Hazardous areas vs Ex

A hazardous area is an area (three-dimensional space) in which a flammable atmosphere is or may be expected to be present, and require special precautions for the construction, installation and use of equipment. Examples of hazardous areas are:
– flammable liquid and gas storage tanks and associated equipment (e.g. release points such as vents, fill points, dip points, safety relief devices)
– flammable liquid and gas dispensing equipment (e.g. service stations, depots and airports, LP gas filling stations)
– storage areas for flammable liquids in packages (e.g. warehouses, store rooms, workshops)
– storage areas for flammable gases in cylinders
– mixing and blending vessels for flammable product formulations road and rail tanker loading facilities for flammable liquids and gases
– fume cupboards used for flammable liquids and gases
– laboratory areas where flammable liquids are used and stored

– spray painting booths used for flammable paints and lacquers
– landfill gas (e.g. methane), sewage treatment and sewage pumping plants
– flammable solvent printing processes
– accidental puncturing and spilling contents of containers containing flammable liquids
– application of flammable sealants and adhesives in enclosed areas
– areas around activities generating fine dusts of combustible material (sugar, grain, polymers, dry organic residues)
– and many more…
Recent statistics show the most developing industrial area is the Ex one…
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Never accept only a 2D plan about hazardous area classification (HAC), pls ask for detailed description of HAC and 3D if possible.