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.”

Composting toilets reduce the volume of humanure and other organic materials on site over months or years through predominantly mesophilic composting and yield a fertilizer that is, after the legally required period, able to be used in horticultural or agricultural applications. Composting toilets are also becoming more common as an accepted alternative in homes, where the odor-free operation of a properly functioning unit appeals more to some houseowners than conventional toilets, with their consumption of large quantities of clean water and discharge of large amounts of sewage.

Composting toilets have entered the mainstream plumbing realm by being tested and, if approved, certified to the ANSI/NSF-41 Standard. They can be tested and certified for ANSI/NSF-41 by any ANSI accredited testing laboratories such as Canadian Standards Association, CSA International, National Sanitation Foundation and Underwriters Laboratories.

Waterless, odorless composting toilets ensure that houses can remain occupied in drought areas where water is shut off for periods of time. An example is southern Spain, where at least one composting toilet per house could provide acceptable sanitation for as long as the drought prevails and water is unavailable. Likewise it provides always-usable public toilet facilities under such circumstances. This is becoming a very important application for the technology in areas all over the world where there is only periodic availability of water.