This European Standard specifies general requirements for the performance of procedures for the determination of the concentration of chemical agents in workplace atmospheres as required by the Chemical Agents Directive 98/24/EC (see reference [9]). The requirements given apply to all measuring procedures, irrespective of the physical form of the chemical agent (gas, vapour, airborne particles), the sampling method and the analytical method used.This European Standard is applicable to — all steps of a measuring procedure, — measuring procedures with separate sampling and analysis steps, and — direct-reading devices.