Classified Location Determination
| Jurisdiction | Source of Hazard | Continuous Hazard | Intermittent Hazard | Accidental Hazard | Standard |
| IEC / EC | Gas | Zone 0 | Zone 1 | Zone 2 | IEC 60079 |
| USA – NEC 505 | Gas | Zone 0 | Zone 1 | Zone 2 | NEC 505 |
| Canada | Gas | Zone 0 | Zone 1 | Zone 2 | CEC 18 |
| IEC / EC | Dust | Zone 20 | Zone 21 | Zone 22 | IEC 61241 |
| USA – NEC 506 | Dust | Zone 20 | Zone 21 | Zone 22 | NEC 506 |
| USA – NEC 500 | Gas, Dust, | Division 1 | Division 1 | Division 2 | NEC 500 |
| Canada | Fibres & Flyings | Division 1 | Division 1 | Division 2 | CEC 18 |
Gas Hazard Classifications
| Representative Gas | IEC / EC | USA NEC 505 / Canada CEC 18 | USA NEC 500 / Canada CEC Annex J |
| Acetylene | Group IIC | Group IIC | Class I, Group A |
| Hydrogen | Group IIB+H2 | Group IIB+H2 | Class I, Group B |
| Ethylene | Group IIB | Group IIB | Class I, Group C |
| Propane | Group IIA | Group IIA | Class I, Group D |
| Methane | Group I* | Mining* | Mining* |
| *Not within the scope of NEC 500 & 505—under jurisdiction of MSHA. Not within the scope of CEC 18. | |||
Dust Hazard Classifications
| Material | IEC / EC 60079 | IEC / EC 61241 | USA NEC 506 | USA NEC 500 / Canda CEC 18 |
| Metal Dusts | Group IIIC | Group D | – | Class II, Group E |
| Carbonaceous Dusts | Group IIIB | Group D | Group D | Class II, Group F |
| Non-Conductive Dusts | Group IIIB | Group D | Group D | Class II, Group G |
| Fibers & Flyings | Group IIIA | Group D | Group D | Class III |
Protection Methods – USA Under NEC 500
| Method | Basis | Standard | Division 1 | Division 2 |
| Intrinsic Safety | Energy limiting | FM 3610 / ISA12.02.01 | Yes | Yes |
| Non-Incendive | Energy limiting, mechanical seal | FM 3611 | No | Yes |
| Exlosion Proof | Containment | FM 3615 | Yes | Yes |
| Pressurization ‘X’ | Exclusion | FM3620 | Yes | Yes |
| Pressurization ‘Y’ | Exclusion | FM3620 | Yes | Yes |
| Pressurization ‘Z’ | Exclusion | FM3620 | No | Yes |
Protection Methods, Gas Hazards – USA Under NEC 505 / IEC / EU
| Method | Symbol | Basis | Standard | Zone 0 | Zone 1 | Zone 2 |
| Intrinsic Safety | ia | Limit spark energy and surface temperatures | 60079-11 | Yes | Yes | Yes |
| Intrinsic Safety | ib | Limit spark energy and surface temperatures | 60079-11 | No | Yes | Yes |
| Intrinsic Safety | ic | Limit spark energy and surface temperatures | 60079-11 | No | No | Yes |
| Energy Limitation | nL | Limit spark energy and surface temperatures | 60079-15 | No | No | Yes |
| Increased Safety | e | No arcs, sparks, or hot surfaces | 60079-7 | No | Yes | Yes |
| Non Sparking | nA | No arcs, sparks, or hot surfaces | 60079-15 | No | No | Yes |
| Flameproof | d | Contain the explosion, quench the flame | 60079-1 | No | Yes | Yes |
| Enclosed Break | nC | Contain the explosion, quench the flame | 60079-15 | No | No | Yes |
| Sand Filling | q | Quench the flame | 60079-5 | No | Yes | Yes |
| Pressurization | px | Exclude the flammable gas | 60079-2 | No | Yes | Yes |
| Pressurization | py | Exclude the flammable gas | 60079-2 | No | Yes | Yes |
| Pressurization | pz | Exclude the flammable gas | 60079-2 | No | No | Yes |
| Simple Pressurization | nZ | Exclude the flammable gas | 60079-15 | No | No | Yes |
| Sealing | nC | Exclude the flammable gas | 60079-15 | No | No | Yes |
| Restricted Breathing | nR | Exclude the flammable gas | 60079-15 | No | No | Yes |
| Encapsulation | ma | Exclude the flammable gas | 60079-18 | Yes | Yes | Yes |
| Encapsulation | mb | Exclude the flammable gas | 60079-18 | No | Yes | Yes |
| Oil Immersion | o | Exclude the flammable gas | 60079-6 | No | Yes | Yes |
Ingress Protection Codes to IEC 60529
| First Numeral: | Second Numeral: | ||
| Protection against solid objects | Protection against liquids | ||
| 0 | No special protection | 0 | No special protection |
| 1 | Objects >50mm diameter, e.g. hand | 1 | Vertically dripping water |
| 2 | Objects >12.5mm diameter, e.g. finger | 2 | Dripping water when tilted up to 15° |
| 3 | Objects >2.5mm diameter, e.g. tool | 3 | Sprayed water up to 60° from vertical |
| 4 | Objects >1.0mm diameter, e.g. wire | 4 | Splashed water from any direction |
| 5 | Dust protected. Ingress insufficient to prevent satisfactory operation | 5 | Water projected by 6.3mm nozzle from any direction: 12.5 L/min, 100kPa, 3 min. |
| 6 | Dust tight, no ingress permitted | 6 | Water projected by 12.5mm nozzle from any direction: 100 L/min, 100kPa, 3 min. |
| 7 | Temporary submersion up to 1 meter | ||
| 8 | Continuous submersion to a stated depth | ||
