At what locations must air monitoring be collected outside the negative pressure enclosure?

Air monitoring outside the negative pressure enclosure is essential to ensure that no asbestos fibers escape the controlled area during abatement activities. The correct answer specifies monitoring at the negative air unit exhaust port and at the entrance to the decontamination facility.

Monitoring at the negative air unit exhaust port is critical because this location will show whether any asbestos fibers have escaped the enclosure due to potential leaks or inefficiencies in the air filtration system. By ensuring that the air quality is monitored at this point, workers can confirm the effectiveness of the negative pressure setup designed to contain airborne contaminants.

Additionally, monitoring at the entrance to the decontamination facility is important because this area serves as a transition point between the contaminated space and the uncontaminated environment. Ensuring that air quality is safe at this point protects workers and prevents cross-contamination with clean areas.

The other locations mentioned in the other choices may also seem relevant for air quality checks, but they do not focus specifically on the critical containment boundaries of the asbestos work environment. Monitoring might not be as effective or necessary at those specific points outside of the main regulated areas.