In recent years, several commercial compost-toilet systems have begun to compete with and replace conventional water closets in high-use public facilities. There they have found a market because of their resilience and the environmental advantages of not discharging pollutants into the environment. Outstanding among these is the three-storey C.K. Choi Building, which contains 5 compost toilets (10 seats) for 300 full-time employees. The IslandWood School on Bainbridge Island, WA (USA), relies entirely on compost toilets. Facilities Manager Dean Newcomb says, “All of the comments about the compost-toilet systems have been favorable. We keep the bathrooms immaculate, and the fan in the vent system generally works well, so it really gets rid of the misconception that these are smelly systems.”

A composting toilet is any system that converts human waste into an organic compost and usable soil, through the natural breakdown of organic matter into its essential minerals. Aerobic microbes do this in the presence of moisture and air, by oxidizing the carbon in the organic material to carbon dioxide gas, and converting hydrogen atoms to water vapour.

"Self-contained" composting toilets complete the composting "in-situ,", while "central unit" ones flush waste to a remote composting unit below the toilet. Vacuum-flush systems can flush horizontally or upward.

Composting toilets can be installed anywhere, such as a cabin, cottage, bunkie, yurt, RV, pool cabana, boat, shed, barn, or home.