Asbestos is a naturally occurring fibrous mineral used in many construction products. It is considered to be a carcinogen. Asbestos has been used in: sealant, putty, and spackling compounds; vinyl floor tiles, backing for vinyl sheet flooring, and flooring adhesives; ceiling tiles; textured paint; exterior wall and ceiling insulation; roofing shingles; cement board for many uses, including siding; door gaskets for furnaces and wood-burning stoves; concrete piping; paper, millboard and cement board sheets used to protect walls and floors around wood-burning stoves; fabric connectors between pieces of metal ductwork; hot water and steam piping insulation, blanket covering and tape; and as insulation on boilers, oil-fired furnaces, and coal-fired furnaces. The use of asbestos was phased out in 1978, but many older houses contain asbestos-bearing products.
Products containing asbestos are not always a health hazard. The potential health risk occurs when these products become worn or deteriorate in a way that releases asbestos fibers into the air. Of particular concern are those asbestos-containing products that are soft, that were sprayed or troweled on, or that have become crumbly. In this condition, asbestos is considered to be in a friable state.
The U.S. Environmental Protection Agency believes that as long as the asbestos-bearing product is intact, is not likely to be disturbed, and is in an area where repairs or rehabilitation will not occur, it is best to leave the product in place. If it is deteriorated, it may be enclosed, coated or sealed up (encapsulated) in place, depending upon the degree of deterioration. Otherwise, it should be removed by a certified professional.
A certified environmental professional could perform an inspection and make the decision whether to enclose, coat, encapsulate or remove deteriorated asbestos-containing products. Testing by a qualified laboratory, as directed by the environmental professional, may be needed in order to make an informed decision. Encapsulation, removal and disposal of asbestos products must be done by a qualified asbestos-abatement contractor.