Although the first patent application for a composting toilet was filed by Thomas Swinburne in 1838, the idea of recycling human waste was by no means new at this time. The Chinese had already been composting human and animal waste for use as fertilizer for thousands of years. However unattractive this process may seem, it is certainly more environmentally viable than a modern sewage system. Composting cuts down on water pollution, and human excreta contain valuable nutrients that can help farmers reduce the amount of chemical fertilizers they use on crops.
Swinburne's "earth closet" was the first device that can be described as a composting toilet, that is, one that deposits earth or peat onto feces to kick start the composting process. But it was not until Henry Moule established the Moule Patent Earth-Closet Company in the 1860s that they became more commonly used. Some schools and military camps reportedly preferred composting toilets because they were cheaper to install than the water-closet alternative.
A variety of designs for composting toilets now exist, including the popular "Rota-Loo," which houses a rotating tank underneath the toilet. Modern composting toilets can even combine vaults for kitchen and toilet waste into a single storage space, which is emptied roughly once a year.
There are many areas of the world where communities would benefit from composting toilets. World Health Organization figures from 2004 estimate that as many as 2.6 billion people are without "improved" sanitation, although the definition of "improved" is still debated. Some communities in developing countries use simple "drop and store" facilities as latrines, but these are often unhygienic and can be a source of contamination and disease.
