It is important to understand that the effects of electricity on the human body depend on various factors, including the current (expressed in amperes), the duration of the contact, the moisture of the skin, the health condition of the person, and the path that the electric current takes through the body. Therefore, it is difficult to specify an exact current that is always fatal for a human.

It is generally believed that a current of approximately 100 milliamperes (0.1 amperes) can be potentially life-threatening. Exposure to such a current can cause heart arrhythmias that may be fatal.

However, it is important to note that even lower currents can be dangerous, especially if the electric current passes through the heart or other vital organs, or if the contact is prolonged.

The exact threshold for fatal currents can vary from person to person and depends on individual factors such as health condition, humidity levels, and other circumstances. It is always crucial to be careful when dealing with electricity and to follow safety measures to prevent electric shocks. In the event of an electric shock, it is always important to seek medical assistance immediately, even if symptoms are not immediately apparent.