This standard describes a method for the measurement of the decontamination index of pollution control systems e. g. capture devices including local exhaust ventilation, water spray systems and, when appropriate, separation equipment installed on a machine. This method uses the real pollutant (see 4.2 of EN 1093-1: 1998 " Safety of machinery - Evaluation of the emission of airborne hazardous substances - Part 1: Selection of test methods") and can be operated in room or field environments. It should be observed that during the test, especially during the shutdown or the removal of the pollution control system, the concentration of hazardous substances , if present, can reach levels which are liable to incur a risk to the health of the operators or other occupants present in the room. Warning: This standard does not deal with the protective measures required to control these risks. Measurement of the decontamination index of pollution control system can serve for the: evaluation of the performance of a pollution control system of a machine; evaluation of the improvement of a pollution control system; comparison of pollution control systems for machines of similar design; ranking of pollution control systems according to their decontamination efficiency; determination of the air flow rate in the case of an exhaust system to achieve a given level; determination of the state of the art of pollution control systems for machines with respect to the decontamination efficiency.