Waste Gases: exhaust gases released from combustion, natural gas heating or thermal heat machines. Given complete combustion, the components of waste gases are carbon dioxide, steam and possibly sulphur dioxide; waste gases from incomplete combustion contain carbon monoxide, hydrogen, oxygen, hydrocarbons and possibly soot. Legal regulations on waste gases in Austria can be found in the Clean Air Act for Boiler Plants (Federal Law Gazette No. 380/1988), the Clean Air Ordinance for Boiler Plants (Federal Law Gazette 785/1994), the Waste Disposal and Recycling Act (Federal Law Gazette 325/1990), the Commercial Code of 1994 (Federal Law Gazette 194/1994) and provincial legal regulations. Limits on and tests of automobile emissions are governed by the implementing regulation of the Motor Vehicle Act.