Question

Explain how permeation of a hazardous chemical into PPE differs from degradation and penetration. Provide examples of each.

Answer 1

The employees at work who are exposed to hazardous chemicals need to use Personal Protective Equipment (PPE) to protect themselves. PPE usually includes gloves and chemically protective working suits available in a variety of materials. However, it is not possible for any material to provide protection from all the perils. The PPE might prove to be ineffective or unsuitable for the employees because of the problem of penetration, permeation or degradation. Therefore, rigorous tests are carried out by the company to ensure the effectiveness of the chemically protective equipment. The clothing must be selected according to the task required to be performed.

The three basic problems that forms the base for selection of PPE are explained as follows:

• Penetration: Penetration means passing of the chemicals through the PPE without changing its form, state and properties. The chemical can pass through open pores, closures or defects in the clothing. For example, any opening in the face mask might lead to workers breathing the hazardous chemicals. Penetration tests are useful for activities where less exposure to danger is expected.
• Permeation: Permeation essentially means diffusion of the chemicals into the clothing. In penetration, the hazardous chemicals move through the PPE without any openings or closures. The chemical gets absorbed in the clothing, further in the worker's body, through diffusion. It generally changes its form and state. Permeation tests passed clothing is used in case of extreme danger.
• Degradation: Degradation means changes in the PPE due to normal wear and tear. The changes include wrinkles on the surface's clothing, changes in color, stiffening and other physical factors.