This European Standard specifies a method based on flame atomic absorption spectrometry (FAAS) for the determination of manganese content present as methylcyclopentadienyl manganese tricarbonyl (MMT 1)) in unleaded petrol from about 2 mg/l to about 8 mg/l. This test method is applicable to unleaded petrol containing up to 3,7 % (m/m) oxygen, including those with ethanol up to 10 % (V/V). NOTE 1 Manganese as MMT is added to petrol to increase antiknock properties. WARNING - The use of this European Standard may involve hazardous materials, operations and equipment. This European Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this European Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.