Why you should always close the toilet lid: Images show how germ-infested water droplets are thrown far into the air when you flush

Joe Pinkstone
Daily Mail.com
Tue, 03 Nov 2020 12:35 UTC

Harpic, the chemical company, used high-speed specialist cameras to capture the firework display of aerosol particles caused by a toilet's sloshing water in a studio

Comment: Leaving aside for the moment how this information is in part being used to further scare the public about coronavirus, the following data is useful to remember - and act on - for any number of infectious or sickening particles spread by toilet water droplets.

A series of startling photos have captured what really happens when a toilet is flushed with the seat lid still up.

Harpic, the chemical company, used high-speed specialist cameras to capture the firework display of aerosol particles spewed into the air by a toilet's sloshing water.

The striking visuals add to a growing movement to encourage people to put the lid down before flushing. A July study found coronavirus particles can be sprayed in a cloud up to three foot high by a single flush.

survey of 2,000 Britons found 55 per cent of UK adults don't close the lid when flushing the toilet - despite almost three quarters (72 per cent) saying they are more hygiene aware than ever before.

Toilet bowl water remains contaminated for several flushes after becoming exposed to harmful pathogens.

The striking visuals add to a growing movement to encourage people to put the lid down before flushing. A July study found coronavirus particles can spray potentially infectious parties in a cloud up to three foot high

The coronavirus is hardy and can survive a trip through a human's digestive system. It is often still present in faeces weeks after symptoms have stopped.

A research and development associate at Harpic, said: 'There has never been a more important time to take extra care around our homes, although the risks associated with germ spread in unhygienic bathrooms are high, the solution to keeping them clean is simple.

'As experts in hygiene, Harpic are on hand to help everyone stay safe at home.

'We hope our new #CloseTheLid campaign helps inspire people to make simple changes to their cleaning routine that can have long-lasting benefits to the health of the nation.'

One flush of a toilet produces thousands of tiny aerosol droplets, which can contain bacteria and viruses and contaminate surfaces up to six feet away, Harpic claims

Some of the particles produced by a flushing toilet are capable of reaching the lower respiratory tract, which can lead to infection.

If a person touches a surface contaminated by the toilet bowl flush, they can then become infected when they touch the nose or mouth.

When asked why they do not close the lid when flushing the toilet, the top reasons from respondents include being unaware of the risks of not flushing (47 per cent), feeling afraid to touch the lid (24 per cent) and general forgetfulness (15 per cent).

The coronavirus is hardy and can survive a trip through a human's digestive system. It is often still present in faeces weeks after symptoms have stopped. A research and development associate at Harpic, said: 'There has never been a more important time to take extra care around our homes'

However, almost all of the 2,000 respondents (95 per cent) admitted they will start to close the lid after being made aware of the risks.

The research commissioned by Harpic revealed Brits are already taking important steps in ramping up their cleaning efforts.

Cleaning the toilet bowl (49 per cent), deep cleaning the bathroom more frequently (45 per cent) and mopping the floor (44 per cent) are the top things the nation has started doing more of over the last six months.

Previous research has found SARS-CoV-2, the virus which causes COVID-19, can be transmitted via faecal particles.

A study published in June in the Lancet identified virus particles in the excrement of COVID-19 patients nearly 5 weeks after the patients tested negative.

These particles were still viable and could cause faecal-oral transmission of the coronavirus, the researchers warned.

Despite this, the general public is less aware of this potential route of transmission than they are other methods of infection.

Comment: 'Because Covid' was the reason behind the following study, but again - good to know in any case since 'the virus' ain't the only virus!

Toilets are a daily necessity but also become dangerous if used improperly, especially against the current scenario of a global pandemic. This paper has used the CFD approach to clarify how toilet flushing can promote virus transmission. The flushing processes of two different types of toilets (single-inlet flushing and annular flushing) have been simulated, and in particular, the fluid flow characteristics and the movement of aerosol particles during flushing have been investigated. Several alarming conclusions can be summarized as follows:

- Strong turbulence has been observed to be generated by both flushing methods.

- An upward velocity of as much as 5 m/s is produced, which is certainly capable of expelling aerosol particles out of the toilet bowl.

- Some 40%-60% of the total number of particles can rise above the toilet seat to cause large-area spread, with the height of these particles reaching 106.5 cm from the ground.

- Even in the post-flushing period (35 s-70 s after the last flushing), the upward velocity of the diffused particles can reach 0.27 cm/s-0.37 cm/s, and they continue to climb.

- The data analysis indicates that given the same amount of water and the same gravitational potential energy, annular flushing causes more virus spread.

Faced with these alarming results, we advocate several safe procedures to adopt when using a toilet:

1. Put the toilet lid down before flushing, which can basically prevent virus transmission.

2. Clean the toilet seat before using it, since floating virus particles could have settled on its surface.

3. Wash hands carefully after flushing, since virus particles may be present on the flush button and door handle.

This paper may also enlighten toilet manufacturers and prompt them to produce better designed toilets in which the lid is automatically put down before flushing and cleaned before and after flushing.