Recyclable lid for Sustain? food pots. This transparent, domed lid is made from a plastic called polyethylene terephthalate (PET) that can be recycled after use. The plastic lid fits our Sustain food pots, sized 12, 16 and 32oz. These pots are great for all kinds of cold food. PET is suitable for temperatures up to 60-70?C so the lids should not be used for hot foods such as soup.