DCHAS-L Discussion List Archive
Date: Fri, 24 Aug 2007 09:40:40 -0400
Reply-To: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Subject: 5 responses RE: [DCHAS-L] LN2 for tissue storage
Below are the off-list responses I received to my inquiry on
Wednesday about liquid nitrogen use. Note the difference in
experience in two different, but adjacent, states. It sounds like
technique plays a role as well...
Thanks for everyone who responded.
- Ralph
From: "Dewinkle, Gary M"
Date: August 22, 2007 6:52:41 PM EDT
Subject: RE: [DCHAS-L] LN2 for tissue storage
Have you checked for information related to bovine semen storage? - it
is my understanding that it is stored in the liquid phase.
Gary De Winkle, CIH, CSP
EMSL Safety & Health Representative
IOPS Program Manager
EMSL/2393
509-372-2931 (Office) or 509-539-8099 (Cell)
Mail Stop K8-80
~~~~~~~~~~~~~~~~~~
From: "Erik A. Talley"
Date: August 22, 2007 10:05:43 PM EDT
Subject: RE: [DCHAS-L] LN2 for tissue storage
Ralph,
There are some serious safety concerns with storing in the liquid phase.
Many of the containers that are used for cryo storage will hold the
LN2 when stored in the liquid phase and then explode when taken out.
This isn't theoretical...it has happened 3 times here, which is why
we created an Update on the issue. We have only found one recommended
solution which involves sealing them in a bag. The EHS Update at
http://www.med.cornell.edu/ehs/updates/ln2.htm
details the issue.
Jim Crandall in my office did the leg work on the issue and can
provide additional details if needed.
Regards,
Erik
~~~~~~~~~~~~~~~~~~
From: "Hadden, Susan [PRDUS]"
Date: August 23, 2007 7:58:20 AM EDT
Subject: RE: [DCHAS-L] LN2 for tissue storage
Our PPE for handling liquid N2 includes: safety glasses AND face
shield, cryogloves and liquid impermeable apron over a lab coat. If
the cryounit will be stored in space with limited air exchange, an O2
sensor with alarm is a must have. (You should do the math to
calculate the N2 gas release if there should be a containment failure.)
~~~~~~~~~~~~~~~~~~
From: "Wawzyniecki Jr, Stefan"
Date: August 23, 2007 9:52:23 AM EDT
Subject: Re: [DCHAS-L] LN2 for tissue storage
Here are 2 comments from our researchers...
"I have been storing samples in liquid nitrogen for many years. The
manufacturers of cryovials say that they can explode if stored in the
liquid phase (i.e., when trapped liquid expands on warming), but in
25 years of doing just this, I have never seen it happen. I usually
leave the vial lids slightly loose to allow escape of gas, but some
people I know punch tiny holes in the lids as a precaution. I
generally wear nitrile gloves (usually double gloves) to remove
cryovials and canes from the storage dewar, and transfer canes to low
styrofoam containers filled with liquid nitrogen to manipulate or
sort samples. Hemostates work well for grabbing vials and lids to
unscrew.
In all these years I have occasionally had minor frostbite on my
fingertips, but nothing worse."
~~~~~~~~~~~~~~~~
"We routinely store cells in the liquid phase of LN2. PPE includes a
face shield and the cryo gloves sold by Fisher and others (easily
found in the LN2 sections of the Fisher catalogue), as well as a lab
coat. Vials are stored in racks, which we let drain when we pull them
out of the liquid phase of LN2. Any remaining liquid will evaporate
rapidly when at air temperature."
~~~~~~~~~~~~~~~~~~
From: "Hunt, Chris (NIH/NIEHS) [E]"
Date: August 23, 2007 7:11:36 PM EDT
Subject: RE: [DCHAS-L] LN2 for tissue storage
This link may provide some useful information.
http://www.wfcc.info/tis/info4.html
Chris Hunt, Jr.,CIH
Safety Officer
Health and Safety Branch
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