This publication presents the current technology in the fields of static electricity@ lightning@ and stray currents applicable to the prevention of hydrocarbon ignition in the petroleum industry. The recommendations for protection are based upon research and practical experience (see Appendixes A and B). Purpose Application of the information contained herein should lead to improved safety practices. This information may also be used to evaluate existing installations and procedures and@ as necessary@ to improve their effectiveness. Furthermore@ when the narrow limits within which static electricity can cause ignition are properly understood@ fire investigators may be encouraged to search more diligently for the true ignition sources in instances where ignition by static electricity is unlikely or impossible. To prevent fires@ whatever their cause@ it is necessary to control one or more of the three elements required for combustion. These elements are fuel (in vapor form or mist)@ air@ and a source of ignition. Significant sources of electrical ignition are: sparks from static electricity@ lightning strokes@ sparks from induced charges which may accompany lightning@ and arcs caused by breaking of circuits involving stray currents. Control procedures relate to the prevention of the arc or spark itself@ or to the prevention of a flammable vapor-air mixture when sparks cannot be prevented.