Why You Should Never Keep Your Toothbrush in the Bathroom

It started, like most bad habits, with convenience.

Every morning, I’d stumble into the bathroom, groggy and disoriented, reach for my toothbrush next to the sink—right by the toilet—and begin my day with minty freshness and, unbeknownst to me, a generous helping of… airborne fecal particles.

I wish I were joking.

My bathroom looked clean. Bleached tiles, lavender-scented hand soap, a stack of fluffy towels folded like a spa brochure. But as it turns out, aesthetics have nothing on aerosolized bacteria.

You see, every time you flush the toilet, you’re not just sending waste down the pipes—you’re launching an invisible cloud of microscopic particles into the air. This phenomenon, known as the “toilet plume,” can travel up to six feet, settling on your sink, your counters, and yes—your toothbrush.

Think of it as the worst kind of housewarming gift.

A study by researchers at Quinnipiac University found that over 60% of toothbrushes stored in bathrooms tested positive for harmful bacteria, including E. coli, Serratia, Giardia, and Salmonella.

Let that sink in: you’re brushing your teeth with a stick that may be wearing microscopic poop particles like a badge of honor.

And the real kicker? It’s not even your own bacteria that’s the biggest problem.

“The main concern is not with the presence of your own fecal matter on your toothbrush,”
explains Lauren Aber, the study’s lead author.
“But rather when a toothbrush is contaminated with fecal matter from someone else…”

So if you’re sharing a bathroom with roommates, kids, or even your significant other, you’re not just sharing space—you might be sharing microbial souvenirs.

And then there’s the issue of humidity. Bathrooms—especially those without proper ventilation—are moisture havens. Bacteria love moisture. So do mold and mildew.

Storing your toothbrush in this swampy environment is like placing a welcome mat for unwanted guests. The dampness allows bacteria to multiply, and if you’re using a toothbrush cap to “protect” it—bad news. That cap traps in moisture, turning your brush into a tiny mold terrarium.

Imagine this: your toothbrush wakes up in the morning, nestled beside the toilet, damp from yesterday’s brush. It yawns, stretches its bristles—and then WHAM! Toilet flush. Airborne particles rain down like a microscopic apocalypse. Later, it’s shoved into a dark, plastic travel cap, still wet, where it marinates in its own filth until morning.

And then you stick it in your mouth.

Charming.

Here’s what the experts recommend:

• Keep it dry: Always store it upright and in the open air to allow full drying.

• Keep it distant: Place it as far away from the toilet as possible—or better yet, outside the bathroom entirely.

• Keep it solo: Don’t let toothbrush heads touch each other. Cross-contamination is real.

• Keep it fresh: Replace your toothbrush every 3–4 months, or sooner if the bristles are frayed.

Dr. Payal Bhalla, Principal Dentist at Quest Dental, puts it plainly:

“Storing your toothbrush in a dry area outside of the bathroom, such as a bedroom cabinet, reduces the risk of contamination drastically.”

Since moving my toothbrush to a small, upright stand on a shelf in my bedroom, I’ve noticed two things:

1. I’m brushing more mindfully (walking to get the toothbrush is a kind of mental ritual).

2. I no longer start my day with invisible poop.

My mouth feels cleaner. My inner germaphobe sleeps better. My toothbrush? Happier.

You brush your teeth every day to stay healthy, fresh, and confident.

So why risk sabotaging all that by storing your toothbrush in a microbial war zone?

A small change in habit could mean fewer bacteria in your mouth, fewer illnesses, and a much healthier start to your day.

Move it out. Dry it off. Let it breathe.
Your toothbrush—and your immune system—will thank you.