The government has failed to see the light when it comes to allowing the installation of glow-in-the-dark safety signs that use radioactive tritium, according to an application for a judicial review.
Popular Signs, the sole Hong Kong distributor of 'self-luminous' gaseous-tritium light devices made by the US-based Isolite Corporation, lodged the application in the High Court on Friday.
It asks the court to quash a decision by the Radiation Board not to allow exemptions from licensing requirements for buildings using two or more of the devices.
Tritium is a radioactive element that is also used in the production of nuclear weapons, luminous watch dials and night-vision equipment.
The board, said Popular Signs, had set a maximum radiation content for buildings that was too low. As a result, companies wishing to install the devices needed to spend extra time and money obtaining licences that needed to be renewed each year.
The signs consist of a glass tube coated on the inside with a luminous material that creates light when exposed to the radiation emitted by decaying tritium atoms.