Coins in PVC

If a coin is placed in a PVC holder, how long will it take until the coin develops the green gunk, or “PVC damage"? 

That very much depends on storage conditions, moisture, direct sunlight, temperature, etc, and maybe the composition of the coin.

As the question was about time, maybe a decade at most before some oils start leaching out of the plastic. Just stay away from them, plastic made with the number 4 in the recycle ♻️ symbol (EU) is the only safe plastic. 

I live in Florida, a pretty humid place, but I live in an air-conditioned home. 

I only use the PVC holders for swaps, for packing, and currently I have some items for reserve and kept them in that type of plastic.

Unless you are talking about very stiff pure PVC containers, simply don't use them … period. It's just a game of chance and entropy with PVC softeners, even under good environmental conditions. There are countless cheap and better alternatives on the market and probably even in your household.

Idolenz

Unless you are talking about very stiff pure PVC containers, simply don't use them … period. It's just a game of chance and entropy with PVC softeners, even under good environmental conditions. There are countless cheap and better alternatives on the market and probably even in your household.

I have the floppy kind of PVC.

That's the bad kind.

Plenty of other plastics are fine.  Polyester, polyethylene, polypropylene and so on.  

tdziemia

That's the bad kind.

Plenty of other plastics are fine.  Polyester, poltethylene, polypropylene and so on.  

Even if the manufacturer claims its “pvc-free”?

BTW, my whole collection is stored in mylar flips in archival safe polypropylene pages. I use the pvc holders for duplicates to give away.

You said “it's the floppy kind of PVC.”  

tdziemia

You said “it's the floppy kind of PVC.”  

 

Yes, the duplicates would be stored in that kind of PVC. They are not part of my collection. 
 

I have used PVC flips for mailing in the past, always with a note that the flips are PVC and should not be used in the mid to long term. I wouldn't use them for storage.