Do you leave the toilet seat up when you flush? A simple question – maybe one you’ve never really thought about before, or maybe it’s your biggest peeve when others do it. Whatever your answer, it’s a very valid question. Because this seemingly benign habit may be the source of a fountain of bacteria erupting in the middle of your home.
Would you stick your head inside your toilet? No, probably not. But flushing with the lid up might be just as gross. Just one simple flush of the toilet can produce thousands of tiny aerosol droplets, which contain bacteria and viruses. And the force of an average flush can propel these droplets up to six feet away.
With this in mind, I did my research to find out just how dangerous the bacteria can be for our spaces and our health (not to mention using it as a secret ulterior motive to convince my flatmates to finally put the seat down).
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What does flushing with the lid up actually do?
Every flush creates a mini ‘toilet plume’. When you flush, rushing water mixes with whatever’s in the bowl, be it water, waste or the bright pink cleaning products you so lovingly picked out. This then creates a burst of tiny droplets that shoot up and out into the surrounding environment in seconds.
Some droplets settle on nearby surfaces, covering everything, from your toothbrush to your best bath towels, while the smallest ones can float around in the air for several minutes. Research has found these aerosols can carry bacteria and viruses, even after multiple flushes, which means they can linger on surfaces and spread via hands later.
Closing the lid helps block some of that spray, though it’s not a perfect seal, so the best defence is a combo: lid down, regular cleaning and always washing your hands afterwards – which, I hope you’re already doing.
What are the dangers?
Below are five evidence‑informed (and, frankly, peace‑preserving) reasons to make the lid‑down habit stick.
It spreads dangerous bacteria
Flush plumes can travel further than you think. Lab studies show that a single flush can send droplets shooting up to 1.5 metres into the air at surprising speed.
Experts say these droplets can stay suspended long enough to be breathed in, with some of them carrying bacteria like E. coli or staphylococcus, or even traces of viruses found in waste water, which can result in the spread of illness around your home.
That’s why the Chartered Institute of Plumbing & Heating Engineering launched its Flip ’n’ Flush campaign, encouraging everyone to pop the lid down before flushing. While the lid isn’t a perfect seal, it does break up the splash and jet of water, which helps reduce the spray. The bottom line? Closing the lid is an easy extra step to keep your bathroom and your health safer.
It contaminates surfaces and products
Think about what’s sitting next to your loo. In most of our bathrooms, the toilet is just a few steps or even inches from the sink, your toothbrush holder and your skincare stash. That’s why experts warn that spray from a flush can land on the very things you put in your mouth or on your face. If that doesn’t make your stomach turn, I don’t know what will.
Studies have found toothbrush holders and taps are among the germiest spots in the home, partly thanks to bacteria kicked up by flushing with an open lid. Closing the lid before you flush (and storing personal items a little further from the toilet or buying a lid for your toothbrush) helps reduce the risk. It’s not foolproof, but it’s a simple habit that makes a real difference.
It puts pets and children at risk
While I’m sure we can all agree that dogs drinking from the toilet bowl in movies is pretty funny, I’m sad to say that in the real world, it’s pretty dangerous.
If your cat or dog loves sneaking a sip from the toilet, it’s time to put a stop to it. Bowl water can contain traces of waste, cleaning chemicals or even harmful germs, none of which are good for your furry friend. In fact, pet experts warn that drop-in cleaners and in-cistern tablets can irritate or even poison pets. The easiest fix? Keep that lid down so they stick to their water bowl.
Toddlers are top‑heavy and curious, which is a risky combo everywhere in the home but especially around a toilet. UK child‑safety groups, including the Child Accident Prevention Trust, list closing the toilet lid and using a childproof toilet lock where needed as part of indoor drowning prevention. While it may seem far-fetched, it is possible for a young child to topple forward and get stuck head‑first in the bowl in seconds. Lid‑down also helps keep little hands out of germy water or splash residue after someone’s been ill, so it’s good practice for keeping little ones safe all round.
It causes stinky odour bursts
Although lids aren’t airtight, closing them before flushing can damp down the initial waft of foul stinky air that may or may not arise from toilet waste. We don't know what you ate last night...
So, it's best to contain smells at the source, alongside ventilating and cleaning, to keep your bathroom smelling fresh, not funky.
It leads to grimy build‑up
Lid-down flushing not only reduces bacteria in your bathroom but also physical grime, making it much easier for you to clean over time. Splash‑out droplets caused by ‘reckless flushing’ contribute to the sticky biofilm that forms on the outside of the bowl, the floor and surrounding fixtures. The CIPHE campaign urges lid‑down flushing as part of broader hygiene to cut down on the spread of ‘nasties’ in family bathrooms and busy public loos.
Flushing with the lid down helps minimise the dispersal of contaminated droplets that otherwise land on hard‑to‑clean nooks and crannies around the base of the toilet and the rest of the room. Over time, that means less grime and fewer deep‑clean sessions – isn’t that what we’re all after?
Toilet seat cleaning kit
Marigold 3 x Bathroom Gloves Medium
