Ignitible fibers and flyings that may be ignited by electrical equipment and wiring are possible fire hazards. Where they are hazards, the areas are classified as Class III areas. Fibers and flyings are quite large compared to combustible dusts or flammable gases or vapors, so excluding them from the interiors of electrical equipment enclosures is relatively easy. Nevertheless, the fibers and flyings must be isolated from ignition sources, including hot surfaces of electrical equipment.
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