Hazardous area (on account of explosive gas atmospheres) called “hazardous locations” in the US
An area (3-dimensional region or space) in which an explosive gas atmosphere is or may be
expected to be present, in quantities such as to require special precautions for the
construction, installation and use of equipment.
Hazardous areas are classified into 3 zones based upon the frequency of the occurrence and duration
of an explosive gas atmosphere, as follows:
Zone 0
Area in which an explosive gas atmosphere is present continuously or for long periods or frequently.
Zone 1
Area in which an explosive gas atmosphere is likely to occur in normal operation occasionally.
Zone 2
Area in which an explosive gas atmosphere is not likely to occur in normal operation but, if it does occur,
will persist for a short period only.
Non hazardous area (safe area )
A non hazardous area is an area in which an explosive atmosphere is not expected to be present.