Three ways to protect people from infections in toilets

Toilets are a hygiene risk for a number of infectious diseases. In places where they are used by many people, such as in offices, schools, hospitals, care homes and public buildings, they are an infection risk to the users. 

There are many hygiene issues in the washroom because of its purpose (human waste) the number of users, the number of common surfaces that people have to touch and the confined space that makes social distancing difficult if more than one person is present. A wide range of infectious microorganisms, including Norovirus, Salmonella and other gut microbes, cold and flu viruses, SARS-CoV-2 and MERS-CoV can be spread between people by touching contaminated surfaces or breathing in contaminated air. 

The hygiene risks can be classified into three areas where action can be taken to protect users from infection.

1. Air hygiene

Airborne diseases caused by bacteria, viruses and fungi can be spread whenever water droplets are created – such as flushing toilets and urinals, water splashing in sinks and drains, and aerosols coming out of leaky sewerage systems. Normal respiratory activity such as breathing, talking, sneezing and coughing produces aerosols (particles <100 microns) and droplets (>100 microns) containing viruses and bacteria from infected people and makes them airborne. 

Poor ventilation will cause airborne microbes to accumulate in the room and also keeps bad odours in the washroom, making it an unpleasant experience and produces a bad impression. The finer aerosols can remain in the air for hours and are spread to other parts of the building by opening and closing the door. 

Toilet sneeze is a major source of infection risk in the washroom. The ‘sneeze effect’, caused by the cascading water when the toilet is flushed, creates a plume of droplets of varying sizes that are launched into the air. These droplets can carry viruses and bacteria from urine and faeces. The larger droplets immediately fall onto nearby surfaces in the cubicle, including the seat, tissue and flush button, but the smaller droplets and aerosols can spread around the washroom in air currents, contaminating other surfaces and the air.

Closing the toilet lid before flushing was found to reduce concentrations of C. difficile in the air above by 12 times, showing it’s effective at preventing a large proportion of sneeze escaping. Closing the lid should therefore be promoted as a means of reducing the spread of infections. 

A study of COVID-19 patients in China found 55% carried SARS-CoV-2 in their faeces and it was present for several weeks after respiratory samples had tested negative. During the SARS outbreak in Hong Kong in 2003, the faulty wastewater plumbing system and bathroom extract ventilation in an apartment block were found to have spread SARS-CoV-2 by sucking air through dry U-bends and into some of the apartments. The result was 342 cases of infection and 42 deaths among the residents.

More cases of infections spreading in apartments have been found during the COVID-19 pandemic in China. These cases show that air hygiene is an important factor for reducing the risk of COVID-19 and other airborne infections. 

Bad odours in washrooms are caused not only by the users, but also by poor maintenance of the toilets, urinals, drain pipes and water supply. Bacteria, uric acid and calcification can build up, generating lingering bad odours and creating reservoirs of infectious material. 

Damp – which is a result of faulty plumbing, poor ventilation or persistent condensation – allows mould growth and production of spores that pollute the air in the room. 

Keeping washrooms safe requires adequate ventilation and air cleaners, if necessary, to reduce the levels of aerosols, pollutants, other particulates (including mould spores) and smells.

2. Surface hygiene

There are many places in the washroom that people touch and can pick up infectious microorganisms or transfer them to surfaces from a contaminated hand. Bacteria and viruses can survive for days on surfaces where they can accumulate, creating reservoirs for spreading infections. 

However, the early fears of fomite (surface) transmission of the SARS-CoV-2 virus appear to have exaggerated the risk. Studies of real-life situations show that a risk only lasts 1–2 hours after an infected person coughs or sneezes on a surface and there is less risk in other situations. Other pathogens, however, can last much longer on surfaces. Many bacteria and fungi can survive for months on surfaces, while respiratory viruses mainly last, at most, a few days.

Microbe-containing droplets from toilet sneeze can land on any surface, such as door handles, toilet flush buttons, the floor, feminine hygiene units (FHUs), wash basins, taps, soap dispensers and unprotected toilet paper and paper towels. Urinals also create a spray of droplets when they are used and during flushing. 

Surfaces inside the cubicles receive the majority of the toilet sneeze – including personal items taken into the cubicle. Moving from the cubicle to the basins, washroom users can cross-contaminate surfaces with their hands as they go through the actions of washing and drying hands. A study of 4800 surfaces in office buildings found the highest microbe readings on the washroom taps, with 75% being classed as “dirty”.

People themselves are also sources of contamination. Droplets of mucus and saliva from coughing, sneezing and talking behave in the same way as toilet sneeze and can carry microorganisms from the respiratory system onto all the washroom surfaces mentioned above. 

Clothes, shoes and personal items can carry dust and soil containing bacteria, viruses, fungal spores and pollen from outside into the washroom and other areas of the building. Personal items such as handbags can be sources of cross-contamination when moving from the cubicle floor or door hook to the sink counter, to the owner’s work space and even to their home — possibly onto a kitchen surface where food is prepared. 

All the surfaces should be cleaned and disinfected regularly with a cleaning fluid that is effective against pathogenic bacteria, viruses, fungi and parasites. Solutions area also available that provide a residual protection for several hours after application.

3. Hand hygiene

Hand hygiene is widely recognised as one of the most important factors in preventing the spread of infectious diseases, especially for food safety and in clinical environments. It’s closely tied to surface hygiene in the washroom because hands need to touch so many surfaces to make use of the facilities. 

Maintaining hand hygiene requires good personal hygiene habits from the users, good maintenance of the washroom to keep hygiene levels high, and adequate facilities for users to wash and dry their hands hygienically. 

Washroom users bring their personal selection of resident and transient skin microbes into the washroom and can transfer them to any of the surfaces and gain high levels of microbes after using a cubicle.

Encouraging users to wash with soap and rinse for a total of 20 seconds is the best way to remove bacteria and viruses. The physical effect of rinsing is the most critical for removing viruses as they are harder to remove than bacteria and parasite cysts and eggs.

Several factors in washroom design can help to improve hand hygiene.

• Use no-touch technology wherever possible, such as taps, soap dispensers, paper dispensers, sanitiser dispenser, doors, and feminine hygiene unit (FHU).
• Protect toilet paper and paper towels from airborne and hand contamination by using a dispenser.
• Provide antibacterial soap, hand lotion to help skin health and hand sanitiser for extra protection.
• Provide a hand-drying option that dries hands quickly, so users will fully dry their hands as wet hands pick up and transmit many times the number of microorganisms.

Studies in the US have shown that regular use of hand sanitiser led to a 30–40% reduction in respiratory and gastrointestinal illnesses in university dormitories, a US army base and an office building.

Hand hygiene can also require psychological input to change poor behaviour when compliance rates are low. This may require education outside the washroom, but a simple addition to the washroom, a pleasant smell, was found to increase handwashing compliance.

Holistic hygiene approach

Prevention of infection in the washroom is dependent on an integrated approach to hygiene, using a combination of air, surface and hand hygiene measures to break the chain of infection. A wide range of solutions is available to protect each risk area and help stop the spread of pathogens. 

These include the following.

• Disinfecting and sanitising solutions and wipes to protect surfaces
• Handwashing, drying, sanitising and moisturising solutions to protect hands and prevent hand-borne transmission of diseases
• Air purification and remediation solutions to protect and enhance the air and create a pleasant experience for washroom users