Atmospheric corrosion is a natural process of metal alteration. The corrosion of a metal usually starts with the appearance of condensed moisture on its surface. Moisture, present on the surface of the metal, forms an electrolyte that allows the circulation of electrons. This process results in visible oxidation (rust or tarnish).
By sublimation, VCI (volatile corrosion inhibitors) vapors saturate the atmosphere inside the packaging and condense on all accessible surfaces of the metal part thus forming a protective ion film.
In most situations, if the absolute sealing of the closure is not necessary, however, it is necessary to limit the exchange of air with the outside