The working group "Air Analyses" of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified the presented analytical method. This analytical method is a validated measurement procedure for the determination of monochloroacetic acid [79-11-8], dichloroacetic acid [79-43-6] and trichloroacetic acid [76-03-9] in workplace air in a concentration range of one tenth up to twice the currently valid occupational exposure limit values (OELVs) in Germany of 2.0, 1.1 and 1.4 mg/m³, respectively. For sampling, a defined volume of air is drawn through a quartz fibre filter which is alkali impregnated with barium hydroxide and inserted into a sampling system for inhalable particles. The flow rate is set to 1 l/min and sampling is performed over a 2-hour period (which corresponds to a sampling volume of 120 l). The collected chloroacetic acids deposited on the filter are extracted by means of an aqueous phosphate buffer solution and analysed by high performance liquid chromatography with UV detection. Quantitative determination is based on multiple-point calibrations with external standards. For an air sample volume of 120 litres, the relative limit of quantification (LOQ) is in the range of 0.005 mg/m³ for monochloroacetic acid and trichloroacetic acid to 0.002 mg/m3 for dichloroacetic acid. The average recoveries of the three chloroacetic acids range from 88.6% to 101.5% and the expanded uncertainty is less than 29%.