The UK has formally granted limited, time‑bound extensions for the use of halon 1211 in portable fire extinguishers aboard specific aircraft. The Ozone‑Depleting Substances (Grant of Halon Derogations) Regulations 2025 were made on 4 December, laid before Parliament on 8 December, and take effect on 30 December 2025. Ministers concluded-after consultation-that, for the aircraft named, no technically and economically feasible alternative is currently available for cabin and crew compartments.

Three end dates are set. Loganair’s listed ATR 42 and 72 aircraft may retain halon 1211 extinguishers until 31 December 2026. Most listed Defence types-including A400M Atlas, Chinook variants, Dakota Mk3F, Merlin variants, P‑8A Poseidon, Shadow R1 and Wildcat-are extended to 30 June 2027. The C‑17 Globemaster III receives a longer derogation to 31 December 2040.

These UK measures operate as a derogation from the baseline end date in Annex VI of the ozone‑depleting substances regime. In the EU, the recast Ozone Regulation confirmed 31 December 2025 as the end date for handheld halon in cabins and crew compartments, following earlier cut‑offs for new designs. EASA’s technical material has been steering operators towards halon‑free replacements by that date.

The environmental stakes are clear. Halon 1211 (bromochlorodifluoromethane) is highly effective against onboard fires but is a potent ozone‑depleting substance, with an ozone depletion potential around three relative to CFC‑11. Under the Montreal Protocol, production in developed countries ended in 1994, with critical‑use exemptions available only where alternatives are not yet viable.

Replacement technology is advancing. The US Federal Aviation Administration recognises 2‑BTP for handheld extinguishers, and manufacturers have secured approvals to retrofit non‑halon units. On 4 December 2025, EASA and the UK Civil Aviation Authority issued STCs covering Learjet cabins for non‑halon installations using 2‑BTP‑based agents, signalling a maturing pathway for business and regional fleets.

Climate performance matters when choosing substitutes. Several legacy options rely on hydrofluorocarbons with high warming impacts-HFC‑227ea has a 100‑year global warming potential of about 3,220 and HFC‑236fa around 9,810-so operators and regulators are increasingly favouring agents with near‑zero ODP and lower GWP where they pass aviation safety tests.

The UK instrument is intentionally narrow in scope. It applies only to the aircraft named in the Schedules, only to portable extinguishers in cabins and crew compartments, and only across England, Wales and Scotland. The Explanatory Note flags that no full impact assessment was produced, indicating government expects limited sector‑wide effects while leaving the general end date framework intact for other users.

For operators of the listed fleets, the practical task is a managed transition: plan procurement of halon‑free extinguishers, secure any required approvals, schedule installations, and manage cylinder decommissioning through approved halon banks to prevent avoidable releases. Long‑running guidance on responsible halon banking shows how leak prevention, recovery and reuse can stretch existing stocks during changeover.

Seen through an Eco Current lens, this is a safety‑first pause with a firm sunset. The derogations buy months-and for one airlifter, years-for complex platforms to complete certification and retrofit work, while preserving hard‑won ozone gains. The measure will be judged on delivery: replacing halon at pace where alternatives are ready, and proving a clear schedule where they are not.