SRB Technologies - Self-Luminous Tritium Exit Signs - FAQ FAQ's How do tritium signs work ? Self-luminous tritium exit and safety signs contain glass tubes internally coated... and safety signs are on and working 24/7 and require no charging, maintenance or testing. You merely install them and dont worry about them for up to 20 years. Are tritium signs.... How long will a SRBT self-luminous tritium exit sign last? Signs with a 10, 15 or 20 year life are available. Tritium decays at a defined rate which allows us to accurately...