Ignition hazards, flammable liquids, vapors

To minimize the hazard of premature ignition of flammable liquid vapors, allow at least two feet of fuse length to extend from the top of an open container of flammable liquid before lighting the fuse. 

Always ventilate spaces with normal air and never pure oxygen. Introducing a source of ignition into a space containing a flammable atmosphere will cause an explosion. Consider hazardous most liquids, vapors, gases, mist, solid materials, and dusts space. 

Flash point of a flammable liquid The lowest temperature at which the liquid gives off enough vapors to form a flammable mixture with air (or pure oxygen, a special case) at or near the surface of the liquid or within its confined container. Some hazardous liquids have flash points at or below ordinary room temperatures and normally are covered by a layer of flammable vapors that will ignite immediately if a source of ignition is brought in contact [32]. Flash points are measured by open cup and closed cup methods. The open cup data is applicable to liquid in open containers and in open pools and usually somewhat higher temperatures than the closed cup. Refer to... 

Scope—Articles 500 Through 505. Articles 500 through 505 cover the requirements for electrical equipment and wiring for all voltages in locations where fire or explosion hazards may exist due to flammable gas or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings. 

Scope. Articles 511 through 517 cover occupancies or parts of occupancies that are or may be hazardous because of atmospheric concentrations of flammable liquids, gases, or vapors, or because of deposits or accumulations of materials that may be readily ignitable. 

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