R-600a — GWP, safety class & UK F-Gas status
Isobutane · natural. Future-proof · ultra-low GWP under UK F-Gas rules — full readout, replacements and timeline below.
R-600a
Isobutane · natural
- UK F-Gas
- No F-Gas quota impact — a hydrocarbon outside the F-Gas Regulation. Highly flammable (A3), so charge is capped (typically 150 g or less) and it is used almost entirely in sealed domestic fridges and freezers. IPCC AR6 does not list isobutane separately; 3 is the long-standing figure, and like all hydrocarbons its real GWP is negligible (propane is 0.02 and n-butane 0.006 under AR6).
- Typical use
- Domestic fridges & freezers
- ODP
- 0
GWP = Global Warming Potential (100-year, CO₂ = 1) · ODP = Ozone Depletion Potential · safety class per ASHRAE Standard 34.
UK F-Gas phase-down timeline
Where the wider phase-down stands.
- 2015
R-22 servicing ban
No virgin or reclaimed HCFCs for servicing. The original ozone phase-out completes.
- 2020
High-GWP service ban
Virgin F-Gas with GWP of 2,500 or more banned for refrigeration of 40 tCO₂e or more — hits R-404A / R-507A.
- Jan 2025
New single-split ban
New single-split AC systems containing under 3 kg of F-gas cannot use refrigerants of 750 GWP or more (retained EU 517/2014, Annex III) — rules out R-410A and R-407C.
- Jan 2027
GB quota step (unchanged by the reform)
The existing GB HFC quota drops a further 22.6%. DEFRA consulted on a more ambitious phase-down (closed Dec 2025) but confirmed in May 2026 it will not legislate in 2026, so this step applies as written — expect price and availability pressure on higher-GWP gases rather than a change of rules.
- 2030
Quota squeeze
The HFC quota drops to about 21% of the 2015 baseline and the reclaimed/recycled exemption for GWP 2,500+ servicing ends — R-404A / R-507A become effectively unavailable.
- 2032
Monobloc ban (EU)
EU Regulation 2024/573 bans F-gases in new self-contained / monobloc AC and heat pumps up to 12 kW (the same rule already caps them at 150 GWP from 2027). GB retains EU 517/2014 and has NOT adopted this step: DEFRA consulted on GB reform (closed Dec 2025) and confirmed in May 2026 that it will not legislate in 2026, with a response summarising feedback due later in the year.
- 2035
Split ban (EU)
EU Regulation 2024/573 bans F-gases in new split AC and heat pumps up to 12 kW. Larger splits above 12 kW are capped at 750 GWP from 2029 and 150 from 2033 under the same regulation. None of this is GB law — GB still follows retained EU 517/2014, and the GB reform was deferred in May 2026.
Frequently asked questions about R-600a
Is R-600a banned in the UK?
No F-Gas quota impact — a hydrocarbon outside the F-Gas Regulation. Highly flammable (A3), so charge is capped (typically 150 g or less) and it is used almost entirely in sealed domestic fridges and freezers. IPCC AR6 does not list isobutane separately; 3 is the long-standing figure, and like all hydrocarbons its real GWP is negligible (propane is 0.02 and n-butane 0.006 under AR6).
What is R-600a's GWP (Global Warming Potential)?
R-600a has a GWP of 3 on an AR4 basis — below both UK F-Gas thresholds (750 and 2,500 GWP).
What replaces R-600a?
R-600a is current-generation in this reference — there's no listed replacement for it.
Is R-600a flammable?
R-600a is ASHRAE 34 safety class A3. It is flammable, so it needs appropriately rated tools, leak detection and charge-limit checks.