[labnetwork] H2SO4 and HF Delivery and Acceptance

[Aaron Hryciw]

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 <(780)%20940-7938>
www.nanofab.ualberta.ca



On Mon, 6 Jul 2026 at 09:30, Prashant Srinivasan <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
>
> [image: Block U Logo]
> *Kathy Anderson*
> *Chemical Engineer III*
> Utah Nanofab
> The University of Utah
> O: 801-213-6555 <(801)%20213-6555> | C: 801-440-1465 <(801)%20440-1465>
> https://www.nanofab.utah.edu
> 36 S Wasatch Drive Suite 2500
> Salt Lake City, UT 84112
> *kathy.anderson at utah.edu <kathy.anderson at utah.edu>*
>
>
> _______________________________________________
> labnetwork mailing listlabnetwork at mtl.mit.eduhttps://mtl.mit.edu/mailman/listinfo.cgi/labnetwork
>
> --
> Prashant Srinivasan
> Teaching Cleanroom Engineer
> Electrical & Computer Engineering
> Univ. of California Santa Barbarahttps://www.ece.ucsb.edu/department-resources/electronics-shop/tcr
>
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