referred to , extinguished, flash point, vapors, propagate, enclosure, flammable materials, Hazardous locations are areas where f l ammable liquids, gases, or or combustible dusts exist in suf fi cient quantities to produce an explosion or fi re. are substances that can ignite easily and burn rapidly. Remove any one side of the triangle and the fi re will be . If the substance or concentration in the oxidizer is either below a speci al value or above a speci al value , ignition might occur; however, a fl ame will not . The oxidizer in all common hazardous location standards and explosion-proof equipment is air at normal atmospheric conditions. The presence of an oxygen-enriched atmosphere or a pressurized alters the conditions for ignition and dictates the use of special means for prevention and containment of explosions. of the liquid is the minimum temperature at which it gives off suf fi cient vapor to form an ignitable mixture with the air near the surface of the liquid within the vessel used.