Hydrocarbon (HC) refrigerant gases: R290, R600a and 12a explained

A hydrocarbon (HC) gas is a compound of carbon and hydrogen only — propane, butane, isobutane — used as a natural refrigerant. It contains no fluorine or chlorine, has zero ozone depletion potential and a global warming potential of about 3 (against 1,430 for R134a). HC refrigerants now replace CFCs, HCFCs and HFCs in domestic fridges, car air-conditioning and heat pumps. Their one constraint is flammability, which calls for a few simple handling rules. This page explains what HC gases are, where they are used, what they bring, and what the regulations say.

Definition: what is a hydrocarbon?

In chemistry, a hydrocarbon is a molecule made only of carbon (C) and hydrogen (H) atoms. Methane (CH₄), propane (C₃H₈) and butane (C₄H₁₀) are the best known; they come from natural gas and crude oil. In refrigeration, the abbreviation HC designates this family of refrigerants, as opposed to fluorinated refrigerants: CFCs (chlorofluorocarbons such as R12), HCFCs (such as R22), HFCs (such as R134a) and HFOs (such as R1234yf). The main hydrocarbon refrigerants carry an "R" number like every refrigerant:

The 12a blend, for instance, is formulated to reproduce the pressure and evaporating temperature of R134a — which is why it can be used in a car air-conditioning system without changing the compressor or the oil. Our Duracool 12a guide covers that use case in detail.

Why hydrocarbons are replacing fluorinated gases

In practice, a system charged with HC runs at a lower discharge pressure: the compressor works less, draws less power and wears less. The manufacturer Duracool quotes energy savings in the 10–30 % range depending on the installation; our commercial-refrigeration customers see it most on old R22 systems that have been converted. And because an HC is neither an HFC nor an HCFC, it is subject neither to F-gas quotas nor to the certification required to buy fluorinated refrigerants.

Where hydrocarbons are used today

• Domestic fridges and freezers: R600a has powered almost every new appliance sold in Europe since the 2000s — there is very probably a hydrocarbon in your kitchen.
• Car air-conditioning: 12a replaces R12 in classic cars and R134a in vehicles built between 1994 and 2017; 12a-yf replaces R1234yf in recent vehicles. See replacement gases for R12 / R134a / 1234yf.
• Fixed air-conditioning and heat pumps: R290 has become the reference fluid for new heat pumps; 22a replaces R22 in older installations. See the replacements for R22, R502, R407C and R404A and for R410A and R32.
• Commercial refrigeration: display cabinets, cold rooms, drink coolers (R290, R1270). See the Greenfreeze refrigerants.
• Motorhomes, boats, refrigerated units: same fluids, same benefits.

Flammability: what you actually need to know

Hydrocarbons are classified A3: non-toxic but flammable. An HC only burns when its concentration in air falls within a narrow window — roughly 2 % to 10 % by volume for propane — and an ignition source is present. Below that the mixture is too lean, above it too rich. The charge of a domestic or automotive system (a few dozen to a few hundred grams) is too small to reach that concentration in a ventilated room, which is why safety standards allow R600a in every kitchen refrigerator.

The practical rules that follow:

• Recharge and service in a ventilated area or outdoors, never in a closed garage.
• No flame, cigarette, grinder or spark nearby during the operation; the gas is heavier than air and pools at floor level.
• Find leaks with an electronic hydrocarbon detector, soapy water or UV dye — never with a flame.
• Label the system after conversion ("charged with hydrocarbon refrigerant") to warn the next technician.
• Store cans and cylinders below 50 °C, out of direct sunlight.

Professional installations are governed by EN 378, ISO 5149, IEC 60335-2-40 (air-conditioning) and IEC 60335-2-89 (commercial refrigeration), which set maximum charges according to room volume and equipment location.

What the regulations say

The EU F-gas Regulation 2024/573, in force since March 2024, only covers fluorinated gases: it cuts HFC quotas year after year, bans new equipment in stages according to GWP, and schedules the complete phase-out of HFCs by 2050. Hydrocarbons are outside its scope — no quotas, no restrictions on sale. National rules vary on who may handle refrigerants: in France, for example, the certification required to buy fluorinated refrigerants does not apply to hydrocarbons, which is why a private individual may recharge his own car air-conditioning with 12a, while from 2027 professional technicians will need certification covering hydrocarbons. Check the rules of your own country before servicing equipment for others. For the full picture, see the 2024 F-gas regulation and its consequences.

The hydrocarbon refrigerants we distribute

All are blends of purified hydrocarbons, free of chlorine and fluorine. To choose the right one and the right quantity: the Duracool 12a guide. To recharge a car: the step-by-step procedure. We ship across Europe.

Frequently asked questions

What does HC gas stand for?

HC stands for hydrocarbon: a gas made of hydrogen and carbon only, such as propane (R290) or isobutane (R600a). In refrigeration, "HC gas" means a hydrocarbon refrigerant, as opposed to fluorinated gases (CFC, HCFC, HFC, HFO).

Is HC gas the same as lighter gas?

Chemically, yes: the propane and isobutane in refrigerants are the same molecules as in lighters and camping cylinders, but purified to a far higher grade (no moisture, no sulphur) and blended to mimic the behaviour of the fluid they replace. Lighter gas is not suitable as a refrigerant.

Does a hydrocarbon damage the compressor or seals?

No: HCs are compatible with mineral, alkylbenzene and PAG/POE oils and with common elastomers. That is one of their advantages for conversions — no oil or seal change.

Can I mix a hydrocarbon with the original gas?

Never mix two different refrigerants in one circuit. For a conversion, recover the old fluid (or let a leaking system empty), pull a vacuum if you can, then charge the calculated amount of HC — about 40 % of the original charge.

HC, HFC, HFO: the difference in one line?

HC = carbon + hydrogen, natural, flammable, GWP ≈ 3. HFC = fluorinated, non-flammable, GWP 1,000–4,000, being phased out. HFO = new-generation fluorinated (R1234yf), low GWP but mildly flammable and expensive. Our full comparison of refrigerant families goes through all of it.