Tritium Exit Signs

Tritium exits signs or gaseous tritium source exit signs are 'EXIT' sign boards, used to indicate emergency exit. They are the most widely used exit signs nowadays. Tritium exit signs are better compared to other traditional or hard-wire exit signs, because they do not require electricity. They work on the principle of radio-luminescence. Earlier, people generally used radium for creating the display boards. Now, a use of radium is prohibited in most of the countries, because it increases the chances of bone cancer. These tritium 'EXIT' signs are nothing but, glass tubes, which are filled with radioactive tritium and coated with phosphor internally. Therefore they are also called gaseous tritium light source that is GTLS. Life span of tritium exit signs depends upon the amount of gaseous tritium present in the exit sign tube. On an average, it is about 10 to 20 years.

Tritium
Tritium is an isotope of hydrogen, whose mass is three times greater than mass of any hydrogen atom. Tritium possesses radioactive characteristics. It is usually in the gaseous form at the normal pressure and room temperature. Tritium nucleus contains one proton and two neutrons. It has a half short life of 12.33 years. Tritium easily combines with other light atoms in comparison with hydrogen atoms. Tritium forms helium-3 by radioactive decaying reaction. Though tritium is a radioactive element, it dose not cause any significant health hazard as long as it is not ingested in substantially greater amount. However, inspiration of gaseous tritium can be dangerous.

Tritium Illumination
Radioactive gaseous tritium is capable of emitting light, visible to humans. The luminescence is created, when the reaction between emitted electron and phosphor takes place. Tritium emits electrons in the process called beta decay. Beta decay is a self-generated process, in which any radioactive unstable atomic nucleus loses energy by emitting beta particles that are electrons. It is a low level beta radiation, which is not capable of penetrating the skin. Therefore it does not cause any serious health problems. This whole process of producing a fluorescent light, with the help of tritium is called tritium illumination. Tritium illumination is used in all tritium source exit signs. The same technology is also used in rifle sights, wrist watches, clocks and key-chains as well.

Advantages of Tritium Exit Signs
Tritium source exit sign boards do not run on electricity, batteries or generators. They illuminate even at the time of power failure. Therefore their usage cost is reduced. There are no chances of explosion, as they are non-electrical equipment. They are very safe to use. These tritium exit signs do not require maintenance. No wiring, no complex mechanism or procedure is needed for installation. They can be replaced or repositioned without much difficulties. They are the most reliable source, which can even work in the electrically .

Disposal of Tritium Exit Signs
Broken or damaged tritium exit sign boards need to be disposed immediately, because these boards contain gaseous tritium, which is not safe for human respiration. It is capable of causing cancer, if it is absorbed in the body at a significant level. Therefore the disposal of tritium source exit signs must be done immediately. It is mandatory to do the HAZMAT clean-up according to the federal law, if these boards break or damage. The clean-up and disposal procedure of the tritium exit signs is a bit expensive. These tritium exit signs are tracked and stipulated by U.S. Environmental Protection Agency (EPA), Nuclear Regulatory Commission and Clean Air Act, for the safety purpose.

What to Do When a Tritium Exit Sign Breaks or Damages

• Vacate the area immediately.
• Open all the doors and windows, which will help in minimizing the concentration of the gas in the air.
• Inform to Nuclear Regulatory Commission and State Radiation Protection Program at the earliest.
• Strictly follow all the rules and regulations, dispose the tritium source exit sign board as per the HAZMAT clean-up procedure.
• Check if there is anyone, who is exposed to the gaseous tritium. Anybody, who is exposed to the tritium gas, needs to be treated immediately.

When a person inhales gaseous tritium, he should be provided an emergency care treatment, even before obtaining a regular medical aid. The person should have a shower bath or in case if he is unconscious, his hands and face should be washed with water. The person's cloths should be changed and kept in a separate isolated bag as they may be contaminated with the gas. The person should drink plenty of liquids, which will help to dissolve inhaled tritium. This will reduce the risk factors involved due to inhalation of tritium. However, immediate and cumulative urine samples of the person should be sent to the Nuclear Regulatory Commission for further diagnosis.