[labnetwork] HF storage

Gustavo de Oliveira Luiz deolivei at ualberta.ca
Wed Feb 15 11:25:19 EST 2023


Hi Savitha,

Here at the University of Alberta's nanoFAB, we store HF and HCl in
completely separate cabinets. In fact, the HF cabinet only contains 49%-HF,
BOE, Borofloat etch (HNO, HF mixture) and CaCl2 (for neutralization of
these solutions after usage). HCl is kept in a cabinet where other acids
and metal etchants may also be found, and it is the responsibility of the
user to read labels before pouring chemicals into beakers or other
containers.

It is understandable that we want to have our labs basically fool-proof,
but space always comes at a premium and it may not be an option to have
separate cabinets for every single chemical we stock — again, we still have
different acids in the same cabinets, only HF and sulfuric have their
unique cabinets. The only option left then is taking administrative action
to make sure users follow basic rules.

We require all users to be trained and signed off by a staff member before
they can process by themselves. Whenever something this serious happens, we
remove their user status and set them back to trainee, and they are not
allowed to process alone until they regain a staff memeber's confidence
that they can do so safely. And, of course, reincidence is followed by more
drastic consequences affecting their access to the process or even the
clean room.

I echo Rich's motto, everyone must be a little bit afraid of these
chemicals, just enough so we remember to be careful around them.

Best,
--
Gustavo de Oliveira Luiz, PhD
Applications/Research Specialist
nanoFAB, University of Alberta

On Wed, Feb 15, 2023 at 9:14 AM Hosler, Richard S <hosler0 at purdue.edu>
wrote:

> For our RCA process at Purdue/BNC, we have a small (6ft.) dedicated
> Kinetics RCA cleaning hood with heated below deck level baths for SC1/SC2
> and a smaller unheated bath for HF. I have installed a separate cabinet for
> the HF and HCl adjacent to the hood. This is marked as for RCA only to a)
> separate the RCA supplies from the main supply and b) to shorten the
> distance between the cabinet and hood.
>
>
>
> The HF is in a smaller semi-opaque white bottle that is easy to determine
> the level. The HCl bottles are double the size and glass. Each has their
> own shelf to visually separate them as well. H2O2 goes into a small fridge
> on the other side of the hood, again to separate the supply and provide
> quick access.
>
>
>
> Access to this hood is restricted by requiring a 2 hour training session
> in which the user sets up, uses, and cleans up the process from start to
> finish. Prior HF procedures that are outlined originally in the cleanroom
> access training are reinforced here and the nearest HF exposure kit (6ft
> behind the user) is pointed out.
>
>
>
> Basically the strategy is a sort of defense-in-depth of individual
> mistake-proofing features. To my knowledge we haven’t had any exposure
> incidents stemming from this hood in the ~4 years it’s been operational.
>
>
>
> My catchphrase when working with RCA and Piranha is as follows: “If you
> ever stop being scared and respectful of these chemicals, you need to  stop
> working with them.”
>
>
>
> Rich Hosler
>
> Research Engineer (Thermal/PECVD)
>
> Purdue University – Birck Nanotechnology Center
>
> hosler0 at purdue.edu
>
>
>
> *From:* labnetwork <labnetwork-bounces at mtl.mit.edu> * On Behalf Of *Savitha
> P
> *Sent:* Wednesday, February 15, 2023 7:19 AM
> *To:* labnetwork at mtl.mit.edu
> *Subject:* Re: [labnetwork] HF storage
>
>
>
> ---- *External Email*: Use caution with attachments, links, or sharing
> data ----
>
>
>
> Hi!
>
>
>
> We recently had a couple of occasions where users had mistakenly used
> Hydrofluoric acid in place of Hydrochloric acid during RCA cleaning. To
> avoid this, one of the suggestions we have received from our OLSEH is to
> store HF in a different coloured bottle (currently all acids are stored in
> white translucent polypropylene bottles which are properly labelled).
> Accordingly, we had considered storing HF in opaque, brown colour HDPE
> bottles. However, that was not deemed acceptable by a section of users
> saying bottles should be translucent so that acid level inside can be
> judged.
>
>
>
> Could you please let me know how small quantities of HF are stored in your
> respective fabs. Is there any regulation governing storage of HF, so that
> we could implement the same.
>
>
>
> Thanks and regards,
>
> Savitha
>
>
>
> Dr. Savitha P
> Chief Operating Officer
>
> National Nanofabrication Centre
> Centre for Nanoscience and Engineering
> Indian Institute of Science
> Bangalore - 560012
> India.
> Ph. +91 80 2293 3319
> www.cense.iisc.ac.in
> _______________________________________________
> labnetwork mailing list
> labnetwork at mtl.mit.edu
> https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork
>
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