Freezing objects

Ellen Roblee <robleee [at] nmaicrc__si__edu> writes

>...  Could those of
>you who have seen damage caused by freezing for pest control please
>share your observations? The damage we are concerned about includes
>cracking, crack propagation, delamination, fatty bloom, spew (spue
>for some of us), loss of adhesion, exacerbation of bead disease and
>so forth.

I think this brings up something that conservators know about
treatments that should be translated into the realm of pest control
applications:  that every treatment has a small but unpredictable
possibility of unwanted change to an object (aka damage).  This
means that unnecessary treatments are not a good idea.  In the case
of routine freezing for pest control, the same applies.  Since
freezing is not preventive, then only infested things should be
chosen.

Although it may be better to use other pest control methods rather
than freezing for something that might be changed somewhat by such
treatment, subtle kinds of changes that are side effects of
treatment need to be balanced with the benefits of treatment.  So
for certain objects that are difficult to treat for infestation in
other ways, or where there are no facilities for other types of
treatment, the potential for small-scale changes needs to be
balanced against the potential damage from pests, the potential
health consequences of chemical treatment, etc.

In other words, although we should obviously learn as much as
possible about the possibility of collateral damage, objects are too
complex to be able to predict exactly what will be "damaged," and
the definition of significant damage that is represented by perhaps
microscopic changes in the material of objects is not a simple
matter.  It is unfortunately not possible to simply say that if a
treatment is going to damage, or might damage, an object, we can't
use that treatment.

B. Appelbaum



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                  Conservation DistList Instance 14:58
                   Distributed: Tuesday, May 1, 2001
                       Message Id: cdl-14-58-001
                                  ***