Mutagenicity screening of selected water-based dispersions and materials utilized in cardboard and wood coatings using the standard and 384-well Ames tests

Novel biobased materials and processing techniques are actively developed for sustainable coatings. This study investigated the potential mutagenicity of novel materials and derived dispersions used for biobased paper and wood coatings using a pilot 384-well test. The standard Ames test was performed for selected materials to compare and validate the results with the non-standard 384-well test. Salmonella Typhimurium strains (TA100 and TA98) were used for testing. Experimental dispersions were prepared using suberin and betulin extracted from outer birch bark. The test set of seven samples (n = 7) included commercial reference samples and additives. Both test methods were suitable for these samples but also highlighted method-specific differences and challenges. For suberin-derived materials and betulin at 0.5–1% concentration, neither of the tests indicated mutagenicity. In the case of some industrial samples, the 384-well test and the standard Ames test gave clearly contradictory results. These can be explained by the test limitations, such as the sample color or compositional instability of dispersions. To summarize, this study indicated the need to test the novel coating materials with multiple concentrations, and several bacterial strains carrying different types of genetic mutations, as well as to use complementary genotoxicity tests for a more accurate toxicity profile.