The One Thing You Should Never Do In A Public Restroom, According To A Germ Expert

Droplets and aerosol particles can spray up to six feet out of the toilet when we flush.

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Using a public restroom is rarely a joyous occasion. They’re filled with sights and smells that can strike fear in the hardest of hearts (and stomachs), and still, most of us have to venture into them at some point if we ever want to live a life outside of our homes. So how can we make our time in a public bathroom better or safer or, at the very least, less gross? That’s we ― Raj Punjabi and Noah Michelson, hosts of ― asked microbiologist to school us on when he dropped by our studio.

“Every time I talk about toilet seats and toilets, I’m always saying, ‘Well, it’s not germy — everything is germier than a toilet seat,’” Tetro told us. “[I’m basing that on] studies that were done back in the 1970s and controlled laboratory environments that were mimicking the home..



. [but those toilets] also had a lid.” That lid, which is absent from the vast majority of toilets in public restrooms, is key, he said, to containing what scientists call a “poo plume,” the droplets and aerosol particles that can spray up to six feet out of the toilet when we flush.

“As a result of [there not being a lid], there’s that plume that comes from the toilet that ends up on the seat, and no matter where you go, you’re always going to find that about 50% of the [public restroom] toilet seats at any given time are going to have some kind of poo germs on them in the range ofhundreds [of particles],” he said. Those poo particles can contain E. coli, salmonella, or even norovirus, all of which, if present in high enough concentrations, can make us sick — but not from sitting on the toilet seat.

“We do see potentially some low level of all sorts of different types of bacteria and viruses that could potentially cause an infection, but the reality is, unless you have a cut, then there’s really no opportunity for that to get into your skin to cause a problem,” Tetro, the author of and explained. However, droplets in the air are a different matter altogether. That’s why he says we should flush the toilet before using it to “get a fresh” bowl and never stay in the stall after flushing.

“Make sure that you kind of get out of the stall for 30 seconds to let whatever was aerosol or the droplets to fall and then you can go back in,” he said, noting that he actually does this himself. “So here’s the problem: If it’s norovirus or some of the more really troublesome bacteria like E.coli 0157:H7, then you may actually end up getting exposed to a high enough level that it could potentially cause infection,” he warned.

That’s because the droplets from the plume could land in your mouth or nose — which is even more of a danger if you’re standing in close proximity to a public restroom toilet that features an extremely powerful flusher. “So if you’re gonna go for the clean or for the fresh bowl, make sure that your face is nowhere near that plume,” he added. Once you’ve finished your business, don’t stick around in the stall after you’ve flushed either — unless you want to be showered by a plume of your own poo particles.

We also chatted with Tetro about the germiest part of a public restroom (spoiler: it’s not the toilet seat), what to do if there’s no soap in the bathroom, and much more. Listen to the full episode above or . For more from Jason Tetro,.