In the world of ATEX equipment a key role is played by notified bodies (as defined in the ATEX Directive), also called certification bodies (in Italian legislation 60079-0). These are third parties called to certify certain product and quality standards.
by Andrea Battauz, R&D Project Engineer of Cortem Group
The ATEX 2014/34/EU directive is part of a set of European laws created to harmonise various regulations within the European Union.
The basic concept of this harmonization is the elimination of customs barriers internal to the European Union. Similar directives are the Machinery Directive or the Electromagnetic Compatibility Directive.
The ATEX 2014/34/EU Directive indicates the obligations and responsibilities for the persons placing products on the market and/or putting them into service. They may be the manufacturer, his legal representative, or any other person responsible. The use of the equipment is instead defined in 1999/92/EC Directive, in which specific reference is made to the zoning of the installation site. The latter is the Directive speaking of the risks to which workers are exposed in the places where it is possible to form an explosive mixture.
The ATEX Directive 2014/34 /EU was published in Italy in the Official Gazette of the Italian Republic number 121 of 25/05/2016.
The ATEX 2014/34/EU Directive operates from the outset a distinction between devices of group I and II.
Group I: appliances intended for underground work in mines and their surface facilities, where there is a risk of being exposed to the release of firedamp and/or combustible dusts. Grisù is a gas, mainly composed of methane, which is found in mines where it tends to accumulate in pockets inside tunnels.
The most part of situations are related to the extraction of coal and sulphur.
Group II: appliances intended for environments in which an explosive atmosphere due to mixtures of air and gases, vapours, mists or mixtures of air and dust is detected, always, often or for long periods.
The devices of this group are common in the energy industry linked to fossil fuels such as oil and natural gas, in the petrochemical industry and in all those industrial contexts where explosive gases can be found. Sometimes these gases can be produced during the process, such as the hydrogen produced in the charging boxes of forklifts.
Explosive atmospheres due to the presence of dust, in contexts other than the mine, have been regulated following the scheme already used for those with the presence of gas. In this sector we can find industries of primary importance such as food or fiber textile processing ones.
The combination between equipment thus defined and the zones, as envisaged in the Directive 1999/92/ EC, is based on the concept of adopting a higher level of protection of the equipment where the probability of the formation of an explosive atmosphere is greater.
In Table 1 we report this combination together with the EPL, which stands for Equipment Protection Level, recently introduced in the legislation to improve the understanding of the equipment markings.
Table 1: appliance category, zones and EPL
In the world of ATEX equipment a key role is played by notified bodies (as defined in the ATEX Directive), also called certification bodies (in Italian legislation 60079-0).
These are third parties called to certify certain product and quality standards.
Their list can be found in the NANDO database where it is also possible to find the status of these organisms (active, withdrawn, terminated, or suspended) .
Some of these are names known to the public such as IMQ, CESI or TUV.
For the ATEX directive, the involvement of the notified body is all the greater when the type of product is critical in terms of safety. Thus, the notified body has a greater role in appliances intended to have a high level of safety while giving way to a manufacturer self-certification for appliances with a low level of safety.
From the guidelines for the application of the directive we obtain the following tables.
Table 2: Involvement of the notified body in the development phase of the equipment according to the ATEX directive and related EPL according to current legislation 
Table 3: Involvement of the notified body in the production of the equipment according to the ATEX directive and related EPL according to current legislation 
It should be noted that, within the category 2, is made a distinction between the electrical devices (together engines with internal combustion) and the so-called non-electrical or mechanical. The latter are considered less critical and do not need a notified body that verifies the design and production directly in the company, but rather a deposit of the technical file with them. In this framework, manufacturers of fans, augers, pumps, and gearboxes are included.
In category 1, on the other hand, the notified body must always be involved
.In the European market, where the ATEX directive is in force, category 3, which is linked to installation in Zone 2 or 22, requires only self-certification by the manufacturer. The level of quality construction and design of the category 3 products is not subjected to analysis by a third party.
In the context of the ATEX directive, the role of notified bodies is central both in the production and in the development of ATEX equipment.We also mentioned the clear difference in the European market between products for Zone 2 and 22 and the others according to ATEX directive, a difference of which the end user is often unaware.
Reference standards and bibliography:
 in this normal sense with regard to the risk of ignition it is a higher level than the devices normally marked CE
 ATEX 2014-34-EU Guidelines - 3rd Edition May 2020
Note that Annexes V, VI, IX allow the production through other procedures, always seeing the notified body involved.