Controlled Atmosphere (CA) storage is used to extend the
storage life of seasonal perishable produce when refrigeration
alone is not sufficient. This technique can be used for many
fruits and vegetables and, historically has been the principle
storage method for the world's apple crop.

CA storage is a completely natural process that changes the
ratio of the constituent gases in the normal atmosphere so that
the respiration activity of the produce being stored is reduced
to a minimum.

Apples are the pre-eminent product stored under CA conditions
but it is also an important storage technique for many other commodities.