Oil & Gas: Hazardous Area Classification

The oil and gas industry is hazardous as it is prone to explosions that occur in the presence of 3 substances: flammable gas or dust, oxygen, and an ignition source. Hence, to prevent explosions from occurring, we need to ensure that these 3 substances are not present at the same time. Conversely, as both flammable gas and dust are indispensable in the oil and gas industry, and oxygen is a necessity, the determining factor lies in the prevention of ignition sources.

There are different types of hazardous areas and they are classified into zones based on their risk factors. Here we introduce the 3 different zones: Zone 0, Zone 1, and Zone 2.
What are the different zones?

The hazardous areas are classified into zones based on their likelihood and duration of occurrence of an explosive atmosphere.

The zones are:

Zone 0: Explosive gas-air mixture is continuously present, or present for long periods.
Zone 1: Explosive gas-air mixture is likely to be present in normal operation.
Zone 2: Explosive gas-air mixture is not likely to be present, or present for short periods.

The different zones require dissimilar protection measures in terms of enclosure type, whereas Zone 0 requires Ex 'd' protection, and Zones 1 and 2 require Ex 'e' protection.
Oil & Gas cables are structurally designed to fit their respective zones.