This part of ISO 10648 gives a classification of containment enclosures according to leak tightness and specifies methods for checking this tightness for the following tests: — manufacturing test at the factory, — acceptance test at the laboratory, — test before commissioning, — periodical tests during operation. These last two tests shall comply with relevant standards and local regulations. The object of this part of ISO 10648 is to provide manufacturers, suppliers, users and the competent authorities with uniform principles in test procedures for testing the leak tightness of containment enclosures and for ascertaining the leak rate. The tests cover the containment enclosures equipped with the basic components (see ISO 10648-1:—, annex B). All openings (for example glove ports and ventilation openings) are sealed with tight-fitting or sealable covers. If additional equipments are to be used, a new control test taking into account these equipments should be performed.