VOL.: 77 (2000) (p. 487)
Chem. Abstr. Name: Nitromethane
5. Summary of Data Reported and Evaluation
5.1 Exposure data
Nitromethane is a volatile liquid that is added in small amounts to many halogenated solvents and aerosol propellants as a stabilizer. It is also used as a polar solvent for certain polymers and resins, in specialized fuels and in explosives. Exposures may occur from the use of solvents, propellants and fuels containing nitromethane.
5.2 Human carcinogenicity data
No data were available to the Working Group.
5.3 Animal carcinogenicity data
Nitromethane was tested for carcinogenicity by inhalation in one experiment in mice and in two experiments in rats. In mice, it increased the incidence of Harderian gland and lung tumours in males and females as well as of hepatocellular adenomas in females. In one experiment in rats, nitromethane increased the incidence of benign and malignant mammary gland tumours in females, but produced no increase in the incidence of tumours in a second study in a different strain of rat.
5.4 Other relevant data
Nitromethane produces histidinaemia in rats by decreasing hepatic histidase activity, leading to increased tissue levels of histidine.
Neurological effects were observed in nitromethane-exposed rats.
Nitromethane caused mild degeneration of the olfactory epithelium of exposed rats and mice and microcytic anaemia with minimal to mild hyperplasia of the bone marrow in rats.
No data on reproductive or developmental effects in humans were available.
In rats and mice, dose-related decreases in sperm motility were found after inhalation of nitromethane. In females, estrous cycle length was increased in mice but not in similarly exposed rats.
Nitromethane gave negative results in all short-term tests for genetic effects, with the exception of a cell transformation assay in which it was positive at high concentration.
No epidemiological data relevant to the carcinogenicity of nitromethane were available.
There is sufficient evidence in experimental animals for the carcinogenicity of nitromethane.
Nitromethane is possibly carcinogenic to humans (Group 2B).For definition of the italicized terms, see Preamble Evaluation.
See Also: Toxicological Abbreviations Nitromethane (ICSC)