''Vinegar syndrome'' decaying archives of cellulose acetate microfilm stock

[areoform]

The problem is temperature. At sub-zero temperatures, these reactions are temperature dependent and they exponentially slow down the lower the temperature is. Here's a table from a monograph written by an expert,

    Effects of Cold Storage on Acetate Base Film 
    .
    Lifetime for New Film,            Years Storage Conditions
         45                             70˚F at 50%RH
        175                             55˚F at 40%RH
       1900                             30˚F at 30%RH (using a refrigerator)
       1600                             30˚F at 30%RH + 5 days-out-of-storage/year 
     31,500                              0˚F at 30%RH (using upright freezer)
       1900                              0˚F at 30%RH + 5 days-out-of-storage/year
    110,000                            -15˚F at 30%RH (using commercial freezer)
       1900                            -15˚F at 30%RH + 5 days-out-of-storage/year

Source, https://cool.culturalheritage.org/videopreservation/library/...

    > The library plans to dispose of its acetate film collection after the rare film reels and microfiches have been copied over, in part due to health and safety concerns. In its most advanced state Duncan says vinegar syndrome can cause contact burns, as well as irritation to the nose and lungs.

The real story here isn't that the film is decaying, but rather that we don't want these films to rot away while, at the same time, not valuing them enough to chuck them in a freezer and pay for the cooling bills.

[cf100clunk]

The article describes efforts at the University of Calgary to refrigerate affected materials to buy time for their copying/digitizing.

[dylan604]

There's also a distinct smell to magnetic tapes, though not vinegar. I'm mainly familiar with video tapes, but I'm assuming audio tapes will suffer similarly since they are nearly the same. In particular, 1" Type-C video tapes often came in hard plastic sealed/locking cases. There were many times we'd receive a very old master, and open it up to the tell tale smell of a tape that was not going to be in very good shape.

[hexis]

I read the title too quickly and thought this was about the indie DVD/Blu-ray/4K distributor named after the phenomenon - https://vinegarsyndrome.com/

[abeppu]

> polyester film — a newer film type that can last 500 years

How does one confidently establish that about tech that has been around for less than a century? Not saying it's wrong, but curious what should constitute convincing evidence.

[mrguyorama]

Typically it's done through simulated aging. You expose the item to extremes of temperature and maybe light cycling or something, depending on the environment you want to certify or test it for. Chemistry is mostly deterministic, so this usually works pretty well.

[lm28469]

The plastic might survive 500 years but the images on it won't last anywhere as long.

Getting old slides and negatives from your parents will show you that, most of them already faded or color shifted heavily. You still need controled temperature and humidity for that

[rpd9803]

When I worked at the George Eastman Museum many moons ago, the staff entrance had a distinct vinegar-like odor that I believe was from vinegar syndrome isolation storage for the film collection at some point in its history before the archive building was made in '89. That place has an AMAZING collection.

[WalterBright]

I don't understand why someone doesn't make a machine that you can put a roll of microfilm in, and it will automatically scan them frame by frame.

[cf100clunk]

Microfilm and microfiche digitizers have been around for quite awhile. One of the major issues for archivists in getting such work done is the trouble with handling delicate items that are decomposing. The article talks about those challenges.

[dylan604]

Why do you assume this doesn't exist? I'm not personally familiar with any that do, but based on all of the other scanning devices from professional to DIY, I'd assume someone on the internet has done this.

[tokai]

Its not an issue of technology but of man-hours to digitize and index the film collection.

[at_a_remove]

We had a vault kept "cool" for old film, but for my money it wasn't enough, I could smell the vault from fifty feet away.

[dylan604]

Just be glad it was only the vinegar syndrome you had to deal with and not being nitrate film stock