Hi Martha,
In general, I would not recommend MDF in close contact with collections, unless it has been sealed to prevent off-gassing. Keeping in mind that I don't know exactly what loose objects are stored on the shelves, one thought for a replacement materials is Coroplast, which I've seen working well in similar contexts, and which came up in this group a few years ago, in the
"Wood for storing collections" thread. There are several good responses there, but in particular this one from Rachael Arenstein seems so relevant that I will paste it below:
The reason why conservators like powder coated steel storage is that it is rugged and inert. Adding a fiberboard might help distribute weight, but it is adding a material that off-gasses and introduces a different set of risks for your collection materials. If the pieces are extremely heavy then I agree with Marc that material like Marvelseal and Volara will not stand up well.AIC's Materials Working Group (MWG) is working on information to help people choose materials that can be used safely for storage, display and transport. Our resources are a work in progress, but it is good to bookmark the MWG Reference collection on the CAMEO Materials Database. The template for each material entry includes info on applications, personal health and safety and collection safety. You'll find that there is a Wood & Composites category that has an entry for Medite, Medex and other Medium Density Fiberboard (MDF) products. These boards are used in museums for exhibits and storage but they are all, to some extent, acetic acid emitters. That might be problematic for some materials in your collection. They also add weight to the shelf which seems antithetical to your goal. And you should read the Working Properties section to see if it can be used/worked safely in your space (e.g. do you have the equipment and ventilation to fabricate what you need). As Marc points out, cost is another major consideration.I might recommend using something like Coroplast which is listed in the Boards/Panels > Plastic boards category in CAMEO. It is lighter weight, smooth, inert easier to cut and should withstand moving things on the shelf better than a barrier film on wood/fiberboard.
Hopefully this will lead you to a material that will work well for your collections, but please let me know if you have further questions.
Thank you,
Rebecca
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Rebecca Smyrl
Connecting to Collections Care Monitor
Assistant Conservator for Special Collections
UNC Chapel Hill Libraries
Chapel Hill NC
(919) 962-4250
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