Many buildings contain Asbestos, which was used in spray-applied flame retardant, thermal system insulation, and in a variety of other materials. Asbestos was sometimes "flocked" above false ceilings, inside technical ducts, and in many other small spaces where firefighters would have difficulty gaining access. Structural components like asbestos panels were also used. In residences, asbestos was often a component of a type of flocked acoustic ceiling called "popcorn ceiling" or "cottage cheese ceiling", until its production was banned in the U.S. in 1978. However, the ban allowed installers to use up remaining stocks, so houses built as late as 1986 could still have asbestos in their acoustic ceilings. The only way to be sure is to remove a sample and have it tested by a competent laboratory.

If removal is to be performed when users are still present in the building, it is usually necessary to relocate some users temporarily. Typically, the part of the building from which asbestos is being removed has to be sealed off in order to prevent contamination of the other areas. Methods of sealing off an area often include the use of polyethylene film, duct tape and negative air pressure machines which are fitted with HEPA filters. The idea is that the contained area is pulling fresh air in as to not allow asbestos fibers into the surrounding environment.

Only a special vacuum that's designed for asbestos containment (class H) can be safely used when cleaning up during and after asbestos removal. Ordinary vacuum cleaners cannot be used, even those fitted with a HEPA filter. An ordinary vacuum cleaner will expel the asbestos fibres into the room air.
If the building is closed to normal users, it may be necessary to seal it off from outside atmosphere so that no accessible air is contaminated.

Alternatives to removal

Removal is not the only means of asbestos abatement. Asbestos and asbestos-bearing materials may be "enclosed" or "encapsulated" to prevent building occupants from being exposed to the fibers.