One of the most common and destructive residues encountered on a coin is the plasticizer PVC. The chemical, PVC, makes plastic softer and more pliable and is frequently added to the make up of popular coin holders such as flips. The PVC will come out of the plastic and collect on the surface of the coin inside the PVC-laden holder. If this residue is allowed to sit on the surface and fester long enough, it will eat into the surface of the coin resulting in a certain type of environmental damage known as PVC etching. Even for new coins, PVC residue can be bad news. (NCS)
