Area in which an explosive atmosphere is present, or may be expected to be present in quantities such as to require special precautions for the construction, installation and use of equipment.
Safety 2 Safety S2S - A Gateway for Plant and Process Safety, The European Web Portal for Process Safety, USA 2003. http://www.safety-s2s.eu/modules.php?name=s2s_wp4& idpart=4&op=v&letter=all, (IndS - Amer) {458}