Asbestos fibers are dangerous when inhaled. The microscopic fibers can become lodged in the respiratory system and lead to asbestosis or scarring of the respiratory tissues.
Asbestos was commonly used as a binder and fire retardant in many building products. It can typically be found in acoustical ceiling tiles; thermal insulation of boilers and pipes; steel fireproofing, cement asbestos siding and roofing; tile and sheet floor coverings.
Inspectors are most concerned with what is known as friable asbestos (easily crumbled or pulverized to powder) and often recommend it be removed. It should always be removed and disposed of by a qualified contractor. Contact the Environmental Protection Agency for an updated list of qualified testing and or mitigation contractors.