Under Section 18 of the Clean Air Act 1993, many parts of Scotland are declared Smoke Control Areas by the relevant local authority. If you live in a smoke control area it is an offence to produce smoke from a chimney of a building, or a chimney of any fixed boiler or industrial plant, unless you're burning an authorised fuel or using exempt appliances (e.g. burners or stoves). In practice this means that in a smoke control area it is illegal to burn house coal or wood in an open fire, although it is legal to burn these in a stove or other appliance that has been approved to burn that fuel. It is also illegal to deliver any unauthorised solid fuels, e.g. wood and normal house coal, to any premises in a smoke control area unless the seller can demonstrate that they were aware that the unauthorised solid fuel is to be burnt in an exempt appliance.