Connecting to Collections Care Online Community

Mini fridge for nitrate negative storage?

Viewing 8 reply threads
  • Author
    • #134757
      Carolyn Schimandle

      We have about 200 black and white nitrate negatives. We want to keep them rather than duplicating them to safety film and destroying the originals. We don’t have enough of them to warrant buying a large storage unit, and of course have a limited budget. They are currently in an air-conditioned room that meets the requirements for medium-term storage on the Kodak website.
      For longer term storage we want to get them down to a lower temperature while still keeping lower humidity. Is a frost-free mini-fridge a viable way to do this? Or would it be too small to allow proper air circulation?

    • #134775
      Tara Kennedy

      Hi Carolyn-

      According to NFPA (National Fire Protection Agency) code 40, nitrate film weighing under 25 lbs does not need special housing. I doubt 200 negatives weigh 25 pounds, so you should be in business!

      The problem with refrigeration is that it will increase the relative humidity rather than decrease it. Honestly? If the film is in good shape, you’re better off storing them in a cool, dry place in archival housing. Since nitric acid is one of the offgassing products, you might consider housing them in paper-based materials that contain zeolites/ Microchamber to absorb the excess acids: They have a variety of products made with Microchamber; I just chose these envelopes assuming they were cut negatives.

      That said, are you sure it’s nitrate? Check this list and make sure: Because if it’s not, you don’t have to worry about it!

      Hope this helps!
      Tara Kennedy

    • #134776
      Carolyn Schimandle

      Thanks, Tara. Unfortunately, the link you provided to the Yale library document is not working for me. I’ve gone through the NPS museum handbook and other sources, and based on their methods of determination it is nitrate. And some of the negatives are already showing classic signs of cellulose nitrate deterioration.

      From what I’ve read, the volume of film is a consideration for safety reasons, and I don’t think we have a big concern there. What I am most concerned about is slowing the deterioration process, so we can retain these original items as long as possible. So I believe we still need to look at lowering temperature and humidity. Right?

      Re. counteracting the nitric acid, that is the purpose of the buffered four-flap enclosures. But I looked at more information about the Microchamber enclosures, and it looks like they could be great for our collection because we don’t have very stable environmental conditions until we can develop a better storage situation. Darn–just put money and time into housing in the buffered enclosures.

    • #134777
      Kim R. Du Boise

      Hi Carolyn,

      Don’t beat yourself up…it is Always a good plan to put nitrate negatives (or any negatives) into good paper storage sleeves. The weak nitric acid that would be put off in a degrading negative will be less of a problem in a cooler environment. Here is a link to Tim Vitale’s paper on the Cold Storage of Cultural Artifacts…especially read up on the film and tape sections. This will help. Also included in that paper are links to IPI research & papers on this.

      Tim Vitale – Cold Storage of Cultural Artifacts.pdf

      I believe Hollenger Metal Edge has a kit that is made for special cold storage based on his descriptions. This paper will give you some markers as to the aging and degrading of the films. It is always as good idea to have cool or cold storage for these & acetate films, so this should give you more info. You can always come back here to get more info as we will be tracking this topic to help you.

      Another thought, does your institution have a Disaster Plan that takes into account fire or other disaster/accidents? If not, then you may wish to look into some of the discussions & webinars on this site. You should also invite your Fire Department or Fire Marshall, or other first responders to visit you & your nitrates…and see the other items in the collections. It is better to do this prior to really needing them and they can give you advice on the local codes as well as compliance with the national ones.

      Let us know if you need more info or have more questions after reading these papers. We have a lot of info & specialize in films and A-V materials.

      – Kim Du Boise

    • #134778

      A few years ago, the NPS did a service-wide project to get all of our film-based material into cold storage. What that translated into is standing freezers in all of the parks with materials wrapped in double layers of vapor-proof bags with cardboard humidity indicators clearly visible. Even if you go with a mini-fridge and don’t take the materials all the way down to freezing temperatures, you might want to use that packaging technique to control the storage humidity. Here’s links to the relevant Conservograms:

      If you have other film-based materials, maybe it would be worth investing in a standing freezer?

    • #134779
      Carolyn Schimandle

      Thank you to both Samantha and Kim. We do also have color prints and a few color negatives that will need to be in colder storage as well. I see that the Conserveograms and the paper on cold storage are both more than a decade newer than the National Parks museum handbook. It’s a great resource, but there are probably newer techniques and materials to improve storage since it came out. I will read this with interest.

    • #134780
      Carolyn Schimandle

      And Kim, no disaster plan yet. I did tack a material data sheet for nitrate film up by its temporary storage location. Kodak has one online. Disaster plan is on my to-do list, along with Scope of Collections, both of which I know from past training have to be done, but have always been in place before I started at other locations I’ve worked in collections. This time it’s a brand-new park, brand-new huge collection dating from c. 1860 to 2014 of every material you can imagine. Starting from scratch, which is exciting and a bit overwhelming! So I will be posting questions on this forum A LOT. We’re starting with triage on the most critical items in terms of safety and preservation. Just received the new book Managing Previously Unmanaged Collections, which will probably be my bible.

    • #134782


      Try starting an emergency plan on It is an online, free resource that will guide you through an emergency plan and it can be changed and updated as needed. It is a good place to start. Also, take a look at the Resources on this website – there is quite a bit about preservation of photographs, film and film base.


    • #134783
      Carolyn Schimandle

      Thanks, Susan. dPlan sounds much easier than starting from scratch. And the price is right.

Viewing 8 reply threads
  • The forum ‘Connecting to Collections Care Forum Archives – 2015 through 2018’ is closed to new topics and replies.