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 back the expected completion date to December 16. Replacement of gas mains was proceeding ahead of schedule, but some older houses were unable to accommodate newer appliances and required more work to upgrade them to current standards. Merrimack Valley gas explosions On September 13, 2018, excessive pressure in natural gas lines owned by Columbia Gas caused a series of explosions and fires occurred in as many as 40 homes, with over 80 individual fires, in the Merrimack Valley, Massachusetts towns of Lawrence, Andover, and North Andover. One person was killed and 30,000 were forced to evacuate their homes. According to