Containments are meant to avoid cross-contamination from areas of building material removal or demolition from impacting other areas. This is typically done with HEPA filtered, negative air machines (NAMs) vented to the exterior to create a negative air pressure differentials measured with a manometer with a minimum of ā€“0.02 inches of water column or water gauge.  

This is the basis of asbestos abatement in Federal Law and mold remediation in many guidelines. However,  following this method in all areas is dangerous if you donā€™t understand what is being pulled into the containment from other sources not addressed.