In recent times it has become clear that plastic photographic and reel-to-reel audio tape collections need to be frozen if they are to remain in their current condition and not deteriorate further. BS 4971:2017 Conservation & Care of Archive & Library Collections now covers storage environment standards for these collection types, once included in the old BS/PD5454 (now withdrawn) and following a careful consideration of research and publications it is recognised now that cooled storage, above zero Centigrade, will not preserve plastic negatives and slides etc.
Many NCS members have this kind of material and are finding it deteriorating, producing the tell-tale vinegar smell. Digital copying is a good way of ensuring that users can access this material, but to make it last it needs to be frozen; BS4971 proposes storage at -20C. Digitisation does not have to happen before freezing - if you have large quantities of such material and it will take many years to get them copied and catalogued, you need to freeze the material now so that, when you are ready to copy it, it will still be in a usable state fit to be copied. In recognition of this challenge for our members, we have set up a collaborative freezer storage scheme, alongside our other archival stores. Material needs to be suitably conditioned and packaged for freezing and we have set up a secure conditioning store where collections can come before being re-packaged and placed in the freezer.
We have worked with our storage partner, Restore plc, to establish a collaborative cold storage scheme at Upper Heyford, where members can send acetated plactic material to be conditioned, placed in microclimate packages and placed in deep freeze storage. The annual charge for our cold storage is £30 per standard crate, which will take between 2,500 and c.12,000 images depending on their format. If you would like to discuss cold storage and how we can help you, please contact us on firstname.lastname@example.org