Our Organic Nursing Pads are made from Organic Cotton and PUL, which is a breathable waterproof material. It will give you piece of mind that when your pad is wet it won't leak through your clothing. It is a plastic material however, It is only the outer layer that has PUL. In between is a layer of organic cotton flannel and the outside is organic cotton fleece making them very soft and comfortable against your skin. The cotton fleece is natural and unbleached.