What is the purpose of an airlock in containment zones?

• A. To provide a transitional, controlled space that reduces air exchange between zones and helps maintain pressure differentials.
• B. To allow easy movement of personnel between zones.
• C. To store contaminated equipment for later disposal.
• D. To increase air exchange between containment zones.

Answer: (A)

The key idea is that an airlock acts as a buffering zone to protect the containment area by controlling how air moves between spaces with different pressures. By providing a transitional space with interlocked or carefully sequenced doors and dedicated airflow, it prevents direct, uncontrolled air exchange when people or materials pass through. This helps sustain the pressure differential that keeps contaminants from migrating from dirty to clean areas (and vice versa, depending on the setup). The airlock thus reduces cross-contamination risk and supports proper sequence of entry and exit.

This isn’t about making movement easy, storing contaminated equipment, or increasing air exchange. Those options would undermine containment—an airlock is specifically to limit exchange and maintain separation between zones.