Tritium Signs.... contain an isotope of hydrogen (3H, tritium) that emits beta radiation. The beta radiation from the tritium induces a glow in phosphorous material within the sign. This permits the sign to be illuminated without the use of external electrical power or internal batteries.

Tritium signs serve a vital function in our society. They have helped save countless lives during fires, aircraft accidents, and natural disasters, because they continue to work when there is no power to illuminate other types of signs. Tritium is the ideal radionuclide for this application. With a half-life of about 12 years, these signs can be effective from 10 to 20 years, depending on their design. This means that tritium signs can remain effective for long periods of time, with little or no maintenance costs or waste generation (such as replacement batteries). Even the partly spent tritium can be removed from old signs and reused in making new ones.

Tritium does not pose an external radiation hazard, but may cause dose to humans if ingested, inhaled, or absorbed through the skin. Even though the radiation risk is small compared to the benefit of saving lives, a hazard can be posed to those in the nearby vicinity of a broken tritium sign. In addition, improper disposal of tritium signs in sanitary landfills can result in tritium being transported in water that contacts the disposed waste, eventually contaminating local aquifers and potentially drinking water sources.

Because tritium signs can be a problem when not handled correctly, they are regulated by the U.S. Nuclear Regulatory Commission under a general radioactive materials license. If you possess tritium signs, the general license requires you to fulfill certain obligations as outlined on the sign label. These include assuring that the signs are not abandoned, that you return the signs to the manufacturer at the end of their useful life, and that you properly manage any damaged or broken signs and areas affected by any released tritium.

Dade Moeller is experienced in the safe handling of tritium exit signs, cleanup and recovery following damage or breakage of signs, and returning signs that are no longer in service. We have or can acquire the approvals and licenses required for this type of work. Our clients rely on us to:

• Advise on tritium safety programs
• Help avoid potential litigation
• Communicate and interface with regulators
• Respond promptly if signs are damaged
• Collect and dispose of tritium waste
• Characterize and remove residual tritium
• Assess potential radiation exposures
• Consult with employees on tritium risks

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