Exit Sign Evolution Part Two: From Tritium to Photoluminescent
As exit signs evolve, they are significantly improving in numerous ways. This is no surprise considering the numerous locations that are required to have them installed to keep us safe. With all the exit signs and egress systems out on the market, it can be confusing trying to decide which route to take in terms of a product that offers the best cost savings, is eco-friendly, and highest overall quality. A couple of the most well-known exit sign systems on the market today that offer no electricity needed are tritium and photoluminescent. Last week we discussed how the introduction of the photoluminescent exit signs several decades ago now provides significant cost-savings to its older counterparts through simple installation, low-maintenance, energy usage, and no back-up generators being required. This week will specifically compare the tritium exit sign versus photoluminescent exit sign to understand how the industry is now able to offer a more eco-friendly, electricity free option with similar benefits and no risk.
What is Tritium?
Tritium is naturally produced or man-made and in the form of gas or liquid. In regards to the tritium exit sign, the tritium is man-made. Its most common form is in water because radioactive tritium reacts with oxygen to form water. Since the tritium is odorless, colorless, and tasteless, only special instruments can detect its presence. Today, sources of tritium include commercial nuclear reactors and research reactors, and government weapons production plants. Since the 1950’s, it also has been used to create many self-luminous exit signs and indicators.
Tritium exit signs provided a great benefit when they were originally introduced to the market. At the time, there was no reasonably safe way for an exit sign to light up after the power went out. As we know, when the power goes out is when exit signs are needed the most. Tritium exit signs were introduced to the market to fill this gap, as the tritium gives off low-energy beta radiation that causes the lining of the exit sign to glow after a power failure.
Because tritium is radioactive, it has regulatory requirements to be aware of and follow when purchasing exit signs containing the substance. The Nuclear Regulatory Commission (NRC) under federal regulations (10 CFR 32.51 and 31.5a) or a state authorized to administer its own comparable program (an Agreement State) regulates products containing tritium. For example, manufacturers and distributors creating any tritium products must ensure they receive proper radiation training. Those purchasing an exit sign containing tritium (e.g.: building owners) are not required to have radiation training, but must adhere to an extensive list of legal responsibilities and regulations, some of which include:
- Ensure that all labels affixed to the device are maintained;
- Follow instructions and precautions provided by the label and not remove the labeling or radioactive symbol;
- Notify either the NRC or your state radiation control program immediately if damage to the exit sign results in the breakage of the tubes containing the tritium;
- Ensure that the sign is not abandoned;
- Let the NRC or Agreement State know of changes to the name or address of the general licensee or the person in charge of complying with the regulations;
- Appoint an individual responsible for having knowledge of the appropriate regulations and requirements and the authority for taking actions required to comply;
- Ensure day-to-day compliance with the regulatory requirements.
The reasoning behind this exhaustive list is because if tritium products end up in landfills, incinerators or at scrap metal recycling facilities it can result in tritium releases to the environment or accidental human exposure of this radioactive chemical. Increasingly, states have been working with the NRC to combat rising levels of tritium in landfills and water, which they have found attributable to improper disposal of tritium exit signs. It is the legal responsibility of the building owners to follow the NRC, U.S. Environmental Protection Agency (EPA), U.S Department of Labor (DOL), Occupational Safety and Health Administration (OSHA), and their respective states guidelines regarding tritium.
Many facilities and even countries have banned the use of tritium exit signs because of its potentially harmful nature and being a serious liability for the building owner. The United States Department of Defense’s Unified Facilities Criteria specifically prohibits tritium exit signs in military facilities, California State University also bans them, and the entire city of Berkeley, California has now phased out tritium exit signs in favor of more environmentally friendly options. Even more, purchasing tritium exit signs is no longer an option in any country other than the United States (and a few lagging non-European countries). Canada now refuses the use of tritium exit signs, stating they do not comply with their new technical requirements of brightness. In Europe, they have long been banned as a consequence of their radioactive nature.
Tritium emits fairly low-energy beta particles that are most fatal when inhaled or swallowed. If we breathe in tritium gas or swallow tritiated water, the radiation can damage cells in our body.
Another downside to using tritium in exit signs is that its lifespan is only between 10-20 years. Considering that buildings will stand for well beyond this amount of time, that means the exit signs will have to be disposed of and replaced numerous times if they contain tritium. Disposing of a tritium exit sign is costly and can only be done through an EPA-approved vendor. There had to be a more eco-friendly way to offer a non-electric exit sign option to building owners.
Luckily, the market realized that tritium, although solving their initial need for a product offering light when power goes out, did not satisfy all of the gaps- namely an energy efficient solution that was eco-friendly and cost efficient. This is where photoluminescent technology comes in. The photoluminescent pigments used in these products absorb and store energy from ambient light. In case of sudden darkness, such as a power outage, the photoluminescent material is immediately visible. If you aren’t familiar with photoluminescent exit signs, here are the top four takeaways on this product:
- According to the U.S. Department of Energy, they are the most energy-efficient exit sign on the market today;
- They will cost less up front then tritium exit signs and have virtually no installation or future maintenance costs;
- Photoluminescent exit signs have a serviceable life of 25+ years and disposal is as simple as throwing them away with your recycling (Jessup Manufacturing GloBrite® Eco-Exit Sign);
- Installing them may help contribute points to the entire Leadership in Energy and Environmental Design (LEED) package
In the past decade many buildings, organizations, cities, and even states have gotten behind the eco-friendly option of adapting photoluminescent exit signs into their buildings. It is becoming increasingly common practice in new construction to implement photoluminescent exit signs and egress systems, but also proves an easy update to older buildings. For example, New York City passed Local Law 26 shortly after the tragedy of 9/11, which requires the installation of photoluminescent exit signs and marker systems in new and existing high-rise office buildings. Following suit, Jones County in North Carolina replaced old signs by installing new UL 924-compliant photoluminescent signs in every county building. The State of California Building Code also now requires exit corridors that lead to emergency exit stairwells be outfitted with a photoluminescent means of egress.
Although tritium exit signs came in to fill a need as an alternative to an electric sign, they left much to be desired in terms of being environmentally friendly. With so many concerns surrounding their radioactive nature and damaging effects to the environment, it was only a matter of time before a better option was found. Exit signs that use the innovative technology of photoluminescent are consistently the most eco-friendly exit signs available on the market. Photoluminescent exit signs don’t consume any excess energy like their electric counterparts, and they are completely safe to handle with a long lifespan, unlike tritium exit signs. Being called a “green-dream” product, photoluminescent exit signs are a great chapter in the evolution of exit signs, filling many of the gaps previously found in the market.
Always make sure that you specify an exit sign that is UL 924 Listed, and install it per NFPA 101 and local codes. Contact Jessup Manufacturing to discuss your options for photoluminescent exit signs and egress systems today.