Electrical propulsion equipment can pose a significant hazard to workers, particularly when they are poorly handled or not maintained. Many electrical devices have high voltage or high power requirements, carrying even more risk. The main risks associated with electricity are electric shock, fire and electric arc. Electric shock occurs when the body becomes part of the electrical circuit, either when an individual comes in contact with both wires of an electrical circuit, a wire of a live circuit and the ground, or a metal part that has been activated by contact with an electric conductor.
The severity and effects of an electric shock depend on several factors, such as the way through the body, the amount of current, the duration of exposure and whether the skin is wet or dry. Water is a great conductor of electricity, allowing the current to flow more easily in wet conditions and through wet skin.
The effect of the shock can range from a slight tickling to severe burns to cardiac arrest. The following table shows the general relationship between the degree of injury and the amount of current for a path of 60 cycles of walking hand for the duration of one second of shock. While reading this chart, keep in mind that most electrical circuits can provide, under normal conditions, up to 20,000 milliamps of current.