How low can you go?
Non-intentionally added substances (NIAS) are a challenge for the food contact materials’ industry, and European framework regulation states that suppliers must assess the safety of the final product. However, the risk assessment of NIAS has proven difficult due in part to questions regarding the sensitivity of test methods potency and the small amount of migrate available for toxicological testing. Thus, the question is whether conventional genotoxicity assays are sufficiently sensitive to detect toxicity at very low doses? Publicly available Ames test dose response data for more than 1,200 substances has been collated from the Vitic database. Data analytics have been applied to determine the lowest dose and the fold increase at which a mutagenic response could be detected. This was found to be 1 ng/plate for this data set and showed the Ames test can detect potent mutagens. Using the 10ppb limit set by the food contact industry, 11.3% of substances in this dataset were theoretically detected by the Ames test. 93% of substances below this limit were also positive in the Transgenic Rodent assay, but so were 69% of substance above the limit. This led to an investigation into the lowest effective doses in mammalian genotoxicity assays in vitro. However, no assay was more sensitive than the Ames test, when judged by lowest effective doses.