What are the requirements for emergency lighting systems in a commercial building, according to NFPA 101?

NFPA 101, the Life Safety Code, specifies requirements for emergency lighting systems in commercial buildings to ensure safe evacuation during power outages. Emergency lighting must provide sufficient illumination to allow occupants to safely evacuate the building. Specifically, it must provide an average of 1 foot-candle (10.8 lux) of illumination along the path of egress, measured at floor level. This includes exit access routes, exits, and exit discharge areas. The emergency lighting system must automatically activate within 10 seconds of a power failure. This ensures that the lights come on quickly enough to guide occupants to safety. The emergency lighting system must be powered by a reliable emergency power source, such as a generator or batteries. If batteries are used, they must be capable of providing power for at least 90 minutes. The emergency lighting system must be regularly tested to ensure it is functioning properly. NFPA 101 requires monthly functional tests and annual full-duration tests. Emergency lighting fixtures must be properly located to illuminate the path of egress. This includes providing lighting at exit doors, along corridors, at stairways, and at changes in elevation. The emergency lighting system must be maintained in good working order. This includes replacing burned-out lamps, repairing damaged fixtures, and ensuring that the emergency power source is properly charged and maintained. Exit signs must be illuminated by the emergency lighting system. This ensures that the exit signs remain visible during a power outage.