ATEX Readiness: Explosion Risk, Zones and Equipment Records
Assess explosion risk per place, classify zones, keep the explosion protection document current and match equipment to zones.
In Short
- Gas zones 0-2, dust zones 20-22.
- Revise the EPD on major change.
- Equipment records kept 10 years.
Two EU directives cover explosive atmospheres. Directive 1999/92/EC protects workers: the employer assesses explosion risks, classifies places into zones and keeps an explosion protection document. Directive 2014/34/EU covers equipment and protective systems placed on the market: manufacturers assess conformity, mark equipment by group and category and keep documentation for 10 years. IECEx is an international certification scheme and was not opened for this guide. Orientation, not legal advice. Sources checked 4 Oct 2026.
The Employer's Duty under 1999/92/EC
Article 4 requires the employer to assess the specific risks from explosive atmospheres, taking into account the likelihood that they will occur and persist, the likelihood of ignition sources including static electricity, the installations and substances used, and the scale of possible effects. The assessment must be done overall and for each place.
More on the Employer's Duty under 1999/92/EC
This is a site-specific engineering judgement made by competent people, not a form. Review it when processes, materials, equipment or layout change.
Zones for Gases and Dusts
Places where explosive atmospheres may occur are classified into zones. For gas, vapour or mist: Zone 0 where an explosive atmosphere is present continuously, for long periods or frequently; Zone 1 where it is likely occasionally in normal operation; Zone 2 where it is not likely in normal operation and, if it occurs, persists only briefly.
Zones and Equipment Categories
| Gas/vapour zone | Dust zone | Explosive atmosphere | Equipment category |
|---|---|---|---|
| Zone 0 | Zone 20 | Continuous, long periods or frequent | 1 |
| Zone 1 | Zone 21 | Likely occasionally in normal operation | 1 or 2 |
| Zone 2 | Zone 22 | Not likely; brief if it occurs | 1, 2 or 3 |
- Zone 0
- Dust zone
- Zone 20
- Explosive atmosphere
- Continuous, long periods or frequent
- Equipment category
- 1
- Zone 1
- Dust zone
- Zone 21
- Explosive atmosphere
- Likely occasionally in normal operation
- Equipment category
- 1 or 2
- Zone 2
- Dust zone
- Zone 22
- Explosive atmosphere
- Not likely; brief if it occurs
- Equipment category
- 1, 2 or 3
More on zones for Gases and Dusts
Zones 20, 21 and 22 follow the same logic for combustible dust clouds. The zone decides which equipment category may be used there.
The Explosion Protection Document
Article 8 requires the employer to draw up and keep up to date an explosion protection document. It must show that risks have been determined and assessed, what measures will be taken, which places are classified into zones, and that workplace and equipment are designed, operated and maintained with due regard for safety.
More on the Explosion Protection Document
It must be drawn up before work starts and revised when the workplace, equipment or organisation undergoes significant changes. Keep zone drawings and version history with it.
Equipment under 2014/34/EU
Equipment and protective systems for potentially explosive atmospheres are placed in groups and categories: category 1 for very high, 2 for high and 3 for normal levels of protection. Manufacturers carry out the conformity assessment for the category, draw up an EU declaration of conformity and keep it and the technical documentation for 10 years after placing on the market.
More on equipment under 2014/34/EU
On site, record each item's marking, category and location so you can show it matches the zone where it is installed.
Where V5 fits and where people decide
V5 keeps the equipment register, maintenance and inspection records, calibration, documents and change control linked to each asset and area, with revision history. It does not classify zones, assess explosion risk or approve equipment.
Worked example: change CR-0291 (new dust extractor in blending room)
- RequestEngineering raises change for blending room B2 (Zone 22)
- ReviewEHS reviews risk assessment; zone unchanged
- CheckExtractor marking confirmed category 3D
- UpdateExplosion protection document v7 and zone drawing revised
- CloseAsset added to inspection schedule
More on where V5 fits and where people decide
Your competent engineers and EHS people decide the zones, the measures and whether equipment is suitable. When a change request touches a classified area, your team decides whether the risk assessment and explosion protection document must be revised.
Questions
What is the difference between the two ATEX directives?
1999/92/EC sets employer duties for workplaces; 2014/34/EU sets requirements for equipment and protective systems placed on the market.
What zones apply to dust?
Zones 20, 21 and 22 cover combustible dust clouds, mirroring Zones 0, 1 and 2 for gas, vapour or mist.
When must the explosion protection document be revised?
When the workplace, work equipment or organisation of work undergoes significant changes, extensions or conversions, under Article 8.
How long must equipment documentation be kept?
Manufacturers keep the EU declaration of conformity and technical documentation for 10 years after placing on the market.
Practical orientation, not legal advice. Rules differ by jurisdiction; your quality and compliance team decides what applies.
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