As far back as 600 BC, the ancient Greek philosopher and scientist, Thales of Miletus, observed that, when amber was rubbed against fur, it would emit an invisible force that would attract small fibers and could be discharged with a shock. This observation is one of the first known recorded experiences with what we now understand to be static electricity.
Static electricity fascinated the likes of Benjamin Franklin and Robert Van de Graff. Franklin’s experiment with a kite, a key, and lightning–the result of supercharged static electricity–has become part of American lore. A Van de Graaff generator, capable of generating two million volts during an electrostatic discharge, demonstrates the immense potential power of static electricity in a controlled environment. But, one may be shocked to learn that, in a commercial or industrial facility, an uncontrolled electrostatic discharge of as little as 350 volts can be catastrophic.
When investigating fires or explosions in a commercial or industrial setting, electrostatic discharge should be considered as a potential cause and proven as the ignition source or eliminated before the likelihood of other possible causes can be assessed adequately. To properly assess static electricity, the phenomenon should be understood, the hazard should be recognized and evaluated to determine whether the hazard was controlled properly and adequately, and parties potentially liable for the incident should be identified.
Static electricity is an electrical charge that cannot move and accumulates on the surface of a material. An electrical charge occurs when the electrons of the atoms of one material move to the atoms of another material that is rubbed against or comes into contact with the other and then those materials are separated. If the electrical charge does not have a path to ground, it is unable to move and becomes static.
The static electrical charge can build up and accumulate until the charge finds a way to be released to ground or is discharged in a rapid exchange of electrons to achieve a balanced charge. If the electrical charge accumulates, it can develop enough energy to release as a spark to another object during an electrostatic discharge. A spark from an electrostatic discharge can generate enough energy to serve as the ignition source for an explosive or flammable atmosphere found in some commercial or industrial settings. The dangerous combination of a spark from an electrostatic discharge and an explosive or flammable atmosphere can cause a catastrophic fire or explosion.
In a commercial or an industrial setting, the accumulation of static electricity and electrostatic discharge pose hazards and dangers if four conditions are present: (1) a flammable or explosive atmosphere exists; (2) an electrical charge is generated and accumulates on an object, such as equipment, product, or an operator; (3) a spark can be produced; and (4) the spark has energy greater than the minimum ignition energy of the surrounding explosive atmosphere.
The hazards and risks of static electricity accumulation and electrostatic discharge may be controlled by reducing electrical charge generation, minimizing electrical charge accumulation, diluting the flammable or explosive atmosphere, or eliminating the possibility of a spark with enough energy to ignite the combustible atmosphere. At the facility level, proper bonding and grounding may be critical to reduce electrical charge accumulation, especially where the facility’s process necessarily creates a flammable atmosphere.
When investigating a commercial or industrial fire or explosion, however, system designers, system component manufacturers and suppliers, system installers, and contractors for system inspections and maintenance should not escape close scrutiny. A thorough investigation may reveal, for example, that the system was not properly designed to address static events or conditions; that the system’s component parts were not manufactured with anti-static additives, which can eliminate or reduce the accumulation of static electricity, or with materials, such as stainless steel, that reduce or mitigate the risk of creating a spark, or had other inadequate product design elements for mitigating the risks associated with electrostatic discharge, the accumulation of static electricity, or a combustible atmosphere; that the system was not installed as designed; that a third-party contractor failed to identify a missing or loose bonding or grounding connection; or that the maintenance contractor failed to remedy an identified hazard. Any one of those circumstances, or a combination of them, could be responsible for a fire or explosion where an electrical charge is allowed to generate, accumulate, and discharge a spark in a combustible atmosphere.
When investigating a fire or explosion, especially in a commercial or industrial setting, retaining seasoned, knowledgeable legal counsel to assist with the investigation is valuable for developing recovery opportunities. Subrogation counsel can assemble a team of expert consultants, such as a fire investigator, an electrical engineer, a mechanical engineer, and a chemical engineer, as the circumstances require. The recovery team should consider and investigate electrostatic discharge as a potential cause of the fire or explosion and, as the evidence and findings warrant, further investigate the appropriate entity or entities responsible for the incident due to improper system design, product defect, or any other conditions that led to an electrostatic discharge of sufficient energy to ignite a combustible atmosphere and cause a fire or explosion.
Like Thales, a subrogation recovery team should recognize where static electricity generation and accumulation is possible. Like Franklin, a subrogation recovery team should explore the possible effects of static electricity, and like Van de Graff, a subrogation recovery team should investigate the effects of an uncontrolled electrostatic discharge. Electrostatic discharge can be the cause of a fire or explosion and should be part of a subrogation recovery investigation where a flammable or explosive environment may exist. Confirming or eliminating electrostatic discharge as an ignition source for a fire or explosion loss can be critical to a successful subrogation recovery effort.