The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate four flavouring substances in the Flavouring Group Evaluation 304, Revision 1 (FGE.304Rev1) using the Procedure in Commission Regulation (EC) No 1565/2000. This revision is made due to a re-evaluation of one flavouring substance N-(2-(pyridine-2-yl)ethyl)-3-p-menthanecarboxamide [FL-no: 16.118], as a 90-day dietary rat study has become available. One of the original five flavouring substances [FL-no: 16.124], for which additional data were requested, is no longer supported by the Industry for use as flavouring substance in Europe and will therefore not be considered any further in FGE.304Rev1. Therefore, FGE.304Rev1 will deal with four flavouring substances. None of the four substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded that the four substances [FL-no: 16.117, 16.118, 16.123 and 16.125] do not give rise to safety concern at their levels of dietary intake, estimated on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. Specifications including complete purity criteria and identity for the materials of commerce have been provided for all four candidate substances.