The Dangers of PVC Residue
Posted on 10/1/2005
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.
To combat the ill-effects of PVC, both NCS and NGC recommend submitting your coins in what is referred to as “hard” flips. Hard flips are those that have not been treated with the plasticizer PVC and have a harder more brittle texture than do the “soft” flips that have PVC added to their make up. Flips are intended as a short-term storage option. When selecting a flip for short-term storage, such as those used to submit your coins for professional conservation and grading, choose those with a stiff feel that are free of dangerous plasticizer residues. Even very short periods of storage, such as the time for a package to be delivered through registered mail, can have a negative impact.
A recent submission of modern commemorative coins came to the attention of NCS and points out a problem seen too often. All of the coins had been shipped in the PVC-laden “soft” flips. In a short time, these coins had PVC contamination. All the coins—the recent 2005 Marine Corps issues—had acquired a hazy residue hiding the fields. This residue presents a problem for both the coin’s long-term stability and its ability to grade. With such a hazy PVC residue, the coin would not be able to grade as high as it would otherwise. Removal of the PVC residue allowed the coin to realize its true potential.
This 1924 S 5c is a prime example of the irreversible damage that can happen when a PVC residue is left on a coin’s surface. As PVC contamination advances, the haze on the coin’s surface becomes thicker and green in color. The thick green oily residue is the most destructive PVC contamination. The reverse of this coin was grossly affected by a PVC residue that, once removed, left visible pits all over the surface of the coin.
Even the newest and freshest coins can be adversely affected by PVC. A PVC haze can prevent a coin from grading out as much as it could in the short-term and if left to become more severe could cause irreversible damage to a coin’s surface. For information on how to submit coins with PVC residues for professional conservation, contact NCS Customer Service at 866-627-2646 or NCShelp@NCScoin.com.
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