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


VOL.: 17 (1978) (p. 51)

CAS No.: 924-16-3
Chem. Abstr. Name: N-Butyl-N-nitroso-l-butamine

5. Summary of Data Reported and Evaluation

5.1 Experimental data

N-Nitrosodi-n-butylamine is carcinogenic in all animal species tested: mice, rats, Syrian golden, Chinese and European hamsters, rabbits and guinea-pigs, after its oral, subcutaneous, intraperitoneal or intravenous administration. It produces benign and malignant tumours in the urinary bladder, oesophagus, liver, respiratory tract, stomach and intestine, and also leukaemia; it is particularly effective as a bladder carcinogen. It is carcinogenic following its administration prenatally and in single doses.

The two metabolites, N-nitroso-n-butyl-N-(4-hydroxybutyl)amine and N-nitroso-n-butyl-N-
(3-carboxypropyl)amine are also carcinogenic, the first in mice, rats, hamsters and dogs and the second in rats. When given orally to mice, N-nitroso-n-butyl-N-(4-hydroxybutyl)amine produces carcinomas of the urinary bladder; when given orally or intravesicularly to rats, it produces papillomas and carcinomas of the urinary bladder; when given subcutaneously to hamsters, it produces tumours of the urinary bladder and respiratory tract and cholangiocellular tumours; and when given subcutaneously to dogs, it produces urinary bladder tumours. N-nitroso-n-butyl-N-(3-carboxy-
propyl)amine produces tumours of the urinary bladder in rats after its oral administration or intravesicular instillation.

5.2 Human data

No case reports or epidemiological studies were available to the Working Croup. Available information on occurrence suggests that the general population may be exposed sporadically to low levels of N-nitrosodi-n-butylamine; however, no exposed group suitable for an epidemiological investigation has yet been identified.

5.3 Evaluation

There is sufficient evidence of a carcinogenic effect of N-nitrosodi- n-butylamine in several experimental animal species. Although no epidemiological data were available, N-nitrosodi-n-butylamine should be regarded for practical purposes as if it were carcinogenic to humans.

Previous evaluation: Vol. 4 (1974)

Subsequent evaluation: Suppl. 7 (1987) (p. 67: Group 2B)

For definition of terms, see Preamble Evaluation.


Last updated: 25 March 1998

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