This Emergency Voice Communication System label has been designed to satisfy the requirements of the British Standards as described below:
BS 5839-9:2021 Clause 13.1f)3) states…
Every isolator and protective device that can isolate the supply to the EVC system, other than the main isolator for the building, should be labelled “WARNING. THIS SWITCH ALSO CONTROLS THE SUPPLY TO THE EMERGENCY VOICE COMMUNICATION SYSTEM”, in the case of any switch that disconnects the mains supply to both the EVC system and to other circuits.