If you are caught in an emergency, where the lights have gone off and you are stranded in the dark, photoluminescent signs can be indispensable to point you in the right direction. Basically, they glow in the dark, but in an emergency they do much more.
How does Photoluminescence work?
Photoluminescent materials absorb and store photons (light particles) and release them slowly so the materials can glow in low light conditions. This quality makes them ideal for use in the production of safety signs for industrial and other purposes.
A benefit of photoluminescent signs is that they do not require any batteries and recharge when light sources become available again. However, there are different grades of photoluminescent material depending on how long it takes for its glow in the dark to fade.
Photoluminescent material grades
The Photoluminescent Safety Products Association (PSPA) classification system is based on the luminance fading data as given when tested according to ISO 17398 (also ISO 16069) illuminated with 1000 lux from Xenon D75 (Daylight) source for five minutes.
The photoluminescent system is as follows:
| Luminesces mcd/m2 |
2 min |
10 min |
30 min |
60 min |
| Class A |
108 |
25 |
7 |
3 |
| Class B |
210 |
50 |
15 |
7 |
| Class C |
690 |
140 |
45 |
20 |
| Class D |
1100 |
260 |
85 |
35 |
| Class E |
1800 |
400 |
120 |
55 |
| Class F |
2300 |
520 |
155 |
70 |
| Class G |
3000 |
650 |
190 |
80 |
Legislation states that terrestrial-based safety products need to be manufactured from Class C
Photoluminescent signs
Photoluminescent signs are mainly made from a rigid PVC material to make them more durable. They are perfect to have in case of an emergency, to increase the safety of people in your workplace since normal ones will not be visible in the dark to guide your employees, customers/clients to safety.
