Nanomaterials describe, in principle, materials of which a single unit is sized (in at least one dimension) between 1 to 1000 nanometres (10−9 meter) but usually is 1 to 100 nm (the usual definition of nanoscale).
Flush toilets use large quantities of water and are expensive to operate and maintain. Therefore, European sanitation engineers are advancing a clean, efficient and environmentally friendly alternative.