Reduce Maintenance Cost and Environmental Risk in Campus Buildings
According to the Nuclear Regulatory Commission (NRC), there are more than two million tritium exit signs still being used in schools, office buildings, theaters, stores, and other facilities in the United States. Tritium, a radioactive isotope of hydrogen, must be registered with the NRC and requires special inspection and disposal. Tritium signs have been used in facilities in the past because they don’t require electricity. Combined with other chemicals, the tritium gas creates a continuous, self-powering light source for signage.
Self Powering Light Sources
Early self-powered lighting was created from either radium paint or tritium. When radium was determined to be a health hazard, tritium became the only solution for locations that had no source of electricity. Battery powered signs were sometimes available, but they were less reliable and resulted in more fire code violations. Photoluminescent technology was introduced later as a safer, greener alternative self-powering light source.
Photoluminescent materials used in exit signs are made of microscopic crystals of strontium aluminate embedded in plastic. The strontium aluminate crystals absorb ambient light and release it as light energy, which glows brightly in the dark. Photoluminescent materials constantly absorb and release light energy, although you typically can’t discern the glow in bright sunlight or when lights are on.
Regulatory Requirements for Tritium
Tritium signs were often installed in historic and architecturally significant buildings as a result of older wiring or unique design. Tritium signs are also often found in large buildings that required a lot of exit signs, because drawing no electricity could make a material difference in energy cost savings. The big problem with tritium exit signs is the hazard that they present to people. If a person tampers with a tritium sign, he or she could spread radioactive contamination into the surrounding environment, endangering all who might be in the area. Tritium gas is odorless, colorless, and tasteless, and only special instruments can detect its presence. Any college or university with tritium signs runs the danger of contamination if one is broken.
The Environmental Protection Agency (EPA) has strict guidelines and regulations for the use of tritium signs, including requirements to file reports to the Nuclear Regulatory Commission (NRC) and use designated services for disposal. When tritium signs need to be replaced, they can’t simply be thrown in the trash. They need to be properly removed and placed in a waste repository for radioactive materials managed by a licensee of the NRC. Improper disposal can result in contamination of the immediate area, evacuation anyone nearby, and an expensive cleanup process.
Many universities and colleges are trying to break the cycle of using tritium exit signs. One college in New England decided to replace all their tritium signs with photoluminescent exit signs to eliminate all radioactive materials from its dorms, classrooms, administration buildings, and recreational facilities. Their program has so far replaced over one thousand signs to make a greener campus and to reduce building maintenance.
Replacement Benefits of Photoluminescent Exit Signs
The total cost of reporting, inspecting, maintaining, and disposing of tritium exit signs can be very high. Colleges and universities frequently retrofit these signs with lower cost, no energy, no maintenance, photoluminescent signs. Photoluminescent signs do not require batteries and therefore do not cause fire code violations as electrical signs can when they are not properly maintained. Photoluminescent signs also do not degrade or deteriorate and can easily remain in place for decades. If required, photoluminescent signs are UL924 listed to meet International Fire Code (IFC) and International Building Code (IBC) requirements. There are also photoluminescent signs that can be fully charged with LED ambient light.
To obtain more information on how to select the right photoluminescent exit sign for your building or project,