This International Standard specifies a generic method for the determination and the reporting of time-averaged mass emissions from a specific installation or of a family of installations (or common source type), using data collected by measurements, and by establishing: - mass emission rates by the simultaneous measurement of concentration and gas flow, using standardized manual or automatic methods, and also the estimation of the uncertainty of the measurements; - time-averaged mass emission rates using time series of mass emission rate values, their uncertainty characteristics, and also the determination of the expanded uncertainty of the average; - time-averaged emission factors for a specific installation or of a family of installations and their associated uncertainty characteristics; - a quality management system to assist the process of inventory quality assurance and verification. This International Standard is applicable to the determination of emission factors for stationary sources including emissions from industrial processes where calculation from fuel and raw material is not practical, for greenhouse gases, and air pollutants including fine particulate material. This International Standard does not address compliance monitoring in the context of emission control regulations.