Approximately 1 mA (0.001 A) is enough to produce a tingling sensation. 10 mA is painful. 12-20 mA is enough to paralyze muscles, making it impossible to let go. 60-100 mA causes ventricular fibrillation of the heart. That is, the heart is beating in such a way that it cannot pump blood through the circulatory system. Greater than 200 mA causes the heart to clamp down and stop beating.