Fire exit signs are green and white, pictogram led, and consistent across Europe for one reason: somebody who does not read English, or who cannot read a sign through smoke at floor level, still has to find the way out. The regulations are about being understood rather than about being correct.
What the sign must show
Safety signs for escape routes and emergency exits use a green background with a white pictogram, because green means safe condition in the safety sign system. The pictogram is the running man, with an arrow where direction is needed. Supplementary text may be added but the pictogram carries the message. A sign with words alone does not comply, however clear the words are.
The arrow is the part people get wrong
The arrow says which way to go from where the sign is. A down arrow means go down, an up arrow means straight ahead on a sign mounted above a door in some conventions and up the stairs in others, which is exactly why consistency within one building matters more than any argument about the correct convention. Whatever is chosen, it has to be applied the same way throughout.
Where signs go
At every exit intended for emergency use, and along escape routes wherever the way is not obvious, so that from any point a person can see a sign or reach one before having to choose. Mounted high enough to be seen over people and obstructions, and where smoke logging is a risk, supplemented by way guidance systems at low level. The test is walking the route as a stranger.
Illuminated and photoluminescent signs
A sign that cannot be seen in the dark is not a sign. Internally illuminated signs are lit from within and are usually on the emergency lighting system. Externally illuminated signs rely on an emergency luminaire aimed at them. Photoluminescent signs glow after absorbing light and need to have been charged by the normal lighting, which means they fail in a space that is normally dark.
Questions people ask about fire exit signs regulations
What colour are fire exit signs?
Green with a white pictogram. Green indicates a safe condition in the safety sign system, which is why fire equipment signs are red and escape signs are green.
Do fire exit signs need to be illuminated?
They must be visible in the conditions they are needed in, which normally means internally illuminated, externally lit by emergency lighting, or photoluminescent where the space is normally lit.
Can a fire exit sign be text only?
No. The pictogram carries the message so that people who do not read English can follow it. Text may supplement the pictogram but cannot replace it.