The 1926 UK Smoke Abatement Act reduced smoke emissions from industrial sources. The Clean Air Acts of 1956 and 1968 made it illegal for smoke to be emitted from homes within Smoke Control Areas. Smokeless fuel may be used which produce little or no smoke when burnt. Examples are natural gas, anthracite (a very pure form of coal) and specially developed fuels such as Coalite. Today, most people living in mainland Britain, particularly in urban areas, have gas central heating, and smoke emissions from domestic sources are very low.