Ever popped into a public loo for a quick rinse and instinctively hit the hand blower? Well, one scientist has warned that those dryers are less about hygiene and more about giving bacteria a party in your palms.
Scientist Ruth MacLaren, who shares all sorts of germy truths on her TikTok account @devonscience, recently gave hand dryers a proper once-over.
Think of it like putting your tools through a safety check—but this time, the tools were a petri dish and some bathroom air.
MacLaren’s experiment was simple but the results were a shocker. She exposed one petri dish to the air from a hand dryer and another to the fresh air in her lab. Then, she let both sit overnight, like marinating meat for the barbie.
@devonscience Urghh, don't use a hand dryer😱🦠 —– Update: thank you for all your comments & suggestions. Totally blown away by how far this little video has reached 😮 I'm planning on doing some update videos on this experiment and will post on here, as well as on our FB & IG pages, which you are welcome to follow as well 😉 Thank you, Ruth (from Devon Science) #germs #publictoilet #bacteria #dirty #gross #justdont #scienceteacher #handwashchallenge #handdryer #science #scienceexperiments #microbiology #scienceproject #lesson #handdryer #handdryerbacteria ♬ original sound – Devon Science
The next day, the petri dish from the hand dryer was a smorgasbord of bacteria and even a spot of fungus.
“So many different kinds of bacteria and a fungus too,” MacLaren explained in her video.
Meanwhile, the lab-air dish? Clean as a whistle.
“This is why I do not use hand dryers,” MacLaren declared, demonstrating her method of drying her hands with toilet paper instead.
Why you should “wave off” hand dryers
In the caption of her viral post, which has racked up over 4.5 million views, MacLaren doubled down, writing: “Urghh, don’t use a hand dryer.”
Some sceptics piped up in the comments, pointing out that the test compared lab air to bathroom air, which might not be entirely fair.
So in true tradie fashion—always checking your measurements twice—MacLaren went back and ran more tests.
@devonscience Hand dryer video update: Testing the paper😱🦠 I'm loving the discussions that have come from my initial hand dryer test. Obviously a hot topic for many regarding hygiene & hand dryers. It'd be great if there were some proper scientific studies on this. 🧪Anyway, here are the results from the paper, I also tested another toilet and got similar results. 🧪 I think the bacteria are coming from inside this dryer rather than the air, but I've swabbed the vents to confirm (results to follow), and I hope not all hand dryers would be as grubby as this one! 🧪The bacteria I grew may not be harmful and I'm planning on identifying them —– #germs #publictoilet #bacteria #dirty #gross #justdont #scienceteacher #handwashchallenge #handdryer #science #scienceexperiments #microbiology #scienceproject #lesson #handdryervideo #handdryerbacteria ♬ original sound – Devon Science
She compared air straight from a toilet to air from a hand dryer. Then, just for good measure, she tested bacteria levels from hand dryers versus toilet paper.
The results? The hand dryers blew their bacteria-ridden air way past the competition, proving themselves to be, well, dodgy tools for the job.
“Okay, I’m convinced now,” wrote one user.
The verdict? Stick to the paper
If you’re thinking, “What’s the big deal? My immune system’s tougher than a pair of steel-capped boots,” remember that public bathrooms are already germ havens. Adding a bacterial windstorm to the mix probably isn’t helping.
In response to the massive attention her experiment received, MacLaren wrote: “Totally blown away by how far this little video has reached.” And while it might not change how public restrooms work, it’s a fair warning for us all.
So, next time you’re on a site run or taking a smoko break, you might want to give the hand dryer a miss.
