The Poly Flat Lid is made from Polypropylene #5. It is 100% BPA free, safe and non-leaching. The poly flat lid will fit all ECOtanka bottles except the mega tanka.
 
Care Instructions: ECOtanka Lids: Wash and rinse as you would your dishes, or place in the dishwasher. They may be steralised briefly with boiling water. Please do not place in the freezer.