Asbestos

Asbestos is the commercial and legal name for six naturally occurring silicate minerals that grow as long, thin, flexible fibers: chrysotile (from the serpentine group) and the amphiboles crocidolite, amosite, anthophyllite, tremolite and actinolite in their asbestiform habit. Valued for strength and resistance to heat and chemicals, it causes mesothelioma, lung cancer, asbestosis and other diseases.

Origin

The word comes from the Greek asbestos, meaning "inextinguishable" or "unquenchable." Ancient writers described cloth woven from the fiber that could be cleaned in fire. Industrial mining began in Quebec and elsewhere in the 1870s, and by the mid-twentieth century asbestos was in thousands of products, from insulation and brakes to floor tile, cement pipe and textiles.

Significance in Asbestos Context

"Asbestos" is not a single mineral species but a commercial term, which is why regulations define it as a list: U.S. rules name the six minerals above, and only in their asbestiform (fibrous) form. That definition is the starting point for many disputes: whether a talc or vermiculite contained regulated asbestos, whether particles were asbestiform fibers or cleavage fragments, and whether other fibrous minerals such as winchite, richterite or erionite count. Every form of asbestos is classified by IARC as a Group 1 human carcinogen, and no safe level of exposure has been established. In 2024 EPA banned the remaining uses of chrysotile in the United States, with phase-out periods; asbestos already in buildings and products remains a source of exposure.

Example Sentence

The bulk sample from the boiler room contained 15 percent chrysotile and 5 percent amosite asbestos.

Related Terms

Chrysotile, Amphibole Asbestos, Crocidolite, Amosite, Asbestiform, Regulated Asbestos, Cleavage Fragment, IARC Classification

Notes

• "Asbestos-free" labels and old product names can be misleading; lab analysis is the only way to know.
• All six types are regulated and all cause disease; ask your lawyer before accepting any claim that a product's asbestos was "the safe kind."
• Don't disturb suspected asbestos materials at home; have them tested by an accredited lab.