A standard 220-volt electrical circuit, often used in high-power household circuits or as the standard mains voltage in many countries, carries a significant risk of severe injury or death. While 220V (or 240V) is classified as low voltage in industrial terms, it has more than enough electrical potential to drive a dangerous current through the human body under common circumstances.
The Critical Role of Current, Not Just Voltage
The danger of an electrical shock is often mistakenly attributed solely to the voltage, which is the electrical “pressure” or potential difference. In reality, the physical harm inflicted on the body is caused by the current, measured in amperes, which is the actual flow of electrical charge through tissues. A current between 100 to 200 milliamperes is sufficient to be lethal.
Voltage is the force that pushes current through the body’s natural resistance. Since current flow is directly proportional to voltage, a higher voltage creates a greater potential to drive a lethal amount of current. A 220V source can easily overcome the body’s skin resistance to push a deadly current through internal organs. Even 50 milliamperes (mA) can cause catastrophic damage, and 220V is capable of producing current levels far exceeding that threshold.
How Electrical Current Causes Internal Damage
A sufficient electrical current passing through the body causes damage through three primary mechanisms: disrupting the nervous system, paralyzing muscles, and generating thermal energy. The most common cause of death from low-voltage alternating current (AC) is ventricular fibrillation. This occurs when the current disrupts the heart’s natural rhythm, causing the ventricles to flutter rather than pumping blood effectively.
Current passing through the chest cavity can also paralyze the muscles that control breathing, leading to respiratory arrest. This effect, known as tetany, can make a victim unable to release the electrified object, prolonging the exposure. Beyond the electrophysiological effects, the body’s resistance to current flow generates intense heat, resulting in severe burns. While thermal injuries often manifest as entry and exit wounds on the skin, the most extensive damage occurs to internal tissues and organs along the current’s path.
Factors That Determine Severity of Injury
While 220V provides the necessary potential, the final outcome of an electrical shock depends on several factors. The path the current takes through the body is significant; a current that crosses the chest, passing from one hand to the other or from a hand to a foot, is more likely to be fatal because it involves the heart. A shock passing only through a limb is less likely to cause cardiac arrest but can still cause significant local tissue damage.
The duration of contact is another determining factor, as the longer the current flows, the greater the total energy delivered and the higher the probability of sustained damage. Body resistance also plays a major role, especially the condition of the skin, which provides the majority of the body’s impedance to electrical flow. Wet skin, or skin compromised by cuts, dramatically lowers this resistance, allowing a much higher current to flow from the 220V source, thereby increasing the risk of death.
Immediate Response to Electrical Shock
The immediate response to an electrical shock centers on rescuer safety and rapidly breaking the circuit. Never touch a person who is still in contact with the electrical source, as the current can pass directly to the rescuer. The safest first step is to turn off the power at the main switch or breaker.
If the power cannot be turned off quickly, use a non-conductive object, such as a dry wooden pole, plastic item, or cardboard, to separate the victim from the electrical source. Once the person is clear, call emergency medical services immediately. If the victim is not breathing or shows no signs of circulation, start cardiopulmonary resuscitation (CPR). Any person who has received an electrical shock must receive medical evaluation, as internal damage or delayed cardiac issues may not be immediately apparent.