<unk>  is used in the production of azo dyes and is considered a carcinogen. It contains two benzene rings. This compound has been shown to increase the incidence of tumors in animals.  Because it is structurally similar to benzidine, a known carcinogen, it is believed that it may share a similar mechanism in causing bladder cancer in humans.
3,3-Dichlorobenzidine
Diiodohydroxyquinoline
2,4-Dichlorobenzyl alcohol
Nitrazine
N,N-Dimethyl-P-Toluidine
Chloroethane
Indigo carmine
Trichloroethylene