Soap nuts are a berry off a tree. They contain saponin which when you add water releases a mild soap. They are environmentally friendly and biodegradable. When you are finished, add them to your compost. No added chemicals and they help to break down the grey water in septic tanks. No scent, so if you like a little fragrance in your washing, add a few drops of essential oil to the laundry bag before popping it in the washing machine. Save on water, as our do not need to rinse. And your clothes come out soft because there are no chemicals. Suitable for allergy and eczema sufferers. Safe on babies skin too.