This European Standard specifies general performance requirements for diffusive samplers used for the determination of the concentration of gases and vapours in ambient air. Such requirements apply to all diffusive samplers, irrespective of the physical nature of the rate controlling process and irrespective of the nature of the sorption process and the analytical determination. This standard applies to all stages of the measuring procedure, including deployment, transportation and storage of the sample where appropriate. This standard applies to measuring procedures with separate sampling and analysis stages, and also to direct-reading devices.