Electricity is Dangerous
Electricity is really cool. It can also be extremely dangerous. Obviously, this shouldn’t discourage you from playing with high-powered electrical devices. It’s a good idea to know what you’re getting into, though. When is electricity dangerous?
You could just go read this PDF, but should you really trust the government with your life? Blasted Science has plenty of experience with electricity. Trust us.
How Much is Lethal?
It takes a surprisingly small amount of electricity to kill you. According to Adam Savage, all it takes is 7 milliamps for three seconds. That’s tiny. An LED would barely light up with that amount of current. And since the internal resistance of the human body is about 300 ohms, it would only require 2.1 volts to kill. That’s only slightly more than a AA battery.
Fortunately, our bodies have one big protection to electricity: skin. Dry skin has a resistance of 100,000 ohms to 600,000 ohms. You might think this means that you’d need to be shocked with at least 3430 volts before your life is at risk, but it’s not that simple.
The above calculation applies only to dry skin. Wet skin is much more conductive. Voltages as low as 50 volts can be dangerous when your skin is wet.
At high voltages, skin loses most of its resistance and becomes much more conductive. As eplasty.com puts it,
At 500 V or more, high resistance in the outer layer of the skin breaks down. This lowers the body’s resistance to current flow greatly. The result is an increase in the amount of current that flows with any given voltage. Areas of skin breakdown are sometimes pinhead-sized wounds that can be easily overlooked. They are often a sign that a large amount of current could enter the body. This current can be expected to result in deep tissue injury to muscles, nerves, and other structures. This is one reason why there is often significant deep tissue injury little in the way of skin burns with high-voltage injuries.
In summary, the danger of electricity is highly variable. The best option is to play it safe. Exercise caution with any moderate to high voltage source. We’ve only scratched the surface of electrical dangers. There are many other factors that are beyond the scope of this article.
Does this mean you should avoid electricity at all costs? Of course not! Just don’t be stupid. At least, not as stupid as we are. Blasted Science has made some incredibly poor decisions with electricity in the past. It’s remarkable that we’re all still alive. Please don’t follow our example.