DCHAS-L Discussion List Archive
Date: Mon, 20 Sep 2010 16:18:07 -0700
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: Karen Smith <smithkl**At_Symbol_Here**WHITMAN.EDU>
Subject: Re: Peroxide Question
In-Reply-To: <4A4DBA32095D8F4B8691764CCD57758809673224**At_Symbol_Here**ENTWEXMB0000000.university.harvard.edu>
Our waste handler won't accept bottles over 10ppm peroxide, therefore
that's my limit.
Karen Smith, CSMM
Chemical Hygiene Officer/ Lab Coordiantor
Whitman College
345 Boyer Ave.
Walla Walla, WA 99362
509 527-5272
On Sep 20, 2010, at 12:10 PM, Johnson, Amy Carr wrote:
> Here is a link to the article from which the excerpt below was taken
> regarding safe levels of peroxides
http://www.bnl.gov/esh/cms/PDF/peroxides.pdf
>
>
>
> =93Kelly (7) reviewed the literature to determine the minimum
> hazardous concentration of peroxides in solution
> with organic solvents. Peroxide concentration of 100 ppm has been
> widely used as a control point, but lacks
> scientific justification and is probably based on the practical
> detection limit of the potassium iodide method. Kelly
> reported great disparity (range 50-10,000 ppm as hydrogen peroxide)
> between various references. There was little
> agreement between authors and none provided supporting data. The
> highest level (10,000 ppm) was found in a
> National Safety Council publication (16). However, the NSC
> publication included no supporting references for the
> latter statement or the NSC recommendation for administrative
> control value of 100 ppm.
> The Material Safety Data Sheet for diethyl ether cautions against
> concentrating ether containing peroxide level
> above 100 ppm (10). Presumably, instability and hazard increase with
> concentration such that at some point, the
> solution spontaneously explodes. Kelly suggested that it is likely
> that the control concentration of 100ppm, in some
> cases may be overly conservative by at least an order of magnitude.
> This may apply to the chemicals listed in Table
> 1-B unless the unstable materials are concentrated as result of
> solvent evaporation (7).
> Kelly (7) stated that "theoretically, explosion should be impossible
> for most solutions of <1% peroxides."
> However, to rationally establish a safe/hazard concentration is
> complicated by a number of factors. For example,
> some of the liquid may remain on the threads and cap when
> peroxidized liquids are dispensed from glass containers
> with screw-caps or with ground-glass stoppers. As the solvent
> evaporates, the peroxide can be concentrated to
> dangerous levels within in the threads of the cap. Thus, a volatile
> solvent containing relatively low peroxide
> contamination could explode because of peroxide concentration at the
> cap (3, 7). Dilute solutions of most
> peroxidizable chemicals or solutions in solvents with low volatility
> (B.P. > 300 o C or V.P. <0.1 mm Hg at 20 o C)
> usually do not pose a peroxide hazard and are not likely to
> concentrate. Thus, it is usually unnecessary to treat such
> solutions as peroxide hazards (3, 5).
> Some of the peroxidation products of the chemicals in Group A (Table
> 1) are less structurally stabile than those
> in Group B. Thus even peroxide concentrations of less than 100 ppm
> should be considered very hazardous.
> Unstabilized isopropyl ether can readily form highly unstable
> peroxides. Even low small concentrations produced
> through solvent evaporation are very dangerous and may explode on
> shaking (33). The temperature and
> concentration at which explosion of peroxides of isopropyl ether
> becomes probable has never been authoritatively
> stated (20).=94
>
> Hope this helps-
> From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On
> Behalf Of Bill Galdenzi
> Sent: Friday, September 17, 2010 9:17 AM
> To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
> Subject: [DCHAS-L] Peroxide Question
>
> All,
>
> I have a question: What concentration of peroxide do you folks use
> for your =93acceptable=94 level? What is the basis for this level?
>
> Thanks for your help.
>
> Bill Galdenzi
> Environmental, Health, and Safety
> Boehringer-Ingelheim Pharamceuticals
> (203) 778-7759
> bill.galdenzi**At_Symbol_Here**boehringer-ingelheim.com
>
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