| Group | Ex Risk | Zone | EPL | Minimum type of Protection |
| I (mines) | energized | Ma | ||
| II (gas) | explosive atmosphere > 1000 hrs/yr | 0 | Ga | ia, ma |
| II (gas) | explosive atmosphere between 10 and 1000 hrs/yr | 1 | Gb | ib, mb, px, py, d, e, o, q, s |
| II (gas) | explosive atmosphere between 1 and 10 hrs/yr | 2 | Gc | n, ic, pz |
| III (dust) | explosive surface > 1000 hrs/yr | 20 | Da | ia |
| III (dust) | explosive surface between 10 and 1000 hrs/yr | 21 | Db | ib |
| III (dust) | explosive surface between 1 and 10 hrs/yr | 22 | Dc | ic |
