4-Methylbenzophenone and benzophenone are inactive in the micronucleus assay

Abstract

Many materials in contact with food, including printing inks, the lack of deeper knowledge about possible toxic effects is a problem. Furthermore, some of these substances are not only produced for packaging of foods, they are produced for a variety of purposes and are not meant to come into direct contact with foodstuffs. Two examples on such chemicals in printing inks are benzophenone and 4-methylbenzophenone. Recently, authorities reported that high levels of the photoinitiator 4-methylbenzophenone had been detected in cereal products. Based on this information we have studied 4-methylbenzophenone and the chemically similar benzophenone using the micronucleus assay in vivo and in vitro. To increase the sensitivity we have used the in vivo flow cytomer-based micronucleus assay in mouse. Although doses up to lethality were used and an average of hundred thousand young erythrocytes, polychromatic erythrocytes, analysed from each animal, no genotoxic effect occurred. The 4-methylbenzophenone was also analysed in the in vitro micronucleus assay, using human lymphocytes. The result does not show any dose-related effect. These results show that the occurrence of 4-methylbenzophenone that so far has been detected in foodstuff does not increase the cancer risk through chromosome breaks or mal-distribution of chromosomes.