Does anyone know if you store coins in 2x2 flips in a plastic container that contains PVC, can the vapor from the plastic harm the coin?
I do believe that your coins can get PVC contamination by being in PVC flips too long. Now, having said that I can not tell you how long or under what circumstances that it will happen. I also do not know what effect humidity has on PVC holders. I have had coins in flips for 15-18 years with no problem but a friend of mine had contamination on several coins that were absolutely beautiful. Hopefully some one else will chime in and help with this post as well.
PVC was used to make plastic less brittle. So the hardness of the plastic can give some indication if it contains PVC. If you're refering to the flips containing PVC, yes it can. But if you're referring to the cardboard 2x2 with mylar windows, they do not contain PVC. Now, regarding the plastic containers, if they are made from a material containing PVC, keep in mind the flips are not air-tight, so yes, it is possible vapors can permeate the flips and damage the coin. FYI: http://coins.about.com/od/caringforcoins/f/pvc_damage_faq.htm If you're storing them in tupperware-type containers (made for food storage) they should not contain PVC.
PVC is a plastic and normally it is quite stiff. I realize that there are several here who will disagree with this, but pure PVC is quite safe with coins. However, in order to make the PVC flexible, they add what is called a plasticizer. The plasticizer is the origin of both the smell and the vapors causing the problems. So far as I am aware, PVC with the plasticizer is not permitted to be used with food. Therefore, food containers should be safe to use. I am not aware of any cardboard 2X2 whit PVC. However, a lot of the clear plastic flips are PVC. They are the softer of the ones out there
The problem isn't with the PVC, it's when the plasticizer degrades and hydrochloric acid is formed. HCl can exist as a gas so migration of damage is theoretically possible.....but it's a very slim probablity.
Actually you can get hydrochloric acid (or hydrogen chloride gas) or vinyl chloride monomer from the degradation of PVC. PVC by itself is a brittle polymer and has to be plasticized to make it flexible. Most common plasticizers are high boiling liquids that usually don't contain chlorine.
