CEN/TC 264 (CEN Technical Committee 264) is a technical decision-making body within the CEN system working on standardization in the field of air quality in the European Union. Its goal is to develop functional standards, and methods for air quality characterisation of emissions, ambient air, indoor air, gases in and from the ground and deposition, in particular measurement methods for air pollutants (for example particles, gases, aerosols, odours, microorganisms), meteorological parameters and methods for determination of the efficiency of gas cleaning systems. Topics excluded from this WG are determination of limit values for air pollutants, workplaces and clean rooms, radioactive substances.[1]