Permeation

Permeation has three stages: the chemical is absorbed into the outer surface of the material, it diffuses through the material, and it is released from the inner surface. Because it involves the material itself rather than defects in it, no rinse or visual check can prove the glove is safe. Only test data and sensible replacement schedules can address this.

Permeation is distinct from penetration, where a liquid flows through pinholes, seams or tears, and from degradation, where the chemical changes the physical properties of the material, for example by making it swell, soften or crack. A glove can resist degradation yet allow permeation, or the reverse, so selection charts often report separate ratings.

Two measures describe permeation. Breakthrough time shows when the chemical first appears on the inside, and the permeation rate shows how fast it passes once it has started. A material with a long breakthrough time and a low rate is generally better suited to extended contact. Thicker material usually slows permeation, though it may reduce dexterity.

Practical consequences are simple: choose Chemical-resistant gloves for the particular chemical, limit the time of contact, remove gloves promptly after a splash, and wash hands after use. Skin absorption can matter for chemicals with a skin notation, so ignoring permeation can lead to exposure through the Dermal exposure route.