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 its buildings temporarily. Schools and state offices in the three communities remained closed the following day. First responders from as far away as Boston and Manchester, New Hampshire rushed to Lawrence, Andover, and North Andover as gas and electric lines were shut off to prevent further explosions. The NTSB also sent a team to investigate the situation the following day stating that they were going to look at the design of the pipeline system, maintenance associated with it, the emergency response, and the integrity management system of Columbia Gas. The gas company involved released several updates about the fires and