Electrical equipment in hazardous areas the participation of operations, maintenance, safety, electrical and instrumentation professionals, the use of process diagrams and material flows, MSDS and any pertinent documents, information and knowledge to determine the hazards and their extent and the countermeasures to be employed. Area classification documentations are reviewed and updated to reflect process changes. Soon after the introduction of electric power into coal mines, it was discovered that lethal explosions could be initiated by electrical equipment such as lighting, signals, or motors. The hazard of fire damp or methane accumulation in mines was well known by the time electricity was introduced, along with the
Gas attacks at Hulluch from whence the gas was being discharged. After thirty minutes, groups of German infantry about equipped with pistols and hand grenades, were seen heading for gaps in the British wire and were repulsed by rifle and machine-gun fire. At about the three mines were sprung and another bombardment was fired, before sending another gas cloud, which caused many casualties to a Black Watch company, whose commander had ordered them to remove their gas helmets after the first gas cloud, under the impression that the helmets were useless after one exposure to gas. Behind the second gas cloud, larger parties of