I tend toagree with Tilak Chandra.  If the isovaleryl chloride vapors dissolved in the vacuum pump oil, and the pump outlet is vented to the room, this could be the source of the prolonged odor as the IC out-gasses from the pumpoil.  IF this is the case, and IF the situation is too obnoxious (andperhaps unhealthy), one simple solution is to use metallic piping (no vapor diffusion through the tubing) as much as possible, AND vent the pump to the hood.  Another more costly approach is the above, PLUS use of a vacuum pump that is designed for a continuous purge of nitrogen gas through the pump oil - with venting as described above.  A third additional solution is to use a synthetic pump oil (Flambeau??) in which organics dissolveto a much lesser degree than in petroleum-based pump oils.  All of the above is based on lessons learned when assisting with the design of a vacuum system used for silane, a pyrophoric gas.

In summary, I have described four solutions that may provide improvement of the situation eitheralone or in combination: (a) vent the vacuum pump to the hood, (b) use (grounded) copper piping for runs of vacuum pump line that are in the room, (c) acquire a vacuum pump designed for a slow purge with nitrogen gas, and (d) use a synthetic pump oil.

David Haugen
Argonne National Laboratory - retired

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From: "Tilak CHANDRA" <tchandra**At_Symbol_Here**FPM.WISC.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Wednesday, December 7, 2011 8:36:02 AM
Subject: Re: [DCHAS-L] Isovaleryl chloride odor control

Hi Ralph:

May be researcher bumped some of isovaleryl chloride in the Schlenk line.
During the manipulation sometime there is tendency of bumping the reagent
into line (glass manifold, tube, pump, etc.) if not handled properly. Also,
if the cooling system for the traps is not efficient then it can go into the
vacuumpump. If the pump is not vented to the fume hood, it will give smell
for an extended period.  In this case the Schlenk line was at lower bench,
outside of the fume hood. The boiling point of isovaleryl chloride is115-117
oC and it has strong smell.

Regards,

Tilak
Chemical Safety Specialist
Environment, Health and Safety
University of Wisconsin-Madison
30 East Campus Mall
Madison, WI 53715
Ph. 608-890-0255
FAX 608-262-6767
tchandra**At_Symbol_Here**fpm.wisc.edu

-----Original Message-----
From: DCHAS-L DiscussionList [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of
Ralph B Stuart
Sent: Wednesday, December 07, 2011 7:13 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Isovaleryl chloride odor control

I'm investigating a situation in which someone was working with isovaleryl
chloride which led to an odor release that lasted for a week. After the
material was extracted from the stock container with a syringe in a hood, it
was usedin a Schlenk line outside the hood. Preliminary examination of the
hoodwith dry ice indicates that it's maintaining containment. The lab's
general ventilation rate is high, as there are 10 feet of hood space in 700
I wonder if anyone has experience with a similar situation that could help
explain there the odor came from andwhy lasted so long?

Thanks for any information about this.

-Ralph

Ralph Stuart CIH
Laboratory Ventilation Specialist
Department of Environmental Health and Safety Cornell University

rstuart**At_Symbol_Here**cornell.edu