For definition of Groups, see Preamble Evaluation.
VOL.: 48 (1990) (p. 85)
Chem. Abstr. Name: Dimethyl phosphonate
Dimethyl hydrogen phosphite is used as a flame retardant on Nylon 6 fibres, as a chemical intermediate in the production of pesticides and in lubricant additives and adhesives. No data on occupational exposure levels were available. A potential source of exposure to this chemical is from its occurrence as a degradation product of the chemical intermediate trimethyl phosphite and of pesticides such as trichlorphon and malathion.
Dimethyl hydrogen phosphite was tested for carcinogenicity by oral administration in one strain of mice and in one strain of rats. In rats, it caused an increase in the incidence of alveolar/bronchiolar carcinomas in animals of each sex and of squamous-cell carcinomas of the lung and of papillomas and carcinomas of the forestomach in males.
No data were available to the Working Group.
In single studies, dimethyl hydrogen phosphite induced sister chromatid exchange and chromosomal aberrations in Chinese hamster cells in culture and mutations in mouse cells in culture but did not induce sex-linked recessive lethal mutation in Drosophila. It was not mutagenic to bacteria in the presence or absence of an exogenous metabolic system.
There is limited evidence for the carcinogenicity of dimethyl hydrogen phosphite in experimental animals.
No data were available from studies in humans on the carcinogenicity of dimethyl hydrogen phosphite.
Dimethyl hydrogen phosphite is not classifiable as to its carcinogenicity to humans (Group 3).
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluation: Vol. 71 (1999)
Last updated: 13 April 1999
See Also: Toxicological Abbreviations Dimethyl hydrogen phosphite (ICSC) Dimethyl Hydrogen Phosphite (IARC Summary & Evaluation, Volume 71, 1999)