Asbestos is a hazardous substance that was commonly used in building materials from the 1950s to the 1980s. It was used extensively in the construction of buildings and homes, particularly for insulation, as it is fire-resistant and has excellent thermal insulation properties. However, asbestos is a known carcinogen, and exposure to its fibers can cause serious health problems, including lung cancer, mesothelioma, and asbestosis.