What happens if the signs break?
Keep in mind that, for breakage to occur, the outer aluminium frame and inner protective plastic housing would also have to be destroyed. In this scenario, the released tritium gas would rise and dilute rapidly in the air. If however a person were somehow trapped in a 3m x 3m x 3m room with a sign in which all of the tubes had broken, that person’s radiation exposure would be similar to that received from a dental X-ray. These signs would not be licensed for use if there were any chance that they posed a health risk to the public in a normal accident event. In fact, self-luminous signs have been used extensively throughout the world for more than 25 years without incident.
