AGE CONTROL AND SERVICE LIFE Hose or hose assemblies fabricated from age-sensitive materials are subject to age control. The following definitions are provided to clarify age control, acceptance life, shelf life, and service life: • Age control—The efforts made during manufacture, purchase, and the storage of age- sensitive items and parts made from natural or synthetic rubber materials to assure conformance to the applicable material and performance specifi- cations. Age control is further defined in terms of acceptance life and shelf life. • Acceptance life—The period of time from cure date to the procuring activity’s (organizational-, intermediate-, or depot-level activity) date of acceptance. • Shelf life—The period of time from the date of acceptance or delivery by the organizational-, intermediate-, or depot-level activity to the date of use. • Service life—The period of time from the date of installation to the date of removal. Installation date of the hose or hose assemblies must be identified by a tag. See figure 5-5. Acceptance Life and Shelf Life for Synthetic Rubber Hose and Hose Assemblies The acceptance life (MIL-STD-1523) and shelf life (DOD 4140.27M) for synthetic rubber hose and hose assemblies are established as follows: • Synthetic rubber hose, bulk or assembly, must not exceed 8 years (32 quarters) from the cure date, which must be stenciled on the rubber covering of the bulk hose or provided on an identification band on the metal braid hose or on the hose assemblies. • Synthetic rubber hose and hose assemblies must not exceed 5 years (20 quarters) from the date of delivery to the organizational-, intermediate-, or depot-level activity.    The repair activity maintains a record of delivery dates for bulk hose and hose assemblies to monitor shelf life expiration dates. NOTE: Teflon® (PTFE) rubber hose and hose assemblies do not have shelf life limitations. Service Life for Synthetic Rubber Hose Assemblies Service life is 7 years (28 quarters) for synthetic rubber hoses in critical applications; that is, medium- and high-pressure synthetic rubber hoses exposed to heat, weather, or fuel. NOTE: Service life for Teflon® (PTFE) hose assemblies is determined by CFA and may be on-conditional replacement or hard-time replacement. Rejection Standards Rejection and replacement of hose or hose assemblies after inspections are based on the standards normally specified in the applicable maintenance instruction manual, maintenance requirement cards, and depot-level specifications. Where rejection standards are not specifically outlined or if doubt exists as to the acceptability of a hose or hose assembly, replace the hose or hose assembly. NOTE: Teflon® (PTFE) hose assemblies are replaced only on a conditional basis. STORAGE Hose and hose assemblies fabricated from age-sensitive materials are subject to deterioration by oxygen, ozone, sunlight, heat, moisture, or other environmental factors. These types of hoses and hose assemblies should be stored in a dark, cool, dry place protected from circulating air, sunlight, fuel, oil, water, dust, and ozone (ozone may be generated in an atmosphere where electricity is discharged through oxygen or ambient air). Store hose or hose assemblies by sealing both ends of bulk hose. Cap or plug each hose or hose assembly. Store hose or hose assemblies on racks that support and protect them. Store hose or hose assemblies so that the oldest items are issued first. CAUTION Do not store hose or hose assemblies in piles. Improper storage will cause accelerated deterioration due to both heat and moisture factors. 5-28