The barrier materials covered by this specification are intended for use in specialized military methods of preservation. The combination of all performance characteristics of MIL-PRF-22191; water vapor transmission rate; transparency; contact corrosivity; storage stability; seam strength and fabrication; puncture, aging, blocking, and curl resistance; delamination; waterproofness; water resistance of markings provide the necessary requirements for protection from exposure to the extremes of the navy/naval aviation environment. Navy/naval aviation items are exposed to high moisture, high salt concentration, transfer at sea, rough handling, and minimal storage conditions. There are no commercial equivalents that meet the physical, mechanical, and corrosion requirements necessary to protect materiel that is exposed to the operational naval aviation environment. Specifically, Methods of Preservation 31, 32, 33, 41 and 51 of MIL-STD-2073-1C use MIL-PRF-22191 as the premier source of barrier materials that is transparent and provides waterproof and watervaporproof (and watervaporproof with desiccant) protection for applicable items encountering the above conditions. MIL-PRF-22191 provides the building blocks for applying specialized military preservation techniques approved under MIL-STD-2073-1C.

Type I material is intended to be used in all packaging applications where watervaporproof, greaseproof barrier materials are required.

Type II material is intended to be used in all packaging applications where waterproof, greaseproof barrier materials are required.

Type III material is intended to be used in all packaging applications where waterproof barrier materials are required.

A class system has been established in order to distinguish between materials which do, and do not curl. Class 1 material has unlimited use and is used for the fabrication of bags by manual sealing methods or by automated bag making machines. Class 2 material is used for the fabrication of bags only by automated bag making machines.