Directives and Associated Marking and Certification

ATEX Directive 2014/34/EU

Directive 2014/34/EU (referred to as ATEX 2014 or ‘the equipment directive’), that replaced Directive 94/9/EC (referred to as ATEX 95), is a trade directive. The purpose of the directive is to remove barriers to trade within the EU through the application of common standards of certification for explosion protected equipment.

The Directive stipulates five possible Categories for certified equipment. For Categories 1,2 and 3, the category number would be suffixed by ‘D’ and/or ‘G’ to indicate suitability for Dust and/or Gas atmospheres.

Equipment Categories

Category
M1
Equipment in this category is intended for use in underground parts of mines as well as those parts of surface installations of such mines endangered by firedamp and/or combustible dust and is required to remain functional, even in the event of rare incidents relating to equipment, with an explosive atmosphere present
Category M2 Equipment in this category is intended for use in underground parts of mines as well as those parts of surface installations of such mines likely to be endangered by firedamp and/or combustible dust and is intended to be de-energised in the event of an explosive atmosphere.
Category 1 Equipment in this category is intended for use in areas in which explosive atmospheres caused by mixtures of air and gases, vapours or mists or by air/dust mixtures are present continuously, for long periods or frequently.
Category 2 Equipment in this category is intended for use in areas in which explosive atmospheres caused by gases, vapours, mists or air/dust mixtures are likely to occur occasionally.
Category 3 Equipment in this category is intended for use in areas in which explosive atmospheres caused by gases, vapours, mists, or air/dust mixtures are unlikely to occur or, if they do occur, are likely to do so only infrequently and for a short period omaly.

IEC 60079 Equipment Protection Levels (EPLs)

IEC standard 60079 classifies equipment by Equipment Protection Level. Three protection levels are stated: ‘a’, ‘b’ and ‘c’. EPLs will be prefixed with ‘D’ or ‘G’ to indicate applicability for dust or gas atmospheres.

Relationship Between ATEX Categories, IEC EPLs, Area Zones and Protection Types

Category EPL Zones Protection Type Code
1 a 0,1,2,20,21,22 Intrinsically Safe (a) ia
      Encapsulation (a) ma
      Protection of equipment using optical radiation op is
      Special protection (a) sa
      Protection by enclosure (for dust) (a) ta
2 b 1, 2, 21, 22 Flameproof enclosure d
      Increased safety e
      Intrinsically safe (b) ib
      Encapsulation (b) mb
      Oil immersion o
      Powder filled q
      Pressurised enclosure (gas/vapours) p, px, pxb, py, or pyb
      Pressurised enclosure (dust) pD
      Fieldbus intrinsically safe concept (FISCO) none
      Protection of equipment using optical radiation op is, op sh, op pr
      Special protection (b) sb
      Protection by enclosure (for dust) (b) tb
3 c 2,22 Intrinsically safe (c) ic
      Encapsulation (c) mc
      Non-sparking n or nA
      Restricted breathing nR
      Energy limitation nL
      Protected sparking nC
      Pressurised enclosure (gas/vapours) pz or pzc
      Special protection (c) sc
      Protection by enclosure (for dust) (c) tc