There are numerous examples of situations where bacteria may migrate through a barrier material in the dry state carried by organic or inorganic particles. The dry penetration of bacteria-carrying skin scales through an operating gown or a clean air suit is one example. Penetration through a packaging material during storage is another.

This document ISO 22612 describes a test method, with the associated equipment, that may be used to determine a material's resistance to dry penetration of bacteria on particles in the size range most typical for human skin scales