MIL-PRF-85036B (AS), PERFORMANCE SPECIFICATION BARRIER MATERIALS, HEAVY DUTY, FOR FLEXIBLE ENGINE CONTAINERS (26 FEB 1999) [SUPERSEDING MIL-B-85036A(AS)., This specification establishes the requirements for an opaque, heavy duty barrier material, having a low water vapor transmission rate, and capable of being heat-sealed on both surfaces for use in military packaging (see 6.1).