Definition
Describes a material that does not contain pores or openings through which liquids, gases, or other fluids can pass. A nonporous material forms an impermeable barrier to fluid penetration.
Plain English
A material that fluids and gases cannot soak into or pass through because it has no tiny holes or openings.
Context Anchor
Seen in aircraft maintenance, material selection, sealing, coating, and inspection discussions.
Derivation
From the prefix 'non-' meaning 'not,' combined with 'porous,' from the Latin 'porus' meaning 'pore' or 'small opening.' So nonporous literally means 'without small openings.'
Why Pilots Care
Prevents fuel leaks, maintains pressure integrity in tanks and lines, and stops contamination in hydraulic and pneumatic systems.
Analogy
A sponge is porous because water can soak into it. A sheet of plastic is nonporous because water stays on the surface instead of passing through.
Intuition Check
Nonporous does not mean strong, fireproof, or safe for every aircraft use. It only means the material does not let air or fluid pass through easily.
Example Sentence 1
The fuel tank sealant must cure into a nonporous layer to prevent fuel from seeping through the tank walls.
Example Sentence 2
Integral fuel tanks are built with nonporous liners so vapor cannot escape into the structure.