Freezing glass plate negatives

For insect remediation we are considering freezing glass plate
negatives that are housed in several boxes, separated by pieces of
corrugated cardboard.  Our general practice for freezing buggy boxes
of books and papers is to bag the boxes, bring the temperature down
to -20 deg. F, and leave them for a week before bringing the
temperature up again.

Does anyone have experience freezing glass plate negatives?  Would
this be acceptable procedure for them?  If so, are there specific
guidelines we should follow (such as how slowly to bring up the
temperature afterwards, whether to seal each box in a plastic bag,
etc.)?  We use a Wei T'o freezer (purchased in 2003).

We would appreciate any thoughts or advice.

Martha Little
Library Conservator
University of California
Berkeley CA 94720
510/642-8843

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                  Conservation DistList Instance 28:20
                Distributed: Saturday, October 18, 2014
                       Message Id: cdl-28-20-017
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