Composting toilets use a process of biological degradation to convert nightsoil into a humus-like substance through the aerobic action of micro-organisms and invertebrates. New composting toilet installations presented for sale in Queensland must comply with the design rules set out in Schedule 8, Part 2 of the Environmental Protection (Waste Management) Regulation 2000.

Consumers purchasing a composting toilet should request a written statement of compliance from the manufacturer or distributor. This statement should be submitted to the local council with the approval application. Composting toilets previously approved by Queensland Health or the Environmental Protection Agency should not be taken as evidence for compliance.