Ex Marking (IEC 60079 Series)

Equipment protected by explosion protection standards IEC 60079 (Electrical apparatus for explosive gas atmospheres.

Note: IEC 60079 itself is a set of standards; the formal certificate recognized internationally is IECEx Certificate of Conformity (CoC).
Complete Typical Marking Example

Ex d IIC T6 Gb IP67 Breakdown explanation:
Ex： International symbol for explosion-protected electrical equipment for explosive gas environments.
d： Type of protection (protection concept per IEC 60079):
d: Flameproof enclosure (IEC 60079-1)
ia: Intrinsic safety, Zone 0 (IEC 60079-11)
ib: Intrinsic safety, Zone 1 (IEC 60079-11)
ic: Intrinsic safety, Zone 2 (IEC 60079-11)
e: Increased safety (IEC 60079-7)
p: Pressurized enclosure (IEC 60079-2)
o: Oil immersion
q: Powder filling
m: Encapsulation

IIC： Gas grouping (hazard level of flammable gas):
– IIA: Low risk (Propane)
– IIB: Medium risk (Ethylene)
– IIC: Highest risk (Hydrogen, Acetylene)
Group II = equipment for surface industrial gas hazardous areas; Group I = underground mining equipment.

T6：Temperature class (maximum surface temperature of equipment):
T1: ≤450°C
T2: ≤300°C
T3: ≤200°C
T4: ≤135°C
T5: ≤100°C
T6: ≤85°C

Gb： Equipment protection level (EPL – Equipment Protection Level, IEC 60079-0):
Ga: Zone 0 (ia)
Gb: Zone 1 (d, ib, e)
Gc: Zone 2 (ic)
Letter G stands for Gas atmosphere. For dust hazards, use D (Da/Db/Dd) following IEC 61241.

Official unique certificate number searchable on IECEx global database.