Do Amps Or Volts Kill You? - Let's Talk Science

There’s an old saying: "It's not the volts that kills you, it's the amps." That’s true in a way. But that’s not the whole story!

But wait. What are volts and amps? Amps (A) are the unit we use to measure electric current. An electric current is the flow of negatively charged electrons past a given place over a period of time.

The flow of electrons creates a current. But it does not happen on its own. It needs energy. The amount of energy in each unit of electrical charge is called voltage. Volts (V) is the unit for voltage.

Have you ever watched water flowing through a pipe? Sometimes it can flow quickly. Sometimes it can flow slowly. It depends on the water pressure.

Imagine that an electric current is a water pipe. The amps would be like the volume of water. Volts would be like the water pressure. So the amps measure the amount of electricity in a current. The volts measure that electricity’s strength.

Did you know that your body uses electricity, too? Your muscles, lungs, and heart all need electricity so they can work properly. Electric currents travel well through your blood. But they have a hard time passing through your skin. We can say that your skin resists the flow of electrons. In other words, your skin is a resistor. It helps keep your body safe.

When the voltage of a current goes up, your skin’s resistance goes down. This lets more current flow through your skin. Has anyone ever told you not to touch a live wire of a downed power line? That is because its voltage is very strong. In fact, its voltage will be high enough to overcome your skin’s resistance. It can pass through your skin into your blood vessels. If the level of amps is high enough, it can do some serious damage to your body tissues. It could even kill you!

If your skin is wet, its resistance will be even lower. Has anyone ever told you not to play in a puddle during a thunderstorm? Or has anyone told you not to touch electrical devices when your hands are wet? Now you know why!

So, is it volts or amps that is dangerous? The answer is both!