PERMALIGHT® Photoluminescent Exit Signs are non-electrical and non-radioactive. Charged by 5-foot candles (54 Lux) of ambient fluorescent lighting, the signs release their NFPA 101-/IBC-Code compliant luminance, should building lighting fail. Exit signs use no light bulbs or electrical wiring. American Permalight Inc., Torrance, CA.www.americanpermalight.com