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
2008 Chelopechene explosions to close down as broken glass was reported at Terminal One and some debris landed on the runways. All flights were redirected to Plovdiv International Airport, about 160 kilometers east of Sofia. By Sunday, June 6 there were already rumours circulating that the explosions were intentionally caused. Defence Minister Nikolai Tsonev said that a fire (such as the one that caused the explosions) could not have accidentally occurred, and if it had indeed been an accident, that "whole blocks of flats would have been toppled". Instead, it was carefully engineered to spare casualties, Tsonev told reporters. He said that information