UL is an approved certification body and test laboratory within the IECEx Certified Equipment, Personnel Competency, Certified Service Facilities, Conformity Mark License, and Recognized Training Provider programs. Continue reading to gain a better understanding of IECEx certification and area classification, including an explanation and example of HazLoc markings.

How are IECEx Hazardous Areas classified?

IECEx HAZARDOUS AREAS ARE DIVIDED INTO ZONES, GROUPS, PROTECTION TYPES and EPLs.

Sample Marking:

iec explosion proof standard

  • Gas, Vapor, or Mist
    • Zone 0 – A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in form of gas, vapor or mist is present continuously or for long periods or frequently.
    • Zone 1 – A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in form of gas, vapor or mist is likely to occur in normal operation occasionally.
    • Zone 2 – A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in form of gas, vapor or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.
  • Dust
    • Zone 20 – A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently.
    • Zone 21 – A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally.
    • Zone 22 – A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only.
  • Group I – Zone 0 or 1
    • Mines Susceptible to Firedamp
  • Group II – Zone 0, 1, and 2
    • IIC – Acetylene & Hydrogen
    • IIB + H2 – Hydrogen
    • IIB – Ethylene
    • IIA – Propane
  • Group IIII – Zone 20, 21, and 22
    • IIIC – Conductive Dust
    • IIIB – Non-Conductive Dust
    • IIIA – Combustible Flyings
  • Protection Types – Gas Atmospheres
    • “d” – flameproof enclosure (for EPL Gb or Mb)
    • “e” – increased safety (for EPL Gb or Mb)
    • “ia” – intrinsic safety (for EPL Ga or Ma)
    • “ib” – intrinsic safety (for EPL Gb or Mb)
    • “ic” – intrinsic safety (for EPL Gc)
    • “ma” – encapsulation (for EPL Ga or Ma)
    • “mb” – encapsulation (for EPL Gb or Mb)
    • “mc” – encapsulation (for EPL Gc)
    • “nA” – non-sparking (for EPL Gc)
    • “nC” – protected sparking (for EPL Gc)
    • “nR” – restricted breathing (for EPL Gc)
    • “o” – oil immersion (for EPL Gb)
    • “op is” – inherently safe optical radiation (for EPL Ga, Gb or Gc)
    • “op pr” – protected optical radiation (for EPL Gb or Gc)
    • “op sh” – optical system with interlock (for EPL Ga, Gb or Gc)
    • “pv” – pressurization (for EPL Gb or Gc)
    • “px” – pressurization (for EPL Gb or Mb)
    • “py” – pressurization (for EPL Gb)
    • “pz” – pressurization (for EPL Gc)
    • “q” – powder filling (for EPL Gb or Mb)
  • Protection Types – Dust Atmospheres
    • “ta” – protection by enclosure (for EPL Da)
    • “tb” – protection by enclosure (for EPL Db)
    • “tc” – protection by enclosure (for EPL Dc)
    • “ia” – intrinsic safety (for EPL Da)
    • “ib” – intrinsic safety (for EPL Db)
    • “ma” – encapsulation (for EPL Da)
    • “mb” – encapsulation (for EPL Db)
    • “mc” – encapsulation (for EPL Dc)
    • “p” – pressurization (for EPL Db or Dc)
  • Non-Electrical Protection Types
    • “d” – flameproof
    • “c” – constructional safety
    • “b” – control of ignition
    • “k” – liquid immersion
    • “p” – pressurization
  • Equipment Protection Level (EPL) – Level of protection assigned to equipment based on its likelihood of becoming a source of ignition and distinguishing the differences between explosive gas atmospheres, explosive dust atmospheres, and the explosive atmospheres in mines susceptible to fire damp.
    • EPL Ma – Equipment for installation in a mine susceptible to firedamp, having a very high level of protection, which has sufficient security that it is unlikely to become an ignition source in normal operation, during expected malfunctions or during rare malfunctions, even when left energized in the presence of an outbreak of gas.
    • EPL Mb – Equipment for installation in a mine susceptible to firedamp, having a high level of protection, which has sufficient security that it is unlikely to become a source of ignition in normal operation or during expected malfunctions in the time span between there being an outbreak of gas and the equipment being de-energized.
    • EPL Ga – Equipment for explosive gas atmospheres, having a very high level of protection, which is not a source of ignition in normal operation, during expected malfunctions or during rare malfunctions.
    • EPL Gb – Equipment for explosive gas atmospheres, having a high level of protection, which is not a source of ignition in normal operation or during expected malfunctions.
    • EPL Gc – Equipment for explosive gas atmospheres, having an enhanced level of protection, which is not a source of ignition in normal operation and which may have some additional protection to ensure that it remains inactive as an ignition source in the case of regular expected occurrences (for example failure of a lamp).
    • EPL Da – Equipment for explosive dust atmospheres, having a very high level of protection, which is not a source of ignition in normal operation, during expected malfunctions, or during rare malfunctions.
    • EPL Db – Equipment for explosive dust atmospheres, having a high level of protection, which is not a source of ignition in normal operation or during expected malfunctions.
    • EPL Dc – Equipment for explosive dust atmospheres, having an enhanced level of protection, which is not a source of ignition in normal operation and which may have some additional protection to ensure that it remains inactive as an ignition source in the case of regular expected occurrences (for example failure of a lamp).

I understand the above, but can you please explain the elements of an IECEx marking string?

See below for a sample IECEx marking:

iec explosion proof standard

 

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