Date: Wed, 11 Jan 2012 10:27:26 -0600
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Sender: DCHAS-L Discussion List <dchas-l**At_Symbol_Here**>
From: Janet Baum <baum.janet**At_Symbol_Here**GMAIL.COM>
Subject: Re: Door swing in NMR room?
In-Reply-To: <1a57b56c-7614-4064-acc5-3822febcca0e**At_Symbol_Here**>

Dear Don, This reason has been my experience in designing NMR facilities. It's the over-pressure of helium that kills.
Janet Baum, AIA, DivCHAS
Washington University in St. Louis

OnTue, Jan 10, 2012 at 3:42 PM, Don Abramowitz <dabramow**At_Symbol_Here**> wrote:
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 willtrack 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 beimpossible to open the door if you had to pull it open. By the time theexhaust 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 tothe 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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