This European Standard specifies a method for the determination of the polyunsaturated (+ 4 double bonds) fatty acid (PUFA) methyl esters content of fatty acid methyl ester (FAME) as a whole between 0,6 % (m/m) and 1,5 % (m/m). The method covers the predominant four polyunsaturated fatty acid methyl esters of eicosatetraenoic acid (C 20:4 (n-6)), eicosapentaenoic acid (C 20:5 (n-3)), docosapentaenoic acid (C 22:5 (n 3), and docosahexaenoic acid (C 22:6 (n 3)). Studies have indicated that based on the linearity of results from this European Standard, PUFA methyl esters can be determined in FAME in the range between 0,3 % (m/m) to 3,0 % (m/m). However, the precision was not established in that range, as no samples within the upper ranges where included in the final interlaboratory test (see 10.1). Although the method is applicable to all uses, it is predominantly for FAME for use in diesel engines. NOTE 1 For the purposes of this document, the term "% (m/m)" is used to represent the mass fraction of a material. NOTE 2 This European Standard is based on A.O.C.S Official Method Ce 1b-89 [1].