Is dialysis tubing permeable to iodine?

Dialysis tubing is typically not permeable to iodine. Iodine molecules, being small, can only pass through the pores of semipermeable membranes. Dialysis tubing, especially if made of regenerated cellulose, has a molecular weight cut off of around 12,000-14,000 Da, which is insufficient for iodine molecules (molecular weight of 253.8 g/mol) to diffuse through.