Last month in Command Post, our weekly e-newsletter, I wrote about the exit lights in a nearby movie theater. My companions and I had noticed the exit signs were very dim and not particularly obvious. Two of the four signs were affixed high on the walls, and the two above the emergency doors on each side of the screen weren't visible from the raised seating areas.

The assistant manager of the Cinemark Theater assured us the signs would “glow” in an emergency and were approved by the fire department. The local fire inspector told me that the exit signs met NFPA codes, were approved by the Illinois State Fire Marshal and actually were better than the burned-out bulbs he found on many inspections.

If the faint-green signs weren't obvious to the audience during a movie, how effective would these signs — some affixed up on walls — be in a smoke-filled theater? In contrast, the exit signs at the Lyric Opera of Chicago are the traditional red-on-white “EXIT” illuminated boxes, which are evident on every level of the theater. The red “EXIT” readily identifies an emergency egress. Does green?

According to Don Harton, facilities manager for Cinemark headquarters in Dallas, the exit signs in the theater complex are tritium-powered with a life of 10 years. He also corrected the theater's assistant manager, saying, “Nothing is supposed to glow brighter when the lights are dimmed; the [exit sign] light is simply more evident when the lights are dimmed.”

A spokesman from the Illinois State Fire Marshal's office called me to clarify that the State Fire Marshal's office was not involved in the approval of the exit signs for this theater, as stated by the local fire inspector, as they fall under the authority of the local jurisdiction.

Tritium-powered signs are used across the country, and most are Underwriters Laboratories-listed. According to Mike Shulman, UL emergency lighting equipment manager and principal engineer of operations, tritium-based (also known as self-luminous) exit signs have been listed by UL for more than 30 years and are permitted by NFPA 101 for many code cycles. All listed tritium signs are marked with a replacement date.

“When there is a sufficient amount of ambient lighting in the vicinity of a tritium exit sign, it can easily appear to be completely unilluminated,” Shulman says. “However, even in that condition, the listing requirements demand adequate contrast between the legend [the word “EXIT”] and the frame. That same sign, when the ambient lighting is extinguished (and with a modest amount of time for eye adaptation), should appear to be glowing rather profusely.”

A number of fire chiefs responded to last month's Command Post, raising concerns and invoking the devastating nightclub fires of the past. The fire service learned a great deal from those tragic fires, and those lessons can't be abandoned in the face of technology that dims life safety. Perhaps the NFPA 101 committee needs to visit a few theaters to reevaluate the signs in these settings.

At the Tokyo Fire Frontier conference in 1994, visitors from the U.S. fire service marveled at the exit lighting located on the floors. It's time to follow many other countries and require visible exit lighting on walls and at low levels in public areas. Self-luminous signs may not require an electrician or light bulbs, but what happens if the audience can't see the exits quickly in an emergency?

Manny Muniz, a member of the UL 924 Standards Technical Panel, stated that tritium-powered signs are losing favor because of their expiration dates and the need to track the radioactive materials they contain from manufacture to disposal. The U.S. Air Force and a number of school systems intend to replace all tritium-powered signs.

According to Muniz, the technical panel is currently reviewing the use of the entire UL 924 Standard and would welcome input from the fire service on whether to prohibit the use of tritium-powered or self-luminous signs in areas such as theaters or venues of fluctuating light. Please contact him at manny@mannymuniz.com with your comments on exit signs.

We support new technology when it enhances life safety, but common sense overrules aesthetics in an emergency. Will it take a disaster in a theater before the codes are changed and these dim signs are replaced? I hope not.