However, the International Fire Code 2012 and the NFPA Life Safety Code (NFPA 101) gave the illuminance for the mean of egress as follow;
• Emergency lighting facilities shall be arranged to provide initial illumination that is at least an average of 1 foot-candle (11 lux) and a minimum at any point of 0.1 foot-candle (1 lux) measured along the path of egress at floor level
• Illumination levels shall be permitted to decline to 0.6 foot-candle (6 lux) average and a minimum at any point of 0.06 foot-candle (0.6 lux) at the end of the emergency lighting time duration.
• A maximum-to-minimum illumination uniformity ratio of 40 to 1 shall not be exceeded.
I suggested that we should aim for the average 11 lux of illuminance for the mean of egress first.
Best regards,