Asbestos is a mineral fiber.
In the past, asbestos fibers were used for insulation, heat resistant clothing, roofing and fire proofing because of its strength and resistance to heat. Today, asbestos is still used in gaskets, brakes, roofing and other materials. The mere presence of asbestos materials in a home is usually not a serious problem or hazard. The danger is that asbestos materials may be disturbed or crumble over time, causing the fibers to be released into the air. Asbestos materials that crumble easily if handled, or that have been sawed, scraped or sanded into a power pose the greatest danger.