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Nonsparking tools: A misnomer



The nonsparking tools are frequently referred to as a panacea for all tool–job interactions taking place in an inflammable atmosphere, but an assurance of 100% sparkless operation cannot be insured by their presence alone. If the presence of a high-intensity spark in an inflammable medium is observed, a fire hazard is present. One part is the generation of the spark and other is its conversion to a full-fledged fire. The operating conditions, nature of the environment, interaction physics, and surface conditions play a vital role in achieving a sparkless situation. The conversion of a spark to a full-fledged fire requires evaluation of the spark intensity, heat content, temperature–surface area correlations, and ignition characteristics of the surrounding media. Nonsparking materials produce cold sparks with very little heat content, which cannot initiate a fire even in an atmosphere with very low ignition temperatures. Although several materials are branded as nonsparking, full characterization and detailed theoretical backing are missing. The operating conditions, unsafe working practices, runway speeds, accidental breakage, or fracture can produce adverse situations, which may lead to fire even with nonsparking materials. The so-called nonsparking tools are silent spectators to fire accidents and, in a true sense, they are only spark-reducing tools, wrongly called nonsparking in nature. © 2004 American Institute of Chemical Engineers Process Saf Prog 23: 62–64, 2004