This part of ISO 14952 defines the cleanliness levels used in the cleaning, analysis, and verification procedures for space fluid systems. It establishes a common nomenclature for use in describing cleanliness levels for equipment used in ground support equipment, launch vehicles and spacecraft. This part of ISO 14952 is used to specify the cleanliness level of fluid system components and equipment used in space systems. It is applicable equally to ground support equipment, launch vehicles and spacecraft.