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Application documents, procedures, and online certificate verification.
Zones, Categories, Temperature Classes, and Ex Marking
A practical reference for manufacturers and facility operators — the essentials of explosion protection at a glance
Environment Zone Presence of Explosive Atmosphere Required Category (min.) Gas / Vapour Zone 0 Continuous or long-term Category 1G Zone 1 Likely to occur occasionally in normal operation Category 2G (or 1G) Zone 2 Not expected in normal operation; short-term if it occurs Category 3G (or 1G/2G) Toz Zone 20 Continuous or long-term (dust cloud) Category 1D Zone 21 Likely to occur occasionally in normal operation Category 2D (or 1D) Zone 22 Not expected in normal operation; short-term if it occurs Category 3D (or 1D/2D) For gases, zone classification follows EN 60079-10-1; for dusts, EN 60079-10-2. Group I (mining) equipment is categorised as M1/M2.
Class Max. Surface Temperature Example Substances (ignition temperature) T1 450 °C Methane, hydrogen, propane T2 300 °C Acetylene, ethanol T3 200 °C Petrol, diesel, kerosene T4 135 °C Acetaldehyde, ethyl ether T5 100 °C — T6 85 °C Carbon disulfide Marking Type of Protection Standard Ex d Flameproof enclosure EN/IEC 60079-1 Ex e Increased safety EN/IEC 60079-7 Ex i Intrinsic safety (ia/ib/ic) EN/IEC 60079-11 Ex m Encapsulation EN/IEC 60079-18 Ex p Pressurized enclosure EN/IEC 60079-2 Ex o Oil immersion EN/IEC 60079-6 Ex q Powder filling EN/IEC 60079-5 Ex n Non-sparking (Zone 2) EN/IEC 60079-15 Ex t Dust protection by enclosure EN/IEC 60079-31 Ex h Non-electrical (mechanical) equipment ISO 80079-36 / -37 Example marking of an ATEX-certified equipment:
IIEquipment group: surface industry (I = mining)2GCategory 2, gas atmosphere (Zone 1)Ex dbType of protection: flameproof enclosureIICGas group (IIC: hydrogen, acetylene — most critical)T4Temperature class: max. 135 °C surfaceGbEquipment Protection Level (EPL)On the product label, the CE marking and the notified body's identification number appear before the Ex marking.
ATEX 114 — Directive 2014/34/EU (Manufacturers)
Covers companies that manufacture equipment and protective systems intended for use in explosive atmospheres. Before being CE-marked and placed on the market, products must undergo conformity assessment — through a notified body where required. This is the scope of EST Teknik's certification services.
ATEX 153 — Directive 99/92/EC (Employers)
Covers employers operating workplaces with a risk of explosive atmospheres: zone classification, preparation of the Explosion Protection Document (EPD), and selection of appropriately certified equipment. Products certified under ATEX 114 are a prerequisite for ATEX 153 compliance.
Zone Classification & Equipment Categories
Environment Zone Presence of Explosive Atmosphere Required Category (min.) Gas / Vapor Zone 0 Continuous or long-term Category 1G Zone 1 Likely to occur occasionally during normal operation Category 2G (or 1G) Zone 2 Not expected during normal operation; if it occurs, it is short-term Category 3G (or 1G/2G) Dust Zone 20 Continuous or long-term (dust cloud) Category 1D Zone 21 May occur occasionally during normal operation Category 2D (or 1D) Zone 22 Not expected during normal operation; if it occurs, it is short-term Category 3D (or 1D/2D) Zone classification for gases is performed according to EN 60079-10-1, and for dusts according to EN 60079-10-2. Group I (mining) equipment is categorized as M1/M2.
Temperature Classes (Maximum Surface Temperature)
Class Max. Surface Temperature Examples (ignition temperature) T1 450 °C Methane, hydrogen, propane T2 300 °C Acetylene, ethanol T3 200 °C Gasoline, diesel, kerosene T4 135 °C Acetaldehyde, ethyl ether T5 100 °C – T6 85 °C Carbon disulfide Types of Protection & Standards
Marking Protection Type Standard Ex d Flame-proof enclosure EN/IEC 60079-1 Ex e Increased safety EN/IEC 60079-7 Ex i Intrinsic safety (ia/ib/ic) EN/IEC 60079-11 Ex m Encapsulation EN/IEC 60079-18 Ex p Pressurized enclosure EN/IEC 60079-2 Ex o Oil immersion EN/IEC 60079-6 Ex q Dust-filled EN/IEC 60079-5 Ex n Non-sparking (Zone 2) EN/IEC 60079-15 Ex t Dust protection by enclosure EN/IEC 60079-31 Ex h Non-electrical (mechanical) equipment ISO 80079-36 / -37 How to Read an Ex Marking
Example marking for ATEX-certified equipment:
II
Equipment group: surface industry (I = mining)2G
Category 2, gas atmosphere (Zone 1)Ex db
Protection type: flameproof enclosureIIC
Gas group (IIC: hydrogen, acetylene — most critical)T4
Temperature class: max. 135 °C surface temperatureGb
Equipment Protection Level (EPL)The CE mark and the identification number of the notified body appear before the Ex marking on the product label.
ATEX 114 vs ATEX 153 - Which One Applies to You?
ATEX 114 – Regulation (EU) 2014/34 (Manufacturers)
This applies to companies that manufacture equipment and protective systems intended for use in explosive atmospheres. Before products are placed on the market with the CE marking, they must undergo a conformity assessment by a notified body, if required. This is the scope of EST Teknik’s certification services.
ATEX 153 – Directive 99/92/EC (Employers)
Covers employers operating workplaces with explosive atmosphere risks: zone classification, preparation of an explosion protection document (EPD), and selection of appropriately certified equipment. Products certified under ATEX 114 are a prerequisite for ATEX 153 compliance.
Forms and Procedures
Frequently Asked Questions About ATEX
What is ATEX and what does it stand for?
ATEX is the abbreviation of the French term ATmosphères EXplosives (explosive atmospheres). It refers to the EU legislation on equipment for explosive atmospheres (2014/34/EU) and the workplace safety directive (1999/92/EC).
Which products require ATEX certification?
All electrical and mechanical equipment, protective systems, safety/control/regulating devices and components intended for use in explosive atmospheres are covered: exproof motors, panels, luminaires, fans, pumps, forklifts, elevators, fuel dispensers and similar products. Medical devices, PPE and seagoing vessels are excluded.
When is a notified body assessment required?
For Category 1 and Category 2 (electrical / internal combustion) equipment, EU Type Examination (Module B) and the production-phase modules must be carried out by a notified body. For Category 3, the manufacturer may self-declare via internal production control (Module A); for Category 2 non-electrical equipment the technical file must be lodged with a notified body.
How long does the certification process take?
The duration depends on product complexity, completeness of the technical file and the required tests. With a complete application, the type examination process is typically completed within several weeks to a few months. We clarify the timeline with a free pre-assessment before application.
What does 'exproof' mean?
Exproof (explosion-proof) refers to equipment designed and tested not to become an ignition source in an explosive atmosphere. Protection is achieved through standardised methods such as flameproof enclosure (Ex d), increased safety (Ex e) or intrinsic safety (Ex i).
What do Zone 0, 1 and 2 mean?
Zones classify hazardous areas by the frequency of the explosive atmosphere: in Zone 0 it is present continuously or for long periods, in Zone 1 occasionally in normal operation, and in Zone 2 it is not expected in normal operation and short-lived if it occurs. The dust equivalents are Zones 20, 21 and 22. See the technical guide above for details.
Is the EU Type Examination Certificate sufficient on its own?
No. Module B only certifies the conformity of the design; for placing on the market, the production phase must also be covered by a module (e.g. Module D or E). Only when this combination is complete may the CE marking be affixed.
Are ATEX and IECEx the same?
No. ATEX is a legal requirement for the EU market, while IECEx is a voluntary, global certification scheme operated by the IEC. Since both largely rely on the same IEC 60079 standards, testing can be harmonised planning both schemes together saves time for export-oriented manufacturers.
How can I verify the validity of a certificate?
You can verify certificates issued by EST Teknik via the Certificate Verification section below, and our TÜRKAK accreditation via turkak.org.tr.
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