Applies to therapeutic X-ray equipment with nominal X-ray tube voltages in the range 10 kV to 1 MV when connected to alternating current supply mains. Establishes requirements for the safety of X-ray equipment including the requirement for accuracy and reproducibility of performance to the extent that these are related to radiation quality and the quantity of ionizing radiation produced and thus must be considered as aspects of safety. This consolidated version consists of the first edition (1987) and its amendment 1 (1997). Therefore, no need to order amendment in addition to this publication.