Asbestos is a natural mineral fiber. It was originally added into building material to add fire retardant and thermal insulation properties. As of July 12, 1989 the E.P.A banned the use of most asbestos materials used in homes. If you do find asbestos in your home it is not of major concern as long as this asbestos does not become friable (airborne). If asbestos is not friable it is not harmful. The most cost effective way to ensure that asbestos does not become friable is to have a certified asbestos contractor evaluate and contain the area with an E.P.A approved sealant.