Proof of Principle Anoxia Method Poultry Science 2013

In May 2013, the results of the assessment of the Anoxia Method were published in Poultry Science (2013 Poultry Science 92:1145–1154). The focus of the assessment was on the welfare implications for poultry of the use of high-expansion gas-filled foam as a potentially humane, emergency killing method.

In laboratory trials, broiler chickens, adult laying hens, ducks, and turkeys were exposed to air-, N2-, or CO2-filled high expansion foam (expansion ratio 300:1) under standardized conditions.

One of the main conclusions was that the Anoxia Method is fundamentally different from low expansion fire fighting foam. Physiological observations and postmortem examination showed that the mode of action of the Anoxia Method is anoxia, not occlusion of the airway.

The most important conclusion however is that the trials provide proof – of – principle for the Anoxia Method (submersion in gas-filled, high expansion foam).

McKeegan et al concluded: The Anoxia Method provides a rapid and highly effective method of euthanasia, which may have potential to provide humane emergency killing or routine depopulation.


Pilot study Anoxia method 2008

Outbreaks of highly pathogenic avian influenza have necessitated the large scale killing of poultry that have either contracted or been exposed to the disease. In this pilot study, published in 2008, the conclusion is that the Anoxia method is a potentially acceptable killing method for laying hens.


Nitrogen production

In the attached presentation, you will find a detailed description of a new animal welfare application based on the use of mobile nitrogen generation: The N2GF Technology. Nitrogen gas foam has some astonishing features:

• Simplicity – creating nitrogen gas foam follows a simple protocol – the systems are easy to assemble – easy to operate – easy to clean & disinfect;
• Cost effective – only affordable disposal materials are used for the culling bag – no maintenance costs – low investments. Compared to existing Co2 systems, the consumption of gas is reduced by up to 80%;
• Safe culling – Nitrogen is non-toxic – safe storage/transport – safe disposal;
• Animal welfare – once the animals are exposed to 99,5% nitrogen in the foam, they are stunned and slaughtered within 1,5 minutes by anoxia;
• Stability – when the gas foam is used in a container, the foam at the entrance of the container works as concealment.

This technology forms the basis for a new slaughter concept based on the use of high expansion foam, filled with 99,5% nitrogen.


The official start of the N2GF research project



Starting 01/01/2013 there will be more strict rules for killing of (young) animals. Existing methods are not always suitable for young piglets and poultry, based upon an acceptable level of welfare. Also some methods are relatively expensive or can only be used by veterinarians. Therefore it could be interesting to work with nitrogen gas foam. The possible advantages are:

–       Better for welfare, little stress or pain

–       No rising of nitrogen gas, because of the foam

–       Possible low investment and operating costs

–       Little risk for humans

–       Easy to use and safe for the environment

It has already been proven a good system for poultry (Gerritzen et al, 2010, McKeegan et al 2011 – see their reports on this platform).   This project plan describes the actions needed to develop and test a nitrogen gas foam device for young piglets and poultry.   It only describes the rough outline, and for each sub-theme a specific and detailed work plan needs to be written.   The main activities will take place on the facilities of VIC Sterksel, part of Wageningen UR Livestock Research who will develop specific sub-themes.   Other parties are invited to contribute and participate in this project. The project will be performed for/with N2GF. (


The project starts at January 1, 2013 and will be finalized by June 30, 2013. After the successful completion of this project, a euthanasia device will be developed for young piglets and poultry that is suitable for use on (poultry/pig) farms. Also an e-learning and certification system as well as a vocational training/certification system is available. There are standard operating procedures and product manuals available and the investment- and operating costs are known.


  • Preconditions for dimensioning a nitrogen gas foam euthanasia device are known, also on behalf of safety
  • Effects on pigs are known (pain, stress)
  • Product manuals and Standard Operating Procedures are available
  • Training curricula and demands on certification are available
  • Training  and certification (e-learning and vocational) systems are available
  • Economics (investment and operating costs) are known


The organisation of this project is not fully complete and is open for participation. The current partners are:


  • SHK trading BV (Producer of the N2GF equipment, representative of the patent holder and project initiator)
  • Wageningen UR Livestock Research-  Swine Innovation Centre Sterksel (Project location and facilitator)
  •  ONI Consult (Certification processes)


  • AVT Advanced Video Training Europe AB (development of training curricula, certification materials, online training and visualisation, guidelines, product information and Standard Operating Procedures);  Trollhättan Sweden
  • N2GF (Project leader)



For more information about this project, please contact