NATIONAL ARCHIVES AND RECORDS ADMINISTRATION

Preserving Archival Records
Cold Storage Handling Guidelines

These guidelines should be followed when storing and handling photographs in cold storage vaults at all National Archives facilities.

I.  Supplies Needed for Accessing Photographs Stored in Cold
Storage Vaults

    A.  Clear plastic bags such as Zip-locks or flush-cut bags with
        twist-ties (polyethylene or polypropylene plastic bags).

    B.  Cotton gloves.

    C.  Carts and appropriate containers.

II.  Accessing Photographs from Humidity Controlled Cold Storage
Vaults (Where photographs are not routinely stored sealed in
airtight envelopes or bags)

HANDLE GENTLY--COLD PHOTOGRAPHS ARE  BRITTLE AND ARE EASILY
DAMAGED BY FLEXING.

    A.  Locate individual photographs or box in cold vault.

    B.  Place the photographs or box inside the plastic bag. Squeeze
        out the excess air from the plastic bag and seal the bag.

Do not use the bag if:

        i)  the Zip-lock seal does not work or
        ii) the bag has tears or holes.

    C.  Place bagged photographs or box in a designated holding
        area.   If feasible, spread out bagged items to allow better
        air circulation.  Allow photographs to warm up slowly in a
        cool dry area, such as an office or processing area.

Small quantities of photographs will warm up faster than large
groups or boxes.  Warm up time to room temperature may take 30
minutes for one or two photographs or two to four hours for boxes,
depending on the size of the box and quantity of photographs inside.

DO NOT REMOVE  BAGS UNTIL ITEMS NO LONGER FEEL COOLER THAN
THEIR SURROUNDINGS

DO NOT ATTEMPT TO SPEED UP THE WARMING OF THE ITEMS BY
PLACING NEAR HEAT

    D.  When bagged photographs or boxes no longer feel cool to the
        touch and are at room temperature, wipe off any excess
        moisture condensed on the bag and open bag to remove items.

III.  Refiling from Office Conditions to Humidity Controlled Vaults

Place photographs or box inside cold vault while pulling other
items.  If reshelving a box, open box during this time to let warmer
air escape prior to reshelving.  Handle other photographs carefully
during refiling to avoid flexing cold items.

IV.  Using Cold Vault Acclimation Rooms
(For vaults with climate controlled acclimation rooms)

    A.  Use the acclimation room when entering/exiting a vault in
        order to minimize the influx of warm air and the resulting
        climate fluctuations in the vault.

    B.  The acclimation room climate is set at a temperature and
        relative humidity specific to the climate of the cold
        storage vault so that no moisture condensation will occur on
        materials when:

        i)  moving directly from the cold vault into the
            acclimation room or

        ii) the items have warmed up to acclimation room conditions
            and then are moved to office conditions.

Items do not need to be bagged if moved only from the cold vault to
the acclimation room for inspection, etc. If the items then are
allowed to warm up to acclimation room conditions, they can be moved
to office conditions without the need for bagging. However, items
must still warm up to room temperature prior to use because plastic
film is brittle at cold temperatures.

V. Accessing Photographs from Refrigerators or Vaults without
Humidity Control (Where photographs are routinely stored sealed in
airtight envelopes or bags)

    A.  Photographs or boxes should be sealed in heavyweight plastic
        bags or in special metallic foil/plastic bags when stored in
        stand alone refrigerators and freezers or in low cost vaults
        without climate control.  These types of cold storage
        systems experience wide fluctuations in humidity either
        during normal operation or when opened for access to the
        records.  Humidity levels can fall below the levels
        recommended in order to prevent extreme brittleness or
        levels can rise to the point where photographs become moist
        and allow mold to grow.

    B.  Procedures described above in Section II should be followed
        except that photographs or boxes must be resealed in bags
        prior to refiling in the vault.

VI.  Precautions against Catastrophic Vault Failure

In some cases, photographs are routinely bagged for cold storage as
insurance against catastrophic failure, even when there is adequate
climate control in the cold vault.  Examples of catastrophic failure
include long term power outages, a loss in climate control in which
the temperature and/or relative humidity rises rapidly, or water
release.  Bagging for storage is a wise precaution if the vault is
unreliable in terms of climate control, where there are no backup
power units or redundant climate control systems, or for extremely
valuable photographs where any potential risk is considered
unacceptable.

VII.  Precautions for Accessing/Refiling Records Taken to Offsite
Locations

    A.  Records taken offsite should be placed in an insulated
        container, such as a small picnic cooler or chest, during
        transit. Insulated containers are available in a wide range
        of sizes from beverage size up to several cubic feet in
        capacity. Insulated containers will prevent the records from
        being exposed to extreme weather conditions which could
        accelerate deterioration.

    B.  Records which were offsite should be allowed to acclimate to
        in-house office conditions before they are refiled to cold
        storage.  This acclimation period should be either several
        days for single items or a week for boxes.  This procedure
        is especially important where records might have been
        exposed to higher humidity levels at the offsite location
        (such as a laboratory).