Defra has opened a consultation on ending the use of high-concentration carbon dioxide stunning for pigs, marking the start of the formal policy process for withdrawing a method still widely used before slaughter. The consultation began on 26 October 2026 and runs until 21 December 2026, with ministers proposing a move towards argon gas and automated electrical stunning. (gov.uk) The department says the policy aim is to reduce the panic, breathing difficulty and distress associated with pigs remaining conscious as they enter high-concentration CO2 systems. In policy terms, this is a consultation on a future ban rather than an immediate legal change. (gov.uk)
That distinction matters because the current official guidance for red-meat slaughterhouses still permits carbon dioxide at high concentration for pigs. The guidance requires a minimum concentration of 80% by volume and says pigs must be conveyed to the point of maximum gas concentration within 30 seconds of entering the stunner. (gov.uk) The method is not marginal in current practice. The Food Standards Agency’s 2024/25 animal welfare report says 90% of pigs were stunned using high-concentration CO2, with the remaining 10% stunned electrically, which means any eventual prohibition would reach most of the commercial pig slaughter sector. (gov.uk)
The government’s case rests on an evidence base that has been building for years. In its opinion published in October 2025, the Animal Welfare Committee said exposure of conscious pigs to high concentrations of CO2 is aversive and causes severe pain and distress before unconsciousness. (gov.uk) That report also noted earlier recommendations from the former Farm Animal Welfare Council and the European Food Safety Authority to move away from direct exposure to high-concentration CO2. Defra’s announcement adopts that assessment and presents the phase-out as an animal-welfare measure rather than a food-safety or productivity reform. (gov.uk)
Alternative systems already exist, but the evidence does not suggest a simple one-for-one replacement across every site. Defra has identified argon gas and automated electrical stunning as the main higher-welfare options, and the Animal Welfare Strategy for England says both are commercially feasible alternatives. (gov.uk) The Animal Welfare Committee also recorded the operational limits attached to each route. Inert gases such as argon are less aversive to pigs, but they require longer exposure times and tight control of residual oxygen, while automated or manual electrical systems can induce near-instant unconsciousness but may create handling and restraint problems when pigs have to be separated and moved individually. (gov.uk)
Those trade-offs explain why Defra has been working on this issue with processors, equipment manufacturers, gas suppliers and animal welfare organisations since April 2024. The consultation explicitly asks for views not only on welfare gains, but also on cost, feasibility and timing, with the department signalling that businesses will need an adjustment period. (gov.uk) The structure of the sector helps explain the caution. The Animal Welfare Committee said almost 90% of pigs are processed through specialised, highly mechanised premises using high-concentration CO2, and that the number of abattoirs slaughtering pigs in England has fallen by nearly 100 since 2000. In practical terms, that points to plant conversion, capital spending and staff retraining rather than a minor procedural update. (gov.uk)
The proposal also sits inside a wider animal welfare programme. In the Animal Welfare Strategy for England, published in December 2025, the government said it would ban the use of carbon dioxide gas stunning of pigs, subject to consultation, as part of a broader package on farmed animal welfare and slaughter standards. (gov.uk) There is also a supply-chain argument alongside the welfare case. Defra said moving away from CO2 would reduce dependence on a gas market that has been affected by international disruption, and the Food Standards Agency reported in June 2026 that most CO2 used in UK slaughterhouses was being sourced from Europe and was already subject to contingency planning. (gov.uk)
For processors, farmers and welfare groups, the consultation is therefore about delivery as much as direction. The questions now are how quickly individual sites can change systems, whether throughput can be maintained, and how any new costs are shared across the pork supply chain. Those points are not resolved in the announcement, but the consultation is designed to gather evidence on each of them. (gov.uk) For readers tracking the policy timetable, the immediate date is 21 December 2026, when responses close. After that, the next substantive step will be the government’s consultation response and any follow-on regulatory change needed to remove a method that current guidance still permits. (gov.uk)