Emergency Egress Lighting: Frequently Asked Questions

For decades, emergency egress lighting (a.k.a. backup lights) has helped building occupants evacuate safely from large commercial and residential buildings. But in order for backup lights to work as planned, they must meet critical performance, operational, power supply, and testing guidelines established by the National Fire protection Agency (NFPA). Below, we answer frequently asked questions about emergency egress lighting concerning NFPA guidelines and basic safety concerns.

What are the illumination requirements for emergency lighting?

The NFPA requires that backup lights provide an average initial luminance of at least of 1 ft-candle (10 lux) along the egress path at floor level, with no point registering below 0.1 ft-candle (1 lux). Near the end of the required 90 minutes of emergency lighting, the average luminance along the egress path at floor level can decline to 0.6 ft-candle (6 lux), with no point registering below 0.06 ft-candle (0.6 lux).

What are the power source requirements for emergency lighting?

The NFPA requires emergency lighting to be generator powered or battery powered. Generators that power backup lights must conform to NFPA Standard 110. Batteries that power backup lights must conform to NFPA 101 Section, which requires batteries to be rechargeable and to comply with the National Electric Code (NEC).

Must emergency lighting respond to the absence of utility power automatically?

The NFPA states, “there shall be no appreciable interruption of illumination during the changeover” when maintaining illumination requires switching from one power source to another (e.g. utility power to generator power). Furthermore, when a prime mover-operated electric generator powers backup lights, the NFPA states, “a delay of not more than 10 sec. shall be permitted.” To meet this requirement, a building’s emergency power supply system should ideally feature an automatic transfer switch.

How often must emergency lighting be tested?

The NFPA requires generator powered egress lighting to be tested with a 30 second functional test every 30 days, and battery powered lights to be tested using a 1-1/2 hour functional test once annually. For official testing information, building owners can refer to NFPA 101 Section

Are egress lighting exit signs a valuable safety asset?

Exit signs that contain backup lights are used in buildings across the U.S. However, their look is usually more formidable than their effect. Exit lighting egress signs are not a bad idea. But regular backup lights that meet NFPA requirements work just as well.

Should emergency lighting be supplemented with luminous egress markings?

Supplementing backup lights with luminous markings is a wise idea for two reasons: backup lights can fail due to generator failure, explosions, and falling debris; and they often perform poorly in the presence of smoke. At Jessup Manufacturing, we spent years developing our patented Glo Brite technology, which supplies our luminescent egress products with superior luminance and burn time (up to 96 hours in total darkness).

Could luminescent egress markings replace emergency lighting?

Yes, luminescent egress markings could replace emergency lighting in terms of clarifying egress paths. However, buildings that are required to have backup lights should always keep them, and install luminescent markings for added egress safety.

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