25
October
Technical advices

UNDERSTANDING ATEX LABELS

ATEX LABELLING: GROUPS AND CATEGORIES OF APPLIANCES

The ATEX labels are affixed to electrical and industrial equipments used in environments with risk of fire and explosion to describe their correct scope of use.

For those working in hazardous environments, understanding ATEX labels is useful for choosing the right equipments and reducing risks.

ATEX standards are defined by the Directive 2014/34/EU. This Directive divides the equipments and protection systems in groups according to their use:

Each group is subdivided into categories as shown in the following tables:

 

 

Group I

Category

Protection level

Operating conditions

M1

Very high

Two means of protection

Two failures expected

Powered in case of an explosive atmosphere

M2

Elevato

Guaranteed in normal and heavy-duty operations

Not powered in case of an explosive atmosphere

 

Table 1 - Categories of equipment in Group I

 

 

Group II

Category

Protection level

Presence and duration of a dangerous atmosphere

ZONE

GAS

DUST

1

Very high

Two means of protection

Two failures expected

Always, often or for long periods

0

20

2

High

A means of protection

A breakdown is expected

Likely

1

21

3

Normal

Guaranteed in standard operation

Unlikely

2

22

 

Table 2 - Categories of equipment in Group II

 

 

It is necessary to add the letters G and D to the Category number according to the presence of Gas or Dust and depending if the explosive atmosphereis due to gas or dust (both letters can be used at the same time when the equipment is suitabl for both gas and dust).

As it can be inferred, there is a direct correspondece among Directive defined Groups and Categories and among protection levels and hazardous areas.

 

 

Correspondence between Groups/Categories and EPL

IEC/EN 60079

ATEX 2014/34/UE

Group

Atmosphere

EPL

Protection Level

Group and Category

Zone

Group I

Mining firedamp

Ma

Very high

I M1

/

Mb

High

I M2

/

Group II

GAS (IIA IIB IIC)

Ga

Very high

II 1G

Zone 0

Gb

High

II 2G

Zone 1

Gc

Normal

II 3G

Zone 2

Group III

DUST

(IIIA IIIB IIIC)

Da

Very high

II 1D

Zone 20

Db

High

II 2D

Zone 21

Dc

Normal

II 3D

Zone 22

 

Table 3 - correspondence between Groups/Categories and EPL

 

 

ATEX LABELLING

The label that responds solely and exclusively to the prerequisites of the ATEX Directive must strictly contain the following information:

 

ATEX LABELLING

 

 

Further to the information required by the Directive, the label contains additional technical information such as: type of protection, the Gas or Dust group, the Gas temperature class or the maximum surface temperature for dust and the protection level.

Example:

 

macatura ATEX, contrassegno Ex

 

ATEX MARKING: MANUFACTURER'S DATA

The ATEX labels must contain information about the manufacturer of the equipment.

Manufacturer data:

 

Example of ATEX label:

 

marcatura ATEX dati del costruttore