Designed by researchers at the London School of Hygiene & Tropical Medicine (LSHTM) and Imperial College, the technology consists of single-use tabs of soap, dispensed through various mechanisms.

This early-stage study found that the ‘singular soap’ prompted people who previously did not wash their hands to begin handwashing with soap on average one to two times a day.

In Tanzania, where the study took place, only four to eight per cent of the population in low-income communities regularly practices handwashing with soap, despite World Health Organization guidance that hand hygiene is one of the best ways to prevent transmission of germs.

Within these communities, shared bars of soap are perceived to create a risk of people infecting each other, and when soap is a limited resource its use is prioritised for other purposes such as dishwashing and laundry.

This new technology overcomes the limitations of ordinary soap because the tabs do not need to be shared and are designed only for handwashing. Additionally, the team estimates that the soap tabs can be produced for around one US cent each, making it affordable and sustainable for low-income communities.

It is also environmentally friendly and makes handwashing easier than other settings, because rather than go to where there is a facility with soap and water, you can take the soap with you, in a pocket or a purse. This also means there is no reliance on others providing handwash facilities as in public places.

This product was developed using a mix of behaviour- and human-centred design principles, with the aim for it to be used regularly and strictly for handwashing by individuals in resource-limited settings, like rural or peri-urban areas of Sub-Saharan Africa.

Dr Weston Baxter, project lead and behavioural designer in Imperial’s Dyson School of Design Engineering, said: “Cross-contamination is more salient during a pandemic but is always on people’s minds. The design uses a single-use tab of soap, so every time you wash your hands you’re using a fresh, clean soap. Due to its design, the soap can only be used for its intended purpose, hand-washing.”

While the solution draws on relatively simple technology, it is underpinned by important insights from research conducted by Dr Baxter, Ed Brial, and co-lead Dr Robert Aunger, a public health and behaviour change expert from LSHTM.

Dr Aunger said: “Sometimes we think of innovation as the latest cutting-edge engineering coming out of the lab. But that’s not always the innovation we need to solve the most pressing behavioural issues in the world. Sometimes what is needed is to develop more appropriate technologies and make something that is simple and elegant that can really solve the problem.”

He added that the design approach used in this project is more likely to produce interventions that people will take up and use regularly: “It’s not usually enough to just teach people something, or give them a new technology. You have to understand the psychology of behaviour. Behaviour-change theory is at the core of this design.”