Here's the Cornell University horror story about mixing these two, it sounds impressive... I appologize if this has been posted at the Hive before...
"Date: 9 Apr 1997 14:00:06 GMT
In article <334A4298.C1C@lanl.gov>
"Rebecca M. Chamberlin" writes:
(snip)
> However, using it in an R&D lab is asking for trouble. A classic lab
> accident with piranha solution occurred at Cornell in 1986 or so. The
> grad students in one lab used to rotate responsibility for cleaning all
> of their glass frits by running piranha solution thru them (using "house
> vacuum") into a filter flask. One student made the mistake of leaving a
> trace of acetone in the flask. When the piranha solution hit the
> acetone, it went BLAMMO and a million pieces of glass embedded
> themselves into her face. Thank heavens she was wearing her safety
> glasses or she would most likely be blind now: the lenses in her safety
> glasses were shattered but still intact in the frames. The chemistry
> department took a photo of the glasses and used it in their "Are you
> wearing your safety glasses?" poster for years afterward. Not
> surprisingly, the student decided to leave chemistry after her
> hospitalization.
As it appears that Becky, I and others have not quite gotten the point
across, let me drive it home one more time. While you can usually tell
a conversation among chemists has gotten lame when they start swapping
lab accident stories, it is important that you **understand** that the
risk of using this solution is nowhere near the reward.
What Becky is writing about is 100% true. I saw it. It happened. It
could just as easily happen to you. Read this and then ask whether a
clean frit is worth this.
I was the first one to get to scene of the above incident. We heard a
sound like an M-80 (about a quarter stick of dynamite) from two labs
away. We got there within about 5 seconds to find her on the floor
halfway across the room surrounded by a large pool of blood. The
filter flask that she was using turned to dust; we never found a
fragment larger than about 2 mm even though it had been wrapped in
heavy black electrical tape. The metal 3 prong clamp that held the
flask sheared off at the point where it was clamped to the latticework
in the hood. A row of glass cabinets along one wall were peppered with
holes from the shrapnel. The lab had one of those 100 mm diameter
glass drainpipes running vertically on the wall opposite the hood
(about 8-10 m away) -- the pipe cracked in the middle ...we believe
that it wasn't from shrapnel, but from the compression wave of the
blast.
The student was wearing rubber gloves, a thick sweater, a lab coat, an
apron and safety glasses at the time of the explosion. The hood was
down part way and saved her from catching most of it in the face. The
arm holding the frit caught most of the damage -- the glove was
completely flayed and her arm had several hundred small bits of glass
in it as well as several fairly large lacerations. She had a wound
about 20 mm in diameter just next to her jugular vein. At least one
piece of glass went through her cheek. She (and everything else) was
also covered with hydrogen peroxide and sulfuric acid; something that
we didn't realize until much later because we had no way of knowing
what had happened. I think the bleeding stopped more because she went
into shock than from the pressure were were applying in two different
places.
She spent the next six hours having tiny bits of glass picked out of
her arm, neck and face. I'm told that you continue to have those work
their way out of your skin for the next several weeks after such an
incident -- that you sweep your good hand across the arm and cut
yourself on the glass sticking out of your own skin. This student had
some nerve/tendon damage and lost a bit of the motion in one or two of
her fingers; I can't recall if she had any hearing loss or not. All
things considered, she got off pretty lucky. And yes, she did leave
the program a short time after.
Now consider this: 10 minutes later and the rest of my research group
would have left for dinner. She was working ALONE in her laboratory,
"just cleaning up". Maybe she could have gotten to the phone on her
own...when I got there she was trying to get up, but not very
successfully. Ever try to stand up in a pool of your own blood and
sulfuric acid on a linoleum floor while dazed and injured? Me neither,
but it certainly didn't look very easy. Think about that the next time
you are working a late night alone.
The odd thing here is that if she hadn't been working alone there would
have been many other injuries in that laboratory. We found one large
chunk of glass imbedded in a bookcase over someone's desk. If the
owner of the desk had been there he would have caught this fragment
with the back of his neck. I can not stress enough how **stupid** it
is to put a desk or glovebox opposite a fume hood (or having a desk in
a lab, but that's not always avoidable). Look around your lab and see
if you have that configuration...it's scary. And the next time you see
someone without their safety glasses on, help them find a pair or make
them leave. It is one thing to be an innocent bystander, it is another
to be a stupid bystander.
BTW, the shattered safety glasses Becky is referring to were from a
separate accident at Cornell involving a vacuum line explosion, but
that's another story and I only know it secondhand. Part of their
rather effective campaign to make you think about safety.
Let me just end with the question I posed at the beginning: Were a
batch of clean frits really worth all this?
Rob"