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Can fragrances help combat poor sanitation?


December 14, 2016 • 5 min read

There is a case to be made that there is a logical and evolutionary reason for smell.


"Researchers are developing fragrances in the hopes that people will be encouraged to use toilets if they smell better."

I recently attended the Global Toilet Business Innovation Summit in Mumbai, India. The summit, which was hosted by The Toilet Board Coalition, brought together key players from across the sanitation sector. What was especially refreshing was a significant presence from the private sector. This included large multinationals such as Unilever, Kimberly Clark Corporation, LIXIL and Firmenich, and around 75 small and medium scale entrepreneurs and businesses. The private sector is often spoken of as key to achieving success at scale, yet they are rarely in attendance at such summits.

Undoubtedly, one of the highlights of the three days was a talk from Firmenich on smell science “Eliminating the yuck factor” from public toilets and latrines. A video on the subject was premiered at the summit, and covered on Bill Gates’ Blog. Essentially, Firmenich are working with the Bill and Melinda Gates Foundation (BMGF) to tackle latrine malodour with “smell-cancelling” technology. The argument is that too often in the developing world toilets are not used because they smell bad. To combat this, Firmenich researchers are working on developing fragrances that block certain receptors in our noses, making us unable to register certain malodours. Think of noise-cancelling headphones for example, but applied to your nose instead of your ears. “The question now is whether this technology is good enough to make a difference in communities with poor sanitation,” as Bill Gates has put it.
Innovative solutions to tackling global WASH issues are often cause for much excitement, especially when a large multi-national company is seen to be working on something as exciting as this and is backed by BMGF. There is, after all, plenty of depressing statistics and indicators on access to sanitation in our sector, so why not afford ourselves the opportunity to get excited about something as pioneering and potentially game-changing as this? The question that needs to be asked, however, is not whether this technology is good enough to make a difference, but how can it make a positive difference.

I understand that this technology is still a long way from being useable and available, but let’s just assume for a moment that it is ready to roll out

Would people still be keen on using a latrine if there was poop all around the toilet even if there was no smell? The danger is that this innovation will be seen as a substitute for Operation and Maintenance (O and M) – which will be required more than ever, if a latrine has more users. Caretakers might feel that they no longer need to maintain hygiene standards if there is no smell.

Effective O and M from caretakers is often required to manage the emptying of pits; ensuring there is ready access to water and soap for handwashing and possibly anal cleansing; maintaining hygiene; and, in many situations, to collect user fees. How can we expect them to do all of this, if they can’t keep a latrine clean and smelling decent without the use of this technology?
Are we addressing a simple problem with a complex technical solution? Should we not be concentrating on behaviour change (in that many people are embarrassed to be seen going to a latrine), increasing capacity, and promoting adequate monitoring with suitable incentives?

Just how will this technology be rolled out? I could see it being deployed effectively in the West, but what about Sub-Saharan Africa? Where it would take all of Firmenich and Microsoft’s knowledge and expertise to make this affordable through a robust supply chain.

Public latrines aren’t always used as latrines. I’ve seen them used as homes, for storage, and even for pigeon breeding. What will happen if we make them smell too nice?
There is a direct correlation between smell and the presence of flies. Would this technology also help eliminate vectors? It would be fantastic if it did. However, if it didn’t people might think their toilet is as healthy as it can be, when really there are multiple vectors spreading disease. Our overall target as professionals is to improve public health – not necessarily to increase latrine use.

There is a case to be made that there is a logical and evolutionary reason for smell.

In 2003, researchers at the London School of Tropical Hygiene and Medicine carried out a study on smell and our association of it with disease. One of the researchers at the London School, Val Curtis, echoes a suggestion that goes back to Charles Darwin. That is, poop stinks for our own good. Our disgust towards certain sights and smells, Curtis says, is a “behavioural immune system”. It is an adaptation — biologically rooted, but tweaked by culture and social conditioning — that evolved to keep us from coming into contact with infection and disease. Perhaps we shouldn’t be playing with this formula.

One area where this technology could really have an impact is with container-based sanitation. Many of the enterprises like Clean Team, Sanivation, SOIL or Mosan who are working in and pioneering this approach, rely on business models where waste from households is collected every two or three days (that being the time it takes to start to smell). What if this technology could be used to increase collection time to perhaps every five days? This could have a huge impact, by scaling up access to sanitation and making business models more attractive and cost neutral.

Refugee and IDP camps might also provide an opportunity to trial this technology. The O and M works differently in these settings. There is a reliable supply of international products making their way to the camps via implementing partners, so there shouldn’t be any issues with supply chain or affordability. The focus, therefore, could be less on behaviour change and more on public health impact.

I congratulate Firmenich and BMGF on this project and their early results. Let’s hope if the opportunity comes, we as a sector can utilise it in the right way.

Ammar Fawzi
Global WASH Advisor