The key is the separation of the liquids and solids and the airflow. By separating the waste in side the Kazubaloo System and ensuring that a near continuous flow of air passes over the separated waste the system is designed to ensure that decomposition is an aerobic process. The products of aerobic decomposition are odourless and non-toxic.

Miranda Campbell, Environmental Practices Adviser at the National Trust said: "We had been most worried about the potential for the toilet to smell, but we have had the loo a year now and smell has never been an issue".