Latrine slabs – Alternative materials – ‘Anti sticky’

Scarce water resources are wasted on cleaning latrine slabs
By its nature, faecal material is very ‘sticky’ and it takes a lot of water – or chemicals – to remove it. At the same time water for latrine slab cleaning is scarce. Water also influences the capacity (lifetime) of the latrine in a negative way. Even worse: chemicals used for latrine cleansing kill the biological processes in the latrine pit or raised latrine container.

Is it possible to apply a ‘non-sticky’ material?

Ideally, the surface of a latrine slab should be made in such a way that faeces does not ‘stick’ to it. That would reduce the volume of water needed for cleaning the slab. This ‘non-sticky material could be applied as a special coating.

Objective:

• Research the feasibility of applying non-stick coating to latrine slabs to facilitate easy cleaning and thus minimize the use of water and chemicals for cleansing.

 

Activities undertaken

A desk survey of existing films and coatings has been carried out along with an assessment of the possibilities to apply the films/coatings to latrine slabs including raised latrine.

Besides Nylon, any plastic can be applied as material for latrine slabs with respect to water resistance. However, there is only one kind of non-sticky plastic, which is Fluor Polymers. Non-sticky means hydrophobic conditions. Even though these materials (or coatings) are applied in lots of products to create non-sticky-effect, it is not recommended to apply them on latrine slabs: Fluor Polymers are very costly, are hard to apply as a coating in products, they are soft and therefore sensitive to damage and lastly they are not repairable in the field.

A non-sticky coating would be a good alternative since coatings can be applied later on, even when the latrine slab is at location in the field. Besides, a coating can also apply on other relevant parts, not only for the slab. These coatings are promising according to the suppliers (easy to apply, durable, etc.) however this should be tested since these are subjective sources. Testing is an elaborate and costly affair and currently outside the financial means of ESP. We advise to follow the results of the different researches done by K.K. Nag and by in the framework of the Bill and Melinda Gates Foundation (BMFG) ‘Reinvent the toilet challenge’.

K.K. Nag research. K.K. Nag is the producer of the Nag Magic slab. They have ordered ‘ultra ever dry’ to test out.

BMGF reinvent the toilet research. One of the projects that look into this issue is the ‘pressure cooker’ toilet of Loughborough University. The research will take one more year before it produces results. However this is a ‘cross-cutting’ issue and we are in contact with Mr. Carl Hensman, Programme Officer WASH (carl.hensman@gatesfoundation.org) to be updated on the findings.
Non-sticky sprays from several different companies were found in a market research: WaterBeader, NeverWet, Hydrobead & Ultratech.

Tell us your idea!

If you have any products or ideas, please get in touch with:
Jan Spit, Adviser Sanitation
WASTE advisers on urban environment and development
www.waste.nl
e-mail: jspit@waste.nl
mob: +31 6 57 99 78 74