Asbestos is a naturally occurring fibrous mineral that was widely used in building materials in the UK until it was banned in 1999. While asbestos can be found in a variety of building materials, including insulation, roofing, flooring, and cement products, it is known to cause serious health problems, such as lung cancer, mesothelioma, and asbestosis, when inhaled in large amounts over an extended period of time. If you suspect that a building material may contain asbestos, it's essential to have it properly tested before any renovations, repairs, or demolition work takes place.