This European Standard describes a fuel quality monitoring system (FQMS) for assessing the quality of petrol and automotive diesel fuel placed on the market in any of the Member States within the European Community. European Directive 98/70/EC [1] requires that every separate nationally defined fuel grade should comply with one specification as defined in the Directive. Therefore, for each nationally defined fuel grade, there will be a corresponding European parent fuel grade. For instance, unleaded petrol grades placed on the market in Europe can be 91, 95, 98 RON petrol. See also the example discussed in 5.4.2. Some basic background ideas behind the FQMS are given in Annex A. Since the specifications for automotive fuels contain climatic related requirements, the FQMS is run twice a year, once during the winter period and once during the summer period. Information about the dates for the summer and winter periods in a specific country are defined in the country's national annex to EN 228 and EN 590. Fuel samples taken during transition periods shall not be included in the FQMS. For the purposes of this FQMS, grades of petrol that constitute less than 10% of the total amount of petrol placed on the market in any one country, and grades of automotive diesel fuels that constitute less than 10% of the total amount of automotive diesel fuel dispensed in any country may require separate handling as described in Clause 5 of this European Standard.