Question about archival storage and polypropylene

Is it safe to store vintage clothing, textiles etc. in clear plastic bins?

I have clear, polypropylene Sterlite containers that I store some vintage textiles in (some canvas bags and some wool/cotton quilts). They are stored in a dark, climate controlled space. The bags are laid flat in the bins with acid free tissue paper between each. So realistically, only the edges of the bags could possible touch the plastic bin.

I've read that polypropylene is inert and archival safe but just curious if I'm missing anything.

Thanks!

 

Sounds good to me!

 

I do not know the answer to this, but following because I want to learn!

 

Plastic encourages condensation and mould. I’d prefer museum archive quality card or board boxes.

 

In a climate controlled environment (with humidity under 50%) how does plastic encourage condensation/mold?

I will add that these are not air/water tight containers with o-rings. They are just basic plastic bins.

Thanks

 

I have used them. I like using acid free tissue with it. I also use clean white sheets as wrap. You could put some silicone packs in if you feel like there might be any moisture.

 

If you buy polypropylene containers from archival suppliers, you can be assured that they are, in fact, of archival quality. Commercial manufacturers may not adhere to the same strict standards of purity. There is a chance that unknown additives may be present in a container marked as polypropylene.

That said, for practical purposes the Sterilite containers are probably fairly safe. An extra precaution would be to line them with clean, washed cotton sheets or muslin, as Northern Lights suggested.

Condensation may be trapped in plastic containers if temperatures fluctuate - as the temperature drops, relative humidity rises. But if your space is climate controlled (temperature and relative humidity) this should not be a problem. But lining the boxes with cloth would also act as an additional buffer against such risks.

 

I’d not use basic commercial bins.

 

@research - as you can see, approaches to safe storage may differ.

The best decision will depend on many factors. Museums, which are responsible for preserving their collections in "perpetuity", will try to use the safest (and often more expensive) methods and materials. For a private collection such as yours, the important factors will be the size of the collection, the environmental conditions, your financial resources and, to be realistic, the value of the objects (both monetary and sentimental).

While commercial polypropylene containers may not be perfect, they are better than regular cardboard boxes. If the collection is small enough and you have the resources, archival board boxes could be better. On the other hand, if there are any water pipes running through your storage space or other risk of water damage, polypropylene containers (archival or not) offer more protection.

Improvements in storage materials can be incremental. You might change to archival quality materials as time and money permit. You are ahead of the game if you have good environmental controls, as you have described. It is also important to monitor conditions in storage, to catch any potential problems quickly.

The Canadian Conservation Institute has a series of Notes discussing collections care, which you might find of interest. Scroll down the list and you will find a series covering textiles:

https://www.canada.ca/en/conservati...ns/canadian-conservation-institute-notes.html

 

Thank you!
Yes, the reason I have used plastic in the past is because I store my items in a climate controlled storage facility that does have pipes for a sprinkler system. Water damage from that does concern me a lot. Also, I have never been able to find museum grade archival cardboard boxes large enough or my items. The plastic bins actually aren't even as large as I'd like.

Can I ask if you have any resources explaining the difference between museum grade and commercial grade polypropylene? I didn't realize there were different kinds and cannot find any information that says that.

Your link above to the CCI lists commercial polypropylene boxes as an archival solution. They do not reference a specific "museum" grade.

 

Here are a few companies that specifically sell archival storage supplies. I have not searched their inventory for polypropylene containers.

http://www.shopbrodart.com/archival...5jU-Tm8d1ok0NNbl76MW2fbd2vZGfovRoC_koQAvD_BwE

https://www.gaylord.com/c/Preservation

https://www.universityproducts.com/

https://www.conservationresources.com/archival-storage-supplies.html

https://www.archivalmethods.com/

 

Thanks. I've used most of those companies before.
Still can't find a difference between the polypropylene commercial companies use vs. archival storage companies but I will keep looking into it!

 

Reputable archival supply companies make an effort to work with manufacturers to insure that the materials used are of known composition and as inert as possible. They may be able to provide you with a chemical analysis of their products, if requested.

Manufacturers that are not specifically focused on archival quality are under no obligation to reveal their formulations, considering it proprietary information. They may also change their formulations at any time, without notice.

If you really want to get into the weeds I can recommend this website, which provides a searchable index to the conservation literature:

https://aata.getty.edu/primo-explore/search?vid=AATA

 

Thanks.

For anybody following along, I reached out directly to Gaylord and they told me there are not different grades of polypropylene. They said all polypropylene is archival safe and there would be no difference that they know of between commercial polypropylene and the polypropylene they use in their museum/archival products.

 

Guess you should have asked them in the first place.....

Now, call Sterilite.

 

Just my two cents.

I used to volunteer where state artifacts were housed in acid-free cardboard boxes. One of the tasks was to re-house them in new boxes as the boxes did become acidic over time. We tested with a ph marker.

I know there was a museum housing some artifacts in plastic boxes. They had a fire and I remember the heat melted the plastic and bonded to some things that might have survived better in cardboard. Mostly things like ceramics I think.

Nothing is perfect I guess.

 

Polypropylene itself is considered safe. However, products are not made from the specific resin alone.

"Additives are absolutely essential in the development of commercial polymeric materials." (https://pubs.acs.org/doi/10.1021/acsomega.9b03058)
"Various low-molecular organic compounds are used for the modification of polypropylene in bulk. The list of effective modifiers includes fatty acids, their salts, unsaturated dicarboxylic acids and their anhydrides, plasticzers, surfactants, organic peroxides and ketones. Most of the relevant data can be found in patent literature." (https://www.researchgate.net/public...ce_modification_of_polypropylene_by_additives)
"Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature." (https://www.sciencedirect.com/science/article/pii/S030438941730763X)

With regard to polypropylene materials used for archival storage, it would be safest to use those that have been formulated and tested for conservation standards. Other products may include unknown additives that might have detrimental effects.

 

Didn't think of it until now! What would I ask Sterlite?

 

That makes sense, however, Gaylord has confirmed they use regular commercial polypropylene in their archaical products (at least that is what the one person I spoke with said)

Do you know which archival material companies adhere to the standards you posted here? I reached out to Gaylord because they seemed like the biggest company dealing in these things.

Just curious what suppliers use plastic that is formulated and tested for conservation standards.

Lots to learn for sure!

 

Yeah, I think you're right. We can only do the best we can!