All chemicals will eventually permeate protective clothing. Breakthrough, or permeation, resistance is related to the concentration and temperature of the challenge chemical, environmental temperature and thickness of the barrier material. Therefore, higher temperatures can result in faster breakthrough. Similarly, lower temperatures can lead to longer breakthrough for certain chemical/material combinations.
ASTM F739 is the standard test for permeation. It measures the resistance of protective clothing materials to permeation by liquid or gaseous chemicals under the condition of continuous contact. The test determines both the breakthrough time and steady-state permeation rate of chemicals through a sample of the protective barrier.