Exit signs serve an important purpose, directing building occupants to safety in an emergency. Today’s exit signs are well lit, easy to read, and clearly point the way out, but this wasn’t always the case. Before the Occupational Health and Safety Administration (OSHA) and National Fire Protection Association (NFPA) developed standards with required specifications, exit signs varied greatly in size and illumination. Now most local building and fire codes follow the OSHA and NFPA guidelines.
Early exit signs were generally made of metal and often lit by nearby incandescent light bulbs or not lit at all. Sometimes they were made of white glass fixtures with the letters “E-X-I-T” written in red and fit over a single bulb. These methods had a major flaw during an emergency: If the power went out, you couldn’t see the sign. Even if a sign stayed lit, it wasn’t big or bright enough to see through the smoke.
Today’s signs are normally illuminated by:
- electric lights with local, rechargeable power sources
- electric lights with the building's emergency lighting circuits providing backup power from an uninterruptible power supply (UPS) or generator
- photoluminescence (glow in the dark) or phosphorescence (light absorbed from surroundings and slowly reemitted)
Other NFPA specifications require exit signs to be no less than 6 inches high, with letters at least a .75-wide stroke width and 2 inches wide (except the letter “I”). There are many other very specific guidelines.
Older exit signs focused on style and design rather than safety and uniformity. You’d think coming across out-of-date exit signs would be rare these days, but that’s not true. In our travels as Verisk field analysts, we regularly encounter some stylish but highly nonconforming exit signs. That’s one of the many things our field teams see when conducting property surveys for insurers or Property Condition Assessments (PCA) for commercial lenders.
The next time you’re in an older building, take a look around for old style exit signs. They aren’t functional by today’s standards and are retained only for their historic significance or decoration, but they’re also mini history lessons on fire safety improvements.
For more information on our field surveys, please go to our website. Nick Scafidi, CFPS, technical trainer at ISO Community Hazard Mitigation, also contributed to this article.