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Environmental Health and Safety


Peroxide Forming Chemicals

Certain commonly used chemicals in the laboratory can form peroxides upon exposure to oxygen in air. Formation and accumulation of peroxides makes peroxide-forming chemicals low-power explosives that are sensitive to shock, sparks and ignition sources. The inventory of such chemicals must be restricted to amounts needed for short-term use so that the chemicals are used up before significant formation and accumulation of peroxides occur. Here are important guidelines for proper storage, labeling and disposal of peroxide formers:

  • purchase peroxide formers that have added inhibitors, in the smallest, reasonable amount possible before it expires
  • label the container with date received and date opened
  • do not transfer from its original container
  • store in a cool, dark place, away from sunlight, heat, or sources of spark or ignition
  • dispose of peroxide formers according to the schedule for each class as defined below

Compounds known to autoxidize to form peroxides

  • Ethers containing primary and secondary alkyl groups (never distill an ether before it has been shown to be free of peroxide)
  • Compounds containing benzylic hydrogens
  • Compounds containing allylic hydrogens (C=C—CH)
  • Compounds containing a tertiary C—H group (e.g., decalin and 2,5-dimethylhexane
  • Compounds containing conjugated, polyunsaturated alkenes and alkynes (e.g., 1,3-butadiene, vinyl acetylene)
  • Compounds containing secondary or tertiary C—H groups adjacent to an amide (e.g., 1-methyl-2-pyrrolidinone)

Source:
Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards: Updated Version.
National Research Council (US) Committee on Prudent Practices in the Laboratory.
Washington (DC): National Academies Press (US); 2011.

 

Class A: SEVERE PEROXIDE HAZARD
Chemicals that form explosive levels of peroxides without concentration.

Disposal Schedule:
Discard within 12 months of date received, within 3 months of date opened, or within manufacturer expiration date, whichever comes first.

Examples
Isopropyl ether
Butadiene (liquid monomer)
Chlorobutadiene (chloroprene)
Potassium amide
Potassium metal
Sodium amide (sodamide)
Tetrafluoroethylene
Divinyl acetylene
Vinylidene chloride

Class B: CONCENTRATION HAZARD
These chemicals are a peroxide hazard on concentration (distillation/evaporation).

Disposal Schedule:
Discard within 12 months of date received, within 6 months of date opened, or within manufacturer expiration date, whichever comes first.

Examples
Acetal
Cumene
Cyclohexene
Cyclooctene
Cyclopentene
Diaacetylene
Dicyclopentadiene
Diethylene glycol dimethyl
ether (diglyme)
Diethyl ether
Dioxane (p-dioxane) e.g. 1,4 dioxane
Ethylene glycol dimethyl
ether (glyme)
Furan
Methyl acetylene
Methyl cyclopentane
Methyl-isobutyl ketone
Tetrahydrofuran
Tetrahydronaphthalene
Vinyl ethers

Class C: SHOCK AND HEAT SENSITIVE
Unsaturated monomers that may autopolymerize as a result of peroxide accumulation if inhibitors have been removed or are depleted. DO NOT purchase in uninhibited form!

Disposal Schedule:
Discard within 12 months of date received, within 6 months of date opened, or within manufacturer expiration date, whichever comes first. If substance does not have inhibitor, discard within 24 hours of opening the container!

Examples:
Acrylic acid
Butadiene (gas)
Chlorotrifluoroethylene
Ethyl acrylate
Methyl methacrylate
Styrene
Vinyl acetate
Vinyl chloride
Vinyl pyridine

Source:
Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards: Updated Version.
National Research Council (US) Committee on Prudent Practices in the Laboratory.
Washington (DC): National Academies Press (US); 2011.