Russ,
Let me put a physician toxicologist (Medical Toxicologist) slant on
this. I refer you to our published papers:
Hall AH, Blomet J, Gross M, Nehles J: Hexafluorine for emergent
decontamination of hydrofluoric acid eye/skin splashes. Semiconductor
Safety Association Journal 2000; 14:30-33.
Mathieu L, Nehles J, Blomet J, Hall AH: Efficacy of Hexafluorine for
emergent decontamination of hydrofluoric acid eye and skin splashes.
Vet Human Toxicol 2001; 43:263-265.
Soderberg K, Kuusinen L, Mathieu L, Hall AH: An improved method for
emergent decontamination of ocular and dermal hydrofluoric acid
splashes. Vet Human Toxicol 2004; 46(4):216-218.
Frankly, I think no one should handle HF without proper PPE. It will
depend on the AMOUNT and the CONCENTRATION. With <20%, you have what
has been called a "stealth acid" because the pain (out of proportion to
the physical signs) will not begin until several hours after exposure
(hence the very excellent comments about pin holes in a glove). With
concentrated >50%, 70%, anhydrous HF, the pain will start immediately.
My personal experience with a very large number of cases is that anyone
who gets 50% or greater concentration HF on 20-25% total body surface
area or 1-2% on the face or in the groin DIES. HF exposure is not a
good thing. And yet, for what it's used for, there are no really viable
alternatives for process product substitution.
Hexafluourine=AE is a new HF decontaminant solution that can be kept
right at the workstation and there is empirical and experimental
evidence that it is better than water for initial decontamination should
someone be HF exposed.
Alan H. Hall, M.D.
TCMTS, Inc.
ahalltoxic**At_Symbol_Here**msn.com
----- Original Message -----
From: Russ Phifer
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Sent: Thursday, December 01, 2005 6:06 AM
Subject: [DCHAS-L] Hydrofluoric acid handling
I received the following request for information from Ernie Lippert, a
former CHAS member. I provided my own response, but suggested he
might also
want to get the opinion of the DCHAS-L, so here it is. My response
follows
his question; I'd also be curious what everyone else says.
Russ Phifer
With regards to bench chemists using HF there are two schools of
thought:
(1) to wear gloves, or (2) not to wear gloves during operations
digesting of
silicate glasses in Pt dishes. It has been our practice not to wear
gloves
during these operations.
Pt tipped tongs are used to remove the dishes from the hotplate, etc.
It has
been a long established practice in our laboratory (from which I am
now
retired but active as a consultant) not to use gloves because good
tactile
sense is paramount in handling HF. Further, our chemists are almost
paranoid
about rinsing their hands. Over the past 40 years or so our safety
record
with respect to HF has been excellent with (to my recollection) only
one
serious incident.
In this current age of PPE it is sometimes hard to argue that perhaps
not
wearing gloves is the best option. I can offer two arguments: (1) the
loss
of tactile sense, and (2) the possibility of a pinhole in the glove.
This
could be disastrous since the wearing of gloves gives a false sense of
security and precludes frequent washing. A HF burn does not manifest
itself
for some hours, after which time extremely serious consequences
result.
My question to you is do you know of any discussions in the literature
that
speak to the laboratory handling of HF? I will greatly appreciate your
counsel and your thoughts on this matter.
Regards,
Ernest L. Lippert (Ernie)
ACS Member No. 00228463
_____
From: Ernest L. Lippert [mailto:ernielippert**At_Symbol_Here**toast.net]
Sent: Wednesday, November 30, 2005 6:20 PM
To: Russ Phifer
Subject: Re: Attn: Russ Phifer
Russ,
I think it might be interesting to poll the DCHAS-L list on this
question.
Eye protection is a no-brainer but, while neoprene gloves might sound
like a
good idea (particularly to those who may not have experience with this
specific operation), they do reduce dexterity. I wonder if others
might have
the same take on it that I do.
Regards,
Ernie
----- Original Message -----
From: HYPERLINK
"mailto:rphifer**At_Symbol_Here**glasmesh.com"Russ
Phifer
To: HYPERLINK
"mailto:ernielippert**At_Symbol_Here**toast.net"'Ernest L. Lippert'
Sent: Wednesday, November 30, 2005 12:53 PM
Subject: RE: Attn: Russ Phifer
Ernie -
I would be glad to send this request out to the DCHAS-L list as a
whole to
see what response you get, but I would bet the sentiment would be
entirely
towards the wearing of gloves. I refer you to page 339 of Prudent
Practices
in the Laboratory: Handling and Disposal of Chemicals, which
addresses the
handling of hydrofluoric acid by stating "splash goggles and neoprene
gloves
should be worn at all times to prevent eye and skin contact".
Please let me know if there is anything else you'd like on this.
Russ Phifer
Chair, DivCHAS
WC Environmental, LLC
PO Box 1718, 1085C Andrew Drive
West Chester, PA 19380
610-696-9220 ext. 12 /610-344-7519 fax
rphifer**At_Symbol_Here**glasmesh.com
_____
From: Ernest L. Lippert [mailto:ernielippert**At_Symbol_Here**toast.net]
Sent: Tuesday, November 29, 2005 11:32 PM
To: rphifer**At_Symbol_Here**glasmesh.com
Subject: Attn: Russ Phifer
Dear Russ,
You may not remember me but I was once semi-active in CHAS a number of
years
ago. I now solicit your help in providing information concerning
hydrofluoric acid.
With regards to bench chemists using HF there are two schools of
thought:
(1) to wear gloves, or (2) not to wear gloves during operations
digesting of
silicate glasses in Pt dishes. It has been our practice not to wear
gloves
during these operations.
Pt tipped tongs are used to remove the dishes from the hotplate, etc.
It has
been a long established practice in our laboratory (from which I am
now
retired but active as a consultant) not to use gloves because good
tactile
sense is paramount in handling HF. Further, our chemists are almost
paranoid
about rinsing their hands. Over the past 40 years or so our safety
record
with respect to HF has been excellent with (to my recollection) only
one
serious incident.
In this current age of PPE it is sometimes hard to argue that perhaps
not
wearing gloves is the best option. I can offer two arguments: (1) the
loss
of tactile sense, and (2) the possibility of a pinhole in the glove.
This
could be disastrous since the wearing of gloves gives a false sense of
security and precludes frequent washing. A HF burn does not manifest
itself
for some hours, after which time extremely serious consequences
result.
My question to you is do you know of any discussions in the literature
that
speak to the laboratory handling of HF? I will greatly appreciate your
counsel and your thoughts on this matter.
Regards,
Ernest L. Lippert (Ernie)
ACS Member No. 00228463
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