The conservators at Shelburne Museum have favored freezing over fumigation
wherever possible. Although we don't have very much in the way of taxidermy
or natural history collections, we have routinely used freezing for textiles and
other organic materials, including furs and bearskin sleigh rugs. Small items go
right into a regular household chest freezer designated for this purpose, and
larger items get taken to a commercial food warehouse freezer, which is
inexpensive. We have found it is important to drop the temperature quickly in
order to *shock* the bugs, so they don't have time to adjust to the cold, we keep
the object frozen 10-14 days, warm it up to room temp for a few days and then
refreeze for another 10-14 days. The freezers are kept at about -15 to -20 degrees
F. Of course, this is only for objects that can handle the shock of a rapid
temperature drop. We've experimented a bit on trying to freeze more temp. and
humidity sensitive objects by trying to freeze them in a vacuum sealed container
to mitigate humidity fluctuations, but results are inconclusive. If anyone else has
tried this, I would love to hear about it.
 
I have also been following Vinod's work on fumigation with CO2 and nirogen
atmospheres, and it looks very promising, especially for humidity sensitive
materials.
 
Jennifer Baker
Conservation Fellow
Shelburne Museum
Shelburne, VT
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