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Yeah, don't buy it. Just make it as needed and keep a close eye on the students. These days we only really use it to clean stubborn debris on masks and a few other relatively small volume applications. That said, we do have an acid waste neutralization system. </div>
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-Michael </div>
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<b>From:</b> labnetwork <labnetwork-bounces@mtl.mit.edu> on behalf of Prashant Srinivasan <prashant@ucsb.edu><br>
<b>Sent:</b> Monday, November 17, 2025 8:39 PM<br>
<b>To:</b> Beaudoin, Mario <beaudoin@physics.ubc.ca>; labnetwork@mtl.mit.edu <labnetwork@mtl.mit.edu><br>
<b>Subject:</b> Re: [labnetwork] Nanostrip/Purestrip bottle leakage: what do most labs do?</div>
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<span style="font-size: 10pt; color: black;"><b>CAUTION:</b> This email originated from outside of our organization. Do not click links, open attachments, or respond unless you recognize the sender's email address and know the contents are safe.</span></p>
<p style="margin-top: 1em; margin-bottom: 1em;">Mario,</p>
<p style="margin-top: 1em; margin-bottom: 1em;">Is there a particular reason you absolutely need Piranha? I made the switch to RCA in our teaching cleanroom after getting tired of cleaning up spills. Even a few drops burn leave burn marks. RCA is fairly dilute
(5:1/6:1) and the use temperature is only 70 C. Also, adding peroxide isn't as fraught. No matter how "well trained" the students are, the Piranha preparation process is unforgiving. Hazards to users, chemical waste and disposal risk (I don't have neutralization
capabilities) drove my decision making.</p>
<p class="elementToProof" style="margin-top: 1em; margin-bottom: 1em;">Prashant</p>
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<div>On 11/17/2025 10:48 AM, Beaudoin, Mario wrote:</div>
<blockquote>
<p style="margin-top: 1em; margin-bottom: 1em;">Dear Labnetwork,</p>
<p style="margin-top: 1em; margin-bottom: 1em;">As many labs do, because of safety concerns for the students, I banned the use the real pirahna etch in favor of Purestrip (Transene version of nanostrip). The problem I have is that the solution eventually leaks
from the bottle. I have heard of others mentioning this also. </p>
<p style="margin-top: 1em; margin-bottom: 1em;">I am now thinking of revising this policy and going back to old pirahna, despite the issues with safety and aging H2O2.</p>
<p style="margin-top: 1em; margin-bottom: 1em;">Anyone have comments?</p>
<p style="margin-top: 1em; margin-bottom: 1em;">Mario</p>
<div>--<br>
<img size="22739" data-outlook-trace="F:1|T:1" src="cid:part1.3RNpK0vD.7A01NJAU@ucsb.edu"></div>
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<pre><div>--
Prashant Srinivasan,
Teaching Cleanroom Engineer
Electrical & Computer Engineering
University of California, Santa Barbara
Santa Barbara, California 93106
<a data-auth="NotApplicable" originalsrc="https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr" class="x_moz-txt-link-freetext OWAAutoLink" id="OWA3827356a-1b6f-89a7-22c3-8463aaf6ebb8" href="https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr">https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr</a></div></pre>
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