How do you safely remove asbestos from a building that is occupied?

Throughout history asbestos has been used in a variety of building materials.  These building materials can be found in public, private, and residential buildings.  The question is, once it’s discovered, how can it be removed and can it be removed safely in an occupied building?  Although asbestos can cause health hazards, if the abatement project is performed properly, there is no need to vacate the building or worry about contaminating adjacent areas.

After a thorough inspection of the building confirms the presence of asbestos containing material, it is important to decide what action to take at that point.  If the asbestos is in good condition, it can simply be managed in place.  That means it needs to be routinely inspected and maintai
ned in good condition.  If the asbestos is damaged or deteriorating it needs to be removed or sealed to eliminate any health risks.  Asbestos is only harmful when it is disrupted and fibers are dispersed through the air and inhaled.  For that reason the EPA and OSHA have instituted certain regulations to ensure thorough removal as well as safety for workers and building occupants.

Performing asbestos abatement in one section of a building can seem dangerous to people in other areas and the number one concern of course, is safety.  Safety for the abatement workers as well as the occupants of the building, whether tenants or employees.  Before beginning any asbestos removal project, the removal area must be isolated from the other areas of the building.   The area where asbestos abatement will be performed is referred to as the “regulated area”.  Once regulated areas are designated, signs must clearly state that entering is a danger, and the area is reserved for authorized personnel only.  Personal protective equipment (PPE) is required to enter the area, and there is absolutely no eating, drinking, chewing gum or tobacco.  Once the area is isolated and signs are posted, it must be kept off limits to all unauthorized people.
 

After separating the removal area it must be meticulously sealed off from the non-regulated areas.  First, all moveable items must be removed from the area.  Anything that cannot be removed from the work area needs to be wrapped in polyethylene sheeting and secured with an airtight tape seal.  Polyethylene sheeting with a minimum thickness of 4 mils is used to cover walls and 6 mil thick poly sheeting should be used on all floors.  In heavy traffic areas or areas needing extra protection, an extra layer of poly sheeting should be used.  

Once abatement begins, OSHA requires the use of wet methods of removal, HEPA vacuums, and prompt cleanup for materials that contain any amount of asbestos. These requirements are necessary regardless of the level of exposure during the removal activities. The wet method of removal will reduce airborne fiber concentrations, and require the use of a surfactant or wetting agent to be added to the water. The vacuums used must come equipped with HEPA filters which will retain 99.97% of all fibers. Also negative air machines are used to continuously draw air from the abatement area to the outside of the building. The negative air machines are also equipped with HEPA filters. As the asbestos containing materials are removed, they must be containerized promptly and kept wet. These containers can be 6 mil plastic bags or plastic lined drums. This method of prompt cleanup will prevent the asbestos waste from drying out and releasing asbestos fibers into the air. Air testing is conducted inside and outside the abatement area to confirm that no fibers are released from the work area that could pose health risks to building occupants. Observing these work practices will ensure that no asbestos fibers escape the designated area and protect building occupants.