Date: Thu, 15 Apr 2010 18:08:39 -0400
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Ernest Lippert <ernielippert**At_Symbol_Here**TOAST.NET>
Subject: Re: Perchloric Acid Fume Hood Decommissioning
In-Reply-To: <u2q38a464b21004151038mee36ee9q8f9bc24e4af31eb2**At_Symbol_Here**mail.gmail.com>

Wendy, We moved several perchloric acid hoods some years ago without incident. The city fire department was quite willing to standby at the scene. Wash down with plenty of water from the top down. Perchlorates like to build up at bends so go slow and wash well, particularly the fans. Don't rely on the old-timers, the hoods were used with perchloric acid. Take care, Ernie Lippert On Thu, Apr 15, 2010 at 1:38 PM, 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. > > 1. No one remembers any hot perchloric acid work ever being performed in > this hood (I'm still tracking down the recently retired folks to see what > they know), and it has been either sealed shut or used as a regular chemical > fume hood over the past 10-15 years. I'm not sure whether trusting in > people's memories over the course of the hood's life is the best policy. > > 2. The duct system is plumbed above the bench of the hood so that it > washes a six foot run of ducting and the hood itself. The plumbing does NOT > extend any farther up the duct system, nor out onto the roof where it vents, > which leads us to......... > > 3. The duct takes a turn approximately two feet above where it emerges > from the roof, and has approximately 3-4 feet of vertical run to the blower > assembly. > > The plan under consideration at the moment is to start on the roof and > check each section for the presence of perchlorates, then spray the heck out > of it with water before removing just that section. > > I'm hoping for some feedback regarding other people's experiences, > suggestions for procedure / materials, and anything else the combined wisdom > of these fine groups can give us to perform this remodel safely and in a > timely fashion. I know the contractors would like to start within the next > couple of weeks. > > Pictures of the rooftop portion of the hood's exhaust system have been > posted to the AIHAH and Hazmat group sites on Yahoo, but I'm still working > on how to share my Flickr account with folks - perhaps just contacting me > off-list? > > Thanks in advance, > Wendy > > -- > 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 > >

Wendy,
We moved several perchloric acid hoods some years ago without incident . The city fire department was quite willing to standby at the scene. Wash down with plenty of water from the top down. Perchlorates like to build up at bends so go slow and wash well, particularly the fans. =A0Don't rely on the old-timers, the hoods were used with perchloric acid.
Take care,
Ernie Lippert

On Thu, Apr 15, 2010 at 1:38 PM, Wendy Campbell <wendy campbell**At_Symbol_Here**boisestate.edu> wrote:
We are in the process of remodel ing a building, which currently houses an old perchloric acid fume hood.=A0 I'm still tracking down how old it is, but I'm fairly sure it' s at least 30 years of age.=A0 As part of the remodel, the perc hood is to be removed.=A0 There are several issues here.=A0

1.=A0 No one remembers any hot perchloric acid work ever being performe d in this hood (I'm still tracking down the recently retired folks to s ee what they know), and it has been either sealed shut or used as a regular chemical fume hood over the past 10-15 years.=A0 I'm not sure whether trusting in people's memories over the course of the hood's life is the best policy.

2.=A0 The duct system is plumbed above the bench of the hood so that it washes a six foot run of ducting and the hood itself.=A0 The plumbing does NOT extend any farther up the duct system, nor out onto the roof where it vents, which leads us to.........

3.=A0 The duct takes a turn approximately two feet above where it emerg es from the roof, and has approximately 3-4 feet of vertical run to the blo wer assembly.=A0

The plan under consideration at the moment is to s tart on the roof and check each section for the presence of perchlorates, t hen spray the heck out of it with water before removing just that section. =A0

I'm hoping for some feedback regarding other people's experienc es, suggestions for procedure / materials, and anything else the combined w isdom of these fine groups can give us to perform this remodel safely and i n a timely fashion.=A0 I know the contractors would like to start within th e next couple of weeks.=A0

Pictures of the rooftop portion of the hood's exhaust system have b een posted to the AIHAH and Hazmat group sites on Yahoo, but I'm still working on how to share my Flickr account with folks - perhaps just contact ing me off-list?

Thanks in advance,
Wendy

--
Wendy Campbell, ASP
Occupational Health and Safety Officer
E nvironmental Health and Safety
Boise State University
1910 Universit y Drive
Boise, Idaho 83725-1826
Office: (208) 426-3303
Fax: =A0(208) 426-3343


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