Which material was once commonly used as insulation?

Asbestos was widely used as insulation material in various construction applications due to its excellent properties, such as thermal resistance, sound insulation, and fire retardancy. In addition to insulation, it was commonly used in roofing, flooring, and other building materials. However, its use has drastically declined due to the serious health risks associated with asbestos exposure, including lung cancer, mesothelioma, and asbestosis. The recognition of these dangers led to strict regulations and a significant reduction in its use in the building industry. Understanding the historical prevalence of asbestos helps to illustrate the changes in material safety standards and practices over time.