Photoluminescent Fire Exit Signs - Glow in the dark fire exit signs - Photoluminescent Fire exit signs or emergency exit signs indicate the direction of the exit in the event of a fire or emergency that requires a building to be evacuated. Photoluminescent or glow in the dark signs use a material which self charges using ambient light. In the event of power failure causing low light or a fire and smoke filled room, these safety signs will glow brightly enough to be seen. This increased visibility ensure the safety message or warning can be clearly seen when its most needed. Fire exit signs must be placed to show the route you want people to take in the event of a fire, which is effectively the shortest route to safety. They play an important role in signaling fire safety, along with fire alarm call point signs, fire extinguisher signs, fire door signs and signs for assembly points.