Why Do Toilets Have Lids

Toilets are used very regularly. Almost always the lid is kept up, and never closed. So, in this article, I will explain why toilets have lids.

In general, toilet lids are to stop the spread of bacteria from inside the toilet, and to stop things from accidentally being dropped in the toilet. Studies have shown that flushing the toilet with the toilet seat down reduces airborne bacteria by water flushing by 50%.

Below, I will explain the details of the study, and cover whether the lid should be kept down whenever a toilet is not in use. As well as, if it’s good to put the seat down before flushing or not.

Why Putting the Lid Down Before Flushing is Better

It has been found that putting the toilet lid down and then flushing it, is better than flushing it with the toilet lid up. But, here’s exactly why putting the lid down before flushing a toilet is better.

Overall, flushing with the lid down reduces bacteria that gets into the air by 50%. This bacteria is transported in tiny droplets of water that are created by the motion of the water as it flushes.

These micro-droplets eventually settle on surfaces in the bathroom. You’ve likely seen a waterfall. Around the base of a waterfall, you can typically see a fine mist. Especially, when the sun is shining directly on the base of a waterfall.

Here’s a video of mist that forms in a waterfall, so you can see how this mist forms when you flush a toilet:

This is the same process that occurs when you flush a toilet but on a much smaller scale. Also, toilets are typically located next to a vanity unit, or where it’s easy for something to fall into the toilet. It’s kind of gross to fish something out of the toilet if you drop something in there. 

So, keeping the lid down will stop this from happening. For example, if there is something on the vanity unit, like a toothbrush or container of floss, it’s easy to knock it off with your jacket, or your hand where it can end up landing in the toilet. 

According to the Microbiology Society, a study showed that airborne particles are kicked up and put into the air by flushing. These are very tiny droplets of water that are virtually invisible to the naked eye. With them come any bacteria, and microparticles of poop and urine.

toilet bowl with closed toilet lid

With the lid closed these particles collect on the lid and over time will dry. So, it’s a good idea not to touch the lid where possible without washing your hand after. This bacteria can get on the toilet seat. However, separate studies have concluded that bacteria that get in and around the toilet aren’t a potential health risk.

Using a toilet seat cover is a common practice. As you may know, these sit on the toilet seat and are flushed into the toilet after use. Many people wonder whether toilet seat covers are flushable, and if they cause the toilet to clog. 

I explained this in detail by examining what toilet seat covers are made of and summarized in this article about toilet seat covers.

If you have a medium to large pet dog, it’s common for them to drink water from the toilet bowl. When you have a dog that does this it’s best to close and keep the lid closed when not in use. Dogs have a habit of liking people, and it can potentially spread bacteria.

What Toilet Lid Covers Do

You may have seen a fluffy toilet lid cover. They aren’t very common but I often wondered what the point of having one is. I looked into it and here’s what I found.

As a general rule, they are used to decorate the toilet. Some people use a fluffy toilet lid cover and have matching towels, and rugs. They do virtually nothing to keep the toilet warm. Some also wrap under the lid and stop the lid from being as loud when you put it down.

In general, these are reasonably unhygienic. The reason is the underside touches the toilet seat. And toilet seats contain bacteria, and if not cleaned properly after use can have urine. Therefore, unless you really like the way they look, it’s best not to use a toilet lid cover.

closing the toilet lid

Should You Put the Seat Down Before Flushing

It’s generally only males who will leave the toilet seat up when they use it to go pee. While there’s no hard and fast rule about leaving it up or down it does annoy some people. But, is it better to put the lid down before flushing?

As a general rule, it’s not better to put the seat down before flushing. But, it is better to put the lid down before flushing. Studies have shown that it reduces bacteria that get into the air by 50%.

Putting the toilet seat down does create a physical barrier between the mist that is created by toilet flushing. But, it only covers about 10% of the area and so only has a minor effect on stopping the toilet mist from being spread around a bathroom.

Should the toilet seat be up or down when pooping


In general, the toilet seat should always be down when pooping. A toilet seat is much more comfortable than sitting on the bowl. It’s also typically made of material that warms up faster than the porcelain that a toilet seat is made of. 

The rim of a toilet bowl is typically very narrow. Porcelain is also very slippery when it gets wet. As you sit on a toilet condensation from the heat of your butt can make the toilet rim wet. And there’s a risk you can fall part way into the toilet. 

It’s very difficult to climb out if that happens, and your butt could make contact with the interior of the toilet bowl. A toilet bowl typically is unhygienic, and you shouldn’t touch it if you can.

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