Containment (Source Removal / Negative Air Containment)

Containment means sealing off the work area during a mold or water job so contaminants do not spread to the rest of the building. Source removal means physically removing the moldy or contaminated material rather than just treating it in place. Negative air containment adds a machine that pulls air out of the sealed area and exhausts it outdoors, which keeps air pressure inside the containment lower than the surrounding rooms so spores and dust are pulled inward instead of escaping. EPA guidance recommends ventilating the work area and exhausting air outdoors when cleaning mold, which is the same underlying idea in simpler form.