From: Slawomir Janicki <slawomir.janicki**At_Symbol_Here**COMCAST.NET>
Subject: Re: [DCHAS-L] Met-L-X or Lith-X Extinguishing Medium
Date: Thu, 30 Jan 2014 13:56:37 -0500
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: 007e01cf1ded$017dccb0$04796610$**At_Symbol_Here**
In-Reply-To <1B6A9D383A771846BE7E63C1D8758E2F061A3A**At_Symbol_Here**>

I thought that sand (SiO2) reacted with some metals. I remember an experiment where sand mixed with Mg shavings started an exothermic reaction that produced Si and MgO. The glass test tube glowed red and partially melted from the heat of the reaction. I would think that Li, Na, K, and Cs would be more aggressive toward sand than Mg.


I would think that this kind of reaction could make a metal fire situation worse, although the slag produced could potentially cut off oxygen from the metal.


Slawomir Janicki


From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of STRAUGHN, John
Sent: Thursday, January 30, 2014 12:52 PM
Subject: Re: [DCHAS-L] Met-L-X or Lith-X Extinguishing Medium


The specialized class-D extinguisher materials are specifically for the burning active metals, especially lithium, which is the most reducing of them. The metal alkyls are quite different even though they react as readily with air as do metals. The metals in the case of alkyls are not as elemental, but as essentially ions, ie. inert. The carbon anion is very reactive with oxygen but releases about the same energy per oxygen atom as any ordinary organic compound. The active metals, as elements, produce much greater heat per oxygen atom (or mole of them) than carbon compounds. Smothering those with sand or lime should suffice. The alkylide ion reacts with hydrogen ion, water is a strong acid by comparison and thus vigorous, but it doesn’t become hydrogen in the process. A light alkylide will become a hydrocarbon vapor and ignite in air if auto-ignition temperature and limits of flammability happen to be co-incident.

Bretherick’s handbook has a very good summary on materials for extinguishing fires of the group 1 metals.


From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Brandon S. Chance
Sent: Wednesday, January 29, 2014 4:22 PM
Subject: [DCHAS-L] Met-L-X or Lith-X Extinguishing Medium




I am looking into the advantages and disadvantages of using Met-L-X or Lith-X scoopable dry powder extinguishing agent versus outfitting labs with the extremely large dry powder extinguishers that this material traditionally comes in.  I am hoping for a solution for the usual pyrophoric and reactive metal suspects; alkyllithiums, trimethyl aluminum, diethyl zinc, potassium, sodium, magnesium, etc.


If anyone has an experience with using or training with this extinguishing, I would appreciate any insight that you might have.  I have already contacted Ansul and am awaiting their response.





Brandon S. Chance, M.S., CCHO

Program Manager, Chemical Safety

Environmental Health and Safety

Princeton University

262 Alexander Street

Princeton, NJ 08540

609-258-7882 (office)

609-955-1289 (mobile)

609-258-1804 (fax)


"The second I feel like I made it, the second I feel like I've arrived, that's the second someone will take my spot. And I like my spot." J.J. Watt – Houston Texans

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