Can Iodine Diffuse Through Dialysis Tubing?

Can Iodine Diffuse Through Dialysis Tubing? Glucose, starch and iodine (potassium iodide) will readily pass through the membrane of the dialysis tubing. Can iodine pass through plastic bag? Yes, the plastic bag is permeable to iodine, because iodine got in with the starch and it turned purple. Why is it not good to store iodine