Electric Shock: Effects on the Body and Emergency Response
Understanding why electricity injures people is what makes the safety rules make sense. The key insight: it's the current (milliamperes) through the body — not voltage alone — that hurts you.
1. Current levels and effects (60 Hz AC, hand-to-hand)
| Current | Effect |
|---|---|
| ~1 mA | perception (tingle) |
| ~5 mA | felt, can still let go |
| ~6–30 mA (≈10 mA) | painful; muscles freeze — "can't let go" |
| ~50–150 mA (>75–100 mA) | severe; respiratory arrest; ventricular fibrillation (fatal) |
- The most dangerous path is hand-to-hand across the chest/heart.
- Wet or sweaty skin lowers body resistance, so the same voltage drives more current — more dangerous.
- Even 120 V can kill — it can push enough current through a wet body / heart path to be lethal. "Low voltage" is not "safe voltage."