4-Aminobiphenyl
4-Aminobiphenyl (4-ABP) is an organic compound with the formula C6H5C6H4NH2. It is an amine derivative of biphenyl. It is a colorless solid, although aged samples can appear colored. 4-Aminobiphenyl was commonly used in the past as a rubber antioxidant and an intermediate for dyes.[5] Exposure to this aryl-amine can happen through contact with chemical dyes and from inhalation of cigarette smoke.[6] Researches showed that 4-aminobiphenyl is responsible for bladder cancer in humans and dogs by damaging DNA.[7] Due to its carcinogenic effects, commercial production of 4-aminobiphenyl ceased in the United States in the 1950s.[8]
Toxicity[edit]
Human toxicity[edit]
Toxic fumes arise from this compound when heated to decomposition.[13] Excessive inhalation exposure of 4-aminobiphenyl may induce acute toxicity such as headache, lethargy, cyanosis and burning sensations mainly in the urinary tract.[14]
4-Aminobiphenyl is a human carcinogen, specifically to the tissues involving the urinary system, i.e., the bladder, ureter, and renal pelvis. In one study, out of 171 workers in a plant manufacturing 4-aminobiphenyl, 11% of them developed bladder tumors.[13] Tumors appeared on subjects which were exposed by 4-aminobiphenyl in a range of duration from 1.5 to 19 years. The compound can be metabolized by humans which the product may form adducts with DNA in human urothelial mucosa and bladder tumor tissues. Levels of these adducts in smokers of blond and black tobacco were found to be proportional to bladder cancer risk.[13]
Animal toxicity[edit]
The LD50 (dogs, oral) is 25 mg/kg.[15] The oral LD50 for rats are 500 mg/kg body weight and for rabbits are 690 mg/kg body weight.[16] Repeated oral administration of a 25% 4-aminobiphenyl solution in olive oil led rabbits to weight loss, anemia, decrease in the number of lymphocytes, increase of granulocytes or the rod neutrophilic granulocyte and to a pronounced hematuria or hemoglobinuria.[14]