Carbon dioxide in the stunning of pigs
Every year, millions of pigs suffer distress and pain when killed using carbon dioxide (CO2) in the UK. But it currently remains the most commercially viable method at scale for slaughter/killing pigs. We have raised major concerns about the use of high concentrations of CO2 for many years.
The problem with using CO2
The most common slaughter/killing method used for pigs is carried out using carbon dioxide gas. During this process, pigs are exposed to and inhale high concentrations of CO2, eventually killing them. 90% of pigs in the UK are killed in this way.
There are significant animal welfare concerns associated with the use of CO2, and pigs can experience significant distress before becoming unconscious. This is an urgent animal welfare issue, pigs deserve better.
There are currently no other humane alternatives that are both legal and commercially viable for the industry.
TIMELINE
What we have done so far
For many years, the RSPCA, as well as other organisations, groups and pig farmers themselves have raised major concerns around the use of high concentrations of carbon dioxide (CO2) in the killing of pigs.
AUGUST 2018
In a joint letter with Compassion in World Farming, the RSPCA wrote to DEFRA and asked for a ban on the use of high concentrations of CO2 for killing pigs and to develop humane alternatives no later than 1st January 2024.
all year 2019
We were involved in the Eurogroup for Animals Technical Working Group for CO2. This working group developed the position paper which formed the basis for the European Commission to fund research in this area.
Early 2020
Attended the LAPS (Low Atmospheric Pressure Stunning) project results, which was a potential alternative funded by DEFRA and the Humane Slaughter Association. The research showed that LAPS was not a humane alternative for stunning/killing pigs.
FEBRUARY 2024
Wrote to DEFRA urging the government to address the issue of CO2 stunning/killing two decades on since the Farm Animal Welfare Council (now Animal Welfare Council) recommended a phase out.
MAY 2024
We joined the industry convened CO2 alternatives working group along with vets, scientists, and researchers across Europe and Australia, as well as specialists from AHDB, the National Pig Association, Red Tractor and the Humane Slaughter Association.
NOVEMBER 2024
We joined the PigStun workshop run by EU research groups funded by the European Commission to look into alternatives to CO2.
DECEMBER 2024
We gave evidence to the government’s Animal Welfare Committee on CO2 and alternatives, and urgently called for a more humane method than high concentration CO2.
JANUARY 2025
We responded to DEFRA’s consultation on the Welfare of Animals at the Time of Killing and urged the government to move away from CO2 killing for pigs.
OUR AMBITION
We demand an alternative
We are calling for a rapid phase-out of high-concentration CO2 systems and the trialling of more humane alternatives in the UK.*
We know there are promising alternatives from EU research but we need these trialed in the UK. Gases like argon offer potential improvements in animal welfare because they do not cause the same painful and distressing effects as CO2. Implementing alternative gas mixtures or stunning methods is crucial to improving animal welfare.
The RSPCA is continuing to work with the pig industry, the UK Government and with research teams to find alternatives to this method of killing. We will not stop until a more humane alternative has been found.
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Our welfare standards
We are working hard to keep pushing the UK government to take action and provide a humane alternative to CO2 gas stunning/killing. Currently CO2 is allowed in the RSPCA welfare standards for pigs because there is no legal commercially viable humane alternative available. This is changing with recent research from Europe. In addition, the RSPCA welfare standards have safeguards in place, above the legal minimum requirements for slaughter/killing protocols, to reduce suffering and ensure a higher level of welfare. For example, RSPCA Assured members must ensure the average minimum CO2 concentration is 90% which exceeds the legal requirement of 80%. This means pigs fall unconscious more quickly, reducing stress and suffering.
We want to update our welfare standards as soon as possible to prohibit the use of CO2 gas, but that can't happen until a suitable, humane alternative is found - so we’re putting the pressure on those who can change this, to do so.
Related farming content
*While there are currently no legal commercially viable humane alternatives available it is permitted in the RSPCA welfare standards for pigs. If it was not permitted, it would not be possible to give farmed pigs better protection throughout their lives through the RSPCA standards. However, new RSPCA pig welfare standards this year make it clear we will be updating the standards with a phase-out date as soon as alternatives are available.