Do you close the toilet lid before you hit the flush button? That small habit turns out to matter more than most people realize. A string of studies from researchers overseas has found that flushing with the lid open sends droplets and aerosols carrying pathogens shooting into the air, in some cases reaching as high as 163 centimeters, right into the breathing zone of an average adult, and close enough to contaminate toothbrushes, towels and other items sitting nearby in the bathroom.
What Happens The Moment You Flush
Researchers at the University of Colorado Boulder, publishing their findings in the UK-based journal Scientific Reports, used high-speed cameras paired with green laser light to track the paths of individual droplets during a flush.
The moment the flush is triggered, water droplets carrying pathogens are ejected outward at roughly 2 meters per second, climbing to a height of 1.5 meters within just 8 seconds. Larger droplets fall back down within a few seconds, but the researchers found that the finest aerosol particles, carrying trace amounts of fecal matter, urine or vomit, can stay suspended in the air for more than 20 seconds. For anyone infected with COVID-19, the flu or another respiratory virus, that lingering aerosol raises the odds that it gets inhaled or spreads to nearby surfaces.
Why Closing The Lid Cuts The Risk
A separate review by Australia's Flinders University, which pulled together findings from 22 related studies, reached a similar conclusion: the high-velocity water striking the inside of the bowl during a flush releases large volumes of suspended particles that can reach as high as 163 centimeters. Lira Adiyani, the review's lead author, recommends making it a daily habit to close the toilet lid before flushing, saying the simple step can substantially cut down exposure to airborne pathogen particles.
Three Ways To Keep Your Bathroom Germ Free
Beyond making a habit of closing the lid before flushing, experts point to three additional steps worth building into a regular bathroom routine.
Wash Your Hands Thoroughly After Flushing
Whether at home or in a public restroom, always wash your hands with soap after touching shared fixtures or the flush button, and dry them with a clean towel or paper towel.
Keep Personal Items Covered
Toothbrushes, rinse cups, cosmetics and bath products should be stored inside a closed cabinet or fitted with a cover, rather than left out in the open where airborne particles can settle on them.
Disinfect The Toilet And Lid Regularly
Wipe down the toilet seat and lid periodically with 75 percent alcohol, or with a bleach solution diluted at a 1-to-1,000 ratio with water. Let the disinfectant sit for a few minutes before rinsing it off with clean water.