Should You Flush the Toilet With the Lid Up or Down?

Flushing a toilet with a lid closed may seem like a good idea. Scientifically, it is only partially true because it makes little to no difference for viral particles. Additionally, you may not know that flushing a toilet with a lid open has many benefits. 

So which one is the best to do daily, which is more sanitary and keeps your bathroom surroundings germ-free? Let’s find out.

What Scientists Say About It?

Like other debates, this argument also spurred scientists to research it, and they came to very interesting conclusions. 

In a recent study published in the American Journal of Infection Control, there is no significant difference in spreading microscopic viral particles to bathroom surroundings whether the toilet is flushed with a lid closed or open. The study also found that the most effective way to control the spread of these viral particles is by disinfecting the toilets and bathroom surfaces. 

Other research has also reached the same conclusion. For example, a research team at the University of Arizona found that flushing a toilet with a lid open or closed doesn’t make much of a difference in residential restrooms. 

However, many experts suggest that while flushing a toilet with a lid closed or open may not prevent microscopic viral particles from spreading, it keeps certain bacteria, microbes, and odors at bay to a certain level. That’s why they insist that flushing a toilet with a lid closed is more hygienic and sanitary. 

Whether flushing a toilet with the lid closed and open makes any difference is still an ongoing topic that researchers are exploring and striving to discover new findings. However, scientists are currently focused on understanding toilet plume aerosols, their dispersal patterns, and potential risks.

Why Should You Keep the Lid Down During Flush?

We still haven’t reached the final verdict. The question remains unanswered: What is the preferred protocol—closing or leaving the toilet lid open when flushing?

While flushing with the lid shut or open can’t contain the viral particles that somehow escape the toilet, a closed lid stops or reduces the spread of many other airborne particles, bacteria, and germs during flush. 

In a 2013 study released by the University of Oklahoma, researchers uncovered that after flushing toilets, water droplets, pathogens, and other fecal matter can disperse into the air and settle on a nearby surface. This dispersal can happen in an upward direction almost immediately after the flush. 

However, when you close the lid during the flush, these airborne germs and particles remain contained within the toilet bowl, reducing the bacterial presence. However, they have not been completely eliminated from the air samples. 

Despite lid closure, minuscule droplets may still find their way out, possibly escaping through the crevice between the toilet cover and seat.

Additionally, scientists from the University of Colorado Boulder visualized with an experiment using bright green lasers and a camera that aerosol plumes are rapidly released into the air during the flush of the flushometer-type toilets, which are lidless. 

The aim was to visually capture the decades-old phenomenon of tiny particles being shot into the air during flushing. Through camera footage, the researchers successfully measured the speed and distance of particle dispersion, providing valuable insights into this previously unseen process.

The research findings revealed that within a mere eight seconds, particles were shot at astonishing speeds of 6.6 feet per second, soaring up to 4.9 feet above the toilet. Larger droplets swiftly landed on nearby surfaces, while smaller ones remained suspended in the air for minutes or even longer, as observed in the study.

Are There Any Benefits to Keeping the Lid Up During Flush?

You may be surprised that keeping a lid up still has some functional benefits. All the toilet flushes are not equally powerful and some lose their efficiency with age. So, a single flush may not be enough to drain all the waste from the toilet bowl. Flushing a toilet with the lid open allows you to check if any waste remains in the toilet. 

Additionally, an open-lid toilet doesn’t trap odors. As a result, these odors can escape the bathroom quickly through the windows, keeping it smell-free. However, it would be best if you considered the potential downsides of keeping the lid open. 

Although we can’t forget, flushing with the lid up can release aerosolized particles into the air, potentially spreading bacteria and germs around the bathroom. This could pose a hygiene risk, especially in shared spaces. So, the arguments or benefits of a closed toilet lid certainly outweigh those of an open toilet lid during flush.

How to Avoid Contracting Bathroom Pathogens?

Some viral particles and pathogens may still escape containment, whether the toilet lid is closed or open. This makes the bathroom a breeding ground for pathogens, and contracting them could make you sick. Symptoms commonly associated with sickness caused by bathroom pathogens include vomiting, diarrhea, fever, and abdominal pain.

But we can not avoid using the toilet, right? So, how will we avoid contacting bathroom pathogens? According to experts, the best way to prevent contracting contagious pathogens and viral particles is to wash your hands with soap every time you use your toilet. 

Hands can easily pick up germs, bacteria, and viruses from various surfaces, including toilet handles, faucets, and door handles in public restrooms. Now, washing hands for 20 seconds helps remove these harmful pathogens, reducing the risk of spreading illness.

But some public restrooms don’t have soap for washing hands. That’s why it is wise to carry hand sanitizer and disinfectant wipes to keep yourself safe. Also, some people smoke inside the bathroom or scroll on their phones while sitting on the toilet. 

We suggest not doing it, as these devices, which you carry everywhere, may also contract contagious pathogens.


In short, flushing a toilet while keeping the lid up is a better option than keeping it open. While viral particles may still escape the toilet to air despite the toilet lid remaining down, closing the lid prevents many toilet plume aerosols from spreading. 

However, neither of these methods can eliminate the plumes that may contain viruses and bacteria. So, you must be careful not to contract any of these plumes. Also, to kill viruses, germs, and bacteria, you need to disinfect your toilet and bathroom once every week. 

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