Mutagenicity of rubber additives and curing fumes. Results from five short-term bioassays

The mutagenicity of rubber additives and curing fumes from some rubber formulations were studied in five short-term tests: point mutations in Chinese hamster V79 cells, the induction of sister chromatid exchanges in Chinese hamster ovary cells, micronuclei in erythrocytes of Chinese hamster bone marrow, sex-linked recessive lethal mutations in Drosophila melanogaster, and reverse mutations in the Salmonella/microsome assay. When 46 rubber additives were tested with Salmonella, 15 compounds were mutagenic, 16 were negative, and 15 were negative with no observed toxicity. Only one negative response was obtained for the nine tested samples of curing fumes. Thiuram and dithiocarbamate additives and some curing fumes with mutagenic responses in Salmonella were the primary objects of study in the other four test systems. Although the results of these four tests did not completely parallel the Salmonella results, they indicate that the individual compounds and the curing fumes from different types of rubber formulations may involve genotoxic risks.