The information provided in SAE AIR 825/6 applies to On Board Oxygen Generating Systems (OBOGS) ? Molecular Sieve, that utilize the ability of molecular sieve materials by using Pressure Swing Adsorption Process (PSA) to separate and concentrate oxygen in the product gas from the surrounding air, respectively air provided by any compressor or by the aircraft engine (so called: Bleed Air), and to provide this oxygen enriched air or product gas as supplemental oxygen for breathing gas supply of crew and passengers onboard aircraft. The distribution system and the provided oxygen concentration have to fulfill the respective FAA/JAA regulations. Equipment using this technology to provide supplemental oxygen for breating gas supply of crew and passengers onboard aircraft, the suitable breathing gas oxygen partial pressure or oxygen concentration requirements are specified in SAE AIR 825/2 and the oxygen purity requirements in SAE AS 8010.