Green Safes eco-friendly compostable soup cup lids are made from corn! This plant-based material is crystallized poly-lactic acid also referred to as CPLA. This particular material has an additive called talc, which allows the PLA material to withstand higher temperatures. These lids are a great alternative to petroleum-based products. Intended for hot foods up to 200 degrees, not microwavable, and will commercially compost within 90-120 days.