One of the most frequent questions engineers ask before inspecting Ex-Proof / ATEX & IECEx Hazardous Area Electrical Inspection is: "Which standard should I cite on the certificate, and where do the pass/fail limits come from?" This reference guide maps IEC 60079-14 / IEC 60079-17 to national regulatory adoptions and provides the complete standard annex tables.
1. National & Regional Standard Equivalence Matrix
| Region / Language | Adopted National Standard & Regulatory Code |
|---|---|
| International / UK (EN) | IEC 60079-14 / IEC 60079-17 |
| Turkey (TR · Türkçe) | TS EN 60079-14 / TS EN 60079-17 / ÇSGB Patlayıcı Ortam Yön. |
| Germany / DACH (DE · Deutsch) | DIN EN 60079-14 / 60079-17 (VDE 0165) / BetrSichV |
| France (FR · Français) | NF EN 60079-14 / 60079-17 / Directive ATEX 1999/92/CE |
| Spain (ES · Español) | UNE-EN 60079-14 / REBT ITC-BT-29 / RD 681/2003 |
| Italy (IT · Italiano) | CEI EN 60079-14 / 60079-17 (CEI 31-33) / D.Lgs 81/08 Tit. XI |
| Gulf / Middle East (AR · العربية) | IEC 60079-14 / IEC 60079-17 / SASO / DEWA / ADDC |
2. Normative Acceptance Criteria & Mathematical Basis
Deterministic ATEX (2014/34/EU) & IEC 60079-14 / 60079-17 compliance engine: verifies Equipment Protection Level (EPL Ga/Gb/Gc & Da/Db/Dc) against Hazardous Zone (0/1/2 & 20/21/22), Gas/Dust Group hierarchy (IIC > IIB > IIA), Temperature Class (T1-T6) vs Auto-Ignition Temperature (AIT), Intrinsic Safety (Ex i) loop parameters (Uo <= Ui, C_cable <= Co), and Ex e motor tE time.
T_surface_max: T_class_max <= T_AIT (Gas) | T_surface <= (2/3) x T_cloud (Dust) — Maximum equipment surface temperature must not exceed the auto-ignition temperature of the explosive atmosphere (IEC 60079-14 §5.6).
Ex_i Loop: Uo <= Ui, Io <= Ii, Po <= Pi, (Ci + C_cable) <= Co, (Li + L_cable) <= Lo — Intrinsic Safety (Ex ia / Ex ib) entity parameter verification between safety barrier and field instrument (IEC 60079-14 §16.2).
3. Official Standard Reference Tables
IEC 60079-14 Table 1 & Table 2: Hazardous Zone, EPL, Gas Group & Temperature Class Matrix (IEC 60079-14 / ATEX Directive 2014/34/EU)
| Hazardous Zone | Permitted EPLs | Typical Protection Concepts (Ex) | Gas / Dust Group Hierarchy |
|---|---|---|---|
| Zone 0 (Gas continuous) | Ga only | Ex ia, Ex ma, Ex da | IIC covers IIB & IIA | IIB covers IIA |
| Zone 1 (Gas intermittent) | Ga or Gb | Ex d (Flameproof), Ex e (Increased Safety), Ex ib, Ex px, Ex mb, Ex q | IIC (H2, C2H2) > IIB (C2H4) > IIA (Propane, CH4) |
| Zone 2 (Gas abnormal) | Ga, Gb, or Gc | Ex ec, Ex nA, Ex nR, Ex ic, Ex pz (plus all Zone 0/1 types) | IIC > IIB > IIA |
| Zone 20 (Dust continuous) | Da only | Ex ta, Ex iaD, Ex maD | IIIC (Conductive dust) covers IIIB & IIIA |
| Zone 21 (Dust intermittent) | Da or Db | Ex tb, Ex ibD, Ex mbD, Ex pxD | IIIB (Non-conductive dust) covers IIIA (Flyings) |
| Zone 22 (Dust abnormal) | Da, Db, or Dc | Ex tc, Ex icD, Ex pzD | IIIC > IIIB > IIIA |
IEC 60079-0 Temperature Classes (T1 - T6) for Group II Electrical Equipment (IEC 60079-0 §5.3.2.2)
| Temperature Class | Max Surface Temp (°C) | Permitted if Gas AIT > | Typical Representative Gases / Vapours |
|---|---|---|---|
| T1 | 450 °C | > 450 °C | Hydrogen (560°C), Methane (537°C), Ammonia (630°C), Propane (470°C) |
| T2 | 300 °C | > 300 °C | Acetylene (305°C), Ethylene (425°C), Ethanol (363°C), n-Butane (365°C) |
| T3 | 200 °C | > 200 °C | Petrol / Gasoline (220-280°C), Diesel / Jet Fuel (210°C), Hydrogen Sulphide (260°C) |
| T4 | 135 °C | > 135 °C | Acetaldehyde (140°C), Diethyl Ether (160°C) |
| T5 | 100 °C | > 100 °C | Special reactive chemical intermediates |
| T6 | 85 °C | > 85 °C | Carbon Disulphide CS2 (95°C), Ethyl Nitrite (90°C) |