Reference Source

122 records

What is the IEC or ATEX equivalent of this North American hazardous-area rating?

122 records covering 96 north american designations, one fact each. Every value is transcribed from the source that states it and carries the sentence it was taken from: 6 sources across 5 sites, last checked 2026-08-06, due for re-check by 2028-08-05. Every record is listed below, each linking the page its value came from.

Records122
Sources6
Verified
Review by
LicenceFacts extracted from freely published manufacturer and industry reference pages. Designation crosswalks are safety facts, not copyrightable expression. NFPA 70 and the IEC 60079 series are not reproduced and were not opened -- the fact is taken, never the document. Four separate publishers, no bulk take from any one.

5 records where two or more sources state different values. Both sides are reproduced on the record page, each with its own source and quote.

About this data

Crosswalk between the two concurrent hazardous-area classification systems: the North American Class / Division system of NEC Articles 500 and 505 (NFPA 70) and the CSA code, against the Zone system of IEC 60079, ATEX and IECEx. Each record is one designation in one system with its stated counterpart in the other, covering area classification (Division 1 and 2 against Zone 0, 1, 2, 20, 21, 22), gas groups (A, B, C, D against IIA, IIB, IIC, IIB+H2), dust groups (E, F, G against IIIA, IIIB, IIIC), protection concepts (explosion-proof against Ex d, intrinsically safe against Ex i, purged/pressurized against Ex p, dust-ignition-proof against Ex t, non-incendive against Ex nA/Ex ec) with the IEC standard number for each, and temperature codes T1 to T6 with their maximum surface temperatures. It also carries the equipment marking codes themselves -- the NEC 500 bracket codes (XP), (IS), (NI), (DIP), (PX), (PY), (PZ) and the NFPA 496 purge Types X, Y and Z, against the NEC 505 and CEC Ex / AEx codes -- each with the country whose column printed it, the hazard class and division or zone it is approved for, and the ISA, UL, FM, NFPA or CSA standard behind it, because the same code means different standards either side of the border: (IS) is UL 913 / FM 3610 in the US and C22.2 No. 157 in Canada. Answers 'is ATEX Ex d IIB T4 the same as Class I Div 1 Group C', 'what does T2D mean and is there an IEC equivalent', 'Division 1 or Zone 1 which is stricter', 'NEC Group B IEC equivalent', and 'can I install Zone 1 equipment in a Division 1 area'. Three things the mapping gets wrong when stated as a simple table: NEC 500 has no Zone 0 equivalent so Division 1 spans Zone 0 and Zone 1 and is under-specified for Zone 0; the North American temperature codes T2A, T2B, T2C, T2D, T3A, T3B, T3C and T4A have no IEC counterpart at all; and publishers disagree on NEC Group B, giving it as IIC or as IIB+H2, which changes the required flameproof gap. Every counterpart is quoted from the page that stated it and attributed, so the disagreement is visible.

The data

North American designationCategoryIEC / ATEX designationBasis or noteIEC standardCountryHazard classDivision or zoneMaximum surface temperature (C)
2 levels (Div 1, Div 2)system attribute3 levels (Zone 0, 1, 2)Risk gradation
AEx dprotection conceptFlame ProofISA 60079-1USClass IZone 1
AEx eprotection conceptIncreased SafetyISA 60079-7USClass IZone 1
AEx iaprotection conceptIntrinsic SafetyISA 60079-11USClass IZone 0
AEx iaDprotection conceptISA 61241-11USZone 20
AEx ibprotection conceptISA 60079-11USClass IZone 1
AEx ibDprotection conceptIntrinsic SafetyISA 61241-11USZone 21
AEx mprotection conceptISA 60079-18USClass IZone 1
AEx maprotection conceptISA 60079-18USClass IZone 0
AEx maDprotection conceptISA 61241-18Zone 20
AEx mbprotection conceptISA 60079-18USClass IZone 1
AEx mbDprotection conceptISA 61241-18USZone 21
AEx nAprotection conceptISA 60079-15USClass IZone 2
AEx nCprotection conceptEnclosed BreakISA 60079-15USClass IZone 2
AEx nRprotection conceptISA 60079-15USClass IZone 2
AEx oprotection conceptOil EmmersionISA 60079-6USClass IZone 1
AEx pDprotection conceptISA 61241-2USZone 21
AEx pxprotection conceptISA 60079-2USClass IZone 1
AEx pyprotection conceptISA 60079-2USClass IZone 1
AEx pzprotection conceptISA 60079-2USClass IZone 2
AEx qprotection conceptPower FilledISA 60079-5USClass IZone 1
AEx tDprotection conceptISA 60079-31USZone 21
Class Iarea classificationZone 0, 1, 2 (gas)Flammable gases and vapors
Class I Division 1area classificationZone 0Continuous hazard
Class I Division 1area classificationZone 1Frequent hazard
Class I Division 2area classificationZone 2Occasional hazard
Class I (gas), II (dust), III (fibers)system attributeZone 0, 1, 2 (gas); Zone 20, 21, 22 (dust)Hazard basis
Class I, Group Agas groupIICAcetylene
Class I, Group Bgas groupIIB + H2Hydrogen
Class I, Group Cgas groupIIBEthylene
Class I, Group Dgas groupIIAPropane
Class IIarea classificationZone 20, 21, 22 (dust)Combustible dust
Class II, Group Edust groupIIICCombustible metal dust
Class II, Group Fdust groupIIIBCombustible carbonaceous dust
Class II, Group Gdust groupCombustible dusts not in group E or F
Class II Groups E, F, Gsystem attributeZone 20, 21, 22 (IIIA, IIIB, IIIC)Dust classification
Class IIIarea classificationIgnitable fibers
Class IIIdust groupIEC considers fibers within the dust framework
Class IIIdust groupIIIACombustible fibres and flyings
(DIP)protection conceptUL 1203USClass IIDivision 1
(DIP) A21protection conceptCSA E61241-1-1CAClass IIDivision 1
(DIP) A22protection conceptCSA E61241-1-1Division 2
Division 1equipment categoryCategory 2Division 1 equipment generally satisfies Category 2
Division 1area classificationZone 0 / Zone 1Hazard present during normal operation
Division 1area classificationZone 0 / Zone 20
Division 1area classificationZone 1 (+ Zone 0)Explosive atmosphere likely during normal operation (10–1000 hrs/yr)
Division 1area classificationZone 1 / Zone 21
Division 2equipment categoryCategory 3Division 2 satisfies Category 3
Division 2sources differarea classificationZone 2Explosive atmosphere not likely; only abnormal conditions (<10 hrs/yr)
Division 2area classificationZone 2 / Zone 22
Dust-ignition-proofprotection conceptEx t (Dust protection by enclosure)Prevent dust ingress and limit surface temperatureIEC 60079-31
Exprotection conceptCSA 60079-0CAClass IDivision 1 & 2
Exprotection conceptISA 60079-0USZone 20, 21, 22
Ex dprotection conceptCSA 60079-1CAClass IZone 1
Ex eprotection conceptCSA E60079-7CAClass IZone 1
EX iaprotection conceptCSA E60079-11CAClass IZone 0
Ex ibprotection conceptCSA E60079-11CAClass IZone 1
Ex mprotection conceptEncapsulatedCSA E60079-18CAClass IZone 1
EX nAprotection conceptCSA E60079-15CAClass IZone 2
Ex nCprotection conceptCSA E60079-15CAClass IZone 2
Ex nLprotection conceptCSA E60079-15CAClass IZone 2
Ex nRprotection conceptCSA E60079-15CAClass IZone 2
EX oprotection conceptCSA E60079-6CAClass IZone 1
Ex pxprotection conceptCSA E60079-2CAClass IZone 1
Ex pyprotection conceptCSA E60079-2CAClass IZone 1
Ex pzprotection conceptCSA E60079-2CAClass IZone 2
Ex qprotection conceptCSA E60079-5CAClass IZone 1
Explosion-proof (XP)protection conceptEx d (Flameproof)Contain the explosion inside the enclosureIEC 60079-1
Explosion-proof (XP), intrinsically safe (IS)system attributeIEC-aligned types (Ex d, Ex i, Ex e, etc.)Protection concept
Group Asources differgas groupIICMESG <0.50 mm
Group Bgas groupIICHydrogen
Group Bgas groupIIC (partially IIB+H₂)MESG <0.50 mm
Group Csources differgas groupIIBMESG 0.50–0.90 mm
Group Dgas groupMethane (mining)
Group Dsources differgas groupIIAMESG >0.90 mm
Group Esources differdust groupCombustible Metal Dusts
Group Fdust groupCarbon dust
Group Gdust groupGrain / flour dust
Groups A, B, C, Dsystem attributeGroups IIC, IIB, IIAGas classification
Hermetically sealedprotection conceptEx nC / Ex mSeal ignition source from atmosphereIEC 60079-15 / -18
Intrinsically Safe (IS)protection conceptEx i (Ex ia, Ex ib)Limit energy below ignition thresholdIEC 60079-11
(IS)protection conceptC22.2 No. 157CAClass IDivision 1
(IS)protection conceptUL 913 / FM 3610USClass IDivision 1
(IS)protection conceptCSA C22.2 No. 157CAClass IIDivision 1
(IS)protection conceptUL 913 / FM 3610USClass IIDivision 1
(IS)protection conceptCSA C22.2 No. 157CAClass IIIDivision 1
(IS)protection conceptUL 913 / FM 3610USClass IIIDivision 1
NFPA 70 (adopted by AHJs)system attributeEU Directive 2014/34/EU / IECEx schemeLegal framework
(NI)protection conceptC22.2 No. 213CAClass IDivision 2
(NI)protection conceptNon-IncendiveISA 12.12.01/FM 3611USClass IDivision 2
(NI)protection conceptDust ProtectedISA 12.12.01 / FM 3611USClass IIDivision 2
Non-incendiveprotection conceptEx nA / Ex ecNormal operation cannot cause ignitionIEC 60079-15 / -7
NRTLs (UL, FM, CSA)system attributeNotified Bodies (ATEX) / ExCBs (IECEx)Certification body
Purged/Pressurizedprotection conceptEx p (Ex px, Ex py, Ex pz)Maintain positive pressure with inert gasIEC 60079-2
(PX)protection conceptNFPA 496CAClass IIDivision 1
(PX)protection conceptNFPA 496 (FM 3620)USClass IIDivision 1
(PY)protection conceptNFPA 496CAClass IIDivision 1
(PY)protection conceptUSClass II
(PZ)protection conceptNFPA 496CAClass IIDivision 2
(PZ)protection conceptNFPA 496 (FM 3620)USClass IIDivision 2
T1temperature codeT1Ignition temperature of gas / dust >450450
T2temperature codeT2Ignition temperature of gas / dust >300-450300
T2Atemperature codeIgnition temperature of gas / dust >280-300280
T2Btemperature codeIgnition temperature of gas / dust >260-280260
T2Ctemperature codeIgnition temperature of gas / dust >230-260230
T2Dtemperature codeIgnition temperature of gas / dust >215-230215
T3temperature codeT3Ignition temperature of gas / dust >200-300200
T3Atemperature codeIgnition temperature of gas / dust >180-200180
T3Btemperature codeIgnition temperature of gas / dust >165-180165
T3Ctemperature codeIgnition temperature of gas / dust >160-165160
T4temperature codeT4Ignition temperature of gas / dust >135-200135
T4Atemperature codeIgnition temperature of gas / dust >120-135120
T5temperature codeT5Ignition temperature of gas / dust >100-135100
T6temperature codeT6Ignition temperature of gas / dust >85-10085
Type Xprotection conceptCAClass I
Type Xprotection conceptNFPA 496 (FM 3620)USClass IDivision 1
Type Yprotection conceptNFPA 496CAClass IDivision 1
Type Yprotection conceptNFPA 496 (FM 3620)USClass IDivision 1
Type Zprotection conceptPressurizedNFPA 496CAClass IDivision 2
Type Zprotection conceptNFPA 496 (FM 3620)USClass IDivision 2
(XP)protection conceptC22.2 No. 30CAClass IDivision 1
(XP)protection conceptExplosion ProofUL 1203USClass IDivision 1

Where this came from

Every record above links the page it was taken from and quotes the sentence that states it. These are the 6 sources this dataset was assembled from.

Machine-readable

From your own code

Same records, same quotes, without scraping the page: refsource is on PyPI and npm. Each value comes back carrying the URL it was read from and the sentence on that page that states it — .source and .quote sit on the value itself rather than in a side channel, so the checking step is available instead of skipped.

pip install refsource
refsource lookup ex-classification-system-crosswalk category="system attribute"

npx -y refsource lookup ex-classification-system-crosswalk category="system attribute"

Set your AI assistant up to use this

Two files and no account. Put this in .mcp.json at the root of your project — Claude Code, Cursor, Windsurf, VS Code and Codex all read that file — and your assistant can look this dataset up instead of recalling it. The server is remote, keyless and read-only.

{
  "mcpServers": {
    "referencesource": {
      "type": "http",
      "url": "https://referencesource.org/mcp"
    }
  }
}

Add to Cursor · or, on the command line: claude mcp add --transport http referencesource https://referencesource.org/mcp --scope project

Then one line in the project's CLAUDE.md or AGENTS.md, so the assistant knows when to reach for it:

When a question needs "North American vs IEC/ATEX explosion protection designations", call the referencesource MCP server at https://referencesource.org/mcp (tool `search_records`, dataset_slug `ex-classification-system-crosswalk`) instead of answering from memory — every record it returns carries its source URL and a verbatim quote from that page.

What each tool does, and the servers built over single registers: Connect your AI assistant.

122 records. last verified against source . due for re-check by .

Licence. Facts extracted from freely published manufacturer and industry reference pages. Designation crosswalks are safety facts, not copyrightable expression. NFPA 70 and the IEC 60079 series are not reproduced and were not opened -- the fact is taken, never the document. Four separate publishers, no bulk take from any one.