This compostable kitchen product line is Biodegradable Products Institute (BPI)-certified and is an environmentally preferable alternative to conventional paper and plastic cups, plates, bowls, and cutlery. In addition to plates and bowls, Sustainable Earth offers compostable cups and lids made of corn-based materials for hot and cold beverages. The line is rounded out by durable, microwave-safe flatware made of sugar cane. Sustainable Earth Compostable Kitchen Products by Staples. Circle 204.