The World Health Organization's International Agency for Research on Cancer now considers cellphones usage to be a possible, or "Class 2B," carcinogen. Here's everything else they consider to be a 2B carcinogen, otherwise presented without comment:

A-alpha-C (2-Amino-9H-pyrido[2,3-b]indole)
Acetaldehyde
Acetamide
Acrylonitrile
AF-2 [2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide]
Aflatoxin M1
para-Aminoazobenzen
ortho-Aminoazotoluene
1-Amino-2,4-dibromoanthraquinone
2-Amino-5-(5-nitro-2-furyl)-1,3,4-thiadiazole
Amsacrine
ortho-Anisidine
Anthraquinone
Antimony trioxide
Aramite®
Auramine
Azaserine
Aziridine
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Benz[j]aceanthrylene
(NB: Overall evaluation upgraded to Group 2B with
supporting mechanistic and other relevant data)
Benz[a]anthracene
Benzo[b]fluoranthene
Benzo[j]fluoranthene
Benzo[k]fluoranthene
Benzofuran
Benzo[c]phenanthrene
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Benzophenone
Benzyl violet 4B
2,2-Bis(bromomethyl)propane-1,3-diol
Bitumens, extracts of steam-refined and air-refined
Bleomycins
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Bracken fern
Bromochloroacetic acid
Bromodichloromethane
Butylated hydroxyanisole (BHA)
beta-Butyrolactone
Caffeic acid
Carbon black
Carbon tetrachloride
Carpentry and joinery
Carrageenan, degraded (Poligeenan)
Catechol
Chlordane
Chlordecone (Kepone)
Chlorendic acid
Chlorinated paraffins of average carbon chain length C12
and average degree of chlorination approximately 60%
para-Chloroaniline
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
(NB: Evaluated as a group)
Cobalt metal without tungsten carbide
Cobalt sulfate and other soluble cobalt(II) salts
Coconut oil diethanolamine condensate
Coffee (urinary bladder)
(NB: There is some evidence of an inverse relationship
between coffee drinking and cancer of the large bowel;
coffee drinking could not be classified as to its
carcinogenicity to other organs)
para-Cresidine
Cumene
Cycasin
Dacarbazine
Dantron (Chrysazin; 1,8-Dihydroxyanthraquinone)
Daunomycin
DDT (4,4'-Dichlorodiphenyltrichloroethane)
N,N'-Diacetylbenzidine
2,4-Diaminoanisole
4,4'-Diaminodiphenyl ether
2,4-Diaminotoluene
Dibenz[a,h]acridine
Dibenz[a,j]acridine
7H-Dibenzo[c,g]carbazole
Dibenzo[a,h]pyrene
Dibenzo[a,i]pyrene
Dibromoacetic acid
Dibromoacetonitrile
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-Dichloro-2-propanol
1,3-Dichloropropene (technical-grade)
Dichlorvos
Diesel fuel, marine
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Diethanolamine
Di(2-ethylhexyl)phthalate
1,2-Diethylhydrazine
Diglycidyl resorcinol ether
Dihydrosafrole
Diisopropyl sulfate
3,3'-Dimethoxybenzidine (ortho-Dianisidine)
para-Dimethylaminoazobenzene
trans-2-[(Dimethylamino)methylimino]-5-[2-(5-nitro-2-furyl)-vinyl]-1,3,4-oxadiazole
2,6-Dimethylaniline (2,6-Xylidine)
Dimethylarsenic acid
3,3'-Dimethylbenzidine (ortho-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
Dry cleaning (occupational exposures in)
Engine exhaust, gasoline
1,2-Epoxybutane
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Ethyl acrylate
Ethylbenzene
Ethyl methanesulfonate
Firefighter (occupational exposure as a)
2-(2-Formylhydrazino)-4-(5-nitro-2-furyl)thiazole
Fuel oils, residual (heavy)
Fumonisin B1
Furan
Fusarium moniliforme, toxins derived from (fumonisin B1,
fumonisin B2, and fusarin C)
Gasoline
(NB: Overall evaluation upgraded to Group 2B with
supporting evidence from other relevant data)
Glu-P-1 (2-Amino-6-methyldipyrido[1,2-a:3',2'-
d]imidazole)
Glu-P-2 (2-Aminodipyrido[1,2-a:3',2'-d]imidazole)
Glycidaldehyde
Griseofulvin
HC Blue No. 1
Heptachlor
Hexachlorobenzene
Hexachlorocyclohexanes
Hexachloroethane
2,4-Hexadienal
Hexamethylphosphoramide
Human immunodeficiency virus type 2 (infection with)
Human papillomavirus types 5 and 8 (in patients with
epidermodysplasia verruciformis)
Human papillomavirus types 26, 53, 66, 67, 70, 73, 82
Human papillomavirus types 30, 34, 69, 85, 97
(NB: Classified by phylogenetic analogy to the HPV genus alpha types classified in Group 1)
Hydrazine
1-Hydroxyanthraquinone
Indeno[1,2,3-cd]pyrene
Iron-dextran complex
Isoprene
Lasiocarpine
Lead
Magenta
Magnetic fields, extremely low-frequency
MeA-alpha-C (2-Amino-3-methyl-9H-pyrido[2,3-b]indole)
Medroxyprogesterone acetate
MeIQ (2-Amino-3,4-dimethylimidazo[4,5-f]quinoline)
MeIQx (2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline)
Merphalan
Methylarsonic acid
2-Methylaziridine (Propyleneimine)
Methylazoxymethanol acetate
5-Methylchrysene
4,4'-Methylene bis(2-methylaniline)
4,4'-Methylenedianiline
Methyleugenol
2-Methylimidazole
4-Methylimidazole
Methyl isobutyl ketone
Methylmercury compounds
(NB: Evaluated as a group)
2-Methyl-1-nitroanthraquinone (uncertain purity)
N-Methyl-N-nitrosourethane
Methylthiouracil
Metronidazole
Michler's base [4,4′-methylenebis(N,N-dimethyl)-benzenamine]
Michler's ketone [4,4′-Bis(dimethylamino)benzophenone]
Microcystin-LR
Mirex
Mitomycin C
Mitoxantrone
3-Monochloro-1,2-propanediol
Monocrotaline
5-(Morpholinomethyl)-3-[(5-nitrofurfurylidene)amino]-2-
oxazolidinone
Nafenopin
Naphthalene
Nickel, metallic and alloys
Niridazole
Nitrilotriacetic acid and its salts
(NB: Evaluated as a group)
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-thiazolyl]acetamide
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
Oil Orange SS
Oxazepam
Palygorskite (Attapulgite) (long fibres, > 5 micrometres)
Panfuran S (containing dihydroxymethylfuratrizine)
Pickled vegetables (traditional in Asia)
Phenazopyridine hydrochloride
Phenobarbital
Phenolphthalein
Phenoxybenzamine hydrochloride
Phenyl glycidyl ether
Phenytoin
PhIP (2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine)
Polybrominated biphenyls
Polychlorophenols and their sodium salts (mixed exposures)
Ponceau 3R
Ponceau MX
Potassium bromate
Printing processes (occupational exposures in)
Progestins
Progestogen-only contraceptives
1,3-Propane sultone
beta-Propiolactone
Propylene oxide
Propylthiouracil
Refractory ceramic fibres
Riddelliine
Safrole
Schistosoma japonicum (infection with)
Sodium ortho-phenylphenate
Special-purpose fibres such as E-glass and '475' glass fibres
Sterigmatocystin
Streptozotocin
Strontium-90 (see Fission products)
Sulfallate
Surgical implants and other foreign bodies:
- Polymeric implants prepared as thin smooth film (with
the exception of poly(glycolic acid))
- Metallic implants prepared as thin smooth films
- Implanted foreign bodies of metallic cobalt, metallic
nickel and an alloy powder containing 66-67% nickel,
13-16% chromium and 7% iron
Talc-based body powder (perineal use of)
Tetrafluoroethylene
Tetranitromethane
Textile manufacturing industry (work in)
Thioacetamide
4,4'-Thiodianiline
Thiouracil
Titanium dioxide
Toluene diisocyanates
Toxaphene (Polychlorinated camphenes)
Trichlormethine (Trimustine hydrochloride)
Trp-P-1 (3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole)
Trp-P-2 (3-Amino-1-methyl-5H-pyrido[4,3-b]indole)
Trypan blue
Uracil mustard
Vanadium pentoxide
Vinyl acetate
4-Vinylcyclohexene
4-Vinylcyclohexene diepoxide
Welding fumes
(NB: Volume 100D concluded that there is sufficient
evidence for ocular melanoma in welders)
Zalcitabine
Zidovudine (AZT)

[IARC (PDF)]