Abstract: A safety switching module (10) including at least two switch units connected in series and a switch control unit (20) for each switch unit (18). Each switch control unit (20) has a switch control input (38,40) to receive a shut down to open the respective switch unit (18). A switch monitoring means (46) is provided for each switch unit (18) to monitor whether the respective switch unit (18) is open or closed and is connected to the respective switch control unit (20) such that the switch control unit (20) can determine that a fault condition exists if the respective switch unit (18) has not opened on receiving the shut down signal. An operation control input (60) is provided on at least one of the switch control units (20) connectable to an operation controller (62) for controlling operation of the load. Each of the switch control units (20) is in communication with each other switch control units (20) to determine if fault conditions exist in any of the switch units (18).