Permeation
Permeation is the molecular passage of a chemical through glove material without visible damage. The process occurs in three phases: absorption at the outer surface, diffusion through the polymer, and desorption at the inner surface.
Key measurements per EN 16523-1:
- Breakthrough time: time from first chemical contact on the outside to first detection on the inside
- Permeation rate: quantity of chemical passing through per unit time and area
- Permeation classes (1–6): Class 1 ≥10 min, Class 2 ≥30 min, …, Class 6 ≥480 min
These classes form the classification basis for EN ISO 374-1 (Type A: Class ≥2 for ≥6 chemicals; Type B: Class ≥2 for ≥3; Type C: Class ≥1).
A critical practical point: once permeation has begun, it cannot be halted by briefly removing the glove. Diffusion continues even after chemical contact ends. Gloves must therefore be discarded after defined wearing times.
Frequently asked questions
What does breakthrough time mean in a permeation test?
Breakthrough time is the time in minutes from first chemical contact on the outer surface to the first detection of the chemical on the inner surface. Longer breakthrough times mean better protection.
What permeation classes does EN 16523-1 define?
Class 1: ≥10 min, Class 2: ≥30 min, Class 3: ≥60 min, Class 4: ≥120 min, Class 5: ≥240 min, Class 6: ≥480 min. Type A (EN ISO 374-1) requires at least Class 2 for ≥6 test chemicals.
Can permeation be detected visually?
No. Permeation occurs at molecular level through intact material – without visible cracks or holes. It can only be detected by chemical measurement methods.