Repeated findings of increased percentage of chromosomal aberrations in the peripheral blood lymphocytes of printers engaged with rotogravure printing resulted in investigation of possible relationship with exposure to rotogravure inks. None of the basic shades of rotogravure inks exhibited mutagenic activity in the Ames test. Examination of urine in the 19 exposed printers and a control group of 22 subjects of the same locality did not show significant mutagenic activity. It became obvious that the Ames test did not show any role of rotogravure inks in the increased exposure to genotoxic chemicals in the printers, who were simultaneous- ly exposed to toluene. Hippuric acid did not exhibit mutagenic activity at concentrations of 10 mg to 15 mg per plate. The results support the hypothesis of genotoxic effects of toluene.

        Key words: rotogravure printing, rotogravure inks, toluene, Ames test, genotoxicity