The purpose of this document is to provide minimum requirements for cleaning aircraft breathing oxygen systems and components, inspection methods and packaging after cleaning, and guidelines for oxygen equipment cleaning areas. Applicability: When this standard is specified in an acquisition document, the applicable requirements of this standard that apply to the acquisition document shall be identified. Application guidance: Certain provisions of this standard and the manufacturer's cleaning inspection and packaging procedures may differ due to oxygen equipment complexity of construction, material, etc. These differences shall be identified in the acquisition document with a determination of what is acceptable; the provisions of this standard, the manufacturer's procedure, or a specified acceptable alternate, as applicable. Classification: For the purpose of this standard, breathing oxygen equipment shall be classified as follows: Class 1: Parts and assemblies exposed to oxygen pressures over 450 psi (3.1 MPa) or liquid oxygen; Class 2: Parts and assemblies exposed to oxygen pressures from 10 to 450 psi (6.89 kPa to 3.1 MPa), inclusive; Class 3: Parts and assemblies exposed to oxygen pressures up to 10 psi (6.9 kPa) (such as face masks, large bore regulator-to- connector hoses, oxygen mask hose connectors, etc.).