.-(1) A hazardous area shall be deemed to be-(i)a zone "0" area, if inflammable gases or vapours are expected to be continuously present in the area; or(ii)a zone "1" area, if inflammable gases or vapours are likely to be present in the area under normal operating conditions; or(iii)a zone "2" area, if inflammable gases or vapours are likely to be present in the area only under abnormal operating conditions or failure or rupture of an equipment.(2)If any question arises as to whether hazardous area is a zone "0" area or a zone "1" or a zone "2" area, the decisions thereon of the Chief Controller shall be final.
