In March 1997, Idaho amended its highway code to allow refrigerants which are nontoxic and nonflammable at or below 1000 F degrees in car air conditioners. Both houses voted for the amendment by overwhelming majorities and the Governor promptly approved it. Environmentally friendly hydrocarbon refrigerants like HC-12a(tm) are now legal in Idaho.
Air, water, carbon dioxide, fluoroiodocarbons (FICs) and chlorofluorocarbons (CFCs) are truly nonflammable refrigerants. Ammonia, hydrocarbons, hydrofluorocarbons like R134a and hydrochlorofluorocarbons like R22 are all flammable under some conditions. Ammonia is toxic and incompatible with materials used in car air conditioners.
Only air, ammonia, water, carbon dioxide and hydrocarbons have negligible global warming, no ozone depletion and manufacturing processes with low environmental impact. Replacing CFC in a car air conditioner by hydrocarbons about halves the global warming emissions from a car. These five refrigerants are acceptable to all national governments except the USEPA does not allow hydrocarbons as replacements for CFCs.
Starting in 1953, fourteen US states and the District of Columbia made laws banning toxic and flammable refrigerants in car air conditioners. Thirty-six US states made no such laws. FICs were not commercially available and air, water and carbon dioxide performed poorly in car air conditioners. A CFC, R12 (known by its DuPont trademark "Freon" in the US) quickly became the only refrigerant used in car air conditioners.
Since the 1st January 1996, it has been illegal to manufacture or import R12 into the US and similar countries due to the Montreal Protocol. All replacement refrigerants which perform well at low cost are however flammable. It would eventually be illegal or with FICs very expensive to use a traditional car air conditioner in the US states banning flammable refrigerants.
Idaho is the first of the fourteen states to amend its Code. Both R134a and hydrocarbon refrigerants like HC-12a(tm) are now legal in car air conditioners. This law is a model for the other thirteen states and the District of Columbia.
The USEPA does not permit hydrocarbon refrigerants to directly replace CFCs in car air conditioners. Since 1995, all new automobiles in the US have been equipped with R134a. It is legal to replace R134a with hydrocarbons in the US. Replacing the R134a by hydrocarbon typically reduces global warming emissions from a car by about 15%.
OZ Technology's Gary Lindgren estimates that worldwide about ten million years of hydrocarbon refrigerant use in car air conditioners has accumulated since 1992. Not one case of injury or property damage, due directly or indirectly to flammable HC refrigerant in car air conditioners has been reported. In 1996, a fire in a car air conditioner was reported to the New Zealand government but on investigation the refrigerant was found to be R134a.
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