The two pest control agents, buprofezin and petroleum oil (Super Royal), were tested to evaluate their potential mutagenicity, in comparison with the organophosphorus insecticide profenofos. Chromosomal aberration analysis was used in both somatic and germ cells of male mice. Single oral treatment at three different dose levels (1/16, 1/8 and 1/4 LD50) for each insecticide induced an increase in the percentage of chromosomal aberrations in bone-marrow cells 24 h post-treatment, indicating a dose-dependent relationship. The percentage of chromosomal aberrations reached 23 +/- 0.73, 10.5 +/- 0.64 and 15 +/- 1.4 after treatment with the highest tested dose of profenofos, buprofezin and Super Royal, respectively. Such percentages did not exceed the corresponding value of the positive control, mitomycin C (29.2 +/- 0.69). The percentage of chromosomal aberrations induced by the different doses of profenofos was still highly significant even after excluding gaps. The same trend of results was noticed only at the highest tested dose of buprofezin and Super Royal. With respect to germ cells, profenofos is also a potent inducer of chromosomal aberrations in 1ry spermatocytes, giving percentages of 14 +/- 1.3 and 19 +/- 1.6 at the two higher doses of 4.25 and 8.5 mg kg(-1) body wt., respectively. Buprofezin and Super Royal had no significant effect on mouse spermatocytes at the tested concentrations. The various types of induced aberrations were examined and recorded in both somatic and germ cells. In conclusion, the present investigation indicates that the two pest control agents buprofezin and Super Royal are relatively much safer compounds than the conventional organophosphorus insecticides.