Asbestos is the general name for a wide variety of silicate minerals, mostly silicates of calcium, magnesium, and iron.

The common characteristics of the silicate minerals collectively known as asbestos are a fibrous structure and resistance to fire. Fabricated into corrugated or flat sheets, asbestos has been used as building material in a wide variety of structures, including many schools built before 1970. Formed into cylinders, it has been used for ducts and pipes. Certain types of asbestos with long fibers have been used as components in protective clothing for firefighters, brake and clutch linings for vehicles, electrical insulation, moldings for automobile components, and linings for chemical containers.

Most products manufactured today do not contain asbestos because of the deleterious health effects that have become apparent since the end of World War II. Today scientists know that asbestos can cause a range of respiratory diseases, especially asbestosis (scarring of...