Explosion Protection Cheat Sheet: ATEX & IECEx Quick Reference
Last updated: March 2026 ยท Based on IEC 60079 (2020 edition) and ATEX 2014/34/EU
A quick-reference guide for engineers, technical sales, and product managers working with explosion-protected equipment. For step-by-step guidance, see the equipment selection guide. For full details on any topic, follow the links to the detailed files.
Quick Qualification Questions
When evaluating whether equipment is suitable for a hazardous area, answer these six questions in order:
- What zone is the area? (0, 1, 2 / 20, 21, 22) โ Zone Classification
- Gas or dust? (or both?) โ Site hazard assessment
- Required gas/dust group? (IIA/IIB/IIC or IIIA/IIIB/IIIC) โ Gas Groups
- Required temperature class? (T1โT6 or specific ยฐC for dust) โ Temperature Classes
- Regional approval required? (ATEX / IECEx / NEC / other) โ Standards
- Which protection method? (Ex d, Ex i, Ex e, Ex p, Ex n, etc.) โ Protection Methods
High-Level Mapping
Zone โ EPL
| Zone | EPL Required | Protection Level |
|---|---|---|
| Zone 0 / 20 | Ga / Da | Very high (2-fault safe) |
| Zone 1 / 21 | Gb / Db | High (1-fault safe) |
| Zone 2 / 22 | Gc / Dc | Enhanced (normal operation safe) |
See EPL for full details.
Hierarchy Rules
These "covers" rules simplify equipment selection:
- Gas groups: IIC covers IIB and IIA. one IIC-rated device works everywhere
- Dust groups: IIIC covers IIIB and IIIA
- Temperature: T6 is the most restrictive and covers T5 through T1
- EPL: Ga equipment can be used in Zones 0, 1, and 2
Protection Method โ Zone Suitability (Quick Reference)
| Method | Zone 0 | Zone 1 | Zone 2 |
|---|---|---|---|
| Ex ia | โ | โ | โ |
| Ex d | โ | โ | |
| Ex e | โ | โ | |
| Ex p | โ | โ | |
| Ex n | โ |
See Protection Methods for the complete matrix including dust zones.
Onboarding Reference
For someone new to explosion protection (or see ATEX for beginners for a gentle introduction), read in this order:
- Fundamentals. what makes an area hazardous
- Zone Classification. how areas are categorized
- Gas Groups and Temperature Classes. fuel properties
- Protection Methods. how equipment is made safe
- EPL. connecting zones to equipment requirements
- Ex Markings. reading equipment labels
- Standards. the regulatory landscape
- Certification. how equipment gets approved
- Installation & Inspection. keeping it safe in the field
Related Files
- Fundamentals. start here if you're new
- Protection Methods. detailed comparison of all methods
- Standards. regional certification requirements
- Certification. the certification process in depth
- Ex Markings. decoding equipment labels. See also how to read an ATEX nameplate
Content Review
Compiled from IEC 60079 series, ATEX 2014/34/EU, and IECEx operational documents. This reference guide does not replace official standards or certified site assessments. Always consult the applicable standard edition and a qualified Ex engineer for your specific application.
Compiled from IEC 60079 series, ATEX 2014/34/EU, and IECEx operational documents. This reference guide does not replace official standards or certified site assessments. Always consult the applicable standard edition and a qualified Ex engineer for your specific application.