What is an 'air lock' in asbestos containment?

• A. A device that seals and isolates the work area using negative pressure
• B. A door that automatically closes when a sensor is triggered
• C. A decontamination entry/exit area used to prevent cross-contamination between clean and dirty zones
• D. A temporary containment tent around the work area

Answer: (D)

An air lock is a transitional space that creates a controlled boundary between the work area and the surrounding environment, helping to keep airborne contaminants from migrating out. In asbestos containment, this means a space where air pressures can be managed and where workers can move in and out without letting fibers escape into clean areas. Describing it as a temporary containment tent around the work area captures this idea: the tent acts as a portable, sealed enclosure that isolates the work zone and supports the needed air management to prevent cross-contamination as people and materials pass through.

Other features mentioned are related components of containment—one describes the overall negative-pressure enclosure, another is the door mechanism, and another is the dedicated decontamination entry/exit area. While these contribute to containment, the defining role of an air lock is the protected, transitional space that keeps the work area isolated during access and removal of PPE and waste, often implemented as a temporary enclosure around the work area.