CFC, HCFC, HFC, HFO and hydrocarbons: the refrigerant families compared

CFC, HCFC, HFC, HFO and HC are the five families of gases used in air-conditioning and refrigeration over the past century. The first three are fluorinated and banned or being phased out because of their effect on the ozone layer (CFC, HCFC) or on the climate (HFC). HFOs are their latest fluorinated replacements; hydrocarbons (HC) are the natural alternative. This page compares them in one table, retraces the bans, and tells you what to replace the gas in your own system with.

The comparison table

GWP (global warming potential) says how many times more a molecule warms the atmosphere than CO₂ over 100 years. One kilogram of R404A released into the air is worth nearly 4 tonnes of CO₂; one kilogram of propane, 3 kilograms.

A century of refrigerants in five steps

1. 1930s — CFCs. R12 (Freon) replaces ammonia and sulphur dioxide, both dangerous, in refrigerators and then in car air-conditioning. Stable, non-toxic, non-flammable, cheap: the perfect refrigerant, for fifty years.
2. 1985–1987 — the ozone hole. The chlorine in CFCs destroys stratospheric ozone. The Montreal Protocol (1987) schedules their phase-out; in Europe CFC production stops in 1995 and R12 disappears from new cars from 1994, replaced by R134a.
3. 1990s–2000s — HCFCs and HFCs. R22 (an HCFC, with a little chlorine) and R134a, R404A, R410A (HFCs, chlorine-free) take over. The ozone layer is saved, but these are powerful greenhouse gases. R22 is banned in turn (virgin in 2010, entirely in 2015).
4. 2006–2017 — the climate. The EU Mobile Air-Conditioning Directive requires a GWP below 150: R134a is banned from new vehicle types (2011) and then from all new cars (2017), replaced by the HFO R1234yf. The F-gas Regulation (2014, recast in 2024) organises the decline of HFCs everywhere else.
5. Today — back to natural fluids. R600a is in almost every new refrigerator, R290 is taking over heat pumps, CO₂ is spreading in commercial refrigeration. The 12a and 22a blends make it possible to convert existing systems instead of replacing them.

Your system still runs on a banned or phased-out gas: what now?

Every conversion follows the same logic: never mix, recover the old fluid, pull a vacuum, charge the HC at the calculated quantity, label the system. The details for car air-conditioning are in the Duracool 12a recharge procedure; to understand hydrocarbons themselves, see what is a hydrocarbon gas.

CFC and HFC: common misconceptions

• "HFCs don't harm the ozone layer, so they're eco-friendly." Wrong: they leave ozone alone, but their greenhouse effect is 1,000 to 4,000 times that of CO₂. That is exactly why they are being phased out in turn.
• "R134a is banned." Not quite: it is banned in new cars since 2017 and subject to quotas elsewhere. An older vehicle can still be recharged with R134a — but only by a certified professional, at a price that rises every year.
• "A flammable gas in an AC system is dangerous." R600a is in every new refrigerator and R290 in heat pumps: standards set maximum charges that make ignition impossible in normal use. The risk is managed by handling rules, not by prohibition.
• "CFC and HFC are the same thing." The C in CFC stands for "chloro": chlorine is what destroys ozone. HFCs contain none; their problem is purely climatic.

Frequently asked questions

What is CFC gas?

A chlorofluorocarbon: a carbon molecule whose hydrogen atoms are replaced by chlorine and fluorine. The best known is R12, sold under the Freon brand. CFCs have been banned since the 1990s.

What is the difference between HFC and CFC?

HFCs (hydrofluorocarbons) contain no chlorine, so they do not deplete the ozone layer. But they are powerful greenhouse gases, hence their progressive elimination under the F-gas Regulation.

What does HFC mean for air conditioners?

Most air conditioners built between the mid-1990s and today run on an HFC — R134a in cars, R410A or R32 in split units. They still work, but recharging them gets more expensive each year as quotas shrink, and new equipment must move to low-GWP fluids.

Does my AC contain CFC gas?

Only if the vehicle is from before 1994 or the installation from before about 1995. An AC from 1994 to 2017 contains R134a (HFC); after 2017, R1234yf (HFO). The label under the bonnet or on the outdoor unit tells you.

Is HC an HFC?

No. HC means hydrocarbon (carbon + hydrogen, no fluorine). It is precisely because it contains no fluorine that it falls outside the F-gas Regulation.

What replaces R12 today?

In a classic car, the 12a hydrocarbon blend (Duracool, Multicool, Climapure), charged straight into the original system through a screw-on R12 fitting. R134a was also used for these conversions, but it needs an oil and seal change — and it is itself on the way out.