How to Read Ex Markings on ATEX & IECEx Equipment

Last updated: March 2026 · Based on IEC 60079 (2020 edition) and ATEX 2014/34/EU

Every certified Ex device carries a marking that encodes its protection type, gas/dust group, temperature class, and equipment protection level. Understanding these markings is essential for selecting, installing, and inspecting equipment. For a step-by-step walkthrough with real photos, see how to read an ATEX nameplate.

ATEX Marking Structure

ATEX equipment carries a structured marking per Directive 2014/34/EU:

ATEX Equipment Groups

ATEX Categories

IECEx Marking Structure

IECEx markings follow IEC 60079-0:

IECEx markings do not include the CE mark, group number, or category. Instead, the IECEx certificate number provides traceability:

Reading the Protection Type

The protection type uses the two-letter "Ex" prefix followed by the method letter and level suffix:

Combined Markings

Equipment with multiple protection methods:

Ex db eb IIC T4 Gb

Main body: flameproof (db). Terminal compartment: increased safety (eb).

Ex db [ib Ga] IIC T4 Gb

Flameproof enclosure (Gb) containing intrinsically safe circuits (Ga). The brackets indicate the IS circuits inside.

Ex db IIC T6...T4 Gb

Temperature class varies with ambient temperature. T6 at standard ambient, T4 at elevated ambient.

Dual Gas and Dust Marking

Equipment certified for both gas and dust:

II 2G  Ex db IIC T4 Gb
II 2D  Ex tb IIIC T125°C Db

Both lines appear on the nameplate. The equipment can be used in gas Zone 1 or dust Zone 21.

Reading Real-World Examples

Example 1: Junction Box

CE 0539 ⟨Ex⟩ II 2G Ex eb IIC T5 Gb

• ATEX Group II, Category 2G (Zone 1 gas)
• Increased safety (Ex eb)
• All gas groups (IIC)
• T5 (max 100°C surface)
• EPL Gb

Example 2: LED Floodlight

CE 0539 ⟨Ex⟩ II 2G Ex db eb IIC T4 Gb
                    II 2D Ex tb IIIC T135°C Db

• Dual rated: gas (Zone 1) and dust (Zone 21)
• Flameproof body with increased safety terminal box
• All gas groups (IIC), all dust groups (IIIC)
• Gas: T4 (135°C max), Dust: 135°C max

Example 3: ATEX Certified iPhone Case (Xshielder)

⟨Ex⟩ II 2G Ex db IIC T4 Gb
     II 2D Ex tb IIIC T135°C Db

• Zone 1 gas + Zone 21 dust
• Flameproof + dust-protected enclosure
• Covers all gas groups and dust groups
• IP65 rated, wireless charging compatible

Example 4: Intrinsically Safe Transmitter

CE 0539 ⟨Ex⟩ II 1G Ex ia IIC T4 Ga

• Category 1G. suitable for Zone 0
• Intrinsically safe (highest level, Ex ia)
• All gas groups (IIC)
• T4 (135°C max)
• EPL Ga (very high protection)

Example 5: Zone 2 Motor

CE 0539 ⟨Ex⟩ II 3G Ex nA IIB T3 Gc

• Category 3G. Zone 2 only
• Non-sparking (Ex nA)
• Gas groups IIA and IIB only (not IIC)
• T3 (200°C max)
• EPL Gc

Additional Markings on the Nameplate

Beyond the Ex marking, equipment labels include:

The "X" suffix is important. it means there are special conditions documented in the certificate that must be observed during installation and use. Always retrieve and read the certificate when you see "X".

NEC/CEC Markings (North America)

North American marking follows a different format:

Class I, Division 1, Groups B, C, D, T4

Or in the Zone system:

Class I, Zone 1, AEx db IIC T4 Gb

The "A" prefix before "Ex" indicates the equipment is certified to North American standards (NEC/CEC) using the Zone system.

Related Files

• Protection Methods. detailed explanation of each method
• Gas Groups. what IIA/IIB/IIC means
• Temperature Classes. what T1–T6 means
• EPL. what Ga/Gb/Gc means
• Standards. which standard governs each marking element
• Certification. how certificates and markings are issued