Asbestos is a category of mineral fibers found in rocks.
Asbestos fibers are extremely durable, lightweight, and fire-resistant. Because of these characteristics, asbestos and asbestos containing materials were widely used in construction and thermal insulation until they were banned in 1978. When disturbed, asbestos crumbles into a dust of tiny fibers which can remain in the air for a long time. These fibers cannot be seen. If inhaled, they can become permanently lodged in our bodies and pose a serious health threat.