Electric current always represents a potential danger to living beings. Even small currents can affect heart activity. Higher currents additionally cause burns on the skin. Since most technical systems operate with alternating current at 50 or 60 hertz, most studies have been carried out at these frequencies.
The perception threshold is around 0.5 mA, although a tingling sensation usually becomes noticeable only at about 3 mA. From 12 mA onward, muscle cramps occur, making it impossible to let go of the cables. At around 40 mA, the threshold is reached where cardiac arrhythmias and diaphragm spasms can appear. At 80 mA, even with short exposure times of less than 300 μs, ventricular fibrillation occurs, which usually results in death.