Pig CO2 Stunning Welfare Science Update

CO2 stunning for pigs remains widespread despite evidence that it causes aversion and distress, with alternatives being developed and piloted but not yet widely adopted.

Key Facts

Approximately 70% of EU pigs are stunned with high-concentration CO2 before slaughter
CO2 at concentrations above 80% is aversive - pigs show panic, vocalisation, and escape attempts before losing consciousness
Unconsciousness is achieved within 30-50 seconds but the pre-unconscious aversion period is a welfare concern
Inert gas stunning using nitrogen or argon causes less aversion but is more technically challenging
Nitrogen-CO2 mixtures at specific concentrations reduce aversion while maintaining practical effectiveness
Several major pork producers and retailers have committed to investigating and transitioning away from high-CO2 stunning
EFSA has concluded that high-concentration CO2 causes aversion and affects animal welfare adversely

Welfare Considerations

Pigs experience genuine fear and distress during exposure to high-concentration CO2 before losing consciousness. This is not a minor welfare concern - it represents millions of pigs experiencing panic in their final minutes. The continued widespread use of CO2 stunning reflects industry inertia and cost factors rather than welfare science. Consumer and retailer pressure for alternatives has increased but needs to be sustained and amplified.

What You Can Do

Support retailers that have committed to transitioning away from high-CO2 pig stunning
Ask food companies about their pig stunning practices and transition timelines
Advocate for regulatory review of CO2 stunning in light of EFSA's welfare assessment
Support research into practical, welfare-positive stunning alternatives for pigs
Choose pork from producers using non-CO2 stunning methods where this information is available