Guide to application of the ATEX 2014/34/UE directive - ANNEX I CRITERIA DETERMINING THE CLASSIFICATION OF EQUIPMENT-GROUPS INTO CATEGORIES

THE ANNEXES TO THE ATEX DIRECTIVE

§ 133  Classification of equipment-groups into categories

The ATEX Directive 2014/34/EU divides equipment into two groups. In order to determine the appropriate conformity assessment procedure, the manufacturer must first come to a decision based on the intended use, as to which group and category the product belongs.

It should be noted that devices have to follow the conformity assessment procedure according to the category of the equipment or protective system they are required for or contribute to. Devices and components may be suitable for one or more category or group of equipment.

• Equipment-group I comprises equipment intended for use in the underground parts of mines, and to those parts of surface installations of such mines, likely to become endangered by firedamp and/or combustible dust.
• Equipment-group II comprises equipment intended for use in other places likely to become endangered by explosive atmospheres.

These groups are sub-divided into categories. The way in which this categorisation has been developed highlights one of the main distinctions of equipment-group I and II. For group I, the categorisation depends on (amongst other factors) whether the product is to be de-energised in the event of an explosive atmosphere occurring. For group II, it depends where the product is intended to be used in and whether a potentially explosive atmosphere, is always present, or is likely to occur for a long or a short period of time.

The various categories of equipment must be capable of functioning in conformity with the operational parameters established by the manufacturer to a certain level of protection – see below Table 5: Levels of protection.

Such table makes references to the concept of “zone” as defined in the ATEX “workplace” Directive 1999/92/EC and it is based on the “normal” correspondence according to Directive 1999/92/EC. It should be noted that, when the group and category are a defined property of the equipment according to the ATEX “product” Directive 2014/34/EU, the zone is a defined property of the physical location and likelihood of an explosive atmosphere being present. Directive 1999/92/EC provides a “normal” correspondence between the zone and the category of equipment that may be installed in the zone. However, it also provides for varying this relationship according to a detailed risk assessment and also allows for the possibility that, in implementing Directive 1999/92/EC, individual Member States, may have changed the “normal” correspondence for particular situations.

Table 5: Levels of protection

(*) See as well the directives on minimum requirements for improving the safety and health protection of workers operating in potentially explosive atmospheres, e.g. those indicated in . The equipment in the various categories must also comply with the relevant essential and supplementary requirements detailed in Annex II to the Directive (essential health and safety requirements).

§ 134  Equipment-group I, category M1

Products of this category are required to remain functional for safety reasons when an explosive atmosphere is present and are characterised by integrated explosion protection measures functioning in such a way that:

- in the event of failure of one integrated measure, at least a second means of protection provides for a sufficient level of safety; or,

- in the event of two faults occurring independently of each other, a sufficient level of safety is ensured.

Products relating to this category must also comply with the supplementary requirements as detailed in Annex II, paragraph 2.0.1 to Directive 2014/34/EU.

Examples of equipment that might be categorised M1 include:

- gas detection system equipment;

- communications equipment;

- equipment used for mine rescue purposes.

All the above may be required to continue operating for safety reasons if an explosive atmosphere has been detected.

§ 135  Equipment-group I, category M2

These products are intended to be de-energised in the event of an explosive atmosphere being detected.

It is nonetheless foreseeable that explosive atmospheres could occur during the operation of category M2 equipment, as the equipment might not be de-energised immediately the atmosphere is detected. It is therefore necessary to incorporate protection measures, which provide a high level of safety. The protection measures relating to products of this category provide a sufficient level of safety during normal operation even in the event of more severe operating conditions arising, from rough handling and changing environmental conditions. This normally also includes the requirement to provide equipment with a sufficient level of safety in the event of operating faults or in dangerous operating conditions which normally have to be taken into account.

Products relating to this category must also comply with the supplementary requirements as detailed in Annex II, paragraph 2.0.2 to Directive 2014/34/EU.

§ 136  Equipment-group II, category 1

This category comprises products designed to be capable of remaining within their operational parameters, stated by the manufacturer, and ensuring a very high level of protection for their intended use in areas in which explosive atmospheres caused by mixtures of air and gases, vapours, mists or air/dusts mixtures are highly likely to occur and are present continuously, for long periods of time or frequently.

Equipment of this category is characterised by integrated explosion protection measures functioning in such a way that:

- in the event of a failure of one integrated measure, at least a second independent means of protection provides for a sufficient level of safety; or,

- in the event of two faults occurring independently of each other a sufficient level of safety is ensured.

It is also considered that equipment may be classed as category 1, if the manufacturer provides a combination of protective measures to prevent an ignition source becoming active under fault conditions, and in addition an integrated protective system (see section § 46) which will control the ignition hazard from a rare malfunction of the equipment.

Products relating to this category must also comply with the supplementary requirements as detailed in Annex II, paragraph 2.1 to Directive 2014/34/EU.

§ 137  Equipment-group II, category 2

This category comprises products designed to be capable of remaining within their operational parameters, stated by the manufacturer, and based on a high level of protection for their intended use, in areas in which explosive atmospheres caused by mixtures of air and gases, vapours, mists or air/dust mixtures are likely to occur.

The explosion protection relating to this category must function in such a way as to provide a sufficient level of safety even in the event of equipment with operating faults or in dangerous operating conditions which normally have to be taken into account.

Products relating to this category must also comply with the supplementary requirements as detailed in Annex II, paragraph 2.2 to Directive 2014/34/EU.

§ 138  Equipment-group II, category 3

This category comprises products designed to be capable of keeping within its operational parameters, stated by the manufacturer, and based upon a normal level of protection for its intended use, considering areas in which explosive atmospheres caused by mixtures of air and gases, vapours, mists or air/dust mixtures are unlikely to occur and if they do occur, do so infrequently and for a short period of time only.

The design of the products of this category must provide a sufficient level of safety during normal operation.

Products relating to this category must also comply with the supplementary requirements as detailed in Annex II, paragraph 2.3 to Directive 2014/34/EU.

Care needs to be taken in assuming what is meant by “normal operation”. For example, normal operation of a luminaire in an industrial application is assumed to include operation with a failed lamp since it is common practice for installations with multiple luminaires on a single circuit to operate for protracted periods with one or more failed lamps. Additional information is usually provided in the relevant European harmonised standards.