| Publisher | IEC |
|---|---|
| Type | Standard (multi-part international series) |
| Scope | Requirements for the classification of explosive atmospheres and for the design, testing, selection, installation, inspection and repair of equipment used in them. |
| Who uses it | Instrument and electrical engineers, Ex inspectors, technicians, equipment manufacturers, certification bodies and operators in oil and gas, chemicals, pharmaceuticals, mining and other process industries. |
| Edition note | Each part of the series has its own edition. Refer to the publisher for the current edition of each part. |
What It Is
IEC 60079 is a large family of international standards covering equipment and installations in explosive atmospheres caused by flammable gases, vapors, mists and combustible dusts. IEC 60079-0 sets general requirements for Ex equipment. Individual parts then define specific protection concepts, such as flameproof enclosures (part 1), pressurization (part 2), increased safety (part 7), intrinsic safety (part 11) and encapsulation (part 18). Parts 10-1 and 10-2 address area classification for gases and dusts.
Other parts address the full life cycle of an installation. IEC 60079-14 covers design, selection and erection of electrical installations, IEC 60079-17 covers inspection and maintenance, and IEC 60079-19 covers repair, overhaul and reclamation of Ex equipment. The series has also absorbed former stand-alone standards; for example, combustible dust content that once sat in IEC 61241 and gas detector performance content that once sat in IEC 61779 are now within the 60079 family.
Why It Matters
An explosion in a refinery, chemical plant, grain facility or mine can kill workers and destroy assets. The IEC 60079 approach reduces that risk by matching the protection built into equipment to the likelihood that an explosive atmosphere is present, and by ensuring installations are correctly built, inspected and maintained over their life.
The series is the technical basis of the IECEx certification system and of the harmonized European standards used for ATEX conformity. In the United States, many parts have been adopted as UL or ISA versions for use with the zone system in NEC Article 505. Engineers working on international projects are expected to be fluent in its terminology and marking.
Key Concepts
- Zones — gas areas are classified as Zone 0, 1 or 2 and dust areas as Zone 20, 21 or 22, according to how frequently and how long an explosive atmosphere is likely to be present.
- Equipment protection level (EPL) — a rating of equipment's level of protection against becoming an ignition source, for example Ga, Gb and Gc for gas and Da, Db and Dc for dust.
- Protection concepts — techniques such as flameproof (d), increased safety (e), intrinsic safety (i), pressurization (p), encapsulation (m), powder filling (q), liquid immersion (o) and dust protection by enclosure (t).
- Equipment groups — Group I for mines susceptible to firedamp, Group II for explosive gas atmospheres (subdivided IIA, IIB, IIC) and Group III for dusts (IIIA, IIIB, IIIC).
- Temperature class — a T1 to T6 rating that limits the maximum surface temperature of equipment so it stays below the ignition temperature of the gas or vapor present.
- Ex marking — a coded marking on equipment that communicates protection concept, group, temperature class and EPL for verification during selection and inspection.
- Inspection grades — IEC 60079-17 describes visual, close and detailed inspections and initial, periodic and sample inspection regimes.
Who Should Know It
- Electrical and instrument engineers designing hazardous area installations
- Ex inspectors and technicians installing and maintaining equipment
- Process safety engineers performing area classification
- Equipment manufacturers and certification personnel
- Operations and maintenance managers at process facilities
Related Standards
- IECEx & ATEX — certification and legal frameworks that rely on IEC 60079 as the technical basis.
- NEC Articles 500-506 — the US hazardous location rules; Article 505 and 506 use the zone approach aligned with IEC 60079.
- IEC 60529 — the IP code is used alongside Ex requirements, especially for dust protection and enclosures.
- IEC 61508 — relevant where Ex equipment or gas detection forms part of a safety-related system.
How ASEEE Uses It
ASEEE hazardous area programs map learning outcomes and assessments to the IEC 60079 series, covering area classification, protection concepts, equipment selection and marking, installation and inspection. See related ASEEE programs.
ASEEE Programs Referencing This Standard
- CompEx Ex01–Ex04 Gas and Vapor Competency
- CompEx Ex01–Ex04 Hazardous Area Inspection & Installation
- EX1: Explosion Protection and Electrical Installation in Hazardous Areas
- Explosion Protection Instructor: Design, Installation and Maintenance
- Explosion-Proof (EX) Inspection, Installation and Maintenance, Levels 1 & 2
- Fixed Gas Detection Systems (FGDS)
- Hazardous Area Classification and Zone Determination
- Intelligent Gas Sensors for MSA & Detcon Systems
Educational summary only. ASEEE is not the publisher of this document and this page does not reproduce or replace it. Always consult the current official edition from IEC for requirements.