This European Standard specifies an inductively coupled plasma optical emission spectrometry (ICP OES) method for the determination of nickel content in the range 4 mg/kg to 55 mg/kg and of vanadium content in the range 4 mg/kg to 150 mg/kg in fuel oils and residual fuel oils. NOTE 1 Nickel content can be determined from 2 mg/kg to 4 mg/kg and vanadium content can be determined from 1 mg/kg to 4 mg/kg. However, the precision was not established as no samples with nickel and vanadium contents in these ranges were included in the interlaboratory test. Nickel and vanadium contents higher than those reported can be determined after sample dilution. However, the precision was not established for diluted samples. NOTE 2 For the purposes of this European Standard, the term ""% (V/V)"" is used to represent the volume fraction (phi). WARNING - The use of this standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.