PVC Residue On Coins

Best way to remove Residue is with acetone.
If the coins have already toned to black, there is not much that can be done to redeem them.

With PVC album pages, residue much of a lesser problem than the gassing out of the softeners that make PVC soft and pliable.
Quite often, this gassing out can be noticed by the PVC becoming oily and the coins darkening as they tone. Copper coins can end up appearing as black disks if left unattended over a period of years. - A good way of ruining a nice set of red or attractively brown toned Cents in high condition.

Another problem is that the Mylar plastic of 2x2 flips can end up sticking solid to the degraded PVC plastic of the album page. When this happens the 2x2 flips have to be replaced, which can be a major problem if you have hundreds of coins and each 2x2 has a full written description of the coin in it.

It is for these reasons that PVC album pages should not be used for the long term permanent storage of coins.

Archival quality album pages made of Mylar or polypropylene do not cause any of the abovementioned problems, and are not very much more expensive to buy.

That's sound advice.

As a couple of very general "rules of thumb":
- PVC residue is green. Copper is the element usually involved in PVC reaction, and most copper corrosion byproducts are green-coloured. So if a coin is copper, bronze, brass or diluted silver, and has bits of green on it, and is less than 500 years old, then it's possible that it's PVC damage. It could of course be ordinary environmental corrosion, so see the other tests below. Metals that do not react strongly with acids (such as gold, high-purity silver and pure nickel) are less prone to being affected by PVC.
- PVC residue is sticky. If the green stuff, or the coin generally, "feels sticky" and not like a normal coin from change, then PVC is a likely reason.
- PVC-affected coins "smell plasticky".
- If a coin has been sitting in a PVC coin album page for a long time, then a "shadow" of the coin is often visible in the album page after the coin is removed.
- Finally, PVC residue washes off in acetone, or other organic solvents. If the green goo comes off in acetone, then it was PVC.

"PVC damage" is caused when acidic plasticizers in the PVC slowly leach out of the plastic, and onto the coin. The acid reacts with the surface of the coin at the point of contact with the plastic. For coins that have not had too much exposure to the PVC, the damage is minimal. But for badly affected coins, the damage is irreversible. Acetone can remove the PVC goo and prevent further damage from happening, but the damage already done cannot be undone. This might be seen as discolouration, and in the "hazing" or dulling of reflective surfaces on high-grade coins.

I don't see any signs of PVC damage, just typical toning. And PVC is much less likely to affect a silver coin than a copper one. I certainly wouldn't break a graded coin out of its holder just to check.

@Zurie: the coin has a nice toning but it also has some kind of dirt or residue around the lettering... its visible for example on WIL of Wilhelm. Could that be PVC residue or just harmless dirt?

All green is not PVC damage. Looks like normal toning to me.

True, most is probably from copper reacting to salts and skin oils