What changed in 2026
The IEC published IEC 60079-10-2:2026 Edition 3.0 on June 29, 2026. It replaces the 2015 edition and addresses the identification and classification of areas where explosive dust atmospheres and combustible dust layers are present.
The official IEC summary makes two purchasing-relevant points clear:
- Explosive dust clouds and combustible dust layers are considered separately.
- The examples assume effective housekeeping. Where housekeeping is not effective, classification must also consider the possibility that accumulated layers can form explosive dust clouds.
The publication is an area-classification standard. It does not certify products and it does not allow a supplier to assign a customer's Zone from a short enquiry.
Zone 20, Zone 21 and Zone 22 in plain English
The official EU workplace definitions in Directive 1999/92/EC classify hazardous places by the frequency and duration of the occurrence of an explosive atmosphere.
| Dust zone | Frequency and duration concept | EU equipment-category starting point, subject to the risk assessment |
|---|---|---|
| Zone 20 | A combustible-dust cloud is present continuously, for long periods or frequently | Category 1 equipment suitable for dust |
| Zone 21 | A combustible-dust cloud is likely to occur occasionally in normal operation | Category 1 or 2 equipment suitable for dust |
| Zone 22 | A combustible-dust cloud is not likely in normal operation, but if it occurs it persists only briefly | Category 1, 2 or 3 equipment suitable for dust |
The table summarizes the EU workplace directive. It is not a substitute for the applicable national rules, project specification or equipment certificate. Under an IEC-based project, buyers may also see dust Equipment Protection Levels Da, Db and Dc. Do not exchange an ATEX category and an IEC EPL as if they were identical document labels. Verify the route required for the destination market.
A Zone number does not describe explosion severity
Zone 20 is not simply a label for a more severe explosion than Zone 21 or Zone 22. The Zone describes the expected frequency and duration of the explosive atmosphere. Consequence, ignition sensitivity, process inventory, confinement and other risk factors require separate assessment.
The distinction matters for search and procurement. A request for "Zone 21 equipment" is more useful than a generic request for "dustproof equipment," but it is still incomplete.
Dustproof is not the same as suitable for combustible dust
A dustproof or high-IP enclosure can help limit solid-particle ingress, but an IP code alone is not evidence that equipment has been assessed for use in an explosive dust atmosphere.
Dust-area selection may require the exact equipment marking, dust group, Equipment Protection Level or ATEX category, maximum surface temperature, ambient range, protection concept, ingress protection and certificate schedule. The article IP66 vs Explosion Proof explains why environmental ingress protection and Ex conformity answer different questions.
Gas-area suitability also does not automatically transfer to dust areas. Gas groups IIA, IIB and IIC and dust groups IIIA, IIIB and IIIC describe different atmosphere families. The exact marking and certificate scope must cover the relevant application.
Why dust layers must be included in the review
Dust on equipment is not only a housekeeping issue. A deposit can affect heat dissipation, and accumulated material can become a source for a dust cloud if it is disturbed. The 2026 IEC summary therefore separates dust-cloud classification from other considerations for dust layers.
Housekeeping assumptions should be documented, credible and maintained. A clean photograph taken during commissioning is not proof that the same condition will exist during normal operation. Process changes, leaks, transfer points, ventilation and cleaning frequency can alter the evidence used for classification.
Information needed before equipment selection
Ask the site owner or responsible engineering team for an approved hazardous-area classification record. A useful buyer enquiry normally includes:
- Installation country and applicable regulatory or certification route
- Approved Zone and the extent of the classified area
- Combustible material and available dust-characterization data
- Dust subgroup, when specified by the project
- Required EPL or ATEX equipment category
- Maximum permitted equipment surface temperature
- Ambient temperature range and other environmental conditions
- Required ingress protection and corrosion resistance
- Supply voltage, load and equipment function
- Cable entries, mounting and enclosure requirements
- Required certificate, declaration, schedule, instructions and inspection records
If any of these inputs are missing, the responsible team should resolve them before a model is approved.
Common mistakes when comparing dust-zone equipment
- Treating all industrial dust as combustible without reviewing material data
- Treating a general "explosion-proof" product name as a complete marking
- Selecting from the Zone number while ignoring dust group and temperature limits
- Assuming an enclosure used in a gas Zone is automatically suitable for a dust Zone
- Treating IP66 as dust-explosion certification
- Ignoring layers, deposits, housekeeping assumptions and abnormal releases
- Accepting a certificate for a similar model rather than the exact model and suffix
- Using a product photograph as evidence of marking or certification
For a structured document workflow, see How to Verify IECEx Certificates and ATEX Documents. For marking fields, see How to Read Ex Markings.
Current MMAIATEX certification status
The public MMAIATEX About page states that ATEX, IECEx and CCC certification work is in progress. Do not infer a certificate from a product category, an Ex-related name or a photograph.
Request current documents for the exact model and configuration. Confirm that the legal manufacturer, product identity, marking, protection concept, dust group, temperature information and conditions align with the project before approval.
Safety disclaimer
This article is general educational information and does not classify a location or approve equipment. Combustible-dust assessment, area classification, equipment selection, installation and inspection must be completed by competent personnel using site-specific data, current standards, applicable law and exact product documents.
Request a dust-area equipment review
Send MMAIATEX the approved Zone, dust information, required EPL or ATEX category, temperature limit, ambient range, IP requirement, electrical duty, entry details and documentation list. We can then identify potentially relevant product information for the responsible team to assess.