Equipment Protection Levels (EPL) Guide | Atexshop

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Equipment Protection Levels (EPLs) provide an alternative way to describe equipment suitability for hazardous areas. While ATEX categories are defined by the European directive, EPLs come from international IEC standards and are increasingly used alongside traditional ATEX marking—especially for equipment destined for global markets.

What EPL Means

IEC 60079-0 defines Equipment Protection Level as the level of protection assigned to equipment based on its likelihood of becoming a source of ignition. The concept closely parallels ATEX categories but uses different terminology. EPLs distinguish how likely it is that equipment might cause ignition under various conditions.

Gas Atmosphere EPLs

For equipment in gas or vapour atmospheres, three levels apply:

EPL Ga: Equipment with "very high" level of protection, not a source of ignition in normal operation, expected malfunctions, or rare malfunctions
EPL Gb: Equipment with "high" level of protection, not a source of ignition in normal operation or expected malfunctions
EPL Gc: Equipment with "enhanced" level of protection, not a source of ignition in normal operation

Dust Atmosphere EPLs

Corresponding levels exist for combustible dust atmospheres:

EPL Da: Very high protection for dust atmospheres (equivalent to Zone 20 suitability)
EPL Db: High protection for dust atmospheres (Zone 21 suitability)
EPL Dc: Enhanced protection for dust atmospheres (Zone 22 suitability)

Mining EPLs

For mining equipment (Group I), two EPLs apply:

EPL Ma: Very high protection, equipment remains energised in explosive atmospheres
EPL Mb: High protection, equipment de-energised when explosive atmosphere detected

EPL to ATEX Category Mapping

The correlation between EPL and ATEX categories is direct:

Ga corresponds to Category 1G (Zone 0 suitable), Gb corresponds to Category 2G (Zone 1 suitable), Gc corresponds to Category 3G (Zone 2 suitable). The same pattern applies for dusts: Da = 1D, Db = 2D, Dc = 3D. For mining: Ma = M1, Mb = M2.

EPL Determined by Protection Type

Each type of protection (Ex d, Ex e, Ex i, etc.) can achieve different EPLs depending on its specific design and level. For intrinsic safety: Ex ia achieves EPL Ga, Ex ib achieves EPL Gb, Ex ic achieves EPL Gc. For flameproof enclosures: standard Ex d achieves EPL Gb, but can achieve Ga when combined with additional measures.

Why EPL Matters

EPL provides a more direct statement of protection capability. Rather than interpreting what "Category 2" means in practice, EPL Gb explicitly states the equipment won't cause ignition during normal operation or expected malfunctions. This clarity aids equipment selection and facilitates international certification acceptance.

Marking with EPL

Modern ATEX marking increasingly includes EPL alongside traditional information. An equipment label might show: "II 2 G Ex db IIC T4 Gb" where "Gb" is the EPL. This dual marking satisfies both EU requirements and international (IECEx) conventions, simplifying documentation for global sales.

Equipment Selection Using EPL

EPL can simplify equipment selection: Zone 0 requires EPL Ga, Zone 1 requires Ga or Gb, Zone 2 requires Ga, Gb, or Gc. The same logic applies to dust zones with Da, Db, Dc. When comparing equipment from different manufacturers, EPL provides a standardised indication of protection capability.