A review article published on September 26, 2018, in the peer-reviewed journal Food Additives & Contaminants: Part A addressed the “suitability of the Ames test to characterize genotoxicity of food contact material [(FCM)] migrates.”
Bernhard Rainer and colleagues from the Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Vienna, Austria, explain that a risk assessment of non-intentionally added substances (NIAS) in FCMs requires that a “potential presence of genotoxic NIAS in FCM migrate” be evaluated. This “raises questions about the limit at which genotoxins can be detected in complex mixtures such as FCM migrates, and if such limits of detection (LOD) would be compatible with safety.” One of the tests often used to test for genotoxicity of FMC migrates is the Ames assay (FPF reported). Therefore, the present review focused on evaluating its suitability for this purpose.
The scientists searched the literature for the “lowest effective concentrations of packaging-related and other chemicals in test media” of Ames test and “used [them] as surrogates of LODs to be benchmarked against a value of 0.01 mg/kg (10 ppb) in migrates.” This value is a “pragmatic threshold used in FCM safety evaluation to prioritize substances requiring proper identification and risk assessment.” The performed analysis showed that “only potent genotoxins can theoretically be detectable at a level of 0.01 mg/kg in migrates or food.” Among the genotoxic chemicals associated with FCMs, only a “minority (10%) . . . could be picked up [by the Ames assay] at a level of 0.01 mg/kg or lower.”
The scientists conclude that “the Ames test in its present form cannot be used as [a] standalone method for evaluating the genotoxic potential of FCM migrates, but must be used together with other information from analytical chemistry and FCM manufacturing.”
Rainer B. et al. (2018). “Suitability of the Ames test to characterize genotoxicity of food contact material migrates.” Food Additives & Contaminants: Part A (published September 26, 2018).
Groh K. and Muncke J. (2017). “In vitro toxicity testing of food contact materials: State-of-the-art and future challenges.” Comprehensive Reviews in Food Science and Food Safety 16:1123-1150.