San Diego Natural History Museum--Your Nature Connection[San Diego Natural History Museum: Collections Care & Conservation]
How do we make them last?

First we have to understand what causes specimens to deteriorate.

Then we figure out ways to prevent the causes.

We practice preventive conservation.

Aerial photo of San Diego showing SDNHM in lower right corner

Detail of topographic map showing Balboa Park and location of museums (center)

Caring for Collections

We must figure out ways to prevent the causes of deterioration, or ways to decrease the impact of the cause.

To do this we consider layers for protection, or each layer of control, and then look for ways to

  • avoid the source of the problem;
  • create a barrier against the source of the problem;
  • detect the problem through monitoring and observation; or
  • respond to the problem and act to minimize its effect.

The layers of control

Locationthe location of the building determines if the specimen's environment will be affected by climatic differences, geologic stability, or broad problems such as air pollution that a museum cannot control. Ideally, we try to avoid the problem, but when that is not possible we have to create barriers.

Q. If the Museum is located near the coast and in the flight path of a major airport, what will be the sources of deterioration that must be controlled?
A. Inappropriate relative humidity, vibration, pollution due to high salt levels in air. Picking a good location will help you avoid problems entirely.

Site—the site within a good location may be affected by vegetation or water drainage patterns. Avoiding the problem would be best!

Q. If the Museum is built in Balboa Park, will it matter where in Balboa Park it is sited?
A. Yes. Building at the bottom of a canyon might cause water drainage problems; water problems can cause mold and mildew on the specimens.

Building—the design of a building determines the quality of the environment for the specimens kept inside. Construction of a new building allows us to avoid many problems; however most museums have to create barriers and/or respond to problems in existing buildings.

Q. The design refers to both the shape of the building and the materials used in construction. Together, they determine whether we can control temperature and relative humidity inside or prevent water leaks. Does this mean that the only good design for the building is an enclosed box?
A. NO! but it does mean that the building is designed differently than for a school or office building. Windows can be placed on certain walls but not others. We decide to use certain types of heating and air conditioning systems. We also worry about where pipes carrying water are positioned relative to the location of specimens. And the list goes on!

Room—the placement and design of rooms within a building act as buffer, and another layer of control, from the outside environment.

Q. The environment that is good for people is not necessarily the same as an environment that is good for the specimens. People like light and warmer temperatures.
Specimens last longer if stored in the dark, with cooler temperatures, and fewer fluctuations in temperature and relative humidity. These conditions slow the deterioration rates and reduce mechanical stress on the specimens.
Which of these 2 rooms would be better for specimens?
#1—A room with windows, facing south
#2—A room in the middle of the building, without windows

A. #2 because the room is likely to have more appropriate temperature and relative humidity levels.

steel mineral case, photo by P.Cato

Cabinet—the quality and design of individual storage cabinets make it possible to create micro-environments that are even more protective than the room environment.

People don't like to work in the dark, so when the workday starts, the lights are turned on. Cabinets protect the specimens from light in the room.
Cabinets with tight seals can also protect specimens from wild changes in relative humidity. Sometimes the air handling system doesn't work as designed or isn't designed to control humidity. When this happens, the cabinets must serve as barriers to the problem.
Cabinets also limit movement for insects, gaseous pollutants, dirt and particulate matter.

Packing bird collection for moving, photo by T.Murray
Packing the bird collection for moving to the new wing of the museum.

Specimen—specimens are made from materials that are naturally deteriorating. We can slow the deterioration by using preparation materials that are considered inert or "archival." This means that they do not react with the specimen or the environment in any way that will speed up the deterioration.

Procedures—procedures help us avoid sources of deterioration.

"Procedures" are the way we do something, whether it's the way we pick up a specimen or pack it for mailing.
Appropriate procedures for handling specimens decrease the amount of breakage.
Good procedures for packing specimens for loans decrease breakage.

We practice preventive conservation.
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