This European Standard specifies a semi-continuous measurement method for the determination of the concentration of benzene present in ambient air based on automated sampling and analysis by gas chromatography. This European Standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate automated gas chromatograph (GC) by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.The method is applicable to the determination of the mass concentration of benzene present in ambient air in the range up to 50 µg/m3 benzene. This concentration range represents the certification range for the type approval test.Other ranges may be used depending on the levels present in ambient air.NOTE 1 When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.The method covers the determination of ambient air concentrations of benzene in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).NOTE 2 50 µg/m3 of benzene corresponds to 15,4 nmol/mol of benzene.