BS ISO 4225:2020 pdf free.Air quality一General aspects一Vocabulary. BS ISO 4225 This document specifies terms and definitions that are related to air quality (see 3.11.1). These are either general terms or are used in connection with the sampling (see 3.3.3.1) and measurement of gases, vapours (see 3.1.5.8) and airborne particles (see 3.2.2.1) for the determination of air quality. The terms included...