Gather compostable materials together using Stalk Market Natur-Bag liners. They're made to fully compost with organic matter for simple, eco-conscious disposal. Made of natural fiber. Used to collect food scraps and other organic waste for composting. Holds up to 55 gallons. BPI Certified Compostable - certified by the Biodegradable Products Institute (BPI) to be compostable in commercial compost facilities (where facilities exist). Product Content Contains Compostable Material - made from materials that can quickly break down in commercial composting facilities (where facilities exist), to help reduce waste while creating usable organic matter.