Once all the demo and cleaning has been completed (and the cleaning is very detailed), a 3rd party testing company comes in while all the containments are still up to do a visual inspection. This visual inspection looks for any visible dust or debris that still needs to be removed. If this visual test is passed, then the inspector sets up equipment that pulls air through a pump to be captured, and then a leaf blower is used to attempt to dislodge any invisible asbestos fibers (and be caught by the pumps). Anything caught by the pumps is looked at through a microscope, and if no asbestos fibers are found, then it is deemed safe to enter without protective clothing. Only then can we remove our containment.