Single-use garments are intended for a one-time wear. Limited-use garments can be worn until they are damaged, altered or contaminated. Reusable garments can be worn multiple times as long as the suits have not become damaged during use (or if so, repaired), the suits have been completely decontaminated after use and the barrier performance of the fabric has not been compromised. Determining whether or not a reusable garment has been fully decontaminated and that the contaminates have not altered the strength or protection capabilities of the garment can be a difficult decision. DuPont chemical protective garments are limited-use garments. As long as they have not been damaged, altered or contaminated, they have sufficient durability to be worn multiple times.
In terms of chemical protective clothing, penetration is the passage of a chemical through a pore or opening in the barrier material. Permeation is the absorption, diffusion and desorption of a chemical through the barrier material at the molecular level.
To help you understand the difference between these two mechanisms, consider this example. Have you ever opened an old bottle of soda to find out that it was flat? There aren't any holes in the bottle. The liquid is still inside. Why is the soda flat? It's flat because the carbon dioxide that gives soda its fizz has permeated through the walls of the bottle over time. If you opened a fresh bottle of soda and did not replace the cap, the carbon dioxide would just escape out of the top of the bottle. That would be penetration.
Penetration tests are well suited for determining particle barrier in fabrics like Tyvek® and ProShield®. Some factors that influence particle penetration include the size of the particle and the size of the pores/openings in the fabric structure. The more open a fabric structure is, the more likely a particle will be able to penetrate the fabric.
Permeation tests, by comparison, are better suited for testing hazardous liquids and vapors. It is the test method of choice for Tychem® fabrics