The Truth About Toilet Lids and Viruses

You Should Know: A new rule of thumb for bathroom hygiene has gained traction in recent years: close the toilet lid before you flush. A 2022 study found that flushing with the lid open creates a plume of microscopic, aerosolized particles that can spread bacteria around a bathroom. Gross — but useful information.

Going Deeper: Because viruses are much smaller than bacteria, researchers wondered whether closing the lid might also limit viral spread. To test this, they applied virus particles to toilets, flushed them, and then measured how much remained in the toilet itself and on nearby floors and walls. The result was unexpected: there was no statistically significant difference in viral contamination whether the lid was up or down.

The Takeaway: Closing the lid didn’t meaningfully reduce virus spread. What did work? Cleaning. Disinfecting toilets proved far more effective at killing germs. Researchers recommend disinfecting at least once or twice a week — and daily when someone in the household is sick. (Worth noting: some members of the research team worked with Lysol’s parent company, Reckitt.)

Bottom Line: Closing the toilet lid can help limit bacteria spread, but regular disinfecting — along with good hand-washing — matters more when it comes to viruses.