The objective of this Safety Guide is to assist Member States in implementing regulatory requirements for radiation sources that will ensure their safety. To that end, this publication provides guidance on infrastructure responsibilities for safety, on methodologies for performing safety assessments and on specific design and operational measures that should be taken to ensure safety throughout the life cycle of radiation generators and sealed radioactive sources. The safety measures recommended are also applicable to radioactive sources in nuclear facilities or radioactive waste disposal facilities, while recognizing that these facilities should in any case provide a high standard of source safety.