This part of ISO 10993 describes: the general principles governing the biological evaluation of medical devices within a risk management process; the general categorization of devices based on the nature and duration of their contact with the body; the evaluation of existing relevant data from all sources; the identification of gaps in the available data set on the basis of a risk analysis; the identification of additional data sets necessary to analyse the biological safety of the medical device; the assessment of the biological safety of the medical device. This part of ISO 10993 does not cover testing of materials and devices that do not come into direct or indirect contact with the patient's body, nor does it cover biological hazards arising from any mechanical failure. Other parts of ISO 10993 cover specific tests, as indicated in the Foreword.