B U r N S C AU S E D B Y E L E C T r I C I T Y
Section 3 Burns Caused by Electricity
❚ Electrical shocks cause burns.
❚ arc-blast—explosive release of mol- ten material from equipment caused by high-amperage arcs
❚ arcing—the luminous electrical dis- charge (bright, electrical sparking) through the air that occurs when high voltages exist across a gap between conductors
The most common shock-related, nonfatal injury is a burn. Burns caused by electricity may be of three types: electrical burns, arc burns, and thermal contact burns. Electrical burns can result when a person touches electrical wiring or equipment that is used or main- tained improperly. Typically, such burns occur on the hands. Electrical burns are one of the most serious injuries you can receive. They need to be given immediate attention. Additionally, clothing may catch fire and a thermal burn may result from the heat of the fire. Contact electrical burns. The knee on the left was energized, and the knee on the right was grounded. Arc Blasts Arc-blasts occur when powerful, high-amperage currents arc through the air. Arcing is the luminous electrical discharge that occurs when high voltages exist across a gap between conductors and current travels through the air. This situation is often caused by equipment failure due to abuse or fatigue. Temperatures as high as 35,000°F have been reached in arc-blasts. A common example of arcing is the flash you sometimes see when you turn a light switch on or off. This is not dangerous because of the low voltage.
There are three primary hazards associated with an arc-blast.
(1) Arcing gives off thermal radiation (heat) and intense light, which can cause burns. Several factors affect the degree of injury, includ- ing skin color, area of skin exposed, and type of clothing worn. Proper clothing, work distances, and overcurrent protection can reduce the risk of such a burn.
(2) A high-voltage arc can produce a considerable pressure wave blast. A person 2 feet away from a 25,000-amp arc feels a force of about 480 pounds on the front of the body. In addition, such an explosion can cause serious ear damage and memory loss due to