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.

What is IECEx Certification?

IEC = International Electrotechnical Commission
Ex = Explosive Atmospheres
IEC + Ex = IECEx
IECEx System = IEC System for Certification to Standards relating to Equipment for use in Explosive Atmospheres

IECEx certification provides assurance that all safety requirements in the IEC standards are met and that both explosive atmosphere areas and personnel working in them are as safe as possible.

What are the benefits to obtaining IECEx certification?

  • Accepted worldwide (see list of IECEx countries on www.iecex.com)
  • Improved safety and reduced testing and certification costs as well as time to market for manufacturer
  • Single qualification process for the assessment and evaluation of Ex Certification Bodies (ExCBs) and single way of conducting Ex testing and certification
  • One international certification database on www.iecex.com

IECEx vs. ATEX

IECEx

  • Jurisdiction is the world, all countries
  • Certification scheme where full compliance with IEC Standards are required
  • ExCBs (Ex Certification Bodies) and ExTLs (Ex Testing Laboratories) are evaluated and qualified according to a single international process and assessed by a team of IECEx assessors
  • Certificate is called a CoC (Certificate of Conformity)
  • All product types require a certificate of conformity (CoC), regardless of zone of use of product
  • IECEx certificates are all available for viewing on www.iecex.com

ATEX

  • Jurisdiction is the European Union (EU)
  • Compliance with ATEX Directive, EHSRs (Essential Health and Safety Requirements), and EN standards is required
  • Certification bodies are known as an ExNB (Ex Notified Body) qualified by official body within their own country issuing notification to the EU Commission
  • Certificate is called EC Type Examination Certificate
  • Assessment and testing process is risk based per ATEX and EU Directives (e.g. Zone 2 can be self-declared due to lower risk)
  • Certificates are available from the respective ExNB

How are IECEx Hazardous Areas classified?

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

  • 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 marking:

iec explosion proof standard

If you have questions or would like a quote, please click here.

Additional Resources

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