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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
“Kelly (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
Hope this helps-
Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On
Behalf Of Bill Galdenzi
Sent: Friday, September 17, 2010 9:17 AM
Subject: [DCHAS-L] Peroxide Question
I have a question: What concentration of peroxide do you folks use for your “acceptable” level? What is the basis for this level?
Thanks for your help.
Environmenta l, Health, and Safety
Boehringer-I ngelheim Pharamceuticals
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