Farmed Animals

Farmed Poultry Slaughter Welfare: Controlled Atmosphere Killing

Controlled atmosphere killing (CAK) using inert gas or CO2 mixtures is increasingly recognized as more humane than electrical water bath stunning for poultry slaughter.

Key Facts

Electrical water bath stunning is the dominant poultry slaughter method globally
Up to 30% of chickens may be inadequately stunned in water bath systems
Controlled atmosphere killing using high-CO2 or inert gas renders birds unconscious in their transport crates
Low-atmosphere pressure stunning (LAPS) is an alternative CAK system
Major US processors including Tyson have begun transitioning to CAK under animal welfare pressure

Welfare Considerations

Electrical water bath stunning requires conscious birds to be shackled upside-down before stunning - a highly stressful procedure. Inadequate stunning leaves birds conscious during neck cutting. CAK systems, by contrast, stun birds while they remain in transport crates without the pre-stun handling stress. While CAK with CO2 involves an aversive initial phase, high-CO2 or inert gas systems minimize this. Welfare science consistently rates CAK as more humane overall.

What You Can Do

Support retailers and brands that have committed to controlled atmosphere killing for poultry
Advocate for CAK to be specified as a requirement in higher welfare poultry certifications
Ask food companies about their slaughter welfare commitments in their poultry supply chains
Reduce poultry consumption or shift to products with verified humane slaughter commitments