Health library

Bathroom germs reach breathing height after flushing

Sept. 21, 2026—Flushing the toilet sets off a whirlpool of turbulence as it washes the contents away. Unfortunately, not everything goes down the drain. Flushing also sets off a toilet plume, a mist of particles that hangs in the air.

The result: If someone is sick with a stomach bug or other illness, flushing can cause others in the household to get sick too.

The science of flushing

Australian researchers conducted a meta-analysis of 22 different studies regarding how harmful microorganisms spread after flushing.

They found that:

• Flushing can shoot aerosols into the air as high as an adult's face, right at breathing height.
• These germs can remain airborne for up to 20 seconds.
• The amount of water and pathogens in the toilet during flushing are the main factors driving the spread of germs.

According to the research, the most effective methods for stopping the spread of disease are keeping the bathroom clean and installing high-efficiency toilets that use less water when they flush.

Meanwhile, steps such as air ventilation or closing the toilet lid are less reliable at preventing aerosol spread. In fact, a 2024 study found that viruses can spread onto bathroom surfaces after flushing even when the lid is down.

What you can do

To help prevent germs from spreading after using the restroom, follow these helpful tips:

• Wash your hands. Washing your hands with soap and water after using the restroom remains one of the most effective ways to prevent the spread of disease. Make sure your hands are squeaky clean by following these five easy steps.
• Clean your bathroom once a week. Scrubbing your toilet with a brush and disinfecting cleaner can cut down viral contamination by up to 99.99%. Make sure to clean and disinfect the floors, countertops and other bathroom surfaces too.
• Turn the fan on. Even though it's less effective than cleaning, the Australian researchers still recommend proper ventilation in the bathroom. Leaving the fan on can remove and disperse these harmful particles from a concentrated area.
• Don't hide your toothbrush. It may be tempting to put your toothbrush in a closed container. However, doing so can make bacteria grow faster than if it was stored upright in the open air.

Sources

• American Dental Association. Toothbrushes.
• Association for Professionals in Infection Control and Epidemiology. New Analysis Shows That Disinfection Is the Most Effective Way to Prevent Viral Contamination of Restroom Surfaces.
• Center for Infectious Disease Research & Policy. Flushing the Toilet May Release Germ Plume at Adult Face Height.
• Centers for Disease Control and Prevention. About Handwashing.
• Science of the Total Environment. Aerosol and Bioaerosol Generation From Toilet Flushing: A Systematic Review and Risk Factor Analysis.