What term refers to the movement of materials through closures like seals or valves?

The term that refers to the movement of materials through closures like seals or valves is "penetration." In the context of hazardous materials and emergency response, penetration specifically describes how substances can enter or transgress barriers such as seals, gaskets, or valves. This phenomenon is critical in understanding how hazardous materials might escape from their containers or systems, potentially leading to exposure or contamination.

Recognizing penetration is essential for first responders, as they need to assess the integrity of containment and take appropriate measures to mitigate the risks associated with hazardous spills or leaks. It highlights the importance of assessing seals and barriers when dealing with tanks, vessels, or systems that contain hazardous substances.

Understanding this term also helps distinguish it from other concepts related to hazardous materials. For example, while leakage might imply unintentional escape from a container, penetration specifically focuses on the process of moving through barriers rather than just indicating an escape. Similarly, filtration refers to the process of separating particles from fluids, and exfiltration generally describes the outward flow of contaminants from a contained area – neither of which addresses the idea of movement through seals or closures specifically.