International Agency for Research on Cancer (IARC) - Summaries & Evaluations
ortho-TOLUIDINE AND ortho-TOLUIDINE HYDROCHLORIDE
VOL.: 27 (1982) (p. 155)
ortho-Toluidine
CAS No.: 95-53-4
Chem. Abstr. Name: Benzenamine, 2-methyl-
ortho-Toluidine hydrochloride
CAS No.: 636-21-5
Chem. Abstr. Name: Benzenamine, 2-methyl-, hydrochloride
5. Summary of Data Reported and Evaluation
5.1 Experimental data
ortho-Toluidine hydrochloride was tested in several experiments, but
only two experiments in mice and two experiments in rats by oral
administration were adequate. It was carcinogenic in mice, producing
hepatocellular carcinomas or adenomas in females and haemangiosarcomas
at all sites in males of one strain and haemangiosarcomas and
haemangiomas of abdominal viscera in animals of both sexes of another
strain. It was carcinogenic in rats: in animals of one strain it
produced sarcomas of multiple organs in animals of both sexes,
fibromas of the subcutaneous tissue and mesotheliomas in males; and
sarcomas of the spleen, transitional-cell papillomas and carcinomas of
the urinary bladder and mammary gland fibroadenomas and adenomas in
females. In male rats of another strain it produced subcutaneous
fibromas and fibrosarcomas as well as a slight increase in the
incidence of multiple tumours, including transitional-cell carcinomas
of the urinary bladder.
ortho-Toluidine gave positive results in Escherichia coli DNA-repair
and phage-induction assays, but it was not mutagenic in Salmonella
typhimurium unless tested in the presence of both norharman and a
metabolic activation system. Urine concentrates from rats treated
with ortho-toluidine were mutagenic for S. typhimurium with metabolic
activation.
5.2 Human data
ortho-Toluidine has been produced commercially since 1880. Its use as
an intermediate in the manufacture of dyes and other chemicals as well
as its occurrence as an impurity in some formulated corrosion
inhibitors could result in occupational exposure.
The epidemiological studies available to the Working Group dealt only
with workers who had been exposed to ortho-toluidine in combination
with other chemicals. The majority were case reports and did not
provide estimates of the population at risk. In one follow-up study,
five cases of bladder cancer (0.08 expected) occurred in 53 men
exposed to ortho-toluidine and to other possibly carcinogenic agents
in the manufacture of Fuchsine and Safranine T.
5.3 Evaluation
There is sufficient evidence for the carcinogenicity of
ortho-toluidine hydrochloride in experimental animals.
An increased incidence of bladder cancer has been observed in workers
exposed to ortho-toluidine, but as all were exposed to other possibly
carcinogenic chemicals, ortho-toluidine cannot be identified
specifically as the responsible agent.
ortho-Toluidine should be regarded, for practical purposes, as if it
presented a carcinogenic risk to humans.
For definition of the italicized terms, see Preamble Evaluation.
Previous evaluation: Vol. 16 (1974)
Subsequent evaluation: Suppl. 7 (1987);
Vol. 77 (2000)
Synonyms for ortho-Toluidine
- 1-Amino-2-methylbenzene
- 2-Amino-1-methylbenzene
- 2-Aminotoluene
- ortho-Aminotoluene
- C.I. Azoic Brown 29 (Component)
- C.I. 37077
- 1-Methyl-2-aminobenzene
- 2-Methyl-1-aminobenzene
- 2-Methylaniline
- ortho-Methylaniline
- 2-Methylbenzenamine
- ortho-Methylbenzenamine
- ortho-Toluidin
- 2-Toluidine
- ortho-Tolylamine
Synonyms for ortho-Toluidine hydrochloride
- 1-Amino-2-methylbenzene hydrochloride
- 2-Amino-1-methylbenzene hydrochloride
- 2-Aminotoluene hydrochloride
- ortho-Aminotoluene hydrochloride
- 1-Methyl-2-aminobenzene hydrochloride
- 2-Methyl-1-aminobenzene hydrochloride
- 2-Methylaniline hydrochloride
- ortho-Methylaniline hydrochloride
- 2-Methylbenzenamine hydrochloride
- ortho-Methylbenzenamine hydrochloride
- ortho-Toluidin hydrochloride
- 2-Toluidine hydrochloride
- ortho-Tolylamine hydrochloride
Last updated: 8 April 1998