We previously reviewed an overview of the Life Safety Code. This continues that discussion to focus on emergency lighting.
Emergency lighting provides a minimum level of illumination for occupants of the building to find their way to the exit and to get out of the building. The performance and testing requirements are found in Chapter 7, Means of Egress, of NFPA 101. The triggers for installing emergency lighting are found on the occupancy chapters, 11 through 43.
Emergency Lighting Performance
The Life Safety Code has specific requirements for the performance of emergency lighting systems. The first requirement is that if the system depends on switching power sources, the maximum delay is 10 seconds. Battery operated units do not have this delay, it applies to emergency power supplies.
The emergency lighting must be provided for 1 ½ hours duration. The duration is to allow an orderly evacuation or relocation of building occupants.
Lighting levels are measured in foot- candles, a measure of lighting intensity or brightness. Lighting levels are specified as an average of 1 ft-candle and at any point the light level cannot be less than 0.1 ft-candle. – Compare this to the building code required average of 10 ft-candles for normal conditions.
At the end of 1 ½ hours the average lighting level must be at least 0.6 ft-candles and not less than 0.06 ft-candles at any point. This accounts for battery drain.
The maximum to minimum illumination ratio cannot exceed 40 to 1. This eliminates blinding effects of high intensity lighting sources.
Emergency Lighting Testing
Emergency lighting systems must be tested to prove they are reliable and will have adequate duration. The light levels were established at time of installation. If there have been changes to the egress paths or building layout, the testing should verify that design criteria are still met. The Life Safety Code allows three different test processes to be used.
A functional hands-on test of the devices – monthly – The period between testing should be a minimum of 3 weeks and a maximum of 5 weeks. Monthly testing should be 30 seconds in duration. A functional test of 1 ½ hours should be done annually
Self-testing and self-diagnostic equipment can be tested using the system every 30 days for a minimum of 30 seconds. An annual duration test of 1 ½ hours is required. The self-testing and diagnostic function must remain in service for the 1 ½ hour test.
Computer based testing can be done every 30 days for a minimum of 30 seconds. An annual 1 ½ hour duration test is required, and the computer monitoring must remain operational for this 1 ½ hour period.
Regardless of method, documentation of the testing is required.
The Driehaus Difference
Our experience is that emergency lighting is often not correctly installed, tested, or maintained. This can create a liability issue for the business owner. Driehaus Insurance Group has the risk management resources available to help you understand these questions. Call us at 513-977-6860 or contact us via our website www.driehausins.com