Green Safes eco-friendly compostable soup cup lids are made from corn! This plant-based material is crystalized polylactic acid (CPLA) also referred to as Ingeo. This particular material has an additive called talc, which allows the Ingeo 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.