pyrene
  • Dibenzo[a,l]pyrene
  • Dibromoacetic acid (DBA)
  • 1,2-Dibromo-3-chloropropane
  • 1,2-Dibromoethane (ethylene dibromide)
  • 2,3-Dibromo-1-propanol
  • Dichloroacetic acid (DCA)
  • 1,4-Dichlorobenzene
  • 3,3'-Dichlorobenzidine and 3,3'-dichlorobenzidine dihydrochloride
  • Dichlorodiphenyltrichloroethane (DDT)
  • 1,2-Dichloroethane (ethylene dichloride)
  • Dichloromethane (methylene chloride)
  • 1,3-Dichloropropene (technical grade)
  • Diepoxybutane
  • Diesel exhaust particulates
  • Di(2-ethylhexyl) phthalate
  • Diethyl sulfate
  • Diglycidyl resorcinol ether
  • 3,3'-Dimethoxybenzidine
  • 4-Dimethylaminoazobenzene
  • 3,3'-Dimethylbenzidine
  • Dimethylcarbamoyl chloride
  • 1,1-Dimethylhydrazine
  • Dimethyl sulfate
  • Dimethylvinyl chloride
  • 1,6-Dinitropyrene
  • 1,8-Dinitropyrene
  • 1,4-Dioxane
  • Disperse Blue 1
  • Dyes metabolized to 3,3'-dimethoxybenzidine
  • Dyes metabolized to 3,3'-dimethylbenzidine
  • Epichlorohydrin
  • Ethylene thiourea
  • Ethyl methanesulfonate
  • Furan
  • Glass wool fibers (inhalable)
  • Glycidol
  • Hexachlorobenzene
  • Hexachloroethane
  • Hexamethylphosphoramide
  • Hydrazine and hydrazine sulfate
  • Hydrazobenzene
  • Indeno[1,2,3-cd]pyrene
  • Iron dextran complex
  • Isoprene
  • Kepone (chlordecone)
  • Lead and lead compounds
  • Lindane, hexachlorocyclohexane (technical grade), and other hexachlorocyclohexane isomers
  • 2-Methylaziridine (propyleneimine)
  • 5-Methylchrysene
  • 4,4'-Methylenebis(2-chloroaniline)
  • 4,4'-Methylenebis(N,N-dimethyl)benzenamine
  • 4,4'-Methylenedianiline and its dihydrochloride salt
  • Methyleugenol
  • Methyl methanesulfonate
  • N-methyl-N'-nitro-N-nitrosoguanidine
  • Metronidazole
  • Michler’s ketone [4,4'-(dimethylamino) benzophenone]
  • Mirex
  • Naphthalene
  • Nickel, metallic
  • Nitrilotriacetic acid
  • o-Nitroanisole
  • Nitrobenzene
  • 6-Nitrochrysene
  • Nitrofen (2,4-dichlorophenyl-p-nitrophenyl ether)
  • Nitrogen mustard hydrochloride
  • Nitromethane
  • 2-Nitropropane
  • 1-Nitropyrene
  • 4-Nitropyrene
  • N-nitrosodi-n-butylamine
  • N-nitrosodiethanolamine
  • N-nitrosodiethylamine
  • N-nitrosodimethylamine
  • N-nitrosodi-n-propylamine
  • N-nitroso-N-ethylurea
  • 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone
  • N-nitroso-N-methylurea
  • N-nitrosomethylvinylamine
  • N-nitrosomorpholine
  • N-nitrosonornicotine
  • N-nitrosopiperidine
  • N-nitrosopyrrolidine
  • N-nitrososarcosine
  • o-Nitrotoluene
  • Norethisterone
  • Ochratoxin A
  • 4,4'-Oxydianiline
  • Oxymetholone
  • Pentachlorophenol and by-products of its synthesis
  • Phenacetin
  • Phenazopyridine hydrochloride
  • Phenolphthalein
  • Phenoxybenzamine hydrochloride
  • Phenytoin and phenytoin sodium
  • Polybrominated biphenyls (PBBs)
  • Polychlorinated biphenyls (PCBs)
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Procarbazine and its hydrochloride
  • Progesterone
  • 1,3-Propane sultone
  • beta-Propiolactone
  • Propylene oxide
  • Propylthiouracil
  • Reserpine
  • Riddelliine
  • Safrole
  • Selenium sulfide
  • Streptozotocin
  • Styrene
  • Styrene-7,8-oxide
  • Sulfallate
  • Tetrachloroethylene (perchloroethylene)
  • Tetrafluoroethylene
  • Tetranitromethane
  • Thioacetamide
  • 4,4'-Thiodianiline
  • Thiourea
  • Toluene diisocyanates
  • Toxaphene
  • Tribromoacetic acid (TBA)
  • 2,4,6-Trichlorophenol
  • 1,2,3-Trichloropropane
  • Tris(2,3-dibromopropyl) phosphate
  • Ultraviolet A (UVA) radiation
  • Ultraviolet B (UVB) radiation
  • Ultraviolet C (UVC) radiation
  • Urethane
  • Vinyl bromide
  • 4-Vinyl-1-cyclohexene diepoxide
  • Vinyl fluoride or vinyl halides

Do carcinogens always cause cancer?

Carcinogens do not cause cancer at all times, under all circumstances. In other words, a carcinogen does not always cause cancer in every person, every time there is any kind of exposure. For example:

  • Some may be carcinogenic only if a person is exposed in a certain way, such as swallowing the substance instead of touching it.
  • Some may only cause cancer in people who have a certain genetic makeup, such as specific concerns related to their ethnicity or family history.
  • Some may lead to cancer only after a very small exposure, while others might take intense exposure over many years to cause cancer.

Even if a substance or exposure is known or suspected to cause cancer, this does not necessarily mean that it can or should be avoided all the time. For example, sunlight is a major source of harmful ultraviolet (UV) rays that are a known cause of skin cancer. While protecting yourself from harmful rays is recommended, completely avoiding the sun isn’t always practical or advised. See How to Interpret News About Cancer Causes to learn more.

Additional resources

In addition to IARC and NTP, other organizations that provide trustworthy sources of information about carcinogens include:

Environmental Protection Agency (EPA)
Website: www.epa.gov
Integrated Risk Information System: www.epa.gov/iris

Food and Drug Administration (FDA)
Website: www.fda.gov

National Cancer Institute
Website: www.cancer.gov
Causes and Prevention: www.cancer.gov/cancertopics/causes

National Institute for Occupational Safety and Health (NIOSH)
Website: www.cdc.gov/niosh
Occupational Cancer: www.cdc.gov/niosh/cancer/about
NIOSH Carcinogen List: www.cdc.gov/niosh/npg/nengapdxa.html

American Cancer Society logo

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

International Agency for Research on Cancer (IARC). Agents Classified by the IARC Monographs, Volumes 1–141. March 2026. Accessed at https://monographs.iarc.who.int/agents-classified-by-the-iarc/ on May 6, 2026.

International Agency for Research on Cancer (IARC). Preamble to the IARC Monographs. 2021. Accessed at https://monographs.iarc.fr/preamble-to-the-iarc-monographs/ on May 6, 2026.

International Agency for Research on Cancer (IARC). IARC Monographs evaluation of the carcinogenicity of tris(chloropropyl) phosphate, butyraldehyde, and cumyl hydroperoxide. March 2026. Accessed at https://www.iarc.who.int/news-events/iarc-monographs-evaluation-of-the-carcinogenicity-of-trischloropropyl-phosphate-butyraldehyde-and-cumyl-hydroperoxide/ on May 6, 2026.

National Cancer Institute (NCI). Environmental Carcinogens and Cancer Risk. 2023. Accessed at https://www.cancer.gov/about-cancer/causes-prevention/risk/substances/carcinogens on May 6, 2026.

US Department of Health and Human Services. National Toxicology Program. Report on Carcinogens, Fifteenth Edition. U.S. Department of Health and Human Services. Published December 21, 2021. Accessed at https://ntp.niehs.nih.gov/research/assessments/cancer/roc onMay 6, 2026.

Last Revised: May 6, 2026

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.

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