A hazardous area is typically defined as a space in which an explosive atmosphere is present, or may be expected to be present.
IEC 60079-0 sets out the accepted explosion protection techniques, which are accepted in principle throughout the world.
The various protection techniques function in the following ways:
- Prevention of arcs, sparks and hot surfaces (Ex e, Ex nA)
- Containment of an explosion without external ignition (Ex d, Ex q, Ex nC)
- Limitation of the available energy (Ex i, Ex nL)
- Exclusion of the flammable material (Ex p, Ex nR, Ex m, Ex o, Ex t)