PVC vs. Barex. Are CGG holders really unsafe?

[MW1]

I just finished reading the thread about CGG holders not being archivally safe and I'd like to offer some observations.

 

The use of PVC's was once very common in plastic storage sheets for baseball cards -- everything from storage pages produced by ENOR corporation to Rotman PS 1000 TLs to Safe-T-Durapages produced by U.S. Gerslyn, Ltd. to Protecto CC-8s made by Cal-Cards Ltd. Many of these sheets are over 20 years old and some may even be closer to 30. To this day, I still keep many vintage baseball cards stored in these sheets and I have yet to observe any damage. Some of the sheets have even turned yellow but the baseball cards remain totally unscathed.

 

How can this be? According to some informal reports on the Internet, Polyvinyl Chlorides (PVC's) can cause "paper products [to] dry out completely making them brittle to the touch" or "can also cause a brown discoloration after a number of years...." (Source citation).

 

The problem with this analysis is that no scientific testing is offered as support -- i.e., it is presented in editorialized, pseudo-scientific form (much like an infomercial for oxyclean or a special wax that removes scratches from cars).

 

PVC is actually a common thermoplastic resin used in a wide variety of manufactured products. It is used in the packaging of processed meats, pasta and in some industrial applications (Source). Because the molecules in linear polymers such as PVC are long chains of monomers joined by rigid bonds that prevent monomers from rotating, properties include being a good oxygen barrier and having good chemical resistance.

 

It is important to note that there are many different types of PVC inclusions. There is lightly plasticized PVC, orientated PVC, normal plasticized PVC and heavily plasticized PVC. The type of PVC inclusion will undoubtedly affect a substance's archival properties. Some types of PVC's can remain relatively inert for extended periods of time. I know. I've used plastic sheets containing PVC's to store baseball cards for over two decades with no adverse effects. Also, some Polyvinyl Chloride extractions are combined with other agents such as tri-creylphosphate to produce odorless and acid-resistant synthetics, so the term "PVC" should not always be associated with collectibles in a negative manner.

 

I think one of the misperceptions that has developed in the CGG thread is that non-PVC plastics are archivally safe. This is not necessarily the case. The inclusion of plasticizers or certain solvents can render even the most inert polymers chemically reactive. As a result, some compounds may eventually leech from the plastic film and come into contact with the item being protected. A good example of this phenomenon was produced in a FTIR spectroscopy test conducted by J. Mason Associates in January 2001 (hosted by the American Association of Comicbook Collectors) -- previous link.

 

This investigation determined that "Every plastic film has its strengths and it’s [sic] weaknesses in each of these areas and no two are alike. Some are excellent moisture barriers but poor gas barriers. Others are excellent gas barriers but poor moisture barriers. Generally, the better the gas barrier, the poorer the moisture barrier." Applying this information to both PVC and Barex we find that PVC does a better job of blocking moisture but Barex has a lower gas transmission rate (Source).

 

[Note: Barex is a high nitrite polymer suitable for all types of packaging. It offers high gas barrier and excellent chemical resistance. Barex is also referred to as a rubber-modified copolymer of acrylonitrile and methylacrylate -- a type of polyester. Comparatively speaking, Barex has a much higher cost than PVC.]

 

Interestingly, the FTIR tests also revealed that "in the samples that were submitted for testing, every sample seems to contain an ultraviolet inhibitor which would render each and every sample unsuitable for use by the Library of Congress." And yes, that includes both Barex that is used in the CGC interior holder and Styrene Acrylonitrile Copolymer (SAN) which is used in the CGC exterior holder.

 

So just what SHOULD be used for complete archival protection? Well, according to the US Library of Congress, the preferred material for preserving valuable documents is uncoated archival quality polyester film, such as Mylar® type D or equivalent material such as Melinex® 516 (Source).

 

I think that one problem with the ARDL test posted by kevthemev (see first several posts in the CGG thread) is that it never specified the type of PVC nor the percent inclusion of PVC in the CGG holder. To that extent, any judgments made about the archival properties of the CGG holder are without any substantial scientific support. It may very well be that CGG holders contain Barex just like CGC holders or that the CGC holders contain PVCs in addition to Barex. All that the ARDL test proved (allegedly) is that PVC was a detected polymer.

 

A good resource for more information on this subject and conservation would be the AIC:

 

The American Institute for Conservation of Historic and Artistic Works (AIC) and FAIC Conservation Services Referral System, 1717 K Street N.W. Suite 301, Washington, D.C. 20006; Telephone: (202) 452-9545; Fax: (202) 452-9328.

[MW1]

One more comment. Some of the information in kevthemev's post indicates that "Highly plasticized plastics (such as polyvinyl chloride PVC) are not suitable for long term storage of photographic images and should be avoided."

 

My question is this. There are many different types of PVCs with various inclusions and solvents. Where does the ARDL test show that CGG holders (the inner well) contain highly plasticized PVC's? I'm not asking this to be critical, I just don't see the link.

[blowout]

Do we really need another thread on this subject? The other thread that Kev started has stayed on topic and its sometimes nice to keep all the info in one place.

[MW1]

Do we really need another thread on this subject?

Is it important to be able to distinguish between more rigid, lightly plasticized PVC's and less rigid, highly plasticized PVC's without having it lost somewhere near the end of another 18 page thread....especially given the fact that many collectors here possess comics that are worth hundreds, thousands and even tens of thousands of dollars and which currently reside inside a variety of different protective polymers? I think so...but if it really bothers you, I'd be happy to tack it onto the end of the other thread.

[Kevin Boyd]

All the report says is that lab found that THE basic Polymer of the plastic sheets submitted was Polyvinyl Chloride (PVC).

 

For those of you who don't know what Polymers are:

 

Polymers are large molecules of high molecular weight. They consist of long, repeated and sometimes, branched chains, built up from small sub-units called monomers. Natural polymers include proteins (polymer of amino acids) & cellulose (polymer of sugar molecules). There are many examples of synthetic polymers - e.g. PVC (a polymer of vinyl acetate), PTFE or Teflon (a polymer of molecules containing fluorine and carbon). ). Synthetic polymers are formed by addition or condensation polymerization of monomer.

 

Some more GENERAL information about PVC...

 

PVC = Thermoplastic resins produced by the polymerization of the gas vinyl chloride [CH2CHCl]. Under pressure, vinyl chloride becomes liquefied and is polymerized by one of four basic processes: suspension, emulsion, bulk, or solution polymerization. The pure polymer is hard, brittle and difficult to process, but it becomes flexible when plasticizers are added. A special class of PVC resin of fine particle size, often called dispersion grade resin, can be dispersed in liquid plasticizers to form plastisols. The addition of a volatile diluent or a solvent to the plastisol produces an organosol. Copolymers with vinyl acetate, vinylidene chloride, and maleate and fumarate esters find commercial application. Major markets for PVC are in building/construction, packaging, consumer and institutional products, and electrical/electronic uses.

 

PVC is a tough, environmentally indestructible plastic that releases hydrochloric acid when burned. However, it is generally an unstable plastic, often referred to in some forms as "vinyl" and "Naugahyde," that may exude oily plasticizers or emit corrosive and acidic hydrogen-chloride gas. It is easily identified by its strong plastic odor. Do not use sheet protectors, binders, photo enclosures, corners or any other product made from vinyl with your photographs, negatives and memorabilia.

 

---------

 

Now I don't see anywhere on that report I was provided what type plasticizers used were to make the plastic malleable enough to make the inner well (which is definitely not a rigid but flexible plastic substance which indicates that plasticizers of some kind were used).

 

All I see on that report is that the Polymer (again, one polymer, not many) found is Polyvinyl Chloride and all of the information I've found on the web says that PVC is not to be used for long-term storage of paper products... they don't get into discussions of plasticizers. Why would you believe that a report that CLEARLY says the Polymer is Polyvinyl Chloride that it could in fact be PVC PLUS BAREX (Acrylonitrile Butadiene Methyl Acrylate Copolymer) or other polymers?

 

The test was not "does this plastic contain the polymer PVC?". It was "what is the Polymer analysis of this plastic"? And the answer was clearly PVC. Perhaps there is an analysis of plasticizers used... I don't have it.

 

Perhaps the plasticizers used have made it safe, I don't know, but considering that no one recommends using PVC for storage of paper products I certainly would not want to take that risk. I realize that you say your cards have been stored in PVC sleeves without damage, so maybe PVC can be non-reactive, or perhaps you just got lucky.

 

Kev

[BassGMan]

MW1. All that I can say is WOW! I am very impressed with your post and applaud you for the work you put into it. Also, you seem to be presenting your findings in a neutral and unbiased manner which lends to your credibility. Thanks-----Sid

[MW1]

However, it is generally an unstable plastic, often referred to in some forms as "vinyl" and "Naugahyde," that may exude oily plasticizers or emit corrosive and acidic hydrogen-chloride gas.

Right. That's why it is commonly used to package food. If you took a closer look at your source for that information, you'd find that it comes from this person who appears to have no visible qualifications. You do realize that there are many different types of PVCs which include many different types of plasticizers, right? Don't take this the wrong way but I don't think that the "Scrapbookers Dictionary" is an authority on PVC's.

 

 

Now I don't see anywhere on that report I was provided what type plasticizers used were to make the plastic malleable enough to make the inner well (which is definitely not a rigid but flexible plastic substance which indicates that plasticizers of some kind were used).

Nice strawman. The plastic used in CGG inner wells would definitely not be a heavily plasticized PVC. Compare its rigidity to the flexible plastic "bag" that graded comics are delivered in. See the difference?

 

 

All I see on that report is that the Polymer found is Polyvinyl Chloride and all of the information I've found on the web says that PVC is not to be used for long-term storage of paper products... they don't get into discussions of plasticizers.

Actually, the one you just quoted above does -- "...that may exude oily plasticizers" is the exact phrase used by the "Scrapbookers Dictionary". You are correct about the ARDL test, however; it clearly does not indicate what type of PVC was detected nor does it indicate that the type of PVC that was found is any more unsafe than other typical protective polymers used to encapsulate comic books.

 

 

Perhaps the plasticizers used have made it safe, I don't know, but considering that no one recommends using PVC for storage of paper products I certainly would not want to take that risk.

But how much risk are we talking about? Would it be the same risk that would be associated with walking outside during a thunderstorm or flying on a plane or crossing the street? How can you say that you would not want to take that risk when that risk has no quantification?

 

 

I realize that you say your cards have been stored in PVC sleeves without damage, so maybe PVC can be non-reactive....

Maybe. Just like some types of Barex.

[Rip]

Always great to get your input

[Rickdogg]

Great post!

[BassGMan]

Do we really need another thread on this subject? The other thread that Kev started has stayed on topic and its sometimes nice to keep all the info in one place.

 

How quite naive is this quote?

 

Do you realize the implications of the accusations being made by Mr. Mev and his "buddy". If Mev's information was accurately portrayed then that would be enough information to put CGG out of business. That is serious. Should CGG be put out of business due to some kind of misleading or false information being broadcast to the comic's community? I hardly think so. This is important. And being fair to CGG on this matter is exremely important. Again, as I have claimed before on other CGG-bashing threads, the lynchmob mentality has come on in full force by at least half of the poster's that I have read on the other similar thread.

 

Thanks to MW1 for helping to bring some information to the table that can help us to look at this situation objectively. Mev's findings and the way they are presented, especially with his harsh stance on the accuracy of that information hardly seems objective. ------Sid

[Red Hook]

Do we really need another thread on this subject? The other thread that Kev started has stayed on topic and its sometimes nice to keep all the info in one place.

 

How quite naive is this quote?

 

Do you realize the implications of the accusations being made by Mr. Mev and his "buddy". If Mev's information was accurately portrayed then that would be enough information to put CGG out of business. That is serious. Should CGG be put out of business due to some kind of misleading or false information being broadcast to the comic's community? I hardly think so. This is important. And being fair to CGG on this matter is exremely important. Again, as I have claimed before on other CGG-bashing threads, the lynchmob mentality has come on in full force by at least half of the poster's that I have read on the other similar thread.

 

Thanks to MW1 for helping to bring some information to the table that can help us to look at this situation objectively. Mev's findings and the way they are presented, especially with his harsh stance on the accuracy of that information hardly seems objective. ------Sid

 

With all do respect, I'm still waiting for word on the altered scan CGG submitted recently.....in my opinion, that's enough to put CGG's trustworthiness in dire doubt and put them out of business.

[Kevin Boyd]

I tell you what MW1... how about you provide us with a link that recommends collectors purchase PVC holders (either pPVC or uPVC) to store their paper memorabila.

 

I just spent the last hour or so looking at site after site from the Library of Congress site to a number of coin, stamp, and photography preservation sites and every single one of them tells buyers to avoid buying PVC holders.

 

The only defence for PVC and collectibles that I have found comes from William Souder (1) from the American Philatetic society that seems to have done some work debunking some of PVC's degradation myths... and while his analysis is quite favorable towards the use of unplasticized PVC (uPVC) than the works of other conservators he still warns collectors not to use PVC holders to store stamps in. His conclusion: Though today's plasticizers are much less likely to migrate from their PVC blends onto stamps than earlier versions, the potential is ever-present. Even a careful collector may inadvertently subject a valuable collection to excess pressures and temperatures that could simulate some damaging migration of the plasticizer onto stamps.

 

(1) William Souder, Waldo's Century, American Philatelist, 114 (December 2000), 1102-1106

[Kevin Boyd]

Do you realize the implications of the accusations being made by Mr. Mev and his "buddy". If Mev's information was accurately portrayed then that would be enough information to put CGG out of business. That is serious. Should CGG be put out of business due to some kind of misleading or false information being broadcast to the comic's community?

 

Actually, you can call me Mr. Boyd.

 

How was it inaccurately portrayed?

 

What is false about the information presented?

 

A test was done on a CGG inner well, and that test indicates that the plastic is a PVC Polymer, which is - based on fact or not - STILL not a recommended plastic polymer for long-term storage.

 

Kev

[MW1]

The only defence for PVC and collectibles that I have found comes from William Souder (1) from the American Philatetic society that seems to have done some work debunking some of PVC's degradation myths... and while his analysis is quite favorable towards the use of unplasticized PVC (uPVC) than the works of other conservators he still warns collectors not to use PVC holders to store stamps in.

 

kevthemev,

 

That's not a very accurate or honest representation of Dr. William E. Souder's scientific findings. For those who don't know who we're talking about, here's a list of some of Dr. Sourder's accomplishments:

 

"Following earlier appointments at Northwestern University and the University of Pittsburgh, he retired from the Alabama Eminent Scholar Endowed Chair in Management of Technology at the University of Alabama in Huntsville. He was on the editorial boards of several prominent journals, and is the author of over 200 publications and 6 books on the management of technology. Bill also accumulated twelve years of varied industrial management experience in the chemical industry and seven years of government laboratory experience. He was very active outside the academic field as well. He has founded three small start-up firms, has many years of consulting experience with numerous Fortune 500 firms. He is the recipient of several prestigious awards from both U.S. and foreign governments, including one from the White House for service on the Presidentís Commission on Industrial Policies to Stimulate Innovation and Federal Technology Transfer." (Source citation).

 

 

For those who would like to read the actual and complete findings, here's the link to the article.

 

Basically, Dr. Souder reveals that the commonly held notion that PET (polyethylene terephthalate or Mylar) is good and that PVC is bad is completely without scientific merit. Furthermore, Dr. Souder has concluded "No standardized scale for measuring the degree of 'archivalness' exists."

 

Why is this important? Because PET, a relatively recent polymeric innovation, is backed by absolutely zero scientific experiments that show storage results over period of several decades or longer. Therefore, claims by companies such as Ultra Pro that their Mylar comic bags are 100% archival safe are complete and utter scientific hogwash. Well, at least according to one of the foremost experts in the world on this subject.

 

Moreover, it was found that "PET readily degrades in sunlight unless it contains ultraviolet inhibitors that may do damage to stamps." Not surprisingly, this discovery directly coincides with the results from the FTIR tests which concluded that, "Additives or plasticizers alter the molecular form and a looser molecular structure occurs. This changes the effectiveness of the plastic film, as the ability of gases to permeate the material is increased. As well, in the case of plasticizers, further chemical reactions can occur within the plastic. As a result, the compounds may eventually leech from the plastic film and come into contact with the item being protected." Two independent studies, same result.

 

Dr. Souder then cautions that "Collectors who purchase Mylar/PET should insist on seeing evidence that these products are fabricated from registered DuPont Mylar-D films." Again, this is unequivocally supported by the direct recommendation of the U.S. Library of Congress which specifically mentions Mylar type D.

 

Turning to the subject of PVC's, Dr. Souder points out that a clear distinction needs to be drawn between plasticized (pPVC) and unplasticized (uPVC) PVC. He also states that uPVC ("hard" or "rigid" PVC) appears to be harmless to stamps. And here's the kicker -- "highly flexible films can be made from 'rigid' uPVC." So that means that even extremely flexible interior comic holders can still be made up of harmless unplasticized PVC (uPVC). Yet another hobby myth debunked.

 

Next, Dr. Souder deconstructs the following PVC (mis)perceptions:

 

1. PVC films exude hydrochloric acid at room temperature. This results from a confusion with thermally unstabilized PVC polymers. Products made from uPVC polymers are thermally stabilized to 275 degrees F and cannot exude anything at room temperature.

 

2. PVC films release chlorine gas as they degrade. As in 1., thermally stabilized PVC polymers do not degrade at room temperature. Even the unstabilized polymers degrade into hydrochloric acid and a charred mass. Not gas.

 

3. PVC has loosely bound chlorine atoms that can attack stamps. As in 1. and 2., stabilized uPVC does not exude or degrade at temperatures below 275 degrees F.

 

4. PVC is degraded by humidity. This is easily refuted by the fact that the pipes in our homes are PVC.

 

5. uPVC is a blend of many chemicals. This is incorrect, according to Souder. Modern uPVC films for stamps are typically 98-99 percent uPVC co-polymers, with 1-2 percent thermal stabilizer added to them.

 

6. pPVC films contain plasticizers that dissolve inks on stamps. This confuses uPVC with pPVC. Note that uPVC contains no plasticizers.

 

7. PVC degradation can be detected by a skunky odor. The thermal stabilizers in uPVC films may give off a slightly sulfurous, but harmless, odor. It is not a result of degradation.

 

8. PVC is a deadly poison. According to Souder, this is incorrect, although he quotes a literature on its possible environmental hazards (yeah, don't bury your comic books)

 

 

Finally, Dr. Souder concludes that "uPVC appears to be free of any problems for stamp collectors, as far as tests conducted so far indicate."

 

 

Though today's plasticizers are much less likely to migrate from their PVC blends onto stamps than earlier versions, the potential is ever-present.

 

A contextual misrepresentation. Dr. Souder is referring to pPVC's not uPVC's. Further, Souder goes on to explain that, "Even a careful collector may inadvertently subject a valuable collection to excess pressures and temperatures that could simulate some damaging migration of the plasticizer onto stamps."

 

 

I tell you what MW1... how about you provide us with a link that recommends collectors purchase PVC holders (either pPVC or uPVC) to store their paper memorabila.

There's no need to since you provided one for me. Dr. William E. Souder finds that "uPVC appears to be free of any problems for stamp collectors, as far as tests conducted so far indicate." (see link and info above).

 

 

On a personal note, I should probably mention that I am intimately familiar with the PVC debate that took place just over a decade ago in the sports card and sports collectibles industries. Beginning in the late 1980s/early 90s, a few companies such as Ultra Pro began to market their products (plastic storage sheets) with the interesting guarantee that they contained no PVC's. Within a year or two, information about the horrors of PVC's (it didn't really matter what type, they were all evil) had permeated throughout the hobby. Dealers and customers frenetically emptied their pocketbooks to insure that their collections had the very best non-PVC protection.

 

After the dust began to settle, however, evidence began to emerge that the whole anti-PVC crusade appeared to be more of a marketing ploy than anything else. If I were to compare it to something else of recent memory, I'd say that the problems surrounding PVC's are much like the Y2K bugs that devastated the Internet, paralyzed millions of home computers and shut down major power grids across the world. At least I think that's what happened. Fortunately, all of my old computers and PVC stored baseball cards made it through both cataclysmic events just fine.

[deathlok]

Since you seem to know much more than the average person regarding archival products. Didn't Dupont stop making Mylar products? I had heard that they switched to using Melinex 512 instead.

[MW1]

deathlok,

 

I really don't know. All I can tell you is that I've used both Mylar and PVC storage pages and I've yet to experience any problems.

[deathlok]

In your opinion, as with what I have read so far from other sources. Is the condition articles are stored in more important than the container? For example light, heat, moisture are higher factors in the degradation of paper than the container. I know several people on here including myself stored their comics in Polypropelyne or Polyethelyne bags for a long period of time (5-10 years or more), the books appear fresh looking without dicernable loss of color. Much of this is due to storage conditions, rather than just the bags. Would you agree?

[musicmeta]

This is one of the most informational posts I've ever read. It's going to take me a week to digest everything I read.

I do know that my best friend stored some of his comics in glad wrap back in the early 70's and just a few years ago we took them out of the handmade bags of glad wrap and while the wrap looked yellow awfull, the comics appeared to look OK, with only minimal color fading.

I don't know if there is a connection here, but just thought I would share it.

[davidking623]

Holy Cow It sounds like your baseball cards are doing well in those PVC holders! They are made of a cardboard stock. While Comics are made of paper are we actually comparing Sportscards compared to comics there is a big diffrence in my opinion.I have Sportscards stored in these also for the last 15 years and they seem to be doing fine.I have Becketts in them also and appear to be doing fine. What happens when the Acids take there effect they turn the Page quality from white to off white or off white to Cream. Sportscards dont have pages Im afraid so how can we compare Sportscards to Comic books?

 

Davidking623

[MW1]

Much of this is due to storage conditions, rather than just the bags. Would you agree?

My nonscientific opinion would be yes. Based on various empirical evidence I've seen at work in a host of different baseball card collections, I would agree that storage (environmental) conditions are an important consideration. I've seen (and smelled) what too much heat and humidity can do to paper collectibles. I'd also advise against indulging in any unproved gimmicks like UVA or UVB protectant comic bags. Why introduce potential problems (additives or plasticizers) unless a hostile environment is going to present an atypical need for safer storage?