Switchable emergency lighting enables anyone to use an emergency light like a normal light which you can switch on and off at any time. Most maintained emergency lights can be used in this manner. A switchable emergency light will naturally come alive in the event of a power failure even if it is switched off at the light switch as it will automatically draw power from the back-up battery.
Where one has a switchable emergency light installed one can use the same light for normal day to day purposes without having to have a separate emergency light engineered to illuminate the exit route(s) in case of a blackout or power failure.
Certain types of maintained emergency lights can also be used as non-maintained lights. The switchable function can only be used when the emergency light is set to maintained operation.