When a conductive path, such as a person's hand, comes into close proximity of the material holding a static charge, the static energy is discharged, possibly resulting in a spark. If this spark has enough energy and is discharged in a vapor-air mixture in the flammable range, a fire or explosion may occur. However, flammable liquids are often transferred from container to container in the open air. In these cases, the accumulation of static electricity must be minimized. The easiest way to achieve this is to properly ground and bond all of the electrically conductive materials that the flammable liquid will come into contact with.
Static charges flow from the liquid surface to the earth, where the charge is dissipated.
Static charges flow through the connecting conductor to the adjacent material, where electrical equilibrium is established. A static spark cannot occur between two materials that are electrically bonded together. Furthermore, if the adjacent material is grounded, then the static charge will flow to the earth, where the charge is dissipated. This value is recognized as adequately low for most hazards, such that substantial static charge accumulation is prevented. Bonding and grounding is normally achieved utilizing steel or copper grounding cables and positive clamping metal connectors or clamps.