[labnetwork] Titanium hazard

[Paolini, Steven]

I have had the unfortunate experience of witnessing this a few times over the years and I agree with Leif Johansen about the cause. In most of my experiences, the fire erupted in a HEPA vacuum used for cleaning a source chamber in an E-beam evaporator. The person cleaning the TI pocket would perform some sort of scraping followed by a wipe with isopropanol. In all cases after performing an "autopsy" of the vacuum, there was a clean room wipe or piece of clean room wipe inside the dirt chamber. We didn't believe there was a chemical reaction with the propanol but we did believe that the TI was rapidly oxidizing since it was physically removed from its place, combined with a fuel (isopropanol and wipes), in an environment of rushing air.  The fix was to have a metal bucket of water nearby to dispose of any debris produced by cleaning the TI pocket and having it removed as reactive waste when full.
Steve Paolini
Harvard University Center for Nanoscale Systems

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr.
Sent: Monday, May 06, 2013 9:50 AM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Titanium hazard

Hi Everyone,

Last week one of the staff was wiping off some evaporator parts that were covered with Titanium metal. He was using texwipes soaked with IPA. He tossed the texwipes in the trash then accidentally dropped some wipes saturated with IPA on top of them and a fire started. It self extinguished after 1 minute but it melted the bottom of a plastic trash can.

Have any of you had that happen or something similar? Needless to say this is very alarming and I need to understand what could have caused this and develop a corrective action plan.

Rick


Draper Laboratory
Group Leader Microfabrication Operations
555 Technology Square
Cambridge Ma, 02139-3563

www.draper.com<http://www.draper.com>
rmorrison at draper.com<mailto:rmorrison at draper.com>
W 617-258-3420
C 508-930-3461

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