What are the different ATEX Zones?

ATEX 1

When working with any electronic or electrical equipment in an environment that may be or may become hazardous within European boundaries, the equipment you are using must be ATEX-certified. ATEX certification of electronic or electrical equipment must adhere to the EU directive 2014/34, also known as the ATEX 114 Directive.

The term - ATEX equipment – comes from the French term ‘ATmosphères EXplosives’, which directly translates into English as ‘explosive atmospheres’ and means that the electrical equipment used in these environments must be explosion-proof.

As per the directive, the equipment is classified according to both groups and categories which reflect their use and the environments in which they will be used. To ensure that the equipment is used in the correct manner, the equipment is marked accordingly. Understanding what these markings means and the zoning system is critical for health and safety and compliance. We’ll review the zoning system and the level of hazard present in the given zones, according to likelihood of an explosive atmospheres being present.

We’ll explore the question ‘how to determine which ATEX equipment can be used in which Ex zone?’ and review how to operate within the zoning system safely.

What are ATEX Zones?

ATEX Zones are classified according to their potentially explosive environments. Equipment must be classified and marked as appropriate to be considered ATEX-certified.

When you review the table, the zones are clearly set out. However, it can be hard to work out exactly what to do in every circumstance.

Let’s explore the logic behind the categorisation.

How are ATEX Zones Classified by Risk Level?

There are two different zones that need to be considered – Gas and Dust. The Ex zone for (flammable) gases begins at 0 and for (combustible) dust at 20. Add to this the equipment classifications, which start at 1, and it can begin to feel confusing.

The zones are classified according to the number of times, or frequency, that an explosive atmosphere will happen in the course of normal operations. There will be a classified ATEX zone for dust and, separately, for flammable gases:

Zone 0 (Gas) or 20 (Dust) represents environments with constant explosive atmospheres present, like a confined space.

Zone 1 (Gas) or 21 (Dust) represents intermittently explosive atmospheres.

There are circumstances where explosive atmospheres may be rare during normal operations, but it remains a possibility. Areas like this often occur in the environments around a Zone 1/21, where the risk may extend into the next area. This would see a Zone1/21 sitting beside a Zone 2/22.

Working in an environment in which gases may be present means that they may stem from leaks, have the capacity to leak from the zone themselves or they may be omni-present in the zone due to the nature of the operations. As such, these zones are designated for zones 0/1/2. For dust that may be present in a zone whether directly or through seepage, the zone classification are zones 20/21/22.

What is an EX Zone?

An Ex Zone can be used as a term in place of either ATEX zone or Explosive Atmosphere. All of the above have the potential to be an explosive atmosphere and will be categorised on the type of flammable substance in the environment and its presence within the zone.

The ATEX zones classification system sets out the level of protection necessary required for equipment that is being used in hazardous areas.

Zone 0/20 - Category 1 equipment
Zone 1/21 - Category 2 equipment
Zone 2/22 - Category 3 equipment

Group 1 will be used in mining
Group 2 is to be used in all other gas- and dust-explosive atmospheres

ATEX Equipment Group I:


The equipment that is categorised as ATEX Equipment Group I is for equipment that is to be used specifically and exclusively in the underground sections of mining environments and for use in surface installations with environments which are at risk from combustible dust and/or firedamp.

ATEX Equipment Group II:


The equipment that is categorised as ATEX Equipment Group II is for equipment that is to be used in other areas where explosive atmospheres caused by gas, dust, air, mists and vapours are present. Environments such as this may occur within the oil and gas industry, production facilities and pharmaceutical manufacturing.

ATEX Equipment Categories Within Equipment Group II:

Equipment Category 1


Equipment categorised as ATEX Equipment Group II Category I is required to deliver a very high level of protection. This equipment is either designed for use in Zone 0 areas (gas) or Zone 20 (dust). Equipment such as this may be found within a dust filter and its design must offer protection, even in the case of equipment failure / error. The safety features of the equipment must remain intact, even when two other independent faults occur.

It is very hard for equipment to secure a zone 0 approval as there is a limited number of these environments and the costs associated with maintain certification can be high.

Equipment category 2


Equipment categorised as ATEX Equipment Group II Category II has been classified for use in Zone 1 (gas) or Zone 21 (dust). Offering a high level of protection, Zone I could be found within an agricultural setting, in a silo, or within a food manufacturing setting. Operators can consolidate the health and safety measures taken in Zone I with protective masks. Within Zone I, the category 2 equipment is in place to ensure safety in circumstances in which faults and breakdowns are anticipated.

Equipment category 3


Equipment categorised as ATEX Equipment Group II Category III has been classified for use in Zone 2 (gases) or Zone 22 (dusts). This environment has been designated as requiring protection from explosion during normal operation. Equipment in this category will be common place across manufacturing and chemical industries, such as paint or lacquer production. At this level, safety is usually delivered by regulating the equipment’s surface temperature.

 

Conclusion

The ATEX zones classification system sets out the level of protection necessary required for equipment that is being used in hazardous areas.

Zone 0/20 - Category 1 equipment
Zone 1/21 - Category 2 equipment
Zone 2/22 - Category 3 equipment

Group 1 will be used in mining
Group 2 is to be used in all other gas- and dust-explosive atmospheres

Understanding “Which ATEX equipment do we need in our ATEX zone?” is accompanied by a long list of considerations that need to be taken into account. At Ultrimax, our equipment has been classified to make it easier for you to understand exactly what it is that you need – but you still might like to talk to us directly.

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