It is not certain whether you can catch COVID-19 from toilets, or not. However, as other viruses are known to spread through this route, it makes sense to take careful precautions.

These include:

  • Put the toilet lid down before flushing
  • Clean the toilet seat, lid and flush handle or button frequently
  • Wash hands carefully after using the toilet

The virus that causes COVID-19, SARS-CoV-2, has been found in wastewater from toilets and in samples of faeces. However, it is unclear whether virus particles from the gut spread from person to person and it is known that faecal spread is not the main route of transmission.

A study in China looked at what happens to particles when a toilet is flushed without the lid down. It showed the turbulence caused by the flush can propel very small droplets of water high into the air above the toilet. If the water droplets contain infectious virus particles, they could get into people’s mouth, eyes or noses, causing infection.

Where did the story come from?

BBC News carried an article about the Chinese study, which warned that flushing could create a ‘plume of spray’. The article makes clear that we do not know whether SARS-CoV-2 spreads in this way, but warns that other viruses are known to spread through poor toilet hygiene.

 

What is the basis for the claim?

The study by researchers from three Chinese universities used computer-modelling of fluid dynamics to monitor the flow of particles in water in a toilet when it is flushed. They modelled the trajectories of these particles at the point when the toilet is flushed and for several minutes afterwards. They found:

  • Flushing creates a vortex in the air above the toilet pan, which encourages ‘massive upward transport of Virus particles’, 40% to 60% of which reach above the toilet seat
  • The particles can reach about a metre above the toilet seat
  • The particles remain suspended in the air more than a minute after the flush

Closing the lid on the toilet before flushing, the researchers say, would prevent this transmission of particles. They also recommend cleaning the toilet seat before using it, as it may have been contaminated by flushing particles. And of course, washing hands carefully after using the toilet is important to get rid of any traces of infection from the toilet flushing mechanism or door handle.

The main way in which the coronavirus is passed on is thought to be through droplets from people with the virus coughing, sneezing or breathing out. However, doctors have found virus particles in faeces from infected people, and some people with COVID-19 have had diarrhoea or vomiting. So, it makes sense to be careful with toilet hygiene.

 

What do trusted sources say?

The NHS recommends washing your hands often with soap and water, but does not give specific advice about toilet use. However, washing hands carefully after using the toilet is standard hygiene advice.

 

Analysis by EIU Healthcare, supported by Reckitt Benckiser

 

Citation

  1. Yun-yun L et al. Can a toilet promote virus transmission? From a fluid dynamics perspective. Phys. Fluids 32, 065107 (2020). https://aip.scitation.org/doi/10.1063/5.0013318

 

Reading list

  1. Xiao F, Sun J, Xu Y, Li F, Huang X, Li H, et al. Infectious SARS-CoV-2 in faeces of patient with severe COVID-19. Emerg Infect Dis. 2020 Aug [cited 23 June 2020] https://wwwnc.cdc.gov/eid/article/26/8/20-0681_article
  2. Center for Disease Control, US. Coronavirus Disease 2019 (COVID-19) frequently asked questions. How does the virus spread. https://www.cdc.gov/coronavirus/2019-ncov/faq.html#Spread