Welfare concerns surrounding the use of high concentrations (80% or over) of CO2 to slaughter pigs, were raised by Compassion following news of the recent CO2 shortages.

Compassion has been against the use of high concentrations of CO2 to stun and kill pigs since the mid 90’s, when early evidence demonstrated that pigs had a profound aversive response to the gas, leading to severe respiratory distress.

Its use in commercial systems proliferated as processors addressed the problems associated with handling pigs in single-file races and restrainers - associated with both single/double cradle CO2 and electrical stunning systems - by moving to group handling with high concentration CO2 group kill systems.

Handling systems which allow pigs to move in groups are significantly less stressful than those requiring pigs to move in single file and through restrainers. The use of high concentrations of CO2, however, render them inhumane.

Humane stunning or killing is widely accepted as a involving a method that is either instant or non-aversive (involving no panic, pain or distress).

Both FAWC (2003) and ESFA (2004) called for the use of high concentrations of CO2 to be phased out and alternative non-aversive gases to be developed (within 5 years, FAWC). However, there has been no commercial alternative developed in the intervening period.

Compassion is addressing this issue with a renewed sense of urgency, and along with the RSPCA we are calling for action by the UK Government:

“By no later than 1st January 2024, the RSPCA and Compassion in World Farming want:

the use of high concentrations of carbon dioxide for the killing of pigs to be legally prohibited, and
new, humane systems to be developed and commercially available to replace the use of high concentrations of carbon dioxide.”

As part of this call for more humane slaughter methods, we are urging all food businesses to:

Actively press their suppliers, and give further encouragement to government, to find humane alternatives as a matter of urgency;
Support the call for the use of high concentrations of carbon dioxide for the killing of pigs to be legally prohibited, and new, humane systems to be developed and commercially available to replace the use of high concentrations of carbon dioxide by no later than 1st January 2024;
To be prepared to invest in humane alternatives when commercially available.

Compassion encourages industry to support the development of alternative slaughter methods for pigs that ensure high standards of welfare throughout handling, stunning and killing.

Please consult our Humane Slaughter Summary, which outlines the main principles of humane slaughter and recommendations for its inclusion into corporate animal welfare policies, or talk to one of our Food Business team to find out more.

Calling on industry to find more humane pig slaughter methods