Genotoxic activity of benomyl in different test systems

Abstract
Benomyl (methyl‐1‐[butylcarbamoyl]‐2‐benzimidozole carbamate), a benzimidazole derivative fungicide, was tested in the Ames test for point mutations; in human lymphocyte cultures for cell division disturbances, chromosomal aberrations, and SCE; in rat bone marrow cells in vivo for micronuclei; and in rats in vivo for dominant lethals. Benomyl was negative in the Ames test. In human lymphocytes, benomyl at concentrations of 0.5, 1.0, and 2.0 μg/ml decreased the number of cells undergoing third division whereas at the concentrations of 0.25 to 4.0 μg/ml it strongly increased the number of aneuploid cells. Benomyl was also shown to induce sister chromatid exchanges and micronuclei but not chromosome aberrations. Benomyl decreased the number of female rats with implants but did not cause any dominant lethals.