Publisher Summary Open flames in a hydrocarbon facility are usually available from welding or hot work operations, smoking, and the facility flare. Additionally all petroleum facilities have limitations on areas allowed for smoking. These sources are normally controlled through operational measures supplemented by physical separation. Facility electrical systems and components provide a convenient source of ignition within a hydrocarbon or ordinary occupancies whenever the design, installation, or maintenance is substandard. Electrical systems or components may short, overheat, operate incorrectly, etc. These failures present themselves as available ignition sources for hydrocarbon vapor releases. All electrical installation should be according to the recognized electrical industry standards. The overall intent of the electrical area classification is to provide for safety of personnel and equipment. This is achieved by the elimination of electrical ignition sources near combustible gases or vapors that could explode or burn. It must be remembered that leakages may be large or small in nature and can be orientated in infinite directions, so considerable fuel releases may occur even where ignition sources are readily available. In addition, there are many incidents where large leakages occurred but have not ignited because ignition sources have been removed from the area. Therefore, prevention measures should be employed to avoid the ignition of a hydrocarbon liquid or vapors whenever possible.