
Hydrofluoric Acid: An Invisible Fire (1996) - DEFCON28
http://discovermagazine.com/1996/apr/aninvisiblefire739
======
CaliforniaKarl
Every time I hear anything about Flourine, I’m reminded of “Sand Won’t Save
You This Time”
[http://blogs.sciencemag.org/pipeline/archives/2008/02/26/san...](http://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time)

I also suggest watching the Periodic Table of Videos episode on Flourine:
[https://youtu.be/vtWp45Eewtw](https://youtu.be/vtWp45Eewtw)

~~~
pimeys
The book Ignition!, mentioned in the article/comments, is soon back to
print[0]. After reading these articles I think the book is a must read. Too
bad the Kindle version is quite bad quality.

[0] [https://www.amazon.com/Ignition-Informal-History-Liquid-
Prop...](https://www.amazon.com/Ignition-Informal-History-Liquid-
Propellants/dp/0813595835)

~~~
pixl97
>Ignition!

FOOF

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pdm55
The story I remember most vividly was the researcher, Dr Karen Wetterhahn, who
despite taking great care spilled one or two drops of dimethylmercury on her
latex glove. The glove would prove to be no protection at all - tests later
showed the dimethylmercury would have seeped through her glove and skin in
less than twenty seconds. Karen began displaying the neurological symptons of
mercury poisoning some three months later when it was too late to do anything.
She was dead within the year.

Dimethylmercury and hydrofluoric acid are both mentioned in this list of "10
Ridiculously Dangerous Chemicals",
[https://listverse.com/2016/12/09/10-ridiculously-
dangerous-c...](https://listverse.com/2016/12/09/10-ridiculously-dangerous-
chemicals/).

~~~
klodolph
This video covers that story rather well:
[https://www.youtube.com/watch?v=NJ7M01jV058](https://www.youtube.com/watch?v=NJ7M01jV058)

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knolan
HF is extremely scary, the safety precautions taken to work with it at an acid
bench really bring this home.

I heard a story once of a student putting a bottle into his backpack and
cycling across the city to another university building to use it in another
lab. The mind boggles at the stupidity.

~~~
nerdponx
So why the hell was it sold as a commercial rust remover product?

~~~
gambiting
I'm guessing it came from "another era" where you could buy stuff like this
without an issue?

But even few years ago I visited a wolfram mine in Portugal on a job, and was
told by the guy I worked with at the time that the miners are using stuff
"banned long time ago in UK" to clean the tips of the guiding ropes which we
were replacing. I was never told what it was, but nowadays I suspect it was
HF.

~~~
skykooler
For those who might be confused, "wolfram" refers to Tungsten.

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isoprophlex
I want to point out from professional experience that the dangers of HF as
stated in this article are not embellished in any way. It is really the stuff
of nightmares.

Also it's pretty insane IMO to put it in a bottle labeled 'rust remover'.
That's bound to cause accidents like this with people thinking it's just any
old stain-away soap.

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brobinson
"Invisible fire" reminded me of something which is almost completely invisible
while it burns: methanol

[https://www.youtube.com/watch?v=1ZEEuCHdWFA](https://www.youtube.com/watch?v=1ZEEuCHdWFA)

[https://www.youtube.com/watch?v=Ku7TdLeEGsQ](https://www.youtube.com/watch?v=Ku7TdLeEGsQ)

~~~
leeter
It actually reminded me of the aftermath of an arc flash (
[https://en.wikipedia.org/wiki/Arc_flash](https://en.wikipedia.org/wiki/Arc_flash)
) which while the original arc is visible (and may temporarily blind any that
see it) the plasma that comes out after it is not and is extremely scary
because it's potentially several times hotter than the surface of the sun. The
linked article has a video in it that describes the results.

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danieltillett
I have always had a huge fear of HF, but as a biologist I rarely had to work
with it. The chemical that I did work a lot with that was rather nasty was
phenol (carbolic acid). Splash that on you, or worse get it in your eyes, and
it hurts. I luckily never got it in my eyes, but I had a few cap-failing
eppendoff tubes (being vortexed) end up all over my face. Not nice.

The worst horror story I was told about phenol was of a grad student a few
years before me doing a large DNA extraction using phenol in a 3 litre
measuring cylinder. They filled it with phenol and DNA solution and then
sealed the end using parafilm (a stretchy plastic membrane). They then mixed
the solution by inverting the cylinder. You won't be surprised to learn that
phenol dissolves parafilm and the phenol ran straight down the student's arm
and they ran straight off to hospital.

~~~
classichasclass
We had a tanker truck full of the stuff overturn a couple weeks ago in a
remote area and I got a call from the hazmat guys about running a calcium
gluconate line if the stuff escaped containment. (I work for the health
department.) They usually use oral tape, but they were worried it wouldn't
work fast enough and they couldn't get medical aid fast enough since the
nearest hospital to the truck was about 80 miles away.

Fortunately they were able to right the truck without any spilling.

That one you probably _do_ want a Prop 65 notification for ...

~~~
wbl
Prop 65 doesn't apply to acute toxicity.

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tscs37
HF is a scary bond. I think the only other stuff that scares me more is CF3
and FOOF, the first being very very good at burning stuff that normally
doesn't burn like Asbestos and Sand, the later combusting explosively when
coming into contact with Water Ice at 90K.

To be honest, Flourine is a scary atom. A lot of the bonds it forms are also
scary. And toxic.

~~~
saagarjha
That's what you get when you mix a highly electronegative element with
anything else!

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denom
There was an explosion at a refinery in Superior Wi last week. The blast and
resulting fire was within 200 feet of a tank that can hold 76,000 pounds of
hydrogen fluoride ( _only_ 15,000 lbs were in the tank at the time).

Needless to say, officials are reconsidering the use of Hydrofluoric acid at
the facility: [http://www.duluthnewstribune.com/business/energy-and-
mining/...](http://www.duluthnewstribune.com/business/energy-and-
mining/4439179-officials-will-examine-future-use-hydrogen-fluoride-superior)

------
cowboysauce
The thing I've always found most interesting about hydrofluoric acid is that
it's corrosive and poisonous. Other acids like hydrochloric acid and sulfuric
acid are corrosive, but they're not poisonous like hydrofluoric is. Other
common acids will burn you, but that's the extent of their damage.
Hydrofluoric acid will burn you and absorb into your body, interfering with
calcium ions in a way that can lead to death.

------
superbatfish
This stuff is the active ingredient in glass "etching cream". Amazingly, many
DIY craft videos on YouTube demonstrate it WITHOUT USING GLOVES!

~~~
mtreis86
Armour Etch doesn't have HF, but it does have other fluorides
[https://www.msdsdigital.com/armour-etch-glass-etchant-
msds](https://www.msdsdigital.com/armour-etch-glass-etchant-msds)

~~~
superbatfish
That's interesting. Thanks very much for the correction, and the link!

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et2o
I wonder why they were so worried about radial artery spasm. If it closes off,
you still have sufficient collateral circulation via the ulnar artery. This
happens not infrequently in procedures where you catheterize the radial
artery.

~~~
ItsMe000001
They were worried because they thought the margin you normally have did not
exist in this case, and they tried to avoid any drop in circulation, which
would reduce the amount of fresh calcium brought into the hand, which might
not be compensated by the additional artificial supply if the radial artery's
flow dropped. In those other procedures that you mention you have a bit more
room because normally the tissues are not at their limit of how much of the
various molecules supplied by blood they use.

For those unfamiliar with how blood supplies various molecules, some of it
solved in blood directly, some of it bound to carriers, most famous probably
being oxygen: It's not like in a human supply chain where an empty truck or a
train is loaded to capacity and then again emptied completely when it reaches
a destination point. Instead, it's an equilibrium that changes based on things
like partial pressure or acidity _(pH is very slightly more basic in the
lungs, slightly more acidic in the periphery, because of CO2 - also see "Bohr
effect")_ and a lot of other variables. There is no 0% or a 100%. Here is an
example for a curve for oxygen: [https://courses.lumenlearning.com/wm-
biology2/chapter/transp...](https://courses.lumenlearning.com/wm-
biology2/chapter/transport-of-oxygen-in-the-blood/)

~~~
et2o
I'm highly familiar with details of vascular supply.

My point is that you have to weigh benefits of getting calcium there rapidly
vs. potential harms of radial artery occlusion.

~~~
ItsMe000001
> _I 'm highly familiar with details of vascular supply._

I assumed as much, does that invalidate anything in my comment? I made it
fully expecting that you have the knowledge. That's why I prefaced paragraph
two with _" For those unfamiliar with how blood supplies various
molecules..."_, to avoid that you feel you are the target of a lecture about
things you already know very well.

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downer68
Okay, but what about stannous flouride and sodium fluoride?

No one ever discusses the toothpaste fluorine ions, in conjuction with the
much more terrifying acid, which is the boogey man that haunts the fears
behind fluoridated water, and so on...

~~~
toss1
This is a good little interesting video on fluorine here (previously linked by
someone else), and the ending is the best description of tin fluoride for
teeth I've ever seen -- well worth the ~6min

[https://www.youtube.com/watch?v=vtWp45Eewtw&feature=youtu.be](https://www.youtube.com/watch?v=vtWp45Eewtw&feature=youtu.be)

(edit: added link)

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alex_hitchins
As someone who didn't apply themselves to Chemistry at school, what is the
best way to get a decent understanding of the basics. I love the physics I can
understand and would like to know more than nothing about chemistry.

~~~
ItsMe000001
I recommend not just any chemistry course but specifically this one:

MITx 3.091 "Introduction to Solid State Chemistry"

[https://www.edx.org/course/introduction-solid-state-
chemistr...](https://www.edx.org/course/introduction-solid-state-chemistry-
mitx-3-091x-5)

It's "archived" \- good enough, everything is accessible, you just won't be
able to get a "grade".

It's the gateway to "materials science" too. It is more at the edge of
chemistry, towards physics and engineering. Not to mention that the teaching
in this course is pretty good. Also, it is not dumbed down, you can go to MIT,
take the same course and feel right at home. It's about properties of
materials as a consequence of the chemical/physical properties of the
components (atoms/molecules) and how they are structured (example: diamond and
graphite are both made of carbon, then why are they so different).

If you want to get up to speed on "just chemistry" try Khan Academy, their
explanations are pretty good and you can easily select what interests you
because it is broken down into many small pieces.

~~~
alex_hitchins
Some very good suggestion there, thanks for taking the time to reply. I'd not
even thought about something like the MIT course or indeed Khan Academy but
looks like a good route to a better understanding.

Thanks again!

