If it is a modern freeze, has an audible alarm, plus it likely can send a signal to notify an over-temperature condition. It's easy to add a liquid CO2 cylinder back-up system, that activates automatically, in case of temperature control failure. We had four of these in my labs. In the 13 years I was there, there were several freezer failures, but the contents never got above -20C.
From: "Melissa Charlton-Smith" <charltonsmith**At_Symbol_Here**WVWC.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Friday, January 23, 2015 7:32:12 AM
Subject: Re: [DCHAS-L] Ethanol storage in: minus 80 freezer
Ralph
Have them read NFPA 45 10.5.2 and 12.2.2 and Article 501 of code 70 the
National Electrical code, this should help answer some of your question,
however, below you will find the questions I would ask.
"is it an explosion proof freezer?" i.e. Does it have electrical
components/thermostats inside?
Is it a chest type freezer or upright?
Is the tissue culture stored in a sealed container?
What quantity is being stored?
To explode the LEL (3.3% for 95% ethanol) would need to be met, and there
would need to be an initiation source, could these conditions be met if
the power failed and the freezer warmed up.
how long would the freezer stay below 60F if the power failed for an
extended period of time.
These are just some questions.
Also, I just found a link from Florida State University that sums things
up nicely.
http://pub.extranet.fsu.edu/sites/safety/safetywiki/Wiki%20Pages/NFPA%2045
%20Refrigeration.aspx
Hope this helps,
Mel
Mel Charlton-Smith
Chemistry Lab Coordinator, CHO-NRCC
Coordinator of BS-CHS program, Lecturer
WVWC - Chemistry Dept.
CHS-319
59 College Ave
Buckhannon, WV 26201
charltonsmith**At_Symbol_Here**wvwc.edu
304-473-8355
-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf
Of Wayne Wood
Sent: Friday, January 23, 2015 8:32 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Ethanol storage in: minus 80 freezer
What happens if there is a power failure? Unless the freezer is
intrinsically safe it could very well go KABOOM if it loses temperature
and the compressor kicks back in.
W.
Wayne Wood | Associate Director, University Safety (EHS), University
Services - Directeur Adjoint, Direction de la pr=C3=A9vention (SSE), Services
universitaires | McGill University | 3610 rue McTavish Street, 4th floor |
Montreal, Quebec, Canada, H3A 1Y2 | Tel: (514) 398-2391
-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf
Of Secretary, ACS Division of Chemical Health and Safety
Sent: Friday, January 23, 2015 5:45 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Ethanol storage in: minus 80 freezer
A colleague asked me to pass this question along to the list: Is it ok to
storage ethanol in a -80 freezer? Details below...
- Ralph
Subject: RE: minus 80 storage
Tissue is stored in 95% Ethanol. Even at 95% a freezer -20 or -80 is well
below the flashpoint (60F). Not sure if that matters or not. I am worried
about OSHA and NFPA. I think OSHA 1910 has something to say about
flammables in freezers.
