"Asbestos is a naturally occurring mineral with thin, durable fibers. It is used in many industries because its fibers are excellent insulators (resistant to heat, fire, and chemicals, and do not conduct electricity). It is often used to strengthen cement and other materials. However, it is a particularly dangerous substance. If asbestos-containing products are damaged, small fibers can be inhaled, which over time leads to diseases such as asbestosis, mesothelioma, and other forms of cancer." https://www.seznamzpravy.c...

Really fireproof? .... So why is it called asbestos in Greek ασβεστος, in translate "unquenchable"?
Asbestos fibers... Who knows, knows.