Are Zip-Lock bags made for food preservation PVC free?

TheGoonies1985

I would imagine so since food and material such as PVC should not mix. I want to put some coins together and this would be the easiest way. All silver coins. They are also inside 2 by 2 mylar cardboard protectors.

jmlanzaf

Should be an MSDS on their website

TheGoonies1985

Box says ''Mindfully made without BPA or Phthalates.''

TheGoonies1985

@jmlanzaf said:
Should be an MSDS on their website

Ingredients: Polyethylene, dye and ink.

jmlanzaf

Low density polyethylene

TheGoonies1985

@jmlanzaf said:
Low density polyethylene

So no PVC in polyethylene I would assume?

OAKSTAR

You might get a few helpful hints from this thread.

https://forums.collectors.com/discussion/1108903/my-38-90-jefferson-somewhat-toned-nickel-album#latest

TheGoonies1985

Thanks guys!!!

TheGoonies1985

I will put them in the z-lock bags this evening all coins are silver.

OAKSTAR

I think you're good to go from the results of this thread I posted. But keep in mind, I'm not an expect. I can only tell you the results of my 30+ years.

jmlanzaf

@TheGoonies1985 said:

@jmlanzaf said:
Low density polyethylene

So no PVC in polyethylene I would assume?

No. But it's not just the PVC, poly vinyl chloride, but any plasticizers or additives. They don't list any

TheGoonies1985

@jmlanzaf said:

@TheGoonies1985 said:

@jmlanzaf said:
Low density polyethylene

So no PVC in polyethylene I would assume?

No. But it's not just the PVC, poly vinyl chloride, but why elasticizers or additives.

I am not sure what you mean by this:

''but why elasticizers or additives. They don't list any.''

??

ShaunBC5

I think he’s saying elasticizers and additives can be dangerous, as well, but none are listed by the manufacturer in this case.

TheGoonies1985

@ShaunBC5 said:
I think he’s saying elasticizers and additives can be dangerous, as well, but none are listed by the manufacturer in this case.

And what can those (elasticizers and additives) do to coins? I thought only PVC damage was possible or verdigris on silver coins?

TwoSides2aCoin

I don’t know, but I’ve purchased thousands of coins like that in “collections” over the years. Not that a fraction were collectible. But the PVC was generally coating the collectibles that were separated from the baggies and inserted into “ soft flips”
Go figure. Acetone is the antidote
anyway.

Mr_Spud

I like to use the large freezer style ziplock bags in the safety deposit boxes, but with intercept boxes inside with desiccant cartridges. The freezer bags are thicker than regular ziplock bags so won’t let as much air and humidity in.

jmlanzaf

@TheGoonies1985 said:

@ShaunBC5 said:
I think he’s saying elasticizers and additives can be dangerous, as well, but none are listed by the manufacturer in this case.

And what can those (elasticizers and additives) do to coins? I thought only PVC damage was possible or verdigris on silver coins?

PVC itself is a harmless polymer that does nothing. It's when the PVC breaks down (releasing acid) or releases plasticizers that the problem arises. It is technically incorrect to call it "PVC damage". That term is just short hand for a more complicated chemical process.

Many polymers contain plasticizers and some are also unstable over time or under certain conditions. PVC just gets called out because it was cheap and commonly used in storage media at one time.

jmlanzaf

@TheGoonies1985 said:

@jmlanzaf said:

@TheGoonies1985 said:

@jmlanzaf said:
Low density polyethylene

So no PVC in polyethylene I would assume?

No. But it's not just the PVC, poly vinyl chloride, but why elasticizers or additives.

I am not sure what you mean by this:

''but why elasticizers or additives. They don't list any.''

??

Should be "any" not "why". Damn autocorrect.

messydesk

@TheGoonies1985 said:

@jmlanzaf said:
Low density polyethylene

So no PVC in polyethylene I would assume?

Polyethylene is just a chain of a lot of C2H4 molecules. Other stuff in addition to PE might be nasty with respect to storage, but the PE itself shouldn't be. You can do the Beilstein Test on any plastic to check for presence of chlorine.

TheGoonies1985

So am I OK to store coins in these type of bags or not? I am confused.

TheGoonies1985

I will just ahead and use them and check my coins once every 3-4 months.

Mr_Spud

The ziplock bags shouldn’t harm the coins. People are cautiously telling you this and putting disclaimers in their posts for the rare exceptions that may exist, so it seems confusing, but it’s rare exceptions that you don’t really have to worry about. The bags won’t protect the coins from all sources of corrosion, but they are better than not using them with the exception (here comes my disclaimer) that if you put something like a rubber band inside there with the coins then the bag will trap the corrosive chemicals that rubber bands give off and then the bag ends up indirectly hurting the coins.

Mr_Spud

And here’s a fancier answer from the one of the industries best experts on this topic, Susan Maltby. From https://www.coinworld.com/news/us-coins/added-protection.html . It lists the plastics that are safe for coins and she specifically mentions food grade polyethylene bags as extra protection.

“I recently received an interesting email query from a Coin World reader.

The reader wrote:

“When storing my collection, I am careful to avoid using plastic containers that may contain PVC.

“I recently opened a new safety deposit box at my bank. The new boxes are made from a hard plastic.

“All of my coins are in their own flips and containers. Do I need to be concerned about storing my collection in a plastic safety deposit box?”

The reader is certainly wise to avoid polyvinyl chloride (PVC) near his collection.

Regular readers will remember that PVC suffers from several issues. PVC is available in a plasticized and unplasticized format. Plasticized PVC is unstable with the plasticizer — a phthalate —leaching out over time. The plasticizer causes copper alloy coins to develop the corrosion product that collectors refer to as “green slime.”

Unplasticized PVC can also be problematic. PVC breaks down by a thermal mechanism producing hydrogen chloride gas. This gas is corrosive.

We have clear evidence of this in the conservation literature. Kalvar, a popular microfilm product produced from 1967 to 1970, was found to be unstable. As it broke down it gave off hydrogen chloride that in turn caused corrosion of metal storage cabinets and degraded microfilm storage boxes.

Safe plastics include polyethylene, polypropylene, polystyrene, polyethylene terephthalate (commonly referred to as polyester) and polymethyl methacrylate (e.g., Plexiglas).

My research has shown that plastic safe deposit boxes are made from polypropylene. As such, the box itself should pose no potential harm to the reader’s collection.

Consider carefully what you choose to place in your safe deposit box. Things like poor quality acidic paper and rubber bands can create a polluted environment for your collection, causing coins to corrode and paper notes to degrade.

One drawback of a safe deposit box is that you are sharing the space. Although you can control what you put in your box, you have no control over the neighbors.

Safe deposit boxes have lids, but they are by no means airtight. The air within the vault is shared by all. Some collectors will give their collection a little extra protection by storing them in a food-grade polyethylene bag or container.

This also helps protect collections in the case of a disaster such as a flood or fire. Bank vaults are normally designed to be fireproof but not waterproof. Sprinklers are still the most common form of fire protection.

Susan L. Maltby, Toronto, is a private conservation consultant, with an interest in numismatic preservation.“

pruebas

Ziploc ™️ bags are coin safe. I keep large medals in the freezer version (extra thick).

I also used to keep my 2x2 boxes in the larger size when in my SDB. You never know if the guy with the box above yours is storing wine in his, or rare perfume.

With all the vigilantism going on now, who knows if someone might want to exact revenge on the “bad bank” by putting dead fish in their SDB. It would probably take them a week to get it drilled!

Any of that stuff could cause nasty dripping onto my precious coins!

MetroD

@TheGoonies1985

If you are worried about it, consider zip-lock bags that are specifically designed for silver storage, and incorporate Intercept.

While there are others, here is a potential source.

Edited for clarity.

seatedlib3991

It is also worth noting that small plastic bags, much like toothpastes, can have a wide range of manufacture ingredients. I saw a study where there were over 50 different amounts of floride in different toothpastes; I bet pliable plastics is a similar situation. James

TheGoonies1985

Just decided I will put them inside these and stack them over each other in the PCGS long box I purchased (plastic). I can put a lot of them in a single PCGS long box more than enough space I need and if not will just buy another one. They stay in place easily if you put a slab on each side of the stack they do not move around.

TheGoonies1985

I appreciate all the help here. I now know what I am comfortable with because of it.

Mr_Spud

Saflips are great. Just to complicate things, I like to seal the coins in Saflips with an impulse sealer for added protection from humidity and corrosive gasses that are in normal air.
I use one like this

I’m not saying this is necessary, I like going overboard, and this is easy once you have a sealer

PerryHall

Are you going to heat seal them? That would make the flip air-tight and would give you addition protection from atmospheric contaminants.

TheGoonies1985

@PerryHall said:
Are you going to heat seal them? That would make the flip air-tight and would give you addition protection from atmospheric contaminants.

Most likely yes. Mine as well go the extra mile. I will place my order for a sealer.

TheGoonies1985

@TheGoonies1985 said:
Just decided I will put them inside these and stack them over each other in the PCGS long box I purchased (plastic). I can put a lot of them in a single PCGS long box more than enough space I need and if not will just buy another one. They stay in place easily if you put a slab on each side of the stack they do not move around.

Pruebas had suggested these last year and I ordered them then so I already have a package of 50 to work it now. I will order more if need be.

asheland

I have always known that food grade plastic bags are safe for coins… I have lots of coins and rare silver ingots stored in the little Ziploc type bags.

TheGoonies1985

@asheland said:
I have always known that food grade plastic bags are safe for coins… I have lots of coins and rare silver ingots stored in the little Ziploc type bags.

Thanks

asheland

@TheGoonies1985 said:

@asheland said:
I have always known that food grade plastic bags are safe for coins… I have lots of coins and rare silver ingots stored in the little Ziploc type bags.

Thanks

You’re welcome, happy to help. 👍

TheGoonies1985

So I put the coins in the 2 by 2 mylar's then the whole bunch inside a large zip lock bag and inside my NGC long box. Will check up on them once every 6 months.

I will seal the Mylar's next year just want to see if they are OK without taking that extra step.

ldhair

Not all bags are the same. The name brand ones should be food safe but many bags are not. They are made for packaging other things. The low cost, imported ones are questionable. They were not made for food or coin storage.

TheGoonies1985

@ldhair said:
Not all bags are the same. The name brand ones should be food safe but many bags are not. They are made for packaging other things. The low cost, imported ones are questionable. They were not made for food or coin storage.

The ones I am using have no PVC.

Box states:

60 freezer zip lock bags

Ingredients: Polyethylene, dye and ink

Company: SC Johnson (USA)

Our products are made without BPA or Phthalates

TheGoonies1985

@TheGoonies1985 said:

@ldhair said:
Not all bags are the same. The name brand ones should be food safe but many bags are not. They are made for packaging other things. The low cost, imported ones are questionable. They were not made for food or coin storage.

The ones I am using have no PVC.

Box states:

60 freezer zip lock bags

Ingredients: Polyethylene, dye and ink

Company: SC Johnson (USA)

Our products are made without BPA or Phthalates

Where are SC Johnson Ziploc bags manufactured?

Bay City, Michigan

The SC Johnson facility in Bay City, Michigan is the main hub of our Home Storage business manufacturing billions of Ziploc® bags each year.

TheGoonies1985

I think my zip-lock bags are safe. So I will keep my coins in them. They are all silver coins and all are also inside mylar sleeves.

One last thing the bags I am using give off no odour at all.

TheGoonies1985

One last question the blue part were you zip shut the bag is that also the same type of plastic used for the clear part of the bag? I would imagine it would be. Just wondering since it is blue and the rest clear coloured.

There is also red and ''purple'' in that area?