These hinged lid lunch boxes (slotted closing mechanism - not for use with liquids) are made of sugar cane fiber that is a by-product of the sugar refining process. The boxes are bleached with hydrogen peroxide and do not have any coating, so that they are biodegradable and compostable. They can be used for hot or cold foods, and are thick and sturdy, microwaveable, freezer safe, oil resistant and capable of handling boiling water. Soft white color. Case of 500 (4 packs of 125). Made in Asia. Eco Categories: Recycled, biodegradable, agriculturally based, less toxic.