Chemical permeation is the process by which ...

Chemical permeation is the process by which ...

• A. A chemical moves through a material at the molecular level
• B. A chemical evaporates from the surface
• C. A chemical reacts with the air
• D. A chemical is absorbed and stored in tissue

Answer: (D)

Permeation is about a chemical crossing a barrier, such as skin or a membrane, and entering the tissue on the other side. The best description here is that a chemical is absorbed and stored in tissue, because after it passes the barrier it can be taken up and retained within tissue components, depending on its properties and how it interacts with the tissue. This captures both the crossing of the barrier and the subsequent localization or storage inside the tissue. Evaporation describes the chemical leaving the surface as a vapor, a surface process not involving crossing into tissue; reacting with air is a chemical reaction, not permeation; and merely moving through a material at the molecular level may describe diffusion but doesn’t necessarily imply uptake into tissue and storage.

Permeation is about a chemical crossing a barrier, such as skin or a membrane, and entering the tissue on the other side. The best description here is that a chemical is absorbed and stored in tissue, because after it passes the barrier it can be taken up and retained within tissue components, depending on its properties and how it interacts with the tissue. This captures both the crossing of the barrier and the subsequent localization or storage inside the tissue. Evaporation describes the chemical leaving the surface as a vapor, a surface process not involving crossing into tissue; reacting with air is a chemical reaction, not permeation; and merely moving through a material at the molecular level may describe diffusion but doesn’t necessarily imply uptake into tissue and storage.