A hazardous area can be defined as any location where there is risk of an explosion. But every hazardous area is different and each has specific requirements depending on the nature of the atmosphere and the elements that are present. Where there is potential for an explosive atmosphere, special precautions are needed to prevent fires and explosions. Electronic equipment, including lighting, needs to be purpose designed for use in hazardous areas to prevent a spark occurring and igniting any flammable substances.
The majority of powders that are used in the processing industries are combustible (also referred to as flammable, explosible). An explosion will occur if the concentration of the combustible dust that is suspended in air is sufficient to propagate flame when ignited by a sufficiently energetic ignition source. A systematic approach to identifying dust cloud explosion safety against their consequences generally involves:
Electrostatic charging can occur when solids or liquids move relative to the plant they are contained in or charged by induction. Electrostatic charging therefore occurs frequently in industrial process plant.
If charge is allowed to accumulate and discharge, an electrostatic hazard may arise. A static related incident can cause a serious fire or explosion. These incidents can cause significant loss of life and plant followed by legal action and associated bad publicity.
Any process plant that handles or processes flammable liquids, dusts, gases or vapours is at risk from electrostatic induced ignition.