In addition to the compliance with the two phases previously described, disinfection must be operated:
quickly: the disinfectant is applied to slightly damp surfaces, i. e., immediately after cleaning, which can
be followed by renewed drying.
with an approved disinfectant and according to the manufacturer’s instructions for use: Some
disinfectants have a reduced efficacy in the presence of organic matter. Water quality, hardness and pH
in particular, can also influence the efficacy; e. g., the alkalinity of the environment reduces the activity
of phenolic compounds whereas it favors that of quaternary ammonium compounds. Temperature also
has an influence on efficacy; e. g., for a temperature increase of 10°C, a phenolic derivative is 6 times
more active and a chlorine derivative is 4 times more active. Finally, as previously mentioned, there are
also interferences between detergents and disinfectants.
following a methodical protocol: cleaning/disinfection operations should be described in written
procedures such as Standard Operation Procedure (SOP). It should be simple and easily
understandable and moreover adapted to the conditions of the hatchery, rooms and equipment to be
treated, entry chambers and building surroundings;
with adapted equipment: appropriate materials for the application of the disinfectant must be used, as
well as gloves and safety masks.
2. First Disinfection: Spraying, Application of Foam
Similarly to cleaning, the disinfecting solution can be applied by spraying surfaces under moderate pressure
(20-40 bars), at a water temperature above 25°C to optimize its activity.
Three to four liters of solution will be sprayed to treat a 10 m2
surface, using an angled hose to make it possible
to reach all nooks.
It should then be necessary to wait for the complete drying of surfaces before starting gas disinfection. Indeed, a
dry and disinfected surface is a lot more difficult to colonize for a bacterial population than a damp surface.
3. Second Disinfection: Fumigation or Fogging
This second disinfection in gas phase allows optimal diffusion of biocide molecules, before putting the room
back into service.
Fumigation is very widespread, essentially with formalin or other bactericidal substances and/or fungicides.
This technique allows biochemical as well as mechanical purification of the air through the large diffusion of
biocidal substances, and aggregation and sedimentation of airborne particles by smoke microparticles.
Thermo-fogging uses a cannon that projects the disinfectant, which is sprayed under the action of the heat.
This technique is well adapted to breeding farms, but often proves unsuitable for hatcheries because of the
insufficient size of premises. Moreover, this type of equipment always carries a risk of fire contrary to other
techniques.
Cold fogging, which consists in projecting the disinfectant through the action of compressed air, should
eventually be the reference method in hatcheries. It gathers at the same time the usefulness of gas diffusion of
biocidal molecules, ease of use (even in small premises) and safety for the personnel. Some hatcheries are
equipped with equipments that make it possible to disinfect each room during the night.
Note: Disinfection of the environment of the various rooms regularly closed in the absence of the personnel is
an economical and effective solution. If this disinfection takes place in the presence of hatching eggs, embryos
should to be checked for the absence of negative effects on their development (early embryonic mortality).