Asbestos is the name for a family of minerals that grow in veins of microscopic fibers that have a diversity of distinct characteristics. Asbestos is mined and processed in mass with diverse commercial grades and uses in several products as an ingredient.
Asbestos fibers are strong, durable, resist heat, acids, and friction, and are practically indestructible. Asbestos fibers have a tendency to break up easily in smaller and smaller microscopic tiny particles that simply float in air and stick to clothes and other surfaces. Because of these properties, asbestos was often combined with other materials for use in industry and construction. Colorado Dept of Health Regulation #8 /Regulation #8 Part B - Asbestos

Asbestos becomes a health hazard when these materials disintegrate, collapse, or are otherwise disturbed. Asbestos fibers are so tiny that they can be easily inhaled or swallowed without a person's awareness. When asbestos materials are damaged, unseen fibers are released into the air, where they can stay suspended for a long time. Asbestos can then be inhaled and the fibers can embed deeply in the lungs. These fibers also settle on surfaces and clothing where they can be redistributed into the air by motion such as walking past a contaminated surface.
Once an area or surface is contaminated with asbestos dust, special procedures and equipment are necessary to decontaminate that area or surface, as well as anything inside the area.