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.
- 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. GB retains EU 517/2014 and has not adopted this step — DEFRA consulted on GB reform (closed Dec 2025), response due 2026.
- 2035
Split ban (EU)
EU Regulation 2024/573 bans F-gases in new split AC and heat pumps up to 12 kW. Not yet GB law — GB still follows retained EU 517/2014 pending the delayed HFC phase-down reform.
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.