Definition - What does Impermeable mean?
Impermeable refers to a material characteristic, whereby the material is incapable of allowing (or prevents) the free flow of a gas or liquid through it. Impermeable substances may be naturally occurring or manufactured. Impermeable substances prevent corrosion by isolating metal surfaces from direct contact with water, chemicals, air and other corrosive agents.
Corrosionpedia explains Impermeable
Impermeable substances such as coatings and linings are used as protective covering layers for metallic structures and their alloys. Impermeable substances such as film barriers are vital for many industrial applications.