When egress lighting offers insufficient illumination, it can jeopardize the safety of building occupants during low visibility evacuations. As a result, building owners follow the requirements for emergency egress lighting (a.k.a. backup lighting) set forth by the National Fire Protection Agency (NFPA). To ensure that backup lights perform properly, the NFPA sets requirements for its performance, operation, power source, and testing.
NFPA 101 Section 220.127.116.11 requires backup lights to provide illumination for at least 90 minutes after utility power becomes unavailable. During this time, its brightness must be at least 10.8 lux. When testing backup lights for illumination strength, the reading should be taken at floor level in the egress path that the lights illuminate.
The NFPA requires backup lights to operate automatically. That is, when utility power becomes unavailable, they should provide instant illumination. They should also operate automatically in separate power outages without requiring a manual reset.
The NFPA’s egress lighting requirements require backup lights to be powered in one of two ways: by a generator, or by batteries. NFPA Section 101 18.104.22.168 requires generators that power emergency lighting to be operated in compliance with NFPA Standard 110, which pertains to the construction, installation, maintenance, and testing of emergency backup generators. NFPA 101 Section 22.214.171.124 requires batteries that power emergency lighting to be (a) rechargeable and (b) in compliance with the National Electric Code (NEC).
NFPA 101 Section 126.96.36.199.1 establishes two testing methods for emergency lighting: a 30 second functional test of generator powered lights conducted every 30 days, and a 1-1/2 hour functional test of battery powered lights conducted annually.
Is backup lighting the best option?
Even when it meets the NFPA’s emergency egress lighting requirements, emergency lighting can present problems that lead some building owners to outline their egress paths with luminescent path markings. Unlike emergency lighting, the markings contain no breakable parts, and do not require electricity, making them impervious to falling debris and immune to generator failure.
A famous example of how backup lights can fail occurred during the 1993 World Trade Center Bombing. When the bombs detonated, they destroyed the buildings’ backup generators, thus neutralizing the backup lights in their vertical exit enclosures. As a result of this occurrence, cities and states began implementing luminescent egress markings and safety signs in their buildings’ vertical exit enclosures.
A second reason why building owners implement luminescent egress markings is they perform better in the presence of smoke than backup lights. Whereas Glo Brite luminescent material remains easily visible through thick smoke, emergency lighting is often obscured by smoke, getting lost like a headlight in the fog. In vertical exit enclosures, such an occurrence could lead to dangerous egress jams.
At Jessup Manufacturing, we encourage building owners to meet the NFPA’s egress lighting requirements. But we also encourage them to implement luminescent path markings to guard against backup lighting’s potential pitfalls. By outlining their egress paths with our Glo-Brite luminescent egress markings, building owners can ensure that power outages, fires, or other emergencies never leave their building in the dark.