Fiber box lids are made from bamboo and unbleached plant fiber, an annually renewable resource. They are soak proof and have no wax or plastic lining. Great for hot or cold items, these lids are durable, freezer safe and certified compostable in 2 to 4 months in a commercial composting facility. Food Container Type: Lid; Material(s): Unbleached Plant Fiber; Material Type: Paper; Color(s): Natural.