4. Simple packaging sizing tools

When packaging food in a modified atmosphere, it's important to select a packaging material that will maintain this atmosphere for the desired shelf life.

We'll show that it's quite possible, under certain assumptions, to simply calculate material flows between headspace and external atmosphere and use these flows to identify target or threshold permeabilities.

In this section, we will use the combination of Henry's law and Fick's first law, recalled below, and which we will call Fick's law for simplification: