What is the minimum elevation above the floor surface for ignition sources located in hazardous locations?

The minimum elevation above the floor surface for ignition sources located in hazardous locations is 18 inches. This guideline is set to ensure that potential ignition sources are positioned above the reach of typical flammable vapors, which can accumulate closer to the ground due to their density. By maintaining an elevation at least 18 inches above the floor, the risk of accidental ignition from sources such as electrical equipment or open flames is significantly reduced in environments that may contain combustible or explosive substances. This requirement is critical in maintaining safety standards in industrial and commercial settings where hazardous materials are present, helping to prevent fires or explosions that could result from such ignition sources coming into contact with flammable vapors or dust. The prescribed height is a standard practiced across various codes and regulations, emphasizing the importance of safety in managing hazardous conditions.