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 contact, the moisture of the skin, the health condition of the person, and the path the electric current takes through the body. Therefore, it is difficult to specify an exact current that is always lethal for a human.

Generally, it is believed that a current of about 100 milliamperes (0.1 amperes) can be potentially life-threatening. Exposure to such a current can cause cardiac arrhythmias that can 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 lethal currents can vary from person to person and depends on individual factors such as health condition, moisture levels, and other circumstances. It is always crucial to be cautious when handling electricity and to follow safety measures to prevent electric shocks. In the event of an electric shock, it is always important to seek medical help immediately, even if the symptoms are not immediately visible.