<div dir="ltr"><div>Hi all, </div><div><br></div><div>Just to add a datapoint, we have also seen this with sulfuric acid, not infrequently over the past few years (from both Fisher and VWR), but fortunately not with HF. This is usually evident as soon as we open the boxes, seen as visible droplets of liquid on the bottles (usually sitting near the base of the handle) and/or drips on the sides or bottom of the cardboard boxes. pH test strips on the drips yields a pH of 0, but the acid is not so concentrated as to immediately darken cleanroom wipes, as you would expect for 95% H₂SO₄, so it's a bit of a mystery. We clean these bottles and place them in cabinets in our chemical stock room until they are brought into the cleanroom as needed. While being stored in the stock room, some of bottles "reoffend", with similar drips showing up again days or weeks later, despite having sat undisturbed. </div><div><span style="background-color:transparent"><br></span></div><div><span style="background-color:transparent">We have escalated this with the vendors, but still get at least a few </span>(~5–10%) <span style="background-color:transparent">leaky bottles in most of our orders. At this point, we're still not sure whether this points to a manufacturing defect particular lots of bottles and/or caps, damage during shipping, or something else.</span></div><div><span style="background-color:transparent"><br></span></div><div><span style="background-color:transparent">Cheers, </span></div><div><span style="background-color:transparent"><br></span></div><div><span style="background-color:transparent"> – Aaron</span></div><div><br></div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><u style="font-size:x-small"> </u><span style="font-size:x-small"> </span><br></div><div><span style="font-size:12.8000001907349px"><font size="1"><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="color:rgb(0,0,0);font-family:Arial;white-space:pre-wrap;line-height:1.38;background-color:transparent">Aaron Hryciw, PhD, PEng (he/him)</span></p><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="color:rgb(0,0,0);font-family:Arial;white-space:pre-wrap;line-height:1.38;background-color:transparent">Fabrication Group Manager</span><br></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">University of Alberta - nanoFAB</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">W1-060 ECERF Building</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">9107 - 116 Street</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Edmonton, Alberta</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Canada T6G 2V4 </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Ph: <a href="tel:(780)%20940-7938" value="+17809407938" target="_blank">780-940-7938</a></span></p><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"><a href="http://www.nanofab.ualberta.ca/" style="color:rgb(17,85,204)" target="_blank">www.nanofab.ualberta.ca</a></span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span></font></span><font color="#000000"><br></font><br></div></div></div></div></div></div></div></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 6 Jul 2026 at 09:30, Prashant Srinivasan <<a href="mailto:prashant@ucsb.edu" target="_blank">prashant@ucsb.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><u></u>
<div>
<p>Kathy,</p>
<p><br>
</p>
<p>Could you elaborate a bit on the nature of the contamination?
Appearance? Chemical composition? We purchase from Fisher
Scientific and VWR. </p>
<p><br>
</p>
<p>If you are referring to crystals, especially in BHF, this is
normal. The concentration of Ammonium Fluoride is very high, often
near saturation and crystallization typically occurs when the
temperature drops. If you see crystals around the cap, local
evaporation is the likely cause. In either case, diluting slightly
with DI water or bringing up the bottle to 23- 25 C should solve
the issue. If you have a large amount of crystals, the chemical
composition might have changed. It is hard to say without
pictures. Note that HF (not BHF) should not have crystals.</p>
<p><br>
</p>
<p>Prashant</p>
<p><br>
</p>
<div>On 7/2/2026 11:20 AM, Kathy Anderson
wrote:<br>
</div>
<blockquote type="cite">
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Hello Lab Network,</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
What is your lab's strategy to minimize the occurrence rate of
receiving incoming boxes of H2SO4 or HF bottles with chemical
contaminating the inside of the box and/or the outside of the
bottles?</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Do you have a preferred vendor or vendors you avoid for this
reason? We are experiencing this phenomenon sporadically from
multiple vendors. Some respond by wrapping their bottles or the
rims of bottles before shipping for a time, but not
indefinitely, and some are only willing to replace.</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Kathy</div>
<div id="m_5967847208555949790m_-8485913537483954077Signature">
<div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
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<tbody>
<tr>
<td style="text-align:left;vertical-align:top;width:110px"><span style="font-family:myriad-pro,sans-serif;font-size:17px;color:rgb(71,73,74)"><img alt="Block U Logo" width="110" style="width: 110px; height: auto; max-width: 100%; display: block;" src="https://digital.utah.edu/wp-content/uploads/sites/2/2024/08/block-u-signature.png"></span></td>
<td style="text-align:left;line-height:1.2;vertical-align:top;color:rgb(128,128,128)">
<div style="text-align:left;line-height:1.2;font-family:Arial">
<span style="font-size:14px;color:rgb(102,102,102)"><b>Kathy
Anderson</b></span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(102,102,102)"><b><i>Chemical
Engineer III</i></b></span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(128,128,128)">Utah
Nanofab</span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(128,128,128)">The
University of Utah</span><span style="font-size:12px"><br>
O: </span><span style="font-size:12px;color:rgb(128,128,128)"><a href="tel:(801)%20213-6555" value="+18012136555" target="_blank">801-213-6555</a></span><span style="font-size:12px"> | C:
</span><span style="font-size:12px;color:rgb(128,128,128)"><a href="tel:(801)%20440-1465" value="+18014401465" target="_blank">801-440-1465</a></span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(128,128,128)"><a href="https://www.nanofab.utah.edu" target="_blank">https://www.nanofab.utah.edu</a></span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(128,128,128)">36
S Wasatch Drive Suite 2500</span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(128,128,128)">Salt
Lake City, UT 84112</span><span style="font-size:12px"><br>
</span><span style="font-size:12px;color:rgb(102,102,102)"><i><a href="mailto:kathy.anderson@utah.edu" target="_blank">kathy.anderson@utah.edu</a></i></span></div>
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</table>
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</blockquote>
<pre cols="72">--
Prashant Srinivasan
Teaching Cleanroom Engineer
Electrical & Computer Engineering
Univ. of California Santa Barbara
<a href="https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr" target="_blank">https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr</a></pre>
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