The Ugly Truth about Nuclear Powered Exit Signs

Tritium identifiers have been the common choice among self-luminous products for egress building code compliance. What were the reasons behind the switch from incandescent to nuclear powered exit signs? These products provided the opportunity to remain compliant while decreasing the electrical cost experienced with incandescent alternatives. The radioactive hydrogen isotope in Tritium signs has been used for years to generate self-illumination in consumer products and as part of nuclear weapon development. In small amounts, this form of hydrogen gas is considered to be non-harmful; however, hydrogen can be viewed quite differently if a few minutes are taken to ponder its use in nuclear weaponry. It is how the radioactive particles mix with the environment that causes the most concern. Consider the effects of a nuclear weapon when it is set off and radioactive particles are allowed to enter the local surroundings. Scaling the Effect Down for Egress Compliance The danger of nuclear weaponry is known, but how does this outcome relate to the small amount of radioactive particles used within a Tritium egress sign?  While nuclear powered exit signs do have a far less amount of radioactive particles, these particles mix with the environment in the same manner. A Tritium identifier consists of three main components:

• Radioactive Hydrogen Isotope
• Phosphor Coating
• Holding Tube

The sign is safe as long as the particles remain in the tube; however, a breakage allows the decaying particles to enter the atmosphere. Nuclear powered exit signs are said to be safe even in this event due to the assumption that the particles simply rise and therefore are not inhaled. If this is so, then why are maintenance crews required to take special precautions during the handling of these tubes and why must the Nuclear Regulatory Commission be called at times when a breakage occurs? The answer lies in what happens after a tube is broken or a sign is improperly disposed into a landfill. As a tube busts, the particles rise into the air and mix with additional molecules to form hazardous water. Avoiding Health and Environmental Concerns with Photoluminescent Signs Water formed from a busted tube is capable of entering the human body and the environment. The surrounding area is tainted much like when a nuclear weapon goes off; however, at a much smaller scale. Absorbing or ingesting a small amount does not cause death, but has been proven to be a contributor to cancer and additional health issues. The environmental and health concerns regarding Tritium identifiers are not widely known. Building owners choose these compliance items because they eliminate several electrical costs associated with egress signing. Photoluminescent signs are being used for retrofitting many buildings to eliminate the possible dangers of Tritium as well as decrease costs. These self-luminous alternatives are non-toxic, recyclable, have a longer duration of life, and entail the least overall cost when compared to all other forms of egress signing. Building owners who are concerned about current compliance items have photoluminescent identifiers as a worthwhile retrofit for ensuring occupant safety and creating a more eco-friendly structure.