While it has been generally accepted that toilet plume - tiny droplets and aerosol particles released into the air due to turbulence caused by flushing - offered a small risk of transmission of illnesses, it was always thought that for the healthy and those with good hygiene, it would pose few problems. Then coronavirus struck.

According to current evidence, coronavirus is primarily transmitted between people through respiratory droplets and contact routes. Airborne transmission is possible via aerosols. With some coronavirus patients experiencing symptoms including diarrhoea and vomiting, it’s been discovered the virus survives in the digestive tract and has been found in sewerage systems around the world, making faecal–oral transmission also possible.

Additionally new research warns that 40-60% of toilet plume particles can reach to a height of 106.5 cm above the ground - well in excess of the height of a toilet seat - enabling the spread of particles on nearby surfaces. During computer simulations, particles could also stay suspended in the air long enough to be breathed in post-flushing.

This has big implications both in the home, where family bathrooms are also used for activities such as teeth brushing, and public lavatories, where multiple users can come into contact with airborne particles and contaminated surfaces.

Chief executive of the CIPHE, Kevin Wellman said: “Simply closing the lid when flushing the toilet can remove any associated danger of toilet plume. Needless to say, this should always be backed up by vigorous hand washing routine. Those wanting to be ultra-careful, can also then clean the toilet seat before it is used to further reduce the risk of potential infection.

“While a proven case of transmission of the virus via the risk identified in the research is still to be established, we should take all measures available to help stop the spread of coronavirus and other illnesses such as staphylococcus and E. coli. That’s why we are urging installers to get behind the flip ‘n’ flush campaign, to help keep their customers safe.”