Replacing R12 refrigerant requires choosing a substitute based on whether you are working on an automotive air conditioning system or stationary commercial refrigeration, as R12 is a banned CFC. The best replacement options range from direct “drop-in” chemical blends to hydrocarbon alternatives that don't require changing your existing compressor oil.
RS-24 is an easy-to-use Drop-in replacement for R12, There is no need to change the existing lubricant in the system, thereby avoiding a costly retrofit.
So carmakers were mandated to stop using R12 after the 1994 model year. One current replacement refrigerant is R134a - opens in new window or tab., which serves the same purpose as Freon but is less harmful to the environment. Freon is the well-known trademarked name for dichlorodifluoromethane gas.
When finding an R12 compatible refrigerant, the best choice depends on whether you are doing a full system conversion (retrofitting) or looking for a direct "drop-in" substitute. Here are the primary options:
RS-24 is a “Drop-in” alternative for R12 which also provides a long term solution at the same time.
Oil Can Be Incompatible
As previously stated, R12 systems usually use mineral oil, which is incompatible with R134a. When R134a comes into contact with mineral oil, it can hinder the oil from returning to the compressor, or possibly reduce heat transfer.
R600a (isobutane) is refrigerant grade isobutane used as a replacement for R12 and R134a in a variety of refrigeration applications. R600a (isobutane) is a hydrocarbon that is becoming increasingly popular due to its low Global Warming Potential (GWP).
While the production of new R12 is banned, it is not illegal to sell or use R12. In fact, many of the cylinders and cans of Freon R12 sold for decades throughout the United States are still around today.
Freon™ Hot Shot-2 (R-417C) is a non-ozone depleting A1 refrigerant that can be used as a direct replacement into existing systems that are still operating with R-12, R-134a, or R-500.
When converting an R12 A/C system to R134a, you should initially charge the system with 75% to 85% (often quoted as 80%) of the vehicle's original R12 factory capacity.
Using pure propane (R-290) in an automotive R-12 air conditioning system is not recommended and is illegal in the United States. While propane has similar thermodynamic properties, it is highly flammable. Federal EPA laws strictly prohibit venting or using hydrocarbon replacements in motor vehicle AC systems.
An HCFC Replacement Refrigerant for R-12
Freon™ 409A carries an ASHRAE A1 safety classification and blends R-22, R-142b, and R-124. It can be used in medium- and low-temperature positive displacement equipment.
No, you cannot use R22 instead of R12.
The most common and practical replacement for R12 (Freon) in automotive and stationary systems is R134a. However, switching from R12 to R134a requires retrofitting, which involves replacing the system's O-rings, accumulator/drier, and flushing the old mineral oil out for a compatible PAG or POE synthetic oil.
Refrigerant can only be sold to technicians certified under the Section 608 or Section 609 technician certification programs, where individuals may only purchase refrigerant consistent with the appliances covered by their certification.
Automotive service technicians depend on Freon™ 134a (R-134a) refrigerant, a non-ozone depleting hydrofluorocarbon (HFC) replacement for R-12. Freon™ 134a is the standard in many mobile air conditioning (AC) units, and also replaces R-12 in: Commercial stationary refrigeration systems.
The "best" replacement for R12 depends on your system type and whether you want a direct drop-in or a full retrofit. Because R12 is a banned CFC, alternatives require different handling and oil compatibility.
Finding a direct, zero-modification "drop-in" replacement for R-12 depends on your system type, but R-409A is the most common true drop-in for stationary commercial refrigeration, while R-134a (with conversion fittings) or hydrocarbon blends are popular for automotive applications. These alternatives require little to no flushing or oil changes.
No. The two systems use different and incompatible lubricating oils (R12 uses mineral oil, R134a uses synthetic IIRC). The system seals are intended to work with only the type they were designed for. If the seals aren't lubricated, they dry out and gas escapes.
He said that a lot of people look to buy it and it could be well worth over $1000.
A2L refrigerants, the new refrigerants for 2026, will replace R-410A in new systems. A lot about A2L refrigerants is explained in their name: The “A” means low toxicity. The “2L” is a safety classification, indicating it is mildly flammable.
To buy R-12 refrigerant (Freon), you must legally be a certified technician, though it is readily available through specialized suppliers and online marketplaces.
Yes, R32 is not only currently available, but it is the primary EPA-approved replacement for older refrigerants like R410A in new ductless and mini-split air conditioning systems.
Using pure propane (R-290) in an automotive R-12 air conditioning system is not recommended and is illegal in the United States. While propane has similar thermodynamic properties, it is highly flammable. Federal EPA laws strictly prohibit venting or using hydrocarbon replacements in motor vehicle AC systems.
R12 to R134a Charge Conversion Formula (pounds only)
Take the R12 charge specification and multiply it by 0.9. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge.