If you use or import gas cylinders or fire extinguishers, you must comply with the Hazardous Substances (Compressed Gases) Regulations 2004 which cover all gases, including breathing air.
Cylinders on a ship, which are not part of the fixed systems of the ship, must comply with these regulations unless the ship is a foreign registered vessel. Cylinders used as part of the fixed systems in an aircraft, ship or vehicle must comply with the rules for the relevant transport mode.
Guidance on the regulations can be found in the Guide to Gas Cylinders.
Filling compressed gas containers
People filling compressed gas containers, including cylinders, must be trained and hold an Approved Filler Test Certificate. Training to become an approved filler can be carried out by a test certifier and, in the case of LPG, by a site trainer under the LPG Association Cylinder Filling Training Programme protocol. In all cases the Approved Filler Test Certificate must be issued by a test certifier.
Further information is available in section 7 of the Guide to Gas Cylinders.
Periodic Testing
All cylinders, including fire extinguishers, must be regularly tested to ensure they are safe for continued use. The interval between tests depends on the type of cylinder.
If a cylinder is overdue for a test it cannot be refilled, but may continue to be used.
Requirements are detailed in section 8 of the Guide to Gas Cylinders.