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
Fire rock air and gas to funnel the flame through. Fire rocks come in many different colors and range in sizes from a half-inch to an inch. Fire rock is noted for its ability to withstand high temperatures of direct heat for prolonged periods of time. Unlike river rock, which is non-porous and highly explosive when heated, fire rock is considered a porous substance that is capable of releasing heat through tiny holes in its outer layer. Damp fire rocks have been known to "pop" and throw pea sized pieces of rock as they heat. The moisture that is caught in the