Arguments against non-CO2 refrigerants Butane and propane are very flammable petroleum products; they are used as fuels for gas barbecue grills, disposable lighters, etc. Like gasoline, to which it chemically is closely related, propane tends to explode if mixed with oxygen and ignited in an enclosed container. The use of highly flammable hydrocarbon gases such as butane and propane as automotive refrigerants raises serious safety concerns. The EPA, in evaluating motor vehicle air conditioning substitutes for CFC-12 (Freon, or R-12) under its SNAP program, has classified as "Unacceptable Substitutes" other "Flammable blend[s] of hydrocarbons" because of "insufficient data to demonstrate safety." The EPA defines "Unacceptable" in this context as "illegal for use as a CFC-12 substitute in motor vehicle air conditioners". All of the refrigerants which the EPA approved for motor vehicle use in place of CFC-12 (as of 28 September 2006) contain no more than 4% of total flammable hydrocarbons (butane, isobutane, and/or isopentane). Therefore, it appears unlikely, for safety reasons, that EPA will approve 'Greenfreeze' or similar hydrocarbon-based refrigerants for automotive use. History In September 2007, the German Association of the Automotive Industry (VDA) officially announced its decision to use CO2 as the refrigerant in next-generation air conditioning. Other carmakers from Europe and the rest of the world may follow the German lead. A working group at ACEA, the European carmakers' association, was to be drafting a common position on the issue to be adopted across the whole industry by end-2007. However, on 9 April 2009, German public television channel ARD aired a report claiming that VDA members would be using loopholes in the law to avoid complying with the EU directive. Positions Deutsche Umwelthilfe - Press Release 6 September 2007 Greenpeace Germany - News Release 6 September 2007 Alliance for CO2 Solutions - Press Release 6 September 2007 Alliance for CO2 Solutions - Press Release 30 July 2007 Alliance for CO2 Solutions - Press Release 13 June 2007 Deutsche Umwelthilfe - Press Release 13 July 2007 German Federal Environment Agency (Umweltbundesamt) - Press Release 8 May 2007 Media coverage Spiegel-Online.de (06/09/2007) ENDS Europe Report - August edition European Voice (07/07/12) Euractiv (07/06/26) [(07/06/18)] See also Automobile air conditioning EcoCute, is an energy efficient electric heat pump that uses carbon dioxide as a refrigerant References External links R744.com Website dedicated to CO2 Technology Shecco.com Heating, ventilation, and air conditioning Automotive cooling systems Sustainable design