The Full Circle Walnut Scrubbing Sponges are an environmentally responsible option to choose over synthetic cleaning items and artificial plastic based sponges. Walnut shells are naturally abrasive and help remove baked on food easily during normal cleaning. The plant base of the Full Circle Walnut Scrubbing Sponges means that these sponges are fully biodegradable and break down naturally when disposed of. The tough cleaning fibers intermixed with pulverized walnut shells offer an effective scrubbing surface for bake-ware, cook-ware and general cleaning. The Full Circle Walnut Scrubbing Sponges are safe for most non-stick cookware and will not scratch most surfaces. Affordable enough for general cleaning in bathrooms, kitchens and utility rooms, these sponges are long lasting and can be sterilized in the microwave or washing machine.