| Level of protection | EPL | ATEX Category | Zones of use ** |
| Ia | Ga | 1G | Zones 0,1 & 2 |
| Ib | Gb | 2G | Zones 1 and 2 |
| Ic | Gc | 3G | Zone 2 only |
** Unless a risk assessment, taking into account the possible consequences of an explosion, has called for the use of a higher or lower level of protection.
Level of protection ‘ia’
‘ia’ has the highest integrity, and must remain incapable of causing ignition in normal operation with maximum rated voltage applied, even with two ‘countable’ faults, as defined in the standards.
‘ia’ may be used in locations requiring EPL Ga, Gb & Gc (Cat’s 1G, 2G, & 3G).
Level of protection ‘ib’
‘ib’ must remain incapable of causing ignition in normal operation with maximum rated voltage applied, even with one ‘countable’ faults, as defined in the standards.
‘ib’ equipment may be used in locations requiring EPL’s Gb & Gc (Cat’s 2G, & 3G).
Level of protection ‘ic’
‘ic’ must remain incapable of causing ignition in normal operation with maximum rated voltage applied
‘ic’ equipment may only be used in locations requiring EPL “Gc” / Category 3.
