Fire-prevention through cleaning of hoods and extraction systems

Preemptive intervention to remove unburnt fumes from hoods and extraction systems is the best method of hygienic management to eliminate all fire risk factors due to the presence of fat deposits, equipment malfunction and food contamination

The very nature of these high lipid deposits, combined with very high temperatures can greatly facilitate the combustion process causing a high risk of fire.


The strong adhesiveness and consistency of the deposits makes them able to compromise the regular functioning of the systems, clogging them and modifying their draft. Furthermore, the life of the suction motors is greatly reduced. The deposits present inside the hoods are an ideal organic substrate for microbiological proliferation: for this reason it is necessary to adopt a fast, effective and safe cleaning program.

The consequences of poor maintenance of the unburnt smoke ventilation systems greatly increase the risk of fire and can cause malfunctioning and lead to food contamination.

With regard to the Italian legislation, the art. 4.4.3 lett. e) of the Ministerial Decree of 12 April 1996, containing the "Approval of the technical regulation for fire prevention for the design, construction and operation of thermal plants fueled by gaseous fuels" (published in the Official Gazette 4 May 1996, n. 103, Ordinary Supplement) for hoods and relative suction pipes requires a fire reaction class equal to zero, that is that the set of apparatuses is "incombustible". This point is by now peacefully and constantly interpreted by the competent authorities, in the sense that the suction motor assembly - hood - ducts must be free from grease and / or other materials that can catch fire.

The Alisea guaranteed method for the hygienic management of the unburnt fumes extraction systems starts from the Preliminary Technical Inspection, during which it is checked whether fat, carbonaceous or viscous deposits are present inside the plant, capable of altering the incombustibility ( class 0) of internal surfaces.

In the event that the absence of such deposits emerges with certainty from the Preliminary Technical Inspection, the Certification document of the Hygienic suitability of the plant and the relative record of the activity on the Hygienic Maintenance Register would be drawn up. The Technical Inspection would then be repeated periodically, according to the foreseen surveillance times.



In the event that the presence of such deposits emerges with certainty from the Preliminary Technical Inspection, it would be necessary to carry out the Corrective Cleaning Interventions.

This phase includes the cleaning of all the elements of the system that are in poor hygienic conditions, adopting the most appropriate methodologies for the case and for the contamination index presented by the installation. In this phase the following activities are implemented:

  • Suction Unit Cleaning;
  • Cleaning of the horizontal and vertical ventilation ducts
  • Cleaning the extractor hoods.

Over the course of ten years' experience, Alisea has adapted a diverse technical strategy for cleaning in Kitchen areas with often times difficult access. The working methods adopted by Alisea technicians include:

  • AliFoam method: this method is based on the automated endoscopic spraying treatment of internal surfaces, using a special foaming product capable of dissolving all the fat and carbon residues. Once dissolved, the residues are then removed using an aspirator;
  • AliSteam method: this method is based on the use of an electronic saturated steam generator at 180 ° C, together with a very powerful suction of liquefied fats;
  • AliDust method: this method, particularly suitable in the case of oily and wet residues, uses a special product with very low granulometry, able to absorb fats and allow their removal by suction;
  • AliDry method: this method consists in using a jet of dry ice whose temperature (up to -79 ° C) is able to solidify the fat residues and make them detach from the surfaces. Also in this case the residues will be removed with a powerful aspirator;
  • AliSkin method: this method is used on surfaces with carbonized deposits that are difficult to eliminate. The application of a specific product, equipped with REI certification for its specific field of use, is able to prevent the combustion of such deposits making the use of the plant safe;
  • NanoPrevention method: is aimed at preventing the deposit of grease on the surfaces inside the devices. This intervention is based on the drafting of a particular nanotechnological product on the surfaces that where deposits of carbonaceous or viscous fats is likely. The function is to prevent the adhesion of deposits, thus allowing their removal through normal aspiration.

Following these corrective actions, the Final Technical Inspection would be carried out, with a scrupulous verification of the operations carried out and the results obtained. If it were shown that the corrective action had produced positive results, we would proceed to the drafting of the Certification document of the Hygienic suitability of the plant and to the drafting of the Hygienic Maintenance Plan of the same. Subsequently, all these activities would be recorded on the Hygienic Maintenance Register. The Visual Inspection would then be repeated periodically, according to a prescheduled surveillance schedule.

If the Final Technical Inspection proves that the corrective action has not produced positive results, the work would be repeated, after an analysis of why the previous strategy was unsuccessful.

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