Asbestos was used initially as a heat shield. In the 1950s an asbestos pad sold to housewives to reduce stove heat under a pan and prevent burning.
Sometime in the 1970s, the health connection between Mesothelioma (lung failure/cancer) was discovered.
Manufacturing of asbestos-containing materials was stopped and declared illegal in the United States in 2002. Asbestos had been banned by the EPA in 1975 for TSI (Thermal System Insulation). That’s the usually yellow insulation around the furnace registers in older homes.