Gas & Dust Groups
zone | Concept | Type Of Protection | Symbol |
| zone 0,1,2 | No spark or no thermal effect due to the choice of components and the limitation of energy,taking into account 2 fault | i: intrinsic safety | Exi |
| zone 1 & 2 | All components encapsulated in resin | Ma: encapsulation | Exm |
| zone 1 & 2 | Enclosure which can withstand an explosion and prevent its propagation | d: flameproof enclosure | Exd |
| zone 1 & 2 | Enclosure in which there is no spark or no hot surface in normal opration | e: increasedd safety | Exe |
| zone 1 & 2 | Compnents protected by an enclosure full of oil | o: oil immersion | Exo |
| zone 1 & 2 | Components protected by an enclosure which is pressurized with a protective gas at a higher pressure than the atmosphere | p: pressurization | Exp |
| zone 1 & 2 | All components protected by an enclosure full of filling material | q: power filling | Exq |
| zone 2 | Only used for equipments installed in places where no explosive atomosphere is pesent, or is present for short time | nA nR | Exn |
