header 1

In the production of hatching eggs, egg disinfection in the breeder farm and/or in the hatchery can be an important tool for biosecurity and chick quality, as the presence and spreading of bacteria will have a lot of negative effects.

Over the years, a popular way to disinfect eggs has been Paraformaldehyde (powder or flakes) or Formaline (liquid containing approximately 37% formaldehyde) which is very effective and cheap, but a nuisance for the user and not free of risks. Formaldehyde fumes can be created by mixing with Potassium permanganate or by heating up the powder or liquid.

Because of the risks and nuisance of being exposed to formaldehyde fumes (not only smelly but also carcinogenic), people have moved away from the use of this product. As an alternative often “wet” products are used, like forms of HydrogenPeroxide, acids etc. Although they are effective in disinfection the surface, the products can almost by definition not enter the pores, no matter how fine the mist is, and the problem for egg contamination is located in the pores. And as a lot of people have experienced, wet disinfection can even increase the problem of contamination because of it helps to spread bacteria.

What not everybody is aware of is that formaldehyde can be neutralized very effectively with Ammonia. The two products bind and form a new product called Methanamine, a relatively safe byproduct without smell or toxic characteristics.

The way it is often done is by heating 5 to 7 grams of Paraformaldehyde per m3 of disinfection room for 20 minutes in a simple kitchen electrical frying pan that can be bought in a kitchen utility shop, preferably one with a large diameter to make the evaporation go quick. After those 20 minutes ammonia powder is evaporated from a second frying pan, followed by a short period (20 minutes) of extraction of any left over fumes. We can also use liquid formaline and liqud ammonia but then we need to use more material which will take longer to evaporate. When used in a dry form, we often use ammonium bicarbonate ((NH4)2CO3) or ammonium carbonate ((NH4)HCO3). Both are forms of baking powder, but ammonia carbonate has more ammonia per g than ammonium bi carbonate. Therefore we need to add the same amount of ammonium carbonate or 1.5 times the amount of ammoium bi carbonate compared to the amount of paraformaldehyde.

This process is relatelively easy to do on a farm and a hatchery, without the usual downsides of the smell and the nuisance. We place 2 electrical frying pans in the disinfection room, fill one with paraformaldehyde and the other with ammonium (bi) carbonate. Then we start the pan with paraformaldehyde for 20 minutes, followed by the one with ammonium (bi) carbonate for 20 minutes. As the frying pans normally are equipped with an overheating sensor, the system will normally shut off or slow down when all the material is evaporated. Preferably we use a small mixing fan to ensure that the gases are spread throughout the disinfection room. After the proces we often ventilate for another 20 minutes to remove the last remaining gases, but that is not really needed.

Although this is a cheap and effective process that does not expose humans or the environment to formaldehyde fumes, the local legislation can still be a problem, as not all the authorities will accept this method.