Ga, Gb, Gc are protection levels for equipment used in explosive gas environments and are essential components of explosion-proof equipment labeling.

The equipment used in explosive gas environments has a "very high" level of protection. In normal operation, expected or rare faults that occur are not ignition sources. Ga protection level devices can be used for Zone 0, Zone 1, and Zone 2

※ Gb explosive gas environment equipment has a "high" protection level. It is not an ignition source under normal operation or expected fault conditions. Gb protection level can be used for Zone 1 and Zone 2.

Equipment for explosive gas environments in Gc has a "general" protection level. In normal operation, if it is not the ignition source, additional protective measures can be taken to ensure that effective ignition will not occur in situations where the ignition source is expected to frequently occur (such as lamp failure). Equipment with Gc protection level can use Zone 2.

As is well known, the most dangerous area in Zone 0 can only adopt the equipment protection level of Ga, therefore, the equipment protection level of Ga is higher than that of Gb.