All

Thank you for the initial response; you have confirmed what I noted- the data do not seem to be available.

Allow me to change the question-

Some facts:

The specification for oxygen in cylinder nitrogen is less than 200 ppmv and it goes down as the quality of the nitrogen goes up. Semiconductor grade is < 3 ppmv.

If you were monitoring the oxygen concentration inside a glove box (containment) using nitrogen as the purge gas, what would be the oxygen concentration at which you would say (IN YOUR WRITTEN SOP) that work with a pyrophor can begin.

It would be really helpful to have this answer documented with data; ideally peer-reviewed, but hard anecdotal - not just opinion - would be ok.

And, I really do not care about t-BuLi, but used it as an example. Again, I am trying to find support for pyrophor use which is analogous to hydrogen, where the data clearly support <5% being not ignitable no matter the hydrogen concentration.

Thank you for continuing this discussion

Neal

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Melissa Charlton-Smith
Sent: Friday, September 25, 2015 6:45 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Pyrophorics

Neal, are you speaking the common 1.5% to 1.7% solution in pentane? The LEL of pentane is 1.5% (10% LEL, 1,500 ppm) which doesn't really answer your question about t-BuLi itself. Like you I have searched and the best I could fine was how to isolate t-BuLi solutions to pure crystalline form, but it was never exposed to varying % of oxygen, all was done under argon and/or nitrogen.

Mel

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of NEAL LANGERMAN
Sent: Thursday, September 24, 2015 4:15 PM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Pyrophorics

Does anyone have any citations for the low limiting oxygen concentration of pyrophoric compounds. I am specifically looking for the oxygen percentage at which compounds such as t-BuLi become non-ignitable. For example, that value is 5% for hydrogen. I have found a reference for silane, but, as is typical for silane, there are a myriad of confounding issues.

I have searched both SciFinder and Science Direct and have not found helpful data.

Thanks

Neal

------------------------------------------------------------------------------------

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:

NEAL LANGERMAN, Ph.D.

ADVANCED CHEMICAL SAFETY, Inc.

PO Box 152329

SAN DIEGO CA 92195

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

www.chemical-safety.com

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