This International Standard specifies the different leakage test methods for sealed radioactive sources. It gives a comprehensive set of procedures using radioactive and non-radioactive means. This International Standard applies to the following controls: — quality control allowing validation of required tests for determining the classification of a prototype sealed radioactive source according to ISO 2919, — production control of sealed radioactive sources; — periodic inspections of the sealed radioactive sources performed at regular intervals, during the working life. Annex A of this International Standard gives recommendations to guide the user in his choice of the most suitable method(s) according to control and source type. It is recognized that there may be special circumstances where special tests, not described in this International Standard, may be required. It is emphasized, however, that insofar as production, use, storage and transport of sealed radioactive sources are concerned, compliance with this International Standard is no substitute for complying with the requirements of the relevant IAEA regulations and other relevant national regulations.