significantly cut fuel consumption by the air conditioning device. Carmakers have to make an initial investment estimated at €20 per unit, with no additional costs once CO2 Technology enters into mass production. Usable in Heat Pumps because at least one CO2 system under development can act as a heat pump, supplying cabin heat and windshield defrosting even before the engine has warmed up. Although the Alliance may not mention it, since CO2 is so cheap and relatively harmless to the environment, the reservoirs in such systems could store additional liquid R744 to keep a vehicle cool even when the engine (or compressor) was not running. Technology is readily developed long ago. During the RACE Project from 1994 to 1997, financed by the EU with nearly 2 Million Euros, main producers of cars agreed to develop CO2 car AC systems. See . The result was that car AC systems for CO2 small cars are 45% more expensive than HFKW Units and that for the luxury class the additional cost was irrelevant. There is a final presentation of the Project containing this data. Arguments against CO2 CO2 Technology requires the design of completely new high-pressure systems whereas so-called "drop-in solutions" (the adaptation of current systems to new substances) are potentially more cost-efficient. The Alliance for CO2 Solutions claims, however that the initial costs of CO2 systems will be around €5 higher than drop-in solutions and that over a car's life cycle, CO2 air conditioning systems will be more cost-efficient than any currently used or proposed new chemical blends. (see Arguments for CO2). has been classified as Safety Class A1 (low-toxic, non-flammable refrigerant) by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) – the highest safety class possible. As the charge of CO2 to the air conditioning systems is very small (200-400 g) there is no real danger for the passengers, even in case of accidental release. Arguments for non-CO2 refrigerants Refrigerants such as the Greenpeace-developed 'Greenfreeze', based on purified butane/propane mixtures, are entirely 'natural', and due to increased efficiency over refrigerants such as R134a, allow the use of very small amounts of refrigerant to be used. The use of pure hydrocarbon refrigerants, which are 'backward compatible' with even early Freon (R-12) car air conditioning systems, would allow these systems to be easily converted (without modification), increasing their efficiency, and preventing further release of harmful R-134a and R-12 to the atmosphere.