How long should a negative air pressure unit or cabinet run after clean-up procedures are completed?

The duration for which a negative air pressure unit or cabinet should continue to run after clean-up procedures is critical for ensuring that any potential airborne contaminants are effectively filtered out of the environment. A period of four hours is recommended as it provides adequate time to further reduce airborne particulate levels, enhancing the safety and cleanliness of the area.

Running the unit for this length of time allows for sufficient air exchange and ensures that any residual asbestos fibers or other contaminants that may still be present in the air after the initial clean-up are captured and removed. This practice aligns with safety protocols aimed at minimizing health risks associated with exposure to hazardous materials.

Other durations might not provide the same level of assurance, potentially leaving behind harmful particles. Therefore, adhering to the recommended four-hour run time helps in achieving a safer workspace for workers and residents.