- Photoluminescent Exit Sign ("PL")
A Photoluminescent (PL) exit sign, also known as externally illuminated exit sign is a type of single-purpose exit sign and passive safety device used in buildings to indicate the path of travel to a required exit.
These signs rely on photoluminescent materials that absorb and store light energy from a continuous light source (minimum 100 lux at the sign face with a colour temperature of at least 4000 K). In the event of a power failure, they must emit stored energy in the form of light, maintaining a luminance of at least 30 mcd/m² for a minimum of 90 minutes.
Photoluminescent exit signs exit signs must comply with specific criteria outlined in Section 5 and Appendix D of AS/NZS 2293.1, as modified by Specification S25C of the National Construction Code (NCC).
Key requirements include:
- Illumination Standards: Continuous charging by a dedicated light source and testing under ASTM E2073-10.
- Pictorial Elements: Enlarged elements with photoluminescent borders for visibility.
- Viewing Distance: A maximum allowable distance of 24 metres.
It is important to note that PL exit signs are a passive safety measure and differ from active, electrically illuminated exit signs required for compliance with AS/NZS 2293.1 and Part E4 of the NCC. They are not substitutes for emergency lighting systems and certain exit lighting systems but can complement them in appropriate settings.