The mixture of gases selected for a Modified Atmosphere Packaging depends on the type of product, the packaging materials and the storage temperature. 

The atmosphere in this package consists mainly of adjusted amounts of N2, O2 and CO2. Reducing of Oxygen (O2) helps to reduce the level of oxidation and the development of adverse microorganisms. 

Low O2 levels of 1-2% are used to produce Infant Formula product and powdered milk. 

Carbon dioxide (CO2) levels in excess of 10% are phytotoxic to fruits and vegetables, therefore CO2 is maintained below this level. 

Nitrogen (N2) is an inert gas and, due to its production process, usually has a relatively high purity. It is usually used to displace air, especially atmospheric Oxygen, in food packaging. This prevents the oxidation of food and inhibits the growth of aerobic microorganisms. It is often used as a support or filling gas, since it diffuses very slowly through plastic films and, therefore, stays in the packaging longer and extends shelf life of the product. 

The use of noble gases such as Helium (He), Argon (Ar) and Xenon (Xe) to replace N2 as a balancing gas in the MAP can also be used to preserve and extend shelf life.