Connecting to Collections Care

 View Only

  • 1.  How to determine if plastic sleeve is acid-free?

    Posted 08-07-2024 18:23

    Hi all,

    We recently acquired an archival collection. Hundreds of items came to us in plastic sleeves without a vendor name or serial number. 

    My guess is that the sleeves are not acid-free, but I hate to throw them away if they are. Some items are fragile (e.g., early 20th-century magazine clippings), and I would like to store them in individual sleeves within an acid-free folder so that they have extra protection. 

    Is there a quick, easy, low-cost way test to determine if a plastic sleeve is acid-free? Or am I just going to have to throw them away?

    Thank you so much for any advice.



    ------------------------------
    Sarah Sherman Clark
    Collections Manager / Registrar
    Heritage Museums & Gardens
    Sandwich, MA
    ------------------------------



  • 2.  RE: How to determine if plastic sleeve is acid-free?

    Posted 08-08-2024 09:34

    Hi Sarah,

    I would recommend that the first low-cost test you could easily make is to take a copper wire, insert it into a cork (as a handle), then heat up the end of the copper wire in a flame and get it red hot before poking one of the plastic sleeves. Return the wire into the flame and see if it glows green which would be a good indicator of the presence of chlorine such found with PVC. There is a CCI note in this Bielstein Test that explains the process as well.  While this test does not determine that this particular plastic is "acid-free", it does rule out the presence of detrimental chlorine.

    Good luck!

    Ingrid



    ------------------------------
    Ingrid Neuman
    Senior Conservator
    RISD Museum
    Providence RI
    (617) 947-2189
    ------------------------------



  • 3.  RE: How to determine if plastic sleeve is acid-free?

    Posted 08-08-2024 15:28
    This youtube video is pretty helpful. 

    Megan Hansen
    Curator of Collections/Researcher
    Yankton County Historical Society
    Mead Museum
    82 Mickelson Drive
    Yankton, SD 57078
    (605) 665-3898 ex. 205





  • 4.  RE: How to determine if plastic sleeve is acid-free?

    Posted 08-08-2024 15:28

    Thanks for your question, Sarah. It's a practical one, since this scenario is fairly common.

    Many sleeves manufactured through the 1980s (and some later) were made of PVC (poly vinyl chloride). This plastic is not inert. if you see evidence of off-gassing (usually pink image offset) on the sleeve, discoloration, sticking, or a distinct plastic odor, it's probably PVC and should be removed. They will continue to degrade and potentially damage the artifact inside. Polyester, polypropylene and polyethylene sleeves are more stable and should be safe to retain. 
    One way to determine types of plastic is to do a burn test, but it requires some care to perform these tests safely. If interested, see https://www.boedeker.com/Portals/0/Documents/bpi-burn.pdf for more info.
    The main reason to retain clear plastic protectors is ease of access; items are protected from damage in handling when they are in these sleeves. However, if these items will not be handled - or handled very rarely - plastic sleeves may not be needed; archival paper sleeves and folders may be sufficient. Another consideration: If the items are in a humid environment, photographic prints may stick to any plastic sleeve, especially if tightly packed.
    The overall storage environment should be optimal. NEDCC makes available a variety of reference leaflets regarding environmental parameters. See https://www.nedcc.org/free-resources/preservation-leaflets/overview 
    Connecting to Collections has an upcoming program on Safeguarding Collections that may have some helpful information, too. See https://connectingtocollections.org/calendar/?mc_id=368
    You don't mention film being part of this acquisition, but degrading acetate gives off a vinegar odor. See https://www.filmpreservation.org/preservation-basics/vinegar-syndrome for information. This can be a problem with 
    older films.
    Enjoy exploring your new acquisition! Members who have dealt with similar are most welcome to share the benefit of their experience. 
    Best,
    Karen Jones
    C2CC monitor


    ------------------------------
    Karen Jones
    Book and Paper Conservator
    Freelance/Private Practice/Self-employed/Independent
    Denver CO
    ------------------------------



Related Content