Modified atmosphere

Modified atmosphere is the practice of modifying the composition of the internal atmosphere of a package (commonly food packages, drugs, etc.) in order to improve the shelf life.

The modification process often tries to lower the amount of oxygen (O₂), moving it from 20.9% to 0%, in order to slow down the growth of aerobic organisms and the speed of oxidation reactions. The removed oxygen can be replaced with nitrogen (N₂), commonly acknowledged as an inert gas, or carbon dioxide (CO₂), which can lower the pH or inhibit the growth of bacteria. Carbon monoxide can be used for preserving the red color of meat.