The European Food Safety Authority (EFSA) asked the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (the Panel) to provide scientific advice to the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs in the Member States. In particular, the Panel was requested to evaluate flavouring substances using the Procedure as referred to in the Commission Regulation (EC) No 1565/2000. In the present revision of FGE.218, FGE.218Rev1, there has been a reassessment of one candidate substance, 5-methylfurfural [FL-no: 13.001], for which there was a request for genotoxicity data in FGE.218. Flavouring Group Evaluation 218 (FGE.218) consists of furfural [FL-no: 13.018] and seven substances structurally related to furfural, 5-methylfurfural [FL-no: 13.001], furfuryl alcohol [FL-no: 13.019] and five esters of furfuryl alcohol and aliphatic saturated carboxylic acids [FL-no: 13.057, 13.062, 13.067, 13.068 and 13.128]. In the previous version of this Opinion, FGE.218, the Panel had expressed the following view. The five furfuryl esters are anticipated to be hydrolysed to furfuryl alcohol (and carboxylic acids). Furfuryl alcohol is expected to be oxidised to the alpha,beta-unsaturated aldehyde furfural. However, based on the data then available the Panel concluded that furfural is not of concern with respect to genotoxicity. Furthermore, the Panel concluded that not only furfural but also the structurally related furfuryl alcohol and the five furfuryl esters are not of concern with respect to genotoxicity. Accordingly these seven substances can be evaluated through the Procedure in FGE.66. In the FGE.218 Opinion of 2008 the Panel also expressed its view on 5-hydroxymethylfurfural and 5-methylfurfural. It is anticipated that 5-methylfurfural [FL-no: 13.001] can be oxidised to the primary alcohol 5-hydroxymethylfurfural [FL-no: 13.139]. 5-Hydroxymethylfurfural has been evaluated by EFSA in FGE.13 dealing with furfuryl and furan derivatives. In the latter Opinion, it was concluded that since 5-hydroxymethylfurfural may be metabolised to 5-[(sulphoxy)methyl]furfural which shows genotoxic potential in vitro, 5-hydroxymethylfurfural could not be evaluated through the Procedure. Accordingly, the Panel concluded that 5-methylfurfural could not be evaluated through the Procedure either. Industry has submitted additional data on the 5-hydroxymethylfurfural including metabolism, genotoxicity and carcinogenicity data. Based on these data and further genotoxicity studies identified by EFSA, the Panel concluded that, notwithstanding the indications of in vitro genotoxicity in conditions that favour the formation of 5-[(sulphoxy)methyl]furfural and the limited in vivo genotoxicity study, the essentially negative results of the carcinogenicity study in rats and mice indicate that 5-hydroxymethylfurfural is of no concern under the conditions of intended use. This conclusion is also applicable to 5-methylfurfural, a candidate substance in the current FGE.218Rev1, because this substance may be metabolised to 5-hydroxymethylfurfural. Accordingly, both 5-hydroxymethylfurfural [FL no: 13.001] and 5-methylfurfural [FL-no: 13.139] can be evaluated through the Procedure.