EN 60079 is an extensive series of standards governing electrical equipment for use in explosive atmospheres. It is the technical basis of the ATEX Directive (2014/34/EU) and defines how equipment must be designed, installed and inspected so that it cannot become a source of ignition.
Zone classification
| Zone | Medium | Frequency |
|---|---|---|
| Zone 0 | Gas or vapour | Present continuously or for long periods |
| Zone 1 | Gas or vapour | Likely occasionally in normal operation |
| Zone 2 | Gas or vapour | Unlikely, and only briefly |
| Zone 20 | Dust | Present continuously or for long periods |
| Zone 21 | Dust | Likely occasionally |
| Zone 22 | Dust | Unlikely |
Equipment groups
- Group I
- Mining — underground workings where methane is present
- Group II
- Surface industry — gases and vapours (IIA, IIB, IIC)
- Group III
- Surface industry — dusts (IIIA, IIIB, IIIC)
For PPE the system has two practical consequences: clothing must be antistatic (EN 1149-5) and gloves must conform to EN 16350. Equipment — torches, radios, instruments — must be ATEX certified for the zone it enters.