Do baggies have PVC in them ?

[Rickey]

I have purchased some common coins (90%) in baggies before and was wondering if it is OK for long term storage.

[physics-fan3.14]

There are many different types of baggies. Without more information, there is no way to tell you.

 

Sniff the bag. If it smells like a plastic shower curtain, then it has PVC.

[USAuPzlBxBob]

I've researched this stuff extensively.

 

Most baggies, like sandwich lunch baggies, are polyethylene. If they are much stiffer, not for sandwiches, then they are polypropylene. PE baggies are much, much more prevalent in obtainability. You have to go out of your way to find PP baggies.

 

The "shower curtain" smell test for PVC is spot on.

 

If you were to have examples of all three materials before you, you would have no problem identifying PVC.

 

Both PE and PP are safe for coins, but you really want to get the relief surfaces of coins off of plastic baggies because those "touching" areas will tone differently than other exposed areas. For a coin to tone, it needs oxygen to oxidize its surface. Other elements in the air can impart other discoloration attributes to the oxidation of the base metal, as well. If a plastic touches a surface, it deprives the surface of oxygen in the air from reaching it. A surface will tone unevenly in this way.

 

Just look at some pennies that are toned, that were kept in their paper rolls. The penny up again the end of the roll, where the paper was folded back down onto the penny, will show the creases and paper edge marks on the penny if it has been undisturbed for a long period of time. Sulfur from the paper, micro recesses of free space for air (oxygen), water vapor (humidity) to accelerate acid/base reactions, all combine to transfer colorful artifacts to that end penny. Some of them are really beautiful!

 

Slabbed coins are held in place just by the edges. (Well, NGC, at least.) This is so that the field and relief areas of coins are similarly exposed to their environments, and future rates of oxidation will be uniform and even. And also so that the coins can be viewed almost in their entirety.

 

Other types of holders--AirTites, Cointains, things like this, specifically for holding coins--work well because they are so rigid. The slightest part of a coin that might touch the face of these holders, will then prevent other parts of a coin from also touching. And some of these holders are designed so that they are a little wider in their centers, thereby forcing coins to be held only on their rims. Coins that are oddly sized for standard holder sizes rely on inserts, which I believe may be polypropylene. Those coins can be centered in the inserts, and therefore held only by their edges within the larger overall holder.

[RWB]

Very informative reply, Bob.

 

So....that means it is not the pink flamingos on my shower curtain that smell odd...?

 

[johnny9434]

Very informative reply, Bob.

 

So....that means it is not the pink flamingos on my shower curtain that smell odd...?

 

exacto mundo

[Rickey]

Thank you Bob for your well informed reply.

[ldhair]

Great reply Bob.

Years ago folks would say that anything food grade would not have PVC in it. I'm not sure I trust that anymore. China sends a lot of bags into the US and they don't always follow the rules. I go by smell but wonder if the flame test used on flips will work on bags.

[physics-fan3.14]

Great reply Bob.

Years ago folks would say that anything food grade would not have PVC in it. I'm not sure I trust that anymore. China sends a lot of bags into the US and they don't always follow the rules. I go by smell but wonder if the flame test used on flips will work on bags.

 

Yes, it will.

[RWB]

Please take the coins out of the bag before doing the flame test.....