International Agency for Research on Cancer (IARC) - Summaries & Evaluations

(Group 3)

For definition of Groups, see Preamble Evaluation.

Supplement 7: (1987) (p. 318)

CAS No.: 135-88-6
Chem. Abstr. Name: N-Phenyl-2-naphthalenamine

A. Evidence for carcinogenicity to humans (inadequate)

No excess of bladder tumours was found among men in a rubber processing factory with known exposure to N-phenyl-2-naphthylamine (which contained small amounts of 2-naphthylamine); however, a study of rubber workers who were not exposed to 2-naphthylamine did show an increased incidence of bladder tumours. In the latter study, the men were exposed to several compounds, which probably included N-phenyl-2-naphthylamine [ref: 1].

B. Evidence for carcinogenicity to animals (limited)

N-Phenyl-2-naphthylamine was tested for carcinogenicity by oral administration in mice, rats, hamsters and dogs. No carcinogenicity was reported in most experiments [ref: 1-4]. In one experiment, the total tumour incidence and the incidence of hepatocellular tumours were increased in male mice of one strain [ref: 1]. In another experiment, two rare kidney tumours were seen in female mice [ref: 2]. Subcutaneous administration to mice increased the total tumour incidence [ref: 1] and the incidences of lung [ref: 5] and liver neoplasms [ref: 1]. Repeated subcutaneous injection after previous unilateral nephrectomy in mice resulted in a significant increase in the total tumour incidence and in the incidences of haemangiosarcomas of the kidney and of carcinomas of the lung [ref: 6,7]. Following exposure of mice by inhalation in one study, lung carcinomas were reported [ref: 8].

C. Other relevant data

There is some evidence from one study of 19 human volunteers that up to 0.03% of a single 10-mg dose of N-phenyl-2-naphthylamine is converted to 2-naphthylamine. Similarly, the urine of workers exposed to N-phenyl-2-naphthylamine was found to contain 2-naphthylamine, indicating that N-phenyl-2-naphthylamine is dephenylated in the human body [ref:1]. No data were available on the genetic effects of N-phenyl-2-naphthylamine in humans. It was reported not to be mutagenic to bacteria [ref: 9].

Overall evaluation

N-Phenyl-2-naphthylamine is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.

Also see previous evaluation: Vol. 16 (1978)


1. IARC Monographs, 16, 325-341, 1978

2. National Toxicology Program (1987) Technical Report on the Toxicology and Carcinogenesis Studies of N-Phenyl-2-naphthylamine (CAS No. 135-88-6) in F344/N Rats and B6C3F1 Mice (Feed Studies) (Tech. Rep. No. 333; NIH Publ. No. 87-2589), Research Triangle Park, NC

3. Ketkar, M.B. & Mohr, U. (1982) The chronic effects of magenta, paramagenta and phenyl-b

-naphthylamine in rats after intragastric administration. Cancer Lett., 16, 203-206

4. Green, U., Holste, J. & Spikermann, A.R. (1979) A comparative study of the chronic effects of magenta, paramagenta and phenyl-b-napthylamine in Syrian golden hamsters. J. Cancer Res. clin. Oncol., 95, 51-55

5. Wang, H., Dzeng, R. & Wang, D. (1982) The carcinogenicity of N-phenyl-2-naphthylamine in ICR mice (Chin.). Acta biol. exp. sin., 15, 199-207

6. Wang, D., Zeng, R. & Wang, H. (1983) A comparative study on carcinogenic activity of PBNA and PANA in unilaterally nephrectomized TA-1 mice (Chin.). Acta sci. circumst., 3, 262-266

7. Wang, H., Wang, D. & Dzeng, R. (1984) Carcinogenicity of N-phenyl-1-naphthylamine and N-phenyl-2-naphthylamine in mice. Cancer Res., 44, 3098-3100

8. You, X. & Yao, Y. (1981) Experimental study of inhalation carcinogenesis of N-phenyl-2-naphthylamine aerosol on mice (Chin.). Acta biol. exp. sinica, 14, 139-143

9. IARC Monographs, Suppl. 6, 461-462, 1987


Last updated: 11 March 1998

    See Also:
       Toxicological Abbreviations
       N-Phenyl-2-Naphthylamine (IARC Summary & Evaluation, Volume 16, 1978)