Date: Fri, 23 Sep 2011 09:00:23 -0400
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Ken Kretchman <ken_kretchman**At_Symbol_Here**NCSU.EDU>
Subject: Re: 4% hydrogen mixture
Comments: cc: Eugene_Ngai**At_Symbol_Here**
In-Reply-To: <A4BDFFCAC336824B8501F8FA6E1DA2D4AC51F65585**At_Symbol_Here**>
While I have been long operating with the understanding that this mixture 
is well below a flammable concentration, based on company testing and 
other data also from long ago, I am copying Eugene Ngai of Chemically 
Speaking who has a great deal of experience with gas suppliers and CGA 
with extends over many years...


>>> "Jeskie, Kimberly B."  9/23/2011 8:14 AM >>>
Long story short, the reason I ask this question is that we have a long 
standing debate with our research community who feel strongly that they 
have chosen the 4% mixture because it gives them the reducing environment 
they need while limiting the hazard, that's why they use it.  The DOT 
classification is based on P-32 and the building codes (which is where the 
debate starts) generally site DOT as the go to place for deciding how to 
class materials for the quantities allowed inside buildings. That's where 
we keep coming up against a logistics nightmare. No one can agree on how 
to account for this mixture and most everyone agrees that using the full 
volume of a 4 % mixture just doesn't make common sense. 

One of our Fire Protection Engineers has suggested that the sources of 
information we use to make these decisions may be dated and an analysis 
may be the ticket to put this issue to bed. The P-23 pamphlet references 
Bureau of Mines Bulletin 503-1952 and much of the 503 date is based on 
simple, ad hoc tests on an apparatus dating back to the 1920s.  Some of 
the data is based on earlier work dating back to the 1870s and 1880s.  DOT 
references and accepts ASTM E-681 to classify flammability of gases. 
So...we're debating on whether or not to test the mixture under this newer 
standard, and it sure would be great if it has already been done.


Kimberly Begley Jeskie, MPH-OSHM
Operations Manager
Physical Sciences Directorate
Oak Ridge National Laboratory
(865) 574-4945

-----Original Message-----
From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**] On Behalf Of 
Todd Perkins
Sent: Thursday, September 22, 2011 7:05 PM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU 
Subject: Re: [DCHAS-L] 4% hydrogen mixture

Do you mean test the mixture for flammability per CGA publication P-23? 
 My understanding is that the data is based on experimental observatio
n as well as calculation. I've never had reason to question the data. Have 
you observed something different?

Todd Perkins
Regional Safet Director
Airgas Mid America


- Sent from my mobile phone
On Sep 22, 2011 11:41 AM, Jeskie, Kimberly B. <jeskiekb**At_Symbol_Here**ORNL.GOV> 

Has anyone actually tested a 4% hydrogen/ 96% argon mixture using ASTM 
E-681, as opposed to just taking the P-23 data or the Bureau of Mines 
Bulletin 503-1952 at face value? Kim Kimberly Begley Jeskie, 
MPH-OSHMOperations ManagerPhysical Sciences DirectorateOak Ridge National 
Laboratory(865) 574-4945

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