Product contains compostable elements. Matter Quart Storage Bags powered by revolutionary NatureStar technology, are compostable. Matter brand Quart Storage Bags made using sustainable, natural, and renewable resins that when disposed of properly, will compost in soil in a matter of months . Matter brand Quart Storage Bags are durable and strong, leak-resistant, and refrigerator and freezer safe. The entire lifecycle of Matter brand Quart Storage Bags minimize waste, including adding valuable nutrients back into the earth. From nature, back to nature.