§34 意図された使用場所

This point seeks to provide guidance on the place of installation of equipment and protective systems. In fact, manufacturers of explosion protected equipment (e.g. in cases where potentially explosive atmospheres are conveyed) sometimes feel unsure whether and to what extent their products are covered by Directive

2014/34/EU. This applies especially to cases where only parts of the equipment are in contact with the explosive atmosphere.

Directive 2014/34/EU deals with the special risk of explosion and has one major aim to prevent "own potential sources of ignition" (Article 2(1)) of equipment and protective systems (as far as it has its own potential source of ignition) from becoming active. Beside Article 1(2) no restrictions are made with regard to local and technical conditions.

The probability of occurrence of the potential source of ignition determines the category. The technical requirements are summarised in Annex II 1.0.1; especially the 2nd indent describes the importance of the potential of the source of ignition. For this effect the place of installation is not decisive (see Article 1(1)(b) safety-, controlling-, regulation devices), but the possible effect of the potential source of ignition on a potentially explosive atmosphere.

In the light of these ideas the place of installation "in, at or beside" a potentially explosive atmosphere is not decisive for the application of Directive 2014/34/EU. The decisive fact is whether the potential sources of ignition of equipment are in contact – or have an interface – to a potentially explosive atmosphere, with the effect that the combustion may spread to the entire unburned mixture (see definition "explosive atmosphere", Article 2(4)). In this case the potential source of ignition is in the potentially explosive atmosphere.

Equipment may have an internal explosive mixture (without limitation to dangerous quantities), which has an interface in the sense of a spreading of the combustion to a potentially explosive atmosphere even in the case it is not installed completely inside a potentially explosive atmosphere. An example could be an extraction system installed outside the potentially explosive atmosphere with a ventilator – own potential source of ignition – which exhausts explosive atmosphere out of a storage tank, or another potentially explosive atmosphere, via a pipe acting as connecting interface to the potentially explosive atmosphere.

It is important to underline in this context how machinery having a potentially explosive atmosphere inside under operating conditions, but having no interface to external potentially explosive atmospheres must be considered. Such machines, as an integral whole, do not fall under scope of the ATEX Directive 2014/34/EU.

However, the essential health and safety requirement 1.5.7 "Explosion" in Annex I to the Machinery Directive 2006/42/EC (see section § 233), requires that "Machinery must be designed and constructed in such a way as to avoid any risk of explosion posed by the machinery itself or by gases, liquids, dust, vapours or other substances produced or used by the machinery. Machinery must comply, as far as the risk of explosion due to its use in a potentially explosive atmosphere is concerned, with the provisions of the specific Community [read 'Union'] Directives" (see also the "Guide to application of the Machinery Directive 2006/42/EC", sections §§ 91 and 228).

The Machinery Regulation (EU) 2023/1230 (applicable from 20 January 2027) will modify the requirement 1.5.7 on "Explosion" into: "Machinery or related products shall be designed and constructed in such a way as to avoid any risk of explosion presented by the machinery or related product itself or by gases, liquids, dust, vapours or other substances produced or used by the machinery or related product. Machinery or related product shall comply, as far as the risk of explosion due to its use in a potentially explosive atmosphere is concerned, with the provisions of the specific Union harmonisation legislation”.

It is therefore evident that equipment, protective systems and components intended for use in this potentially explosive atmosphere – and safety and controlling devices outside but contributing to their safe functioning – are within the scope of the ATEX Directive 2014/34/EU. It is understood that the latter applies provided that "atmospheric conditions" in the sense of Directive 2014/34/EU are present in the machine.

In this context the following questions have arisen:

a) Has the manufacturer the obligation to perform a zone classification inside this machinery?

It has been considered that:

the manufacturer of the machine has to carry out a risk analysis, including the risk of explosion;

Annex I to the ATEX Directive 2014/34/EU contains clear and unambiguous definitions concerning the place where they are intended to be used for every single equipment-group and category;

as opposed to the fully harmonising scope of the Machinery Directive, the zone concept applied in the framework of the ATEX "workplace" Directive 1999/92/EC allows Member States to apply more stringent requirements than those defined in this Directive.

In order to avoid a non-harmonised approach in the framework of a fully harmonised field like the Machinery Directive, it is not necessary to apply the zone concept as it is defined in Directive 1999/92/EC. Instead, the manufacturer should:

carry out the risk assessment (the manufacturer could apply the harmonised standard EN 1127-1 which describes the general concepts and methodology for explosion protection);

define the requirements of the equipment to be used inside the potentially explosive atmosphere – and of safety and controlling devices outside, but contributing to their safe functioning – in order to ensure full compliance of the machinery with the requirements of the Machinery Directive;

define the requirements for additional explosion protection measures (e.g. explosion-resistant design, autonomous protective system…) as a result of the risk assessment (e.g. for powder mills);

purchase or produce the equipment having those requirements, i.e. intended to be used under the conditions defined during the risk analysis, and in conformity to Directive 2014/34/EU.

b) Must the "non-electrical" equipment used inside this machinery be also in conformity to 2014/34/EU?

The equipment used inside must be in conformity to the applicable legislation. When the original Machinery Directive 89/392/EEC was drafted, European Directives regulated only electrical equipment for use in potentially explosive atmospheres; therefore, non-electrical equipment was not mentioned.

It is nevertheless a common understanding of the ATEX Committee that after the date of application of the previous ATEX Directive 94/9/EC (1 July 2003), both electrical and non-electrical equipment used in machinery having a potentially explosive atmosphere inside must comply with the ATEX Directive, now 2014/34/EU (from 20 April 2016). This position is also reflected in the Machinery Directive 2006/42/EC.