Water and electricity can be a fatal mix – and both are found in the bathroom

You plug in the hairdryer, turn it on, and nothing happens. Your initial reaction might be frustration, but your bathroom receptacle is trying to warn you. Something’s wrong.

According to the Electrical Safety Foundation International, Ground Fault Circuit Interrupters (GFCIs) have saved thousands of lives since they were introduced into the National Electrical Code in the 1970s. These interrupters are integrated into the outlets you find in your bathroom. They’re likely to be found wherever an outlet is near a water source, which is also why you’ll find them in your kitchen or your laundry room.

True protection

GFCI outlets protect you from electrical shock. You need to get to the bottom of the relationship between water and electricity to understand why these specialized electrical outlets are so important to your safety. You also need to understand how an electrical outlet works.

In the USA, a standard 120-volt electrical outlet has two vertical slots and a round hole below them. Ever notice that the left slot is larger than the right. It’s known as “neutral,” while the right slot is known as “hot.” The hole below is known as “ground.”

When you plug in your hairdryer and turn it on, it completes the circuit and electricity from the right-hand “hot” slot, through your appliance, and returns through the left-hand “neutral” slot. The “neutral” and “ground” slots work together to return the current to its source.

The ground slot is connected to the ground via a rod inserted into the earth outside your home. If the electricity can’t complete the circuit between “hot” and “neutral,” it’s diverted to the “ground” and safely away. That’s the preferred path of electricity. You want it flowing through your hair dryer – or if something’s not right, the ground.

Whose fault is it?

Any abnormal flow of electricity is known as a “fault.” One of the worst types is called a ground fault. That’s when electricity bypasses its intended wiring, in this case your hairdryer, and chooses the path of least resistance to the ground. That would be you. Here’s why you don’t want this to happen and how a GFCI prevents it.

All it takes is about 10 milliamps of electricity to overload the human body and freeze up your muscles. You wouldn’t be able to let go of your hairdryer – or any object causing shock.

A GFCI monitors the flow of electricity from the “hot” slot and then when it returns to the “neutral” slot. It can sense a mismatch as small as 4 to 5 milliamps, and it can react to that mismatch in as little as 1/30th of a second.

Just add water

Those fast reactions are precisely what you need when you’re around sources of water, such as the bathroom. Moisture is one of the biggest causes of ground faults. Water offers the least path of resistance.

Let’s say you’re fresh from a long hot shower that’s fogged up the mirror. There’s a slight film of water on your hairdryer. And maybe you’re standing in a puddle of water. There’s a possibility that when you turn on the hairdryer, you’ve created a path from the “hot” wire in the cord through you, and to the ground. You’ve unintentionally created a ground fault.

Fortunately for you, the hairdryer is plugged into an outlet with a GFCI that will, in a fraction of a second, sense that the expected amount of current is not flowing from “hot” to “neutral” because it’s now flowing through you and making its way to the ground courtesy of the water.

The power is interrupted. It may happen so quickly that you aren’t even aware that you might have been just two seconds away from a serious or even fatal event. You might still receive a painful shock, but you won’t be subjected to the prolonged surge of electricity that injures and kills.


Most homes – especially those built after the 1970s – should already have GFCI outlets installed where required by electrical codes. That’s also the case for office buildings, and it’s why you’ll find these outlets in the restrooms and kitchen areas.

They’re easy to identify because the outlets have a “test” and “reset” button. They should be tested monthly, no matter where they are located. Make this a part of your monthly DIY household habits.

Pushing the “test” button should shut off electricity to the outlet. Pressing the “reset” button reestablishes the circuit.

Check with your office manager or the building management to see who has this responsibility in an office setting. Report any tripped GFCI outlets you encounter.

A GFCI that activates – meaning that it has shut off electricity to the outlets – is telling you that it’s sensing irregular current measurements from the “hot” to the “ground.” Don’t ignore this message.

Experiencing problems with your GFCI outlets? It may be time to replace them. Learn how we can help.