How do restroom hand dryers end up filled with bacteria that is blown onto your clean hands?


I don’t understand how the machines collect bacteria. Is it because of the humidity? Confined air in the space?

In: Biology

There’s bacteria everywhere, on every surface, and even floating in the air. It’s not notable when there is bacteria somewhere, it’s notable when there isn’t!

This sounds like a question that was sparked by some particular headline or source. If this is the case, would you be willing to share it with us? We may be able to give more specific answers. [This youtube video explaining a study from about 5 years ago]( is the last thing about hand dryers and bacteria that I specifically remember hearing about, so there may be a new finding I’m not aware of.

It gets sucked up into the air intake for the fan…drawing in every nasty bacteria, fungus, virus and farticle…whipping them around in a cyclone and blasting them out under pressure right onto your clean hands.

A mix of what mentioned and the fact that your assuming you’re hands are perfectly free of bacteria and clean when you wash them.

First, any surface is going to have some kind of bacteria on it unless it is regularly sterilized, so unless that’s happening the hand dryer isn’t perfectly clean itself.

Next is yea that some room conditions (like humidity) can be good for bacteria growth.

But really the big one is that unless you do a super deep long clean, you hands arent perfectly bacteria free. And the bacteria that’s left on your hands can be blown off you hands and circulated around the room, possibly to another person.

Studies done for hospitals found that air dryers spread bacteria way more than paper hand towels, which is why hospitals typically use paper towels and not air dryers.

the easy answer is that the air dryers are rarely cleaned so the bacteria piles up.

The slighly more complicated answer is bacteria like to grown in warm moist areas; so between the warm air of the air dryer, and the moisture in the surrounding area, like a nice little home for them