Asbestos is actually a group of natural minerals that occur as bundles of fibers that can be separated into thin, durable threads and then woven. It is resistant to heat, fire and chemicals, and does not conduct electricity. This makes asbestos incredibly useful as an ingredient in insulation, cement, ceiling and roofing vinyl, automotive brake materials, paints, coatings, adhesives, plastics and other products where protection from heat is important. Asbestos has been mined and used commercially in North America since the late 1800s, but it has been known to be toxic since about the 1920s. Asbestos has been classified as a known human carcinogen (a substance that causes cancer) by the U.S. Department of Health and Human Services, the Environmental Protection Agency (EPA), and the International Agency for Research on Cancer, according to the National Cancer Institute. Studies have shown that exposure to asbestos may increase the risk of lung cancer and mesothelioma, as well as a variety of other diseases In the late 1970s, the U.S. Consumer Product Safety Commission (CPSC) banned the use of asbestos in wallboard patching compounds and gas fireplaces. In addition, manufacturers of electric hairdryers voluntarily stopped using asbestos in their products in 1979. In 1989, the EPA banned all new uses of asbestos; however, uses developed before 1989 are still allowed.