The Smoke Control Areas (Exempted Fireplaces) (Scotland) Order 1999
Section 20 of the Clean Air Act 1993 generally prohibits the emission of smoke in smoke control areas. The Scottish Ministers may by order made under section 21 of the Act exempt specified classes of fireplace from the provisions of section 20 if they are satisfied that fireplaces can be used for burning fuel (other than authorised fuels) without producing any smoke or a substantial quantity of smoke.