Death Foam
Short answer: When highly pathogenic avian influenza or virulent Newcastle disease hits a commercial flock, U.S. policy aims to kill the infected birds on the farm within 24 to 48 hours to stop the virus spreading.
Water-based foam was developed for this after the 2004 Delmarva bird flu outbreak, and USDA and the AVMA gave it conditional approval in 2006. Firefighting-style foam is spread over floor-reared birds (broilers, turkeys, ducks) until it blocks their airways, causing physical hypoxia. In trials it killed broilers about as fast as CO2 or faster, with far fewer workers exposed to the virus. The AVMA has never classed it as euthanasia. In its 2026 depopulation guidelines, water-based foam is Tier 2, 'permitted in constrained circumstances', ranked below whole-house gassing and nitrogen-filled high-expansion foam.
What should you know about Death Foam?
Quick facts. Each one stands alone and has a stable ID you can cite.
Water-based foam culls poultry by blocking their airways. It was conditionally approved in the U.S. in 2006 after the 2004 Delmarva bird flu outbreak.
The AVMA's 2026 depopulation guidelines rank water-based foam below whole-house gassing, as a method permitted only in constrained circumstances.
Video transcript: Death Foam: Firefighting Foam Is Used to Cull Poultry in Bird Flu Outbreaks
DID YOU KNOW? Foam depopulation is a method used in mass culling of poultry and livestock, primarily during disease outbreaks like avian influenza. It involves flooding an enclosed area with high expansion firefighting foam, which suffocates animals by blocking their airways, leading to rapid asphyxiation. The method is considered efficient, cost effective, and less labor intensive than traditional culling techniques like gassing or manual euthanasia. NOW YOU KNOW!
Burned-in captions, read frame by frame (see transcript.md) · 22.1s Reel ·
The write-up
Firefighting foam is used to cull poultry in bird flu outbreaks. Vets rank it below whole-house gassing, for use only in constrained circumstances.
- Exhibit A
Why whole flocks are killed
In an HPAI outbreak, U.S. policy aims to 'stamp out' the virus by depopulating infected premises within 24 to 48 hours, before more virus is produced.
- Exhibit B
Born of an outbreak
Researchers developed the foam method after the 2004 Delmarva avian influenza outbreak exposed problems with existing methods: too few trained workers, fatigue, and responders' exposure to the virus.
- Exhibit C
How it works
A blanket of foam spread over the birds rapidly blocks their airways. That causes physical hypoxia, whereas CO2 causes chemical hypoxia.
- Exhibit D
Time to death
In small-group trials with broilers, foam stopped activity in about 64 to 73 seconds, compared with 139 seconds under a CO2 tent. Later EEG studies found similar times to unconsciousness for broilers, layers and turkeys, but CO2 was faster for ducks.
- Exhibit E
Conditional approval
USDA and the AVMA conditionally approved water-based foam for floor-reared poultry in 2006. The AVMA's welfare committee said it couldn't reconcile foam with its definition of euthanasia.
- Exhibit F
Where it ranks now
The AVMA's 2026 guidelines list water-based (medium/low-density) foam as Tier 2, permitted in constrained circumstances. Tier 1 (preferred) includes whole-house CO2 or N2 gassing and high-expansion nitrogen-filled foam.
Questions people ask about Death Foam
How does water-based foam kill poultry?
It's physical hypoxia; CO2 causes chemical hypoxia.
Source: Write-up · Exhibit C (How it works) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007); Report of the USAHA Committee on Transmissible Diseases of Poultry (2006)
Which outbreak prompted development of the U.S. foam method?
The response to the 2004 event exposed the limits of existing methods.
Source: Write-up · Exhibit B (Born of an outbreak) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007)
When did USDA and the AVMA conditionally approve water-based foam?
It was approved for floor-reared poultry.
Source: Write-up · Exhibit E (Conditional approval) · USAHA Resolution 44: Water-Based Foam for Mass Depopulation of Poultry (2006); Mass Emergency Water-Based Foam Depopulation of Poultry (Avian Diseases, 2012; PubMed)
Where does water-based foam rank in the AVMA's 2026 guidelines?
Whole-house gassing and nitrogen foam are Tier 1.
Source: Write-up · Exhibit F (Where it ranks now) · HPAI Response Goals & Depopulation Policy (USDA APHIS); AVMA Guidelines for the Depopulation of Animals: 2026 Edition (American Veterinary Medical Association)
For which birds was CO2 faster than foam in EEG studies?
Pekin ducks lost consciousness sooner with CO2.
Source: Write-up · Exhibit D (Time to death) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007); Mass Emergency Water-Based Foam Depopulation of Poultry (Avian Diseases, 2012; PubMed)
Test Your Knowledge
All quizzes →5 questions, all from this case file. Answers are revealed instantly.
How does water-based foam kill poultry?
- Poison
- Blocking the airways, causing hypoxia
- Freezing
- Electric shock
Show the answer
Answer: B. Blocking the airways, causing hypoxia It's physical hypoxia; CO2 causes chemical hypoxia. Source: Write-up · Exhibit C (How it works) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007); Report of the USAHA Committee on Transmissible Diseases of Poultry (2006)
Which outbreak prompted development of the U.S. foam method?
- 2004 Delmarva avian influenza
- 1918 influenza
- 2001 foot-and-mouth disease in the UK
- 2014 Ebola
Show the answer
Answer: A. 2004 Delmarva avian influenza The response to the 2004 event exposed the limits of existing methods. Source: Write-up · Exhibit B (Born of an outbreak) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007)
When did USDA and the AVMA conditionally approve water-based foam?
- 1984
- 2006
- 2015
- 2026
Show the answer
Answer: B. 2006 It was approved for floor-reared poultry. Source: Write-up · Exhibit E (Conditional approval) · USAHA Resolution 44: Water-Based Foam for Mass Depopulation of Poultry (2006); Mass Emergency Water-Based Foam Depopulation of Poultry (Avian Diseases, 2012; PubMed)
Where does water-based foam rank in the AVMA's 2026 guidelines?
- Tier 1, preferred
- Tier 2, permitted in constrained circumstances
- Banned
- Same as euthanasia
Show the answer
Answer: B. Tier 2, permitted in constrained circumstances Whole-house gassing and nitrogen foam are Tier 1. Source: Write-up · Exhibit F (Where it ranks now) · HPAI Response Goals & Depopulation Policy (USDA APHIS); AVMA Guidelines for the Depopulation of Animals: 2026 Edition (American Veterinary Medical Association)
For which birds was CO2 faster than foam in EEG studies?
- Broilers
- Turkeys
- Ducks
- Layer hens
Show the answer
Answer: C. Ducks Pekin ducks lost consciousness sooner with CO2. Source: Write-up · Exhibit D (Time to death) · Benson et al., Foam-Based Mass Emergency Depopulation of Floor-Reared Meat-Type Poultry Operations (Poultry Science, 2007); Mass Emergency Water-Based Foam Depopulation of Poultry (Avian Diseases, 2012; PubMed)
Cite this case file
Easterling, Marcus. "Death Foam." The Detail Department (DetailEnjoyer), case file DD-043, last updated Mar 2, 2025. https://detailenjoyer.com/case/death-foam/
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