From a regulatory point of view, two important distinctions are made in the classification of ATEX areas, between places where the risk of explosion is due to the presence of gas compared to those where it is linked to combustible dusts.
ATEX zones: Gas
The classification of areas with danger of explosion due to the presence of gases, mists or flammable vapors includes:
- Zone 0: the explosive atmosphere is present continuously or for long periods
- Zone 1: during normal activities, the formation of an explosive atmosphere is likely
- Zone 2: area in which the formation of an explosive atmosphere, in the form of a cloud of combustible dust, is not likely to occur, or only for short periods.
The main reference criteria are:
- quantity and position of gas emission sources
- degree of emission (continuous, first degree, second degree)
- degree of ventilation (high, medium, low)
- availability of ventilation (good, adequate, poor).
ATEX zones: Dust
In the evaluation of the risk of explosion, combustible dusts play an important role and absolutely not to be underestimated.
It is often believed that the materials that can cause explosions are mainly those of the metallurgical or woodworking sector; however, the food industry is also directly involved (just think of elements such as sugar, milk powder, wheat powders, cereals, etc.).
Three areas can be identified in the classification of areas with combustible dusts:
- Zone 20: area where there is an explosive atmosphere, in the form of a cloud of combustible dust in the air, continuously, for long periods or frequently
- Zone 21: area in which the formation of an explosive atmosphere, in the form of a cloud of combustible dust in the air, is likely to occur occasionally;
- Zone 22: area in which the formation of an explosive atmosphere, in the form of a cloud of combustible dust, is not likely to occur, or only for short periods.
The employer is obliged to adopt technical and organizational measures appropriate to the nature of the activity carried out, on the basis of the risk assessment, for the prevention of the risk of explosions (Article 289 of the Legislative Decree 81/08, i) . In the event that the activity does not allow to prevent the formation of explosive atmospheres, he must:
- avoid the ignition of explosive atmospheres;
- mitigate the harmful effects of an explosion to prevent the health and safety of workers.
As far as the assessment of the risk of explosion is concerned, art. 294 establishes that the employer must prepare and keep up-to-date an “explosion protection document“.
The main information this document must contain includes:
- the identification and assessment of explosion risks
- the adoption of appropriate measures to achieve the objectives
- the identification of places at risk and those where the minimum requirements apply
- the correct use and maintenance of places, equipment and alarm devices
- the adoption of measures for the safe use of work equipment.
We hope this information will be useful for you to clarify the matter. If you need further specifications regarding the ATEX protection systems produced in our company, you can contact our experts using the contact form you find on our website. to prevent the health and safety of workers.