Section 7.9.1/Emergency Lighting
NFPA 101 Section 7.9 covers emergency lighting for means of egress including minimum illumination levels and 1.5-hour duration.
Emergency lighting must be provided for the means of egress in buildings that require two or more means of egress. The illumination must be at least 1 foot-candle (10.8 lux) at the walking surface initially and must not fall below 0.6 foot-candles (6.5 lux) at any point during the 1.5-hour emergency duration. Emergency lighting must activate automatically within 10 seconds of normal lighting failure. The power source must be an emergency generator, a central battery system, or unit equipment (individual battery packs integrated into light fixtures).
Why this section exists
A power failure during a fire plunges the building into darkness at precisely the moment occupants need to find their way out. Emergency lighting provides the minimum illumination needed to navigate stairs, corridors, and exit paths safely. The 1.5-hour duration ensures the lighting lasts through the evacuation and the fire department operations. The 10-second activation limit prevents a dangerous gap in illumination when normal power fails.
What plan reviewers look for
Plan reviewers check the electrical drawings for emergency lighting fixtures along the entire means of egress: corridors, stairs, exit passageways, and exit discharge paths. They verify the power source (generator, central battery, or unit equipment) and the 1.5-hour duration. They check that the lighting layout provides at least 1 foot-candle average with the minimum/maximum uniformity ratio not exceeding 40:1.
Common violations
Related NFPA 101 requirements
Section 7.10 covers exit signs that complement emergency lighting. Section 7.1.7 covers means of egress illumination during normal conditions (1 foot-candle minimum). NEC Article 700 covers the emergency power system requirements. IBC Section 1008 covers the equivalent emergency lighting requirements.