It is preferable, therefore, to use small containers which can be completely emptied, rather than take the amounts needed for immediate use from a large container over a period of time, unless the rate of use is sufficiently high so that peroxides will have a minimal time in which to form.
Ethyl ether, isopropyl ether, tetrahydrofuran, and many other ethers tend to absorb and react with oxygen from the air to form unstable peroxides which may detonate with extreme violence when they become concentrated by evaporation or distillation, when combined with other compounds that give a detonatable mixture, or when disturbed by unusual heat, shock, or friction. Peroxides formed in compounds by autoxidation have caused many laboratory accidents, including unexpected explosions of the residue of solvents after distillation, and have caused a number of hazardous disposal operations.
Some of the incidents of discovery and disposal of peroxides in ethers have been reported in the literature, some in personal communications, and some in the newspapers. Another explosion cost a graduate student the total sight of one eye and most of the sight of the other, and a third explosion killed a research chemist when he attempted to unscrew the cap from an old bottle of isopropyl ether. Peroxides may form in freshly distilled and undistilled and unstablized ethers within less than 2 weeks, and it has been reported that peroxide formation began in tetrahydrofuran after 3 days and in ethyl ether after 8 days.
These chemicals can form peroxides that are difficult to detect and eliminate. Label these items with a date of receipt and date of opening and dispose of these items 3 months after opening or 12 months if unopened.
These chemicals can undergo explosive polymerization initiated by dissolved oxygen. Label these items with a date of receipt and date of opening and dispose of these items 6 months after opening or 12 months if unopened. When alcohols listed are used for purposes that do not involve heating, chemical reaction, bulk evaporation or other activities that may stress the peroxidizable material, it is not necessary to track and test these containers for peroxidation.
These chemicals may explode when relatively small quantities of peroxides are formed. These items normally have an inhibitor scavenger added to the substance by the manufacturer in order to prevent peroxides from forming. This inhibitor can be removed if it interferes with the use of the chemical or the chemical is redistilled in the lab.
If a lab procedure requires the use of an uninhibited item in this Class, please contact OCRS at Label these items with a date of receipt and date of opening and dispose of inhibited items after 12 months and uninhibited items within 24 hours of use. These chemicals have the potential to form peroxides with varying conditions of use but are normally stable.
Acrylic acid Acrylonitrile Butadiene e 2-butanol Chlorotrifluoroethylene Methyl methacrylate. Di 1-propynl ether Di 2-propynl ether Di-n-propoxymethane 1,2-Epoxyisopropoxypropane 1,2-Epoxyphenoxypropane p-Ethoxyacetophenone 1- 2-Ethoxyethoxy ethyl acetate 2-Ethoxyethyl acetate 2-Ethoxyethyl -a-benzoyl benzoate 1-Ethoxynaphthalene o,p-Ethoxyphenyl isocyanate 1-Ethoxypropyne 3-Ethoxypropionitrile 2-Ethylacrylaldehyde oxime 2-Ethylbutanol Ethyl-b-ethoxypropionate 2-Ethylhexanal Ethyl vinyl ether Furan 2,5-Hexadiynol 4,5-Hexadienynol n-Hexyl ether o.
May become unstable if concentrated intentionally or accidentally by user. Search search Menu. Office of Clinical and Research Safety. Practices for Control of Peroxide Forming Materials Purchase Ideally, purchases of peroxide-forming chemicals should be restricted to ensure that these chemicals are used up completely before they can become peroxidized.
Labeling and Shelf-Life Limitation Peroxides tend to form in materials as a function of age. It is, however, a substance that has extreme physical hazards cognisance of which must always be a priority when planning even the simplest of procedures and the use of best laboratory practice at all times is paramount in ensuring its safe use.
Ether does not require a source of ignition such as a naked flame, or spark to initiate combustion. Ether vapour may be ignited by hot surfaces such as hot plates, steam pipes, electric lamps and static electricity discharges, and since the vapour is heavier than air, it may travel a considerable distance to an ignition source and flash back.
Sufficient static electricity to initiate flash ignition can build up when large quantities of ether is being poured from one vessel into another. Ether vapour forms explosive mixtures with air at concentrations of 1. Carbon dioxide or dry powder extinguishers should be used for ether fires. Ethers absorb and react with oxygen from the air, in the presence of light, forming unstable peroxides that can detonate with extreme violence when they become concentrated through evaporation or distillation and disturbed by heat, shock or friction.
Acute: harmful by inhalation in high concentrations which can cause inebriation, sedation, unconsciousness and respiratory paralysis. Diethyl ether is irritating to the eyes, respiratory system and skin but these effects are usually reversible on removal of exposure. Due, probably in part, to its high volatility the liquid is not easily absorbed through the skin, however repeated contact can remove the skins natural oils and cause dryness, cracking of the skin and other dermal complaints.
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