This part of ISO 29042 specifies a test bench method for the measurement of the pollutant concentration parameter of a given airborne hazardous substance from a machine, using a test bench under specified operating conditions. The method is applicable only to the determination of emitted gases, vapours and respirable particles. It is intended that whenever possible the emission rate be determined in a test bench (see ISO 29042-3). Measurement of the pollutant concentration parameter of a machine can serve for the a) evaluation of the performance of the machine, b) evaluation of the improvement of the machine, c) comparison of machines within different groups of machines with the same intended use (such groups being defined by the function and materials processed), d) ranking of machines from the same group according to their pollutant concentration parameters, and e) determination of the state of the art of a machine with respect to its pollutant concentration parameter.