Professional
experience since 1981 includes responding to two perchloric acid hoods
that
underwent an exothermic event. In both cases, the damage to
instruments
on the floor involved and the floors below were in the five figures.
We
have used an ion specific electrode to detect perchloric acid / misc.
perchlorates
in old systems that measured in the per cent range –
certainly enough
to provide a highly oxidizing environment, especially when in contact
with most
organic solvents. Another problem with old systems is the
corrosion in
the ducts and fan. In one case, most of the remaining duct work
was
multiple layers of paint with traces of the original metal duct
remaining. In
other words, even if there are “acceptable” levels of
perchlorates,
the ventilation system is simply too corroded to be of any use as a
working
fume hood. Be careful of renovations – one auxiliary
(make-up air)
system was remodeled by connecting the make-up air duct to the
ventilation
system. That certainly seems to comply with recycling concepts,
but in a
very bad way. The lab personnel complained of noxious odors and
poor air
flow. After several months of bitch complaining, the
suspended
tile ceiling was removed, allowing everyone to see the auxiliary duct
connected
to the exhaust duct. The second renovation is always more
expensive and
more disruptive than the first one. Money talks, but cheap does
not equal
acceptable.
George
Walton
Reactives
Management Corporation
Chesapeake, VA
757-436-1033
From:
DCHAS-L
Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On
Behalf Of Wendy Campbell
Sent: Tuesday, July 13,
2010 11:53
AM
To:
DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: [DCHAS-L]
Perchloric Acid
Fume Hood Decommissioning
Just FYI for
those who
are interested: at this point, the decommissioning and removal project
for the
perchloric acid hood has been halted due to budget concerns. The
hood
will be left in place, and the department wants to use it as a regular
fume
hood.
I'm still pushing to have it, at the very least,
scoped and washed down thoroughly before they do so, and then
have a
very large sign permanently attached to the hood indicating it's new
status as
a "regular" fume hood.
Thoughts, comments, concerns, experiences are welcome.
Wendy
On Thu, Apr 15, 2010 at 11:38 AM, Wendy Campbell <wendycampbell**At_Symbol_Here**boisestate.edu
>
wrote:
We are in the process of remodeling a building, which currently
houses
an old perchloric acid fume hood. I'm still tracking down how old
it is,
but I'm fairly sure it's at least 30 years of age. As part of the
remodel, the perc hood is to be removed. There are several issues
here.
--
Wendy Campbell, ASP
Occupational Health and Safety Officer
Environmental Health and Safety
Boise State
University
1910 University
Drive
Boise,
Idaho
83725-1826
Office: (208) 426-3303
Fax: (208) 426-3343
