What is a Photoluminescent Exit Sign?

A photoluminescent exit sign is one of two types of building code compliant non-electrical exit signs. The other type of non-electrical exit signs are called tritium exit signs, we cover those as well.

How do photoluminescent exit signs work?

The signs use an industrial-grade pigment that absorbs light "charges" and visibly glows "discharges" when the ambient lighting falls below a certain point. The signs do require a certain amount of light to be continually present on the face of the sign in order to be able to glow in the dark at the required levels for 90 minutes or more per building code. The amount of light depends on the quality of the pigment but the typical amount is 54lux or 5fc although 1fc is achievable. The signs may have either glowing letters or a glowing background.

What are photoluminescent exit signs made of?

The glowing pigment is typically strontium aluminate. The pigment typically appears soft yellow in the light and glows green in the dark which works well with the photoreceptor sensitivity of the human eye. The substrates vary, typically they are one of the following: aluminum, vinyl, thermoplastic, or acrylic.

How are photoluminescent exit signs made?

There are several methods, each with different benefits or draw backs. Here they are:

• Casted individual letters containing mixture of pigment and clear resin. The substrate of the letters is typically white.
• Aluminum sheet with screen printed letters with clear PL pigment infused ink.
• Vinyl letter stickers placed on coated glow-in-the-dark aluminum.
• Vinyl stickers on glow-in-the-dark vinyl substrate. The chevrons are stickers.
• Screen printed glow in the dark letters on painted aluminum substrate. The chevrons are adhesive.
• Vinyl rectangular glow-in-the-dark sheet inserted into thermoplastic molded housing with knocked out EXIT letters with snap out chevrons