-80 is overkill for freezing drawers for pest control and CAN lead to damage. Keep it under -50 and you should be fine (we prefer -45C).
Floyd W. Shockley, Ph.D., F.R.E.S.
Collections Manager (Acting)
Department of Entomology
National Museum of Natural History
P.O. Box 37012, MRC 165
Washington, DC 20013-7012
Tel (office): 202-633-0982
Fax (office): 202-786-2894
Email: [log in to unmask]
Staff Website: http://entomology.si.edu/StaffPages/ShockleyF.html
From: Entomological Collections Network Listserve [mailto:[log in to unmask]]
On Behalf Of Mike Ferro
Sent: Thursday, February 23, 2017 10:38 AM
To: [log in to unmask]
Subject: Re: freezing drawers for pest control
I had a unique experience with freezing. We ran all the drawers (about 1000) in the museum through the -80. Our oldest drawers, so far as I can tell, are from the 1930s and the newest ones are less than a year old. We had the glass crack in a handful of the older drawers, but no major problems.
However, we had a series of drawers from Bioquip made in 2012. I don't know the specifics of the drawers, but whereas normal Bioquip drawers are a "10", these are a "12"—tight, shiny, Ferraris of drawers. Anyway, within a few minutes of taking them out of the -80 to let them warm to room temperature, I began to hear a series of very sharp and alarming "cracks". I figured all the glass would be shattered and all hope was lost. Thankfully, the drawers are in perfect condition (so far as I can tell). However, the drawers had moths in them and a dozen or more specimens in each drawer lost legs or an abdomen. Presumably the vibration associated with whatever was causing the cracking noise damaged the specimens. I haven't tried refreezing the drawers to see if the phenomenon repeats itself or if the drawers are "fixed".
I don't know if it's worth it or not, but pre-freezing new drawers may be a realistic strategy to remove this threat.
On Wed, Feb 22, 2017 at 5:19 PM, luciana <[log in to unmask]> wrote:
Ice accumulation in the freezer will damage the drawers if not bagged (had that happen here). Excess moisture may cause the lids to warp. Repeated hydration and drying process over the years may cause joints to come apart (I got this from a carpenter). By bagging I don't have to worry about it.
On 2/22/2017 3:38 PM, Furth, David wrote:
I started this at USNM in 1995 after some research. I gave a couple talks at ECN a while ago about freezing. Minus 25C will kill anything we need to worry about. No need to bag or repeat freeze - cellulose will reabsorb any moisture. But after freezing do leave drawers, etc. out for enough time for them to re-acclimate - don't open them.
We also talk about this in the Entomology Collections Management Workshop.
From: Entomological Collections Network Listserve [[log in to unmask]] on behalf of Brown, Richard [[log in to unmask]]
Sent: Tuesday, February 21, 2017 11:01 PM
To: [log in to unmask]
Subject: freezing drawers for pest control
We are receiving some major donations, some of which have had some dermestid damage. We have regular freezers as well as an ultra-low freezer. Does anybody know of adverse effects of putting drawers of specimens in an ultra-low freezer before the drawer is brought into museum?
Michael L. Ferro
Collection Manager, Clemson University Arthropod Collection (CUAC)
Dept. of Plant and Environmental Sciences
MAIL: 277 Poole Agricultural Center
OFFICE: 307 Long Hall
Clemson University, Clemson, SC 29634-0310
Subject Editor: The Coleopterists Bulletin; Insecta Mundi