Effects of Electrical Current on the Human Body.
Electrical shock occurs when current passes through the body. The severity of the shock depends on the current’s magnitude, the duration, the contact area, and the path taken by the current through the body.
The shock current received obeys
[provisional cross-reference: ohms-law]
, so high voltages are always more dangerous. But your body resistance is equally important. Body resistance with dry skin may be above 100,000 ohms, However, if the skin is wet or broken, the body’s resistance decreases to a few thousand ohms.Current | Reaction 1 Second contact |
---|---|
< 1 mA | Generally not perceptible. |
1 mA | Threshold of feeling, tingling sensation. |
3 mA | Painful shock. Average individual can let go. |
5 mA | Accepted as maximum harmless current. Strong involuntary reactions may cause indirect accidents. |
6–25 mA | Beginning of sustained muscular contraction. ("Can’t let go" current.) |
9–30 mA | Lung paralysis, Respiratory arrest ‐ usually temporary, but death is possible. |
50 mA | Possible ventricular fibrillation. (heart dysfunction, usually fatal.) |
100–300 mA | Certain ventricular fibrillation, fatal. |
1–4 Amps | Heart paralysis, severe burns. Muscular contraction and nerve damage occur; death is likely. |
5 Amps | Flesh burns, defibrillation, temporary respiratory paralysis. |