Date: Tue, 10 Jan 2012 22:23:38 -0800
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Sender: DCHAS-L Discussion List <dchas-l**At_Symbol_Here**>
From: Jean & Ken Smith <smith.j.k**At_Symbol_Here**SBCGLOBAL.NET>
Subject: Re: Door swing in NMR room?
In-Reply-To: <1a57b56c-7614-4064-acc5-3822febcca0e**At_Symbol_Here**>

Hi Ralph,

The responses are good to the point of the request, but I have one additional item that should be definitely considered.  Have you thought to install an oxygen meter and alarm in the NMR room?  The oxygen can be depleted rapidly and the person inside would be unaware of it if it was a non-rapid release of gas.  We had a number of liquid N2 cylinders in our labs and required the O2 alarms regardless of the ventilation air changes/hour.  It is another level of safety that is needed.


ex CIH now retired


-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Don Abramowitz
Sent: Tuesday, January 10, 2012 1:43 PM
Subject: Re: [DCHAS-L] Door swing in NMR room?


The door swing for the NMR is based on a reason that surprised me when I first came across it.  I learned of the recommendation to have the door swing out into the hallway from the installation manual that came with our new NMR, purchased a couple of years ago.  (Ralph, I will track that down as a reference.)

The reason is that in the event of a quench, the extremely rapid release of gas in the room can pressurize the room to the extent that it would be impossible to open the door if you had to pull it open.  By the time the exhaust ventilation relieved the overpressure, you'd be a goner. 

We had the carpenters reverse the swing of our door.  It was quite simple and inexpensive.


Donald Abramowitz, CIH
Environmental Health & Safety Officer
Bryn Mawr College
Bryn Mawr, PA


A question has arisen here with regard to the direction of the entrance door swing in a room containing an NMR. Some people have suggested that due to the asphyxiation potential of a quenching of the instrument, the door should swing out of the room into hallway. Does anyone know of a regulatory requirement for this or a reference that suggests that this be used as a best practice?

Thanks for any help with this.

- Ralph

Ralph Stuart CIH
Laboratory Ventilation Specialist
Department of Environmental Health and Safety
Cornell University


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