Subject: Re: [DCHAS-L] Isobutane Safety -- Refrigeration Unit
Date: April 5, 2012 9:22:10 PM EDT
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: <DD8008707CBF0242AA5A659D39AD73E60A8D8A3544**At_Symbol_Here**>

This would be a good time to have the students work with the Engineering Department and perform a hazard analysis on the P&ID and then a pre-startup hazard inspection on the as built P&ID and the actual unit.


This would be an opportunity to cross-educate some chemistry students in engineering safety and some engineering students in chemistry.





The information contained in this message is privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer.


ACSafety has a new address:



PO Box 152329


011(619) 990-4908 (phone, 24/7)


We no longer support FAX.


 Please contact me before sending any packages or courier delivery.  The address for those items is:

5340 Caminito Cachorro

San Diego CA 92105


From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Cody, Regina J. (GSFC-6910)
Sent: Thursday, April 05, 2012 2:02 PM
Subject: Re: [DCHAS-L] Isobutane Safety -- Refrigeration Unit


Dear Marjorie,

Since the students are having the unit built and welded, they need to thoroughly leak check the unit before any use, preferably with a helium leak detector.  Especially if they are also going to use ammonia as one of the gases.  The flammability hazard should be considerably reduced if the unit is leak tight and the gas line connections are tight.

Regina Cody

NASA Goddard Space Flight Center


From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of marjorie.markopoulos**At_Symbol_Here**WRIGHT.EDU
Sent: Thursday, April 05, 2012 9:43 AM
Subject: [DCHAS-L] Isobutane Safety -- Refrigeration Unit


A couple of undergraduate students in Mechanical Engineering want to make a Einstein-like refrigeration unit for their senior project.
( -- it’s also on Wikipedia.  These aren't the exact models, but it is the concept.)
They are seeking safety guidance from EHS.  They want to use isobutene (0.337 kg), ammonia (0.21kg), and water (0.636kg) in the table-top system.  They plan on building it in a chemical fume hood and they hope to eventually make it portable for demos. 
The pressure will be no greater than 50psi and the unit will be built with stainless steel and welded together by a professional welder.

1.  Has anyone had such a unit built and what safety requirements were in place:

2.  PPE -- Should we require a Nomex lab coat?  Face shield, in addition to impact resistant goggles?
3.  What's the best way to address the potential flammability issues?  In a fume hood with the sash as low as possible.  Any monitoring or sensing?

Any input that you may have will be helpful.  I also don't want to miss any important questions that I should be asking them.

Thanks to you all in advance!


Marjorie Markopoulos, M.S.

Biological and Chemical Safety Officer

Department of Environmental Health & Safety

Wright State University

3640 Colonel Glenn Hwy.

047 Biological Sciences II

Dayton, OH  45435

Office:  937-775-2797

Cell:  937-239-7936



Previous post   |  Top of Page   |   Next post

The content of this page reflects the personal opinion(s) of the author(s) only, not the American Chemical Society, ILPI, Safety Emporium, or any other party. Use of any information on this page is at the reader's own risk. Unauthorized reproduction of these materials is prohibited. Send questions/comments about the archive to
The maintenance and hosting of the DCHAS-L archive is provided through the generous support of Safety Emporium.