What is the term used to describe the movement of a hazardous chemical through a material on the molecular level?

The term used to describe the movement of a hazardous chemical through a material on a molecular level is permeation. This process involves the penetrative movement of molecules through a barrier or material, resulting in the chemical passing through without altering the physical form of the barrier.

Permeation is particularly significant in haz-mat operations because it can lead to unexpected exposure to hazardous materials if protective equipment, such as gloves or suits, becomes compromised. Understanding permeation helps responders assess risks associated with the materials they might encounter and ensure they use appropriate protective measures.

In contrast, diffusion refers to the process where molecules spread from an area of high concentration to an area of low concentration, which is a broader concept not limited to the molecular passage through materials. Absorption involves the incorporation of a substance into a bulk material, often leading to a chemical change in that material, while desorption is the reverse process where a substance is released from the material. Each of these terms describes different interactions between materials and chemicals, but permeation specifically addresses the molecular transport through a medium, making it the correct choice in this context.