The billionaire philanthropist was speaking at the three-day Reinvented Toilet Expo in Beijing recently, CNN reported. The toilet, which is the brainchild of research projects funded by the Bill and Melinda Gates Foundation, is ready for sale after years of development. The Gates Foundation has committed roughly $200m to the project. The organization expects to spend the same amount again before the innovation is viable for wide-scale distribution. There are multiple designs of the toilet but all work by separating liquid and solid waste, Gates said of the technology. He wanted to show the need for sanitary, off-grid toilets that can remove harmful byproducts from human waste, which helps to stop the spread of disease among the two billion people who don't have access to clean sanitation. The expo featured 20 toilet designs developed by companies from around the world, most of which used clever engineering to separate solid and liquid waste safely and without odor. PREVIOUSLY: Bill And Melinda Gates Are Pledging Major Dollars To Women’s Economic Empowerment "They take both the liquids and solids and do chemical work on it, including burning it in most cases." He compared the change from traditional toilets to waterless models as similar to developments in computing around the time he founded Microsoft in the mid-1970s.  Gates added: "In the way that a personal computer is sort of self-contained, not a gigantic thing, we can do this chemical processing at the household level." Poor sanitation kills half a million children under the age of five every year. It costs the world more than $200bn a year in healthcare costs and lost income, according to the Bill and Melinda Gates Foundation. Gates held up a clear jar of human feces to highlight the importance of dealing with the issue. He said that he brought the jar because it is a good reminder that in it, there could easily be 200 trillion rotavirus cells, 20 billion Shigella bacteria, and 100,000 parasitic worm eggs. The former Microsoft chief executive said the next step for the project is to pitch the concept to manufacturers, adding he expects the market for the toilets to be more than $6bn by 2030. READ NEXT: Watch Bill Gates Try To Guess The Price Of Every Day Items