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
Merrimack Valley gas explosions fires were reported over a very short period of time in the towns of Lawrence, Andover, and North Andover beginning about 4:15pm (EDT). Through the evening emergency crews responded to between 40 and 80 fires. At one time, as many as 18 fires were burning at once, and Andover officials struck a maximum 10-alarm response. Andover's fire chief described "billows of smoke coming from Lawrence behind me, I could see plumes of smoke in front of me within the town of Andover, it just looked like an absolute war zone." A Lawrence resident described finding his boiler on fire after