According to the EPA HC-12a and OZ-12 brand hydrocarbon refrigerant blends are flammable refrigerants.  Their primary components are hydrocarbons, which are flammable substances like propane and butane.  HC-12a and OZ12 are registered trademarks of OZ Technology, Inc.  HC-12a has been marketed since 1994.  OZ-12 was a similar blend marketed until the introduction of HC-12a.  EPA has reviewed both products under the Significant New Alternatives Policy (SNAP) program. 

Note that EPA refers to the chemical composition of HC-12a as Hydrocarbon Blend B.  EPA considers any substance with that chemical composition, no matter what its trade name is, to be Hydrocarbon Blend B and to have the same legal status that HC-12a has.

In order to meet Department of Transportation requirements for shipping HC-12a in six-ounce cans, OZ Technology reduced the vapor pressure of HC-12a in June 1998.  In order to reduce the vapor pressure, OZ Technology changed the composition of HC-12a.  EPA does not consider this reformulated HC-12a to be the same as Hydrocarbon Blend B.  The reformulated HC-12a has not been submitted for SNAP review, and thus cannot be marketed or used as a substitute for ozone-depleting substances.

DURACOOL 12a has the same chemical composition as the HC-12a formulation that was submitted for SNAP review as Hydrocarbon Blend B.  Both HC-12a and DURACOOL 12a are different than the new formulation of HC-12a in six-ounce cans.  DURACOOL 12a is the registered trademark of Duracool Limited, the Canadian company that has manufactured DURACOOL 12a since 1997.  Duracool Limited and OZ Technology, the manufacturer of HC-12a, are separate, unrelated companies with their own manufacturing facilities and distribution mechanisms.

It has been illegal since July 13, 1995, to replace CFC-12 (R-12) with the HC-12a formulation that was submitted for SNAP review in any refrigeration or A?C application other than industrial process refrigeration.  The same prohibition for OZ-12a took effect on April 18, 1994.  Because DURACOOL 12a has the same chemical composition as the HC-12a formulation that was submitted for SNAP review (i.e., Hydrocarbon Blend B), DURACOOL 12a is also subject to the same restrictions.

HC-12a, as reformulated to meet DOT requirements, is not the same as Hydrocarbon Blend B and has been submitted for SNAP review.  OZ Technology is therefore prohibited from marketing this blend as a substitute for any ozone-depleting substance.  In addition, any use of this blend as a substitute for CFC-12 or any other ozone-depleting chemical, in industrial process refrigeration or any other refrigeration or A/C end use, is prohibited under the Clean Air Act.

Since HC-12a as submitted for SNAP review, is chemically different from HC-12a, as reformulated to meet DOT requirements, and since it has a different legal status under the Clean Air Act, users of any substance marketed as HC-12a should be aware of which HC-12a they have purchased.Note that the Clean Air Act does not regulate the use of any of these hydrocarbon refrigerants when they are used as replacements for non-ozone depleting chemicals such as HFC-134a.  However, many states prohibit using flammable refrigerants in motor vehicles, regardless of which original refrigerant was used in the vehicle.

Sale of refrigerants listed under the SNAP program is not regulated under SNAP.  However, statutes and regulations issued by other federal, state, or local agencies may control the sale and advertising of these products.

Since November 15, 1995, the Clean Air Act has prohibited the venting of any refrigerant during the service, maintenance, repair, or disposal of air conditioning and refrigeration systems.  When working on a system containing a hydrocarbon refrigerant such as HC-12a or DURACOOL 12a, the technician must recover the refrigerant into a suitable container and safely dispose of it.

The following states prohibit the use of flammable refrigerants in automobile air conditioners:  Arkansas, Arizona, Connecticut, Florida, Idaho, Indiana, Iowa, Kansas, Louisiana, Maryland, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, and the District of Columbia.