What is IEC 60079-10-1? Area Classification in Explosive Gas Atmospheres.
Short answer: IEC 60079-10-1, explosives gas/vapor It defines the classification of areas in environments as 'zones'. Zones are separated into Zone 0, Zone 1, and Zone 2 according to the frequency and duration of hazardous atmosphere occurrences; this classification is the first and most critical step in determining what equipment can be placed there.
The foundation of explosive atmosphere safety is accurate area classification. Before deciding which equipment should be placed where, it is necessary to know how often and for how long an explosive atmosphere may be present at each point. IEC 60079-10-1 does this using a systematic method: it identifies leakage sources, assesses ventilation, and ultimately creates a 'zone map' of the facility.
Three Hazard Zones
| Area | Explosive atmosphere | Example |
|---|---|---|
| Zone 0 | Continuous or long-term presence | Gas phase inside the tank |
| Zone 1 | It occurs from time to time during normal operation. | Filling/emptying points |
| Zone 2 | It doesn't normally occur, and if it does, it's short-lived. | Flange/connection rings |
What criteria are used for classification?
Region assignment is done by evaluating three main factors. Release source: Where and how frequently might the gas leak (continuous, primary, secondary leakage). Ventilation: The degree and availability of natural or forced ventilation — good ventilation reduces the size of the area. Gas characteristics: Density, lower explosion limit (LEL), and propagation behavior. These factors are combined to calculate the size and type of hazardous area for each leakage source.
Why is this so critical?
Incorrect area classification is harmful in two ways: considering the area safer than it is opens the door to a deadly explosion; considering it more dangerous than it is leads to unnecessarily expensive Ex equipment and operating costs. Correct classification ensures both safety and economy, and Explosion Protection Document (EPD) It forms the basis of the AES system. AES assesses area classification and then equipment suitability together.
Frequently Asked Questions
How do Zone and EPL match?
Zone 0 requires equipment with at least a Ga protection level (EPL), Zone 1 requires at least a Gb, and Zone 2 requires at least a Gc protection level (EPL). The classification directly determines equipment selection.
When should area classification be updated?
It should be updated when processes, equipment, or ventilation change, and during periodic reviews; it is not a static document.
Create an accurate Explosive Atmosphere Map of Your Facility.
Related service: Explosive Atmosphere (ATEX/Ex-Proof) Inspections.