What an Equipment Protection Level tells you
The current general equipment standard, IEC 60079-0:2026, covers general construction, testing and marking requirements for Ex Equipment and Ex Components. EPL is part of the marking and selection language used across the IEC 60079 system.
The code has two useful parts:
- The capital letter identifies the atmosphere family: G for gas, vapour or mist; D for combustible dust; M for mines susceptible to firedamp.
- The lower-case letter identifies the equipment protection level within that family: a, b or c for surface-industry gas and dust applications.
An EPL is not a certificate number, a Zone classification or a complete product specification. It is one field that must align with the rest of the marking and the approved project requirements.
Zone and EPL answer different questions
A hazardous-area Zone describes how often and for how long an explosive atmosphere is expected to be present. The IECEx area-classification reference explains that this classification is the basis for selecting, installing and maintaining equipment.
An EPL describes the protection level assigned to equipment and the operating or malfunction conditions under which it is intended not to become an ignition source. This is why a buyer should read the two records together:
- The hazardous-area classification report establishes the location and Zone.
- The equipment marking and certification documents establish the EPL and other product limits.
Do not select an EPL by looking at a product photograph or by guessing the Zone from the process name.
Conventional Zone and EPL relationship
An official IECEx conference reference presents the following selection relationship. Higher protection levels can be used in the lower-numbered gas or dust Zones shown, subject to the complete project and certificate requirements.
| Atmosphere occurrence concept | Gas Zone | Gas EPL options shown | Dust Zone | Dust EPL options shown |
|---|---|---|---|---|
| Continuous, frequent or long periods | Zone 0 | Ga | Zone 20 | Da |
| Periodic or occasional in normal operation | Zone 1 | Ga or Gb | Zone 21 | Da or Db |
| Not expected in normal operation, or only for short periods | Zone 2 | Ga, Gb or Gc | Zone 22 | Da, Db or Dc |
The table is a concise selection aid, not an area-classification method. The responsible project team may impose additional requirements because of consequences, local rules or a documented risk assessment.
How to read Ga, Gb and Gc
For gas, vapour and mist atmospheres, the public IECEx reference describes the equipment design intent in operating-condition terms:
| EPL | Broad ignition-protection intent | Conventional Zone use shown by IECEx |
|---|---|---|
| Ga | Not an ignition source in normal operation, expected malfunction or rare malfunction | Zone 0, Zone 1 or Zone 2 |
| Gb | Not an ignition source in normal operation or expected malfunction | Zone 1 or Zone 2 |
| Gc | Not an ignition source in normal operation | Zone 2 |
The EPL does not replace the gas group. Equipment marked for IIA, IIB or IIC has a separate atmosphere-group field, and the exact certificate schedule can contain conditions or model limits.
How to read Da, Db and Dc
For combustible-dust atmospheres, the same logic uses the letter D:
| EPL | Broad ignition-protection intent | Conventional Zone use shown by IECEx |
|---|---|---|
| Da | Not an ignition source in normal operation, expected malfunction or rare malfunction | Zone 20, Zone 21 or Zone 22 |
| Db | Not an ignition source in normal operation or expected malfunction | Zone 21 or Zone 22 |
| Dc | Not an ignition source in normal operation | Zone 22 |
Dust selection also requires the relevant dust group and maximum surface-temperature information. A gas EPL does not establish dust suitability, and a dust EPL does not establish gas suitability.
For more context on dust classification, read Zone 20, Zone 21 and Zone 22 Under IEC 60079-10-2:2026.
Why a higher EPL does not solve every mismatch
Choosing Ga instead of Gb, or Da instead of Db, does not make unrelated fields optional. The product still has to match the complete application.
Check at least these items:
- Gas, vapour, mist or combustible-dust atmosphere
- Equipment group and gas or dust subgroup
- Required temperature class or maximum surface temperature
- Minimum and maximum ambient temperature
- Type or combination of explosion-protection techniques
- Ingress protection and corrosion or environmental conditions
- Electrical ratings, function, mounting and cable entries
- Exact model, suffix, certificate status, schedule and special conditions
- Destination-market conformity route and project approval requirements
The new guide to temperature class and ambient temperature explains two temperature fields that frequently appear beside an EPL.
EPL and ATEX equipment category are not the same document field
Projects in the European Union may refer to equipment categories under Directive 2014/34/EU. IEC-based documents commonly use EPLs. The two systems have relationships, but a buyer should not replace one marking with the other in a purchase order without checking the required conformity route and exact product documents.
An IECEx Certificate of Conformity and an EU Declaration of Conformity are also different records. Our article How to Verify IECEx Certificates and ATEX Documents explains the separate checks.
A buyer workflow for checking EPL
- Obtain the approved hazardous-area classification from the responsible site or project team.
- Record whether the atmosphere is gas, vapour, mist or combustible dust.
- Record the Zone and the required EPL or ATEX category exactly as specified.
- Add the gas or dust group, temperature requirement and ambient range.
- Compare the exact equipment marking with the certificate and schedule.
- Check every model suffix, option, cable entry and special condition.
- Confirm the installation and inspection requirements with competent personnel.
- Retain the final approved documents with the equipment record.
For field-by-field marking guidance, see How to Read Ex Markings.
Common EPL mistakes
- Treating Zone 1 and Gb as two names for the same concept
- Assuming any Ga product is automatically suitable for every Zone 0 application
- Applying a gas EPL to a combustible-dust project
- Ignoring the gas group, dust group or temperature information
- Accepting a certificate for a similar model or different suffix
- Treating an IP code as an EPL or Ex approval
- Assuming a product category or photograph proves the marked protection level
- Translating an EPL into an ATEX category without checking the required documents
Current MMAIATEX certification status
The public MMAIATEX About page states that ATEX, IECEx and CCC certification work is in progress. A product name, category, photograph or article must not be used as evidence that a specific model has a completed certificate.
Request current documents for the exact legal manufacturer, model, suffix and configuration. Verify the certificate status, EPL, atmosphere group, temperature information, schedule and conditions through the applicable official system before approval.
Safety disclaimer
This article provides general educational information. It does not classify a location, assign an EPL, interpret a certificate for a specific project or approve equipment. Hazardous-area classification, equipment selection, installation and inspection must be completed by competent personnel using site-specific data, current standards, applicable law and exact product documentation.
Request an EPL-based product review
Send MMAIATEX the destination country, approved Zone, required EPL or ATEX category, gas or dust group, temperature requirement, ambient range, electrical duty, mounting and document list. We can then identify potentially relevant product information for the responsible team to assess.