[labnetwork] H2SO4 and HF Delivery and Acceptance

[Kathy Anderson]

Hi Aaron and all,

Thank you for responding.  I’ve shared this string with the interim U of U Nanofab Cleanroom manager, Jeff Farrer,  who is acting safety manager until a new safety manager is found.  I am off to new things.  If any of you or your colleagues are interested in a Chemical Engineer and Safety position at the U of U Nanofab Cleanroom, pleas econsider applying.  The position is open.

Kathy

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From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Aaron Hryciw <ahryciw at ualberta.ca>
Sent: Tuesday, 22 September 2026 14:59:42
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Subject: Re: [labnetwork] H2SO4 and HF Delivery and Acceptance

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Hi all,

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.

We have escalated this with the vendors, but still get at least a few (~5–10%) 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.

Cheers,

 – Aaron



Aaron Hryciw, PhD, PEng (he/him)

Fabrication Group Manager

University of Alberta - nanoFAB

W1-060 ECERF Building

9107 - 116 Street

Edmonton, Alberta

Canada T6G 2V4 Ph: 780-940-7938<tel:(780)%20940-7938>

www.nanofab.ualberta.ca<http://www.nanofab.ualberta.ca/>



On Mon, 6 Jul 2026 at 09:30, Prashant Srinivasan <prashant at ucsb.edu<mailto:prashant at ucsb.edu>> wrote:

Kathy,


Could you elaborate a bit on the nature of the contamination? Appearance? Chemical composition? We purchase from Fisher Scientific and VWR.


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.


Prashant


On 7/2/2026 11:20 AM, Kathy Anderson wrote:
Hello Lab Network,

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?

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.

Kathy

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Kathy Anderson
Chemical Engineer III
Utah Nanofab
The University of Utah
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https://www.nanofab.utah.edu
36 S Wasatch Drive Suite 2500
Salt Lake City, UT 84112
kathy.anderson at utah.edu<mailto:kathy.anderson at utah.edu>




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--
Prashant Srinivasan
Teaching Cleanroom Engineer
Electrical & Computer Engineering
Univ. of California Santa Barbara
https://www.ece.ucsb.edu/department-resources/electronics-shop/tcr

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