Dentists have recommended that a toothbrush be kept at least 6 feet away from a toilet to avoid airborne particles resulting from the flush.
Why Your Toothbrush Should Be 6 Feet From the Toilet
Here's something to think about next time you brush your teeth: dentists recommend storing your toothbrush at least 6 feet away from your toilet. The reason? Every flush creates an invisible explosion of bacteria, viruses, and yes, fecal matter that can rocket through the air and land directly on your bristles.
This phenomenon has a name that sounds like a rejected superhero origin story: toilet plume. And the science behind it is exactly as disgusting as it sounds.
The Gross Science of Flushing
When you flush, the force of the water creates aerosolized droplets—microscopic particles that become airborne. Research dating back to the 1950s has documented this effect, but a groundbreaking 1975 study by microbiologist Charles P. Gerba brought the phenomenon into the spotlight. His work revealed that these particles don't just hang around the bowl—they travel.
How far? Studies have found that toilet plume can:
- Travel at speeds up to 6.6 feet per second
- Reach heights of nearly 5 feet within seconds
- Ascend as high as 15 feet in some conditions
- Remain airborne for over 30 minutes after flushing
The 6-foot recommendation comes from this research, representing a reasonable safety zone. But here's the kicker: distance alone might not save you.
Your Toothbrush Is Probably Already Contaminated
One study tested toothbrushes in shared bathrooms and found that 54.85% were contaminated with fecal matter. Even more unsettling? There was an 80% chance that the contamination came from someone else using the same bathroom, not even the toothbrush owner.
Research on bioaerosol concentrations found that particles don't necessarily decrease much with distance—they're just floating around your entire bathroom, settling on every surface. So whether your toothbrush is 3 feet or 6 feet away, it's probably hosting some unwanted microscopic guests.
Does Closing the Lid Actually Help?
Yes, and you should absolutely be doing this. Studies found that flushing with the lid down dramatically reduces the spread of bacteria like C. difficile, with concentrations 12 times lower compared to lid-up flushing. Researchers detected airborne bacteria at heights up to 10 inches above the toilet seat and up to 90 minutes post-flush when the lid was left open.
But—and there's always a but—most public restrooms don't have lids. And even with the lid closed, some aerosolization still occurs.
What Should You Actually Do?
Don't panic and move your toothbrush to the kitchen (that has its own contamination issues). Instead:
- Close the toilet lid before flushing—every single time
- Store your toothbrush as far from the toilet as possible—6 feet is ideal if your bathroom allows it
- Keep it upright in a holder to air dry, which helps kill bacteria
- Don't use toothbrush caps—they trap moisture and create a bacteria breeding ground
- Replace your toothbrush every 3-4 months, or sooner if bristles are frayed
And here's some perspective: despite the gross factor, your immune system handles these low-level exposures just fine. There's no epidemic of toilet-plume-induced illnesses. The recommendation is more about minimizing unnecessary exposure than preventing imminent danger.
Still, knowing that invisible poop particles are doing loop-de-loops around your bathroom every time you flush? That's motivation enough to keep that toothbrush as far away as possible—and maybe invest in a toilet with a lid that actually seals.