Deals with criteria for design, construction and test of electro-sensitive protective equipment (ESPE) for protection of machinery using active opto-electronic protective devices (AOPDs) for the sensing function. Particular attention is aimed at features that ensure that a suitable safety related performance is met. Dimensions or configurations of the detection zone and disposition relating to hazardous parts for a particular application, or hazardous state of a machine are not defined. AOPDs using radiation at wavelengths outside the 400 nm to 1500 nm range are not included. EMC emission requirements are not covered.