For definition of Groups, see Preamble Evaluation.
Supplement 7: (1987) (p. 392)
Chem. Abstr. Name: Phosphorothioic acid, O,O-dimethyl O-(4-nitrophenyl) ester
A. Evidence for carcinogenicity to animals (evidence suggesting lack of carcinogenicity)
Methyl parathion was tested adequately by oral administration in the diet of mice and rats. There was no increase in tumour incidence over that in controls [ref: 1].
B. Other relevant data
The incidences of chromosomal aberrations and of dominant lethal mutations were not increased in mice treated in vivo with methyl parathion. In mammalian cells, sister chromatid exchange and presumed gene mutations were induced, but neither chromosomal aberration nor unscheduled DNA synthesis was elicited. Methyl parathion was weakly or nonmutagenic in Drosophila melanogaster and in bacterial systems, but it was mutagenic in yeasts [ref: 1].
Methyl parathion 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. 30 (1983)
1. IARC Monographs, 30, 131-152, 1983
See Also: Toxicological Abbreviations Methyl parathion (EHC 145, 1992) Methyl parathion (HSG 75, 1992) Methyl parathion (ICSC) Methyl Parathion (FAO Meeting Report PL/1965/10/1)