ISO 18413:2015 specifies the content of an inspection document that specifies both the cleanliness requirement for the specified hydraulic fluid power component and the inspection method to be used for evaluating its cleanliness level. In addition, guidelines for relevant extraction methods and analysis methods are given.

Determination of what constitutes as an appropriate cleanliness level requirement for any particular component is beyond the scope of ISO 18413:2015. ISO 12669 provides a method of determining the required cleanliness of a hydraulic system. ISO TR 10686 provides a method of relating the required cleanliness of components to the required cleanliness of the hydraulic system.

For the purposes of ISO 18413:2015, approved functional liquids are considered to be components.

ISO 18413:2015 is applicable to the particulate contamination on the wetted surfaces and volumes of any hydraulic fluid power system component. Appearance defects and liquid or gaseous contamination are not covered by ISO 18413:2015.

ISO 18413:2015 does not address safety problems that might arise from hazardous materials, operations, and equipment associated with its use. The user of ISO 18413:2015 is responsible for establishing appropriate safety and health practices and determining the applicability of regulatory limitations prior to use.