473.1 ml. Made from plant based materials. Microwave safe. Why choose. These 100% compostable bowls are made from plant based materials and deliver the heavy duty quality that you've come to expect of a Hefty bowl. Microwave safe. Heavy duty. Only compostable in industrial facilities. Hefty.com. how2reycle.info. To contact us visit: Hefty.com, call: 1-800-433-2244 or write: Hefty Brands, PO Box 85583, Richmond, VA 23285-5583. Product made in China. Why Choose Hefty EcoSave These 100% compstable bowls are made from plant based materials and deliver the heavy duty quality that you've come to expect of a Hefty bowl.