NPL Non archival materials found in the collections

The process of removing all non archival materials from the collection is a long, and very expensive ongoing project. Old cabinets are replaced with metal ones whenever possible, cardboard boxes and other paper products are swapped out for archival equivalents during inventory projects and re-classifications pushes.

Here are some materials that NPL is working to replace:

Wood

Wood materials should be removed from the collection as soon as economically feasible.  Wood and paper are biologic products and can react with the specimens by producing reactive gases or resins.  They can also provide habitat and sustenance for damaging insects, fungus, and other life forms.  Most of the cabinets currently (August 1999) in use are made of wood.  These will remain in use until new cabinets can be purchased.

Paper

Paper is a wood product and has most of the potential damaging qualities of wood.  Acid-free paper eliminates many of the reactive problems of wood.  Most original documents, including labels, catalogues, letters, and photographs are not made of acid-free paper.  These documents are currently in various stages of disintegration.  The conservation steps, especially cleaning and placing labels in sealed plastic bags, will slow down the disintegration, although it won't stop it.  Removing the documents to a filing system in a controlled environment will help protect them further.

Cotton and other fibrous materials

Natural and synthetic cotton and other batting type fibrous material should be removed from the collection.  The spaces between the fibers become traps for the accumulation of dust, and habitats for insects and other damaging life forms.  Most of these types of material break down after a few years and begin to disintegrate, leaving small hairs and fibers all over the bottom of the tray and drawer.  All fibrous materials should be removed from the collection.

Cotton and fibrous materials are often used as cushion material in the bottoms of trays.  These will be replaced by the foam tray liners.

Cotton is also used as a stopper and cushion for small specimens in vials.  These are often placed above and below a specimen in the vial.  A major problem with fibrous materials used in this manner (in addition to the problems mentioned above) is the fibers themselves.  These often are hooked by small projections on the specimen.  When removing the fibrous plug, the specimen may be caught and flung, inadvertently, across the room.  The fibrous plug may also shrink and fall out of the vial, jeopardizing the specimen.  The cushioning cotton can be replaced with a small strip of Ethafoam® placed above and below the specimen.  The vial should be sealed with a plastic cap that will not fall out of the vial. 

Foam

Most types of foam are manufactured with pore spaces open on all surfaces.  These become traps for the accumulation of dust, and habitats for insects and other damaging life forms.  Most foams break down after a few years (some do so immediately) and begin to disintegrate, leaving small bits of plastic and rubber all over the bottom of the tray and drawer.  All foams other than the archival quality Ethafoam® or its equivalent should be removed from the collection.

Cork

Cork, used extensively as a common vial stopper, is made from the bark of cork trees.  It is therefore a wood product, and will cause many of the same problems as other wood materials.  In addition, cork eventually dries out, shrinks and no longer seals the vial, or can fall out of the vial.  It also becomes brittle, and can disintegrate.  Cork stoppers should be removed from the collection.  Alternate archival quality stoppers are commercially available.

Glass

The risk of shattering glass is too high for our concrete-floored collections area. Plastic vials are used in their place.