Hazardous Area Guide for ATEX & IECEx
The Hazardous Area Guide for ATEX & IECEx is your go-to resource for understanding and navigating the complexities of hazardous area classifications. This guide covers critical aspects of ATEX and IECEx standards, detailing the Zones and Groups that define explosive atmospheres. Whether you’re responsible for safety compliance or managing facilities in hazardous locations, this guide provides essential insights and the latest regulatory information to help you maintain safe and compliant operations.
Typical Equipment Marking for Gas Atmospheres
Typical Equipment Marking for Dust Atmospheres
Gas Zones
| Gas Zones | Definition | ATEX Category | EPL | Required Protection |
|---|---|---|---|---|
| Methane | Mines with methane and dust. Equipment remains energised in explosive atmosphere. | M1 | Ma | Two Faults |
| Methane | Mines with methane and dust. Equipment is de-energised in explosive atmosphere. | M2 | Mb | Severe Normal Operation |
| Zone 0 | Explosive atmosphere present continuously or for long periods, frequently. | 1G | Ga | Two Faults |
| Zone 1 | Explosive atmosphere is likely to occur under normal conditions, occasionally. | 2G | Gb | One Fault |
| Zone 2 | Explosive atmosphere is unlikely to occur under normal conditions, short periods. | 3G | Gc | Normal Operation |
Dust Zones
| Dust Zones | Definition | ATEX Category | EPL | Required Protection |
|---|---|---|---|---|
| Zone 20 | Explosive atmosphere present continuously or for long periods, frequently. | 1D | Da | Two Faults |
| Zone 21 | Explosive atmosphere is likely to occur under normal conditions, occasionally. | 2D | Db | One Faults |
| Zone 22 | Explosive atmosphere is unlikely to occur under normal conditions, short periods. | 3D | Dc | Normal Operation |
Zones of Use
Explosive Atmospheres
Enclosure Ingress Protection (IP) Level
| Enclosure Ingress Protection (IP) Level: To EN/IEC 60529 | |||
|---|---|---|---|
| First Number (Solid objects / dust) | Second Number (Water) | ||
| 0 | No protection | 0 | No protection |
| 1 | Objects > Ø50 mm | 1 | Vertically dripping water |
| 2 | Objects > Ø12.5 mm | 2 | Vertically dripping water with enclosure tilted by 15° |
| 3 | Objects > Ø2.5 mm | 3 | Sprayed water up to 60° from the vertical |
| 4 | Objects > Ø1.0 mm | 4 | Sprayed water from all directions |
| 5 | Dust protected | 5 | Water jets |
| 6 | Dust tight | 6 | Powered water jets |
| - | - | 7 | Temporary submersion less than 1m depth |
| - | - | 8 | Extended submersion greater than 1m depth |
Ambient Temperature Range (Tamb)
Tamb = Temperature relating to the immediate surroundings of the equipment (assumed to be -20°C to +40°C, unless stated).
Protection Concept – Electrical – Gas
| Type of Protection (electrical - gas) | Reference |
|---|---|
| General Requirements | EN/IEC 60079-0 |
| Flameproof - Ex d / da / db / dc | EN/IEC 60079-1 |
| Purge/Pressurised - Ex p / pxb / pyb / pzc | IEC 60079-2 |
| Quartz/Sand Filled - Ex q / qb / qc | EN/IEC 60079-5 |
| Oil Immersion - Ex o / ob / oc | EN/IEC 60079-6 |
| Increased Safety - Ex e / eb / ec | EN/IEC 60079-7 |
| Intrinsic Safety - Ex i / ia / ib / ic | EN/IEC 60079-11 |
| Non Sparking - Ex nA / nC / nL | EN/IEC 60079-15 |
| Encapsulation - Ex m / ma / mb / mc | EN/IEC 60079-18 |
| Optical Radiation - Ex op is / op sh / op pr | EN/IEC 60079-28 |
| Trace Heating Systems - Ex e / Ex 60079-30-1 | EN/IEC 60079-30-1 |
| Special Protection Ex s | EN/IEC 60079-33 |
| Caplights | EN/IEC 60079-35-1 |
| Controlled Spark Duration Power-i | TS 60079-39 |
| Process Sealing | TS 60079-40 |
| Flame Arresters | EN 16852 |
| Diesel Engines | EN 1834-1,2,3 |
Protection Concept – Electrical – Dust
| Type of Protection (electrical - dust) | Reference |
|---|---|
| General Requirements | EN/IEC 60079-0 |
| Enclosure - ta / tb / tc | EN/IEC 60079-31 |
| Purge/Pressurised - Ex p / pxb / pyb / pzc | IEC 60079-2 |
| Intrinsic Safety - Ex i / ia / ib / ic | EN/IEC 60079-11 |
| Encapsulation - Ex m / ma / mb / mc | EN/IEC 60079-18 |
Protection Concept – Non-Electrical
| Type of Protection (non-electrical) (gas & dust) | Reference (ATEX only) | IECEx |
|---|---|---|
| General Requirements | EN 80079-36 | IEC / ISO 80079-36 |
| Flow Restricting Enclosure - fr | EN 13463-2 | - |
| Flameproof - d | EN 13463-3 | - |
| Constructional Safety - c / h | EN 80079-37 | IEC / ISO 80079-37 |
| Control of Ignition - b / h | EN 80079-37 | IEC / ISO 80079-37 |
| Pressurisation - p | EN 60079-2 | - |
| Liquid Immersion - k / h | EN 80079-37 | IEC / ISO 80079-37 |
Gas Groups
| Gas Groups | Gasses are classified according to the ignitability of the gas/air mixture as defined in EN/IEC 60079-20-1 |
|---|---|
| IIA | Acetic Acid, Acetone, Ammonia, Butane, Cyclohexane, Propane, Gasoline (petrol), Methane (natural gas, non-mining), Toluene, Xylene. Methanol (methyl alcohol), Propane-2-ol (iso-propyl alcohol) |
| IIB | Group IIA gases plus, Di-ethyl ether, Ethylene, Ethanol Methyl ethyl ketone (MEK), Propane-1-ol (n-propyl alcohol) |
| IIC | Group IIA and IIB gases plus, Acetylene, Hydrogen |
Dust Groups
| Dust Groups | Dusts are classified by the types of material that make up the dust |
|---|---|
| IIIA | Combustible Fibres and Flyings |
| IIIB | Group IIIA dusts plus, Non-Conductive Dusts |
| IIIC | Group IIIA and IIIB dusts plus, Conductive Dusts |
Equipment Groups
| Equipment Group | Definition |
|---|---|
| Group I | Electrical equipment intended for use in mines susceptible to fire damp |
| Group II | Electrical equipment intended for use in explosive gas atmospheres |
| Group III | Electrical equipment intended for use in explosive dust atmosphere |
Temperature Class (T Class)
| Temperature Class (T Class) | Highest temperature achieved under the most adverse equipment rating and heating conditions. (Flashpoint temperature of some gases) |
|---|---|
| T1: 450°C | Ammonia (630°C), Hydrogen (560°C), Methane (537°C), Propane (470°C) |
| T2: 300°C | Ethylene (425°C), Butane (372°C), Acetylene (305°C) |
| T3: 200°C | Cyclohexane (259°C), Kerosene (210°C) |
| T4: 135°C | Di-ethyl Ether (160°C) |
| T5: 100°C | - |
| T6: 85°C | Carbon Disulphate (95°C) |
DISCLAIMER – this service is provided without warranty or claim of fitness for any purpose. Triple i takes no responsibility for the accuracy of the figures provided and customers should use this service at their own risk.