This document details the checks, inspections and tests to be performed in order to qualify and certify existing seamless steel and aluminium-alloy cylinders of water capacity less than 150 l used for the transport of gases, manufactured in a jurisdiction in accordance with its national regulations, for use in jurisdictions other than that of manufacture or first use. NOTE For specific requirements regarding gas cylinders that have been used in toxic gas service, see 5.7. This document does not address acetylene cylinders.