Electrostatic Discharge (ESD)
Definition - What does Electrostatic Discharge (ESD) mean?
Electrostatic discharge (ESD) refers to the sudden flow of electricity between two objects. All materials can potentially be a source of ESD.
Safeopedia explains Electrostatic Discharge (ESD)
The human body can store significant positive charges, while synthetic materials such as plastics tend to store negative charges. ESD, which can be considered a tiny form of lightning, is a major source of damage to electronic equipment.
The buildup of static charges can be caused by friction between any two objects of differing charge or through the induction charge of an ungrounded metal present within an electric field. Depending on the strength of the charge and the context within which it exists, the ESD that results from these charges can be harmless, annoying, or a fatal hazard.
There are a number of hazards associated with electrostatic discharge. If it occurs in a workplace where combustible gases are present, the resulting spark can cause ignition of the gas, thus leading to a fire or explosion. Hazard protection controls that rely on electronic equipment may also be vulnerable to damage from ESD, potentially increasing the risk of a safety incident.
Finally, ungrounded metal that is present within an electrical field can build up a significant static charge. If an unprotected worker touches this metal, he or she could suffer a potentially fatal shock. The use of high-resistance safety mats (referred to as non-conductive, switchboard, or dielectric matting) can reduce the risk of this latter hazard. Safety mats are made with material that blocks the flow of ESD across their surface, which prevents charged objects from discharging.
Electrostatic discharge hazards are governed by a variety of different standards related to electrical safety. In the United States, NFPA Standard 77 provides consensus best practices for mitigating the risks posed by static electricity.