【国际癌症研究机构二B类致癌物】
2B类致癌物（Group 2B carcinogens），为国际癌症研究机构（International Agency for Research on Cancer，IARC）对致癌物质的分类，此类物质（或其混合物）可能对人类致癌。time=2017-03-05236类物质（如黄樟素、四氯化碳、电磁波、抗甲状腺药物丙硫氧嘧啶（propylthiouracil）、二异氰酸甲苯、抗爱滋病药物齐多夫定（zidovudine）、汽油引擎废气、干洗业等），对人类为有可能致癌物，对动物为很可能也是致癌物。更多详细信息，可以搜寻国际癌症研究机构（IARC）专著。
==物质和物质组合==
*3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone
*Chloroform
*1-Chloro-2-methylpropene
*Chlorophenoxy herbicides
*4-Chloro-ortho-phenylenediamine
*Chloroprene
*Chlorothalonil
*Chrysene
*CI Acid Red 114
*CI Basic Red 9
*CI Direct Blue 15
*Citrus Red No. 2
*Cobalt and cobalt compounds 1
*Cobalt sulfate and other soluble cobalt(II) salts
*Coconut oil diethanolamine condensate
*para-Cresidine
*Cycasin
*Dacarbazine
*Dantron (Chrysazin, 1,8-Dihydroxyanthraquinone)
*Daunomycin
*DDT (p,p-DDT)
*N,N'-Diacetylbenzidine
*2,4-Diaminoanisole
*4,4'-Diaminodiphenyl ether
*2,4-Diaminotoluene
*Dibenza,hacridine
*Dibenza,jacridine
*7H-Dibenzoc,gcarbazole
*Dibenzoa,epyrene
*Dibenzoa,hpyrene
*Dibenzoa,ipyrene
*1,2-Dibromo-3-chloropropane
*2,3-Dibromopropan-1-ol
*Dichloroacetic acid
*para-Dichlorobenzene
*3,3'-Dichlorobenzidine
*3,3'-Dichloro-4,4'-diaminodiphenyl ether
*1,2-Dichloroethane
*Dichloromethane (methylene chloride)
*1,3-Dichloropropene (technical grade)
*Dichlorvos
*1,2-Diethylhydrazine
*Diglycidyl resorcinol ether
*Dihydrosafrole
*Diisopropyl sulfate
*3,3'-Dimethoxybenzidine (o-Dianisidine)
*para-Dimethylaminoazobenzene
*trans-2-(Dimethylamino)methylimino-5-2-(5-nitro-2-furyl)-vinyl-1,3,4-oxadiazole
*2,6-Xylidine (2,6-Dimethylaniline)
*3,3'-Dimethylbenzidine (o-Tolidine)
*1,1-Dimethylhydrazine
*3,7-Dinitrofluoranthene
*3,9-Dinitrofluoranthene
*1,6-Dinitropyrene
*1,8-Dinitropyrene
*2,4-Dinitrotoluene
*2,6-Dinitrotoluene
*1,4-Dioxane
*Disperse Blue 1
*1,2-Epoxybutane
*Ethyl acrylate
*Ethylbenzene
*Ethylene dichloride
*Ethyl methanesulfonate
*Foreign bodies, implanted in tissues
:Polymeric, prepared as thin smooth films (with the exception of poly(glycolic acid))
:Metallic, prepared as thin smooth films
:Metallic cobalt, metallic nickel and an alloy powder containing 66-67% nickel, 13-16% chromium and 7% iron
*2-(2-Formylhydrazino)-4-(5-nitro-2-furyl)thiazole
*Fumonisin B1
*Furan
*Glu-P-1 (2-Amino-6-methyldipyrido1,2-a:3',2'-dimidazole)
*Glu-P-2 (2-Aminodipyrido1,2-a:3',2'-dimidazole)
*Glycidaldehyde
*Griseofulvin
*HC Blue No. 1
*Heptachlor
*Hexachlorobenzene
*Hexachloroethane
*Hexachlorocyclohexanes
*Hexamethylphosphoramide (HMPA)
*Human immunodeficiency virus type 2 (infection with)
*Human papillomaviruses: some types other than 16, 18, 31 and 33
*Hydrazine
*1-Hydroxyanthraquinone
*Indeno1,2,3-cdpyrene
*Iron-dextran complex
*Isoprene
*Lasiocarpine
*Lead
*Magnetic fields (extremely low frequency)
*MeA-a-C (2-Amino-3-methyl-9H-pyrido2,3-bindole)
*Medroxyprogesterone acetate
*MeIQ (2-Amino-3,4-dimethylimidazo4,5-fquinoline)
*MeIQx (2-Amino-3,8-dimethylimidazo4,5-fquinoxaline)
*Merphalan
*2-Methylaziridine (Propyleneimine)
*Methylazoxymethanol acetate
*5-Methylchrysene
*4,4'-Methylene bis(2-methylaniline)
*4,4'-Methylenedianiline
*Methylmercury compounds 1
*2-Methyl-1-nitroanthraquinone (uncertain purity)
*N-Methyl-N-nitrosourethane
*Methylthiouracil
*Metronidazole
*Michler's base (4,4'-methylene-bis(N,N-dimethyl)benzenamine)
*Michler's ketone (4,4'-bis(dimethylamino)benzophenone)
*Microcystin-LR
*Mirex
*Mitomycin C
*Mitoxantrone
*Monocrotaline
*5-(Morpholinomethyl)-3-(5-nitrofurfurylidene)amino-2-oxazolidinone
*Nafenopin
*Naphthalene
*Nickel, metallic and alloys
*Niridazole
*Nitrilotriacetic acid and its salts 1
*5-Nitroacenaphthene
*2-Nitroanisole
*Nitrobenzene
*6-Nitrochrysene
*Nitrofen (technical-grade)
*2-Nitrofluorene
*1-(5-Nitrofurfurylidene)amino-2-imidazolidinone
*N-4-(5-Nitro-2-furyl)-2-thiazolylacetamide
*Nitrogen mustard N-oxide
*Nitromethane
*2-Nitropropane
*1-Nitropyrene
*4-Nitropyrene
*N-Nitrosodi-n-butylamine
*N-Nitrosodiethanolamine
*N-Nitrosodi-n-propylamine
*3-(N-Nitrosomethylamino)propionitrile
*N-Nitrosomethylethylamine
*N-Nitrosomethylvinylamine
*N-Nitrosomorpholine
*N-Nitrosopiperidine
*N-Nitrosopyrrolidine
*N-Nitrososarcosine
*Ochratoxin A
*Oestrogen-progestogen therapy, postmenopausal
*Oil Orange SS
*Oxazepam
*Palygorskite (attapulgite)  (long fibres, >5µm)
*Panfuran S (containing dihydroxymethylfuratrizine)
*Phenazopyridine hydrochloride
*Phenobarbital
*Phenolphthalein
*Phenoxybenzamine hydrochloride
*Phenyl glycidyl ether
*Phenytoin
*PhIP (2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine)
*Polychlorophenols and their sodium salts (mixed exposures)
*Ponceau MX
*Ponceau 3R
*Potassium bromate
*Progestins
*Progestogen-only contraceptives
*1,3-Propane sultone
*β-Propiolactone
*Propylene oxide
*-{zh-hans:丙硫氧嘧啶;zh-hant:硫月尿酮;}-（Propylthiouracil、PTU），抗甲状腺药物
*Radiofrequency electromagnetic fields, such as, but not limited to, those associated with wireless phones
*Refractory ceramic fibres
*Riddelliine
*黄樟素Safrole
*Schistosoma japonicum (infection with)
*Sodium ortho-phenylphenate
*Special-purpose fibres such as E-glass and '475' glass fibres
*Sterigmatocystin
*Streptozotocin
*Styrene
*Sulfallate
*Tetrafluoroethylene
*Tetranitromethane
*Thioacetamide
*4,4'-Thiodianiline
*Thiouracil
*Titanium dioxide
*二异氰酸甲苯（2,4-Toluene diiso-cyanate, 2,4-TDI）
*Trichlormethine (Trimustine hydrochloride)
*Trp-P-1 (3-Amino-1,4-dimethyl-5H-pyrido4,3-bindole)
*Trp-P-2 (3-Amino-1-methyl-5H-pyrido4,3-bindole)
*Trypan blue
*Uracil mustard
*Vanadium pentoxide
*Vinyl acetate
*4-Vinylcyclohexene
*4-Vinylcyclohexene diepoxide
*Zalcitabine
*齐多夫定（Zidovudine，AZT）
==混合物==
*沥青
*角叉菜胶
*氯化石蜡
*柴油
*汽油发动机尾气
*重油
*汽油
*品红染料
*腌、泡制的蔬菜（一些亚洲传统食品）
*多溴化联苯（多溴联苯标准品）
*毒杀芬（多氯莰烯）
*串珠镰刀菌分泌的毒素
*焊接烟尘
==接触场合==
*房屋建材与木工装潢
*钴（未存放于碳化钨盒内）
*干洗
*消防
*印刷过程
*滑石粉（粉尘）
*纺织工业（生产过程）