Ralph-
You will need to figure out volume of room, volume of gas and do a calculation based on expansion ratio with ACH to determine % oxygen. This is a nice document from Jefferson lab with more info": http://www.jlab.org/accel/safetylb/ODH-book.pdf
-Cathy
-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Ralph B Stuart
Sent: Friday, March 08, 2013 10:40 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Liquid nitrogen storage
Does anyone have a rule of thumb for a ventilation rate in a room which is being used to store liquid nitrogen containers? Several credible web sources recommend a "well-ventilated area" without mentioning numbers. We have a room under consideration for this purpose with about 1 air change per hour. This seems low to me, but I thought I would sanity check it with DCHAS-L.
Thanks for any help with this.
- Ralph
Ralph Stuart CIH
Chemical Hygiene Officer
Department of Environmental Health and Safety Cornell University
rstuart**At_Symbol_Here**cornell.edu