FEMA expert panel review of p-mentha-1,8-dien-7-al genotoxicity testing results

p-Mentha-1,8-dien-7-al is a naturally occurring cyclic alpha,beta-unsaturated aldehyde that is used as a flavoring substance throughout the world. Due to the chemical structure and the potential DNA reactivity of the alpha,beta-unsaturated carbonyl moiety, a battery of genotoxicity assays was requested by the European Food Safety Authority. Previous genotoxicity studies on the substance gave mixed results, but both positive and negative results were hampered by not always being performed to any standard guideline. The new test battery data indicated some evidence of mutagenicity in vitro, but an in vivo comet/micronucleus combination assay performed in rats was concluded by the study directors to not result in any biologically relevant positive responses. However, EFSA concluded that the in vivo assay gave evidence that p-mentha-1,8-dien-7-al was of potential genotoxic concern. The Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) has reviewed the newly available data and considered its interpretation relative to standard guidelines such as that established by the Organization for Economic Cooperation and Development, and has concluded that the results in the comet/micronucleus combination assay are consistent with the interpretation by the study directors; namely, that p-mentha-1,8-dien-7-al does not appear to have any in vivo genotoxic potential. •Re-consideration of the available genotoxicity data for p-mentha-1,8-dien-7-al.•The Panel concluded that p-mentha-1,8-dien-7-al does not appear to have any in vivo genotoxic potential.•This conclusion runs counter to that reached by EFSA.•Considering the data interpretations relative to standard guidelines provides some indication for why there is a discrepancy.