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Date: Mon, 5 Jan 2009 16:06:41 -0500
Reply-To: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Subject: 4 Re: [DCHAS-L] UCLA Lab Fire
Date: Mon, 05 Jan 2009 14:17:54 -0500
From: "Margaret Rakas"
Subject: Re: [DCHAS-L] UCLA Lab Fire
>What does "the stopper on the syringe came undone" mean????
Having worked with these MANY years ago, my guess is that the reagent
bottle was pressurized (nitrogen) and so the material in the syringe
was as well; the barrel (or plunger) then has a tendency to push
itself out. I had strong hands from tennis and playing piano, but
sometimes the researcher doesn't, or isn't aware of the pressure
differential and is caught by surprise. You can kinda tell you'll
have to hang on harder (or use a nitrogen bubbler to get the pressure
down a bit, although I'm not sure the chemists would go for that) if
you put the syringe in and the barrel starts to go back quickly even
before you start to draw material.
I am kind of surprised they used water to put out this fire,
though...unless it became a big one.
Other than being prepared for this happening (so have someone to help
you hold the syringe, have the fire extinguisher nearby, prep the
bottle with a small amt of nitrogen through a bubbler if it seems like
the material is REALLY pressurized)--does anyone have anything else
they'd do?
My personal opinion only, not legal advice, and may not be the opinion
of my employer or any group to which I belong...
Margaret
==
Subject: RE: [DCHAS-L] UCLA Lab Fire
Date: Mon, 5 Jan 2009 13:25:14 -0600
From: "Nail, John"
Pyrophoric substances such as t-butyl lithium are stored in septum-
capped bottles and transferred by either syringe or transfer tubes
under positive inert gas (usually nitrogen, can be argon) pressure.
The procedure when syringing is to insert a needle attached to a low
pressure nitrogen or argon line into the septum, insert the syringe
into the septum, then use the positive pressure from the inert gas to
transfer the solution into the syringe. This keeps the solution under
an inert atmosphere and prevents air from entering the bottle and
decomposing the reagent.
There appears to be two likely explanations for this incident: 1) The
pressure on the inert gas line was too high, resulting in blowing out
the septum, or 2) Either the pressure on the inert gas line blew out
the syringe plunger or the victim inadvertently pulled it out of the
syringe.
Due to their nature, pyrophorics are hazardous. The ONLY ways of
minimizing incidents are proper training and proper attention by the
lab workers. Even when everyone is properly trained and working as
they should, fires will occur; these are unavoidable.
I note that this is the first working day of the year; it can take a
day or two to get a person's head back into the lab.
John Nail
Associate Professor of Chemistry
Oklahoma City University
==
Subject: RE: [DCHAS-L] UCLA Lab Fire
Date: Mon, 5 Jan 2009 14:24:37 -0500
From: "Bush, Kimberly"
I noticed this odd description as well. I initially assumed that
stopper meant plunger. Based on the following explanation . . .
" While she was extracting the compound, the stopper on the syringe
> came undone and exposed the chemical to air.
>
> Gibson said he did not know how the stopper came undone but said
the
> syringe was found melted."
I think . . .
The phrase "extracting the compound" must mean that she was pulling
the pyrophoric reagent through a septum on the original container
using a needle/syringe. The reason for using a needle through a
septum, of course, is to avoid exposure to air. It is very likely
that the needle became clogged due to precipitate (solids) in the
reagent or that she did not have a vent needle (or nitrogen line) in
the septum to allow for gas to back fill the volume being removed from
the container. Another possibility is that the needle being used was
too small of a gauge to easily pull the liquid.
Any one of the above situations would obviously make it very difficult
to pull the plunger. A common rookie mistake is to pull like crazy on
the plunger to try to suck up more liquid. A sudden release of this
pressure (needle un clogs, air gets sucked in through hole in septum,
etc) and the plunger may pop out of the syringe. The uncontrolled
nature of this event means that chemical will spill or spray into the
air where it is likely to ignite.
It could also be that the needle, which is usually secured to the
syringe via a luer-lock (screw-on) type connection, came unscrewed
while she was pulling the reagent out through the septum and the
chemical leaked from the syringe and or needle, causing fire. The
pressure then may have then blew out the plunger.
Just my thoughts from the research chemist perspective!
Kimi Bush
Staff Chemist
Med Chem Safety Committee Co-Chair
Merck & Co. Inc.
WP14-3
770 Sumneytown Pike
P.O. Box 4
West Point, PA 19486
ofc: 215-652-2766
cell: 610-223-9227
fax: 215-652-3971
==
Date: Mon, 5 Jan 2009 12:58:33 -0600
From: Jason Jones
Subject: Re: [DCHAS-L] UCLA Lab Fire
The question I would like to know is:
How much water did the fellow researcher assistant use to put the fire
out since the material is water-reactive to begin with?
Jason
Jason Jones
The University Of Mississippi Medical Center
Biological/Chemical Safety Officer
Phone: (601)-984-1981
Pager: (601)-929-3884
jnjones2**At_Symbol_Here**hr.umsmed.edu
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