ISO 29042-8:2011 specifies a room method for the measurement of the pollutant concentration parameter of a given airborne hazardous substance from machines, located in a test room and operating the machines under defined conditions. This method is applicable only to machines with a local exhaust ventilation with an air flow rate ≥500 m3/h and machines without recirculated air.Measurement of the pollutant concentration parameter of a machine can serve for the: a) evaluation of the performance of a 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; e) determination of the state of the art of a machine with respect to its pollutant concentration parameter.