Background

Peroxide forming materials are chemicals which can form shock sensitive peroxide crystals over time or upon exposure to air. Common peroxide forming chemicals in use at Miami University include diethyl ether and tetrahydrofuran (THF). Peroxide formation cannot be prevented once the chemical has been opened unless the chemical is maintained under an inert atmosphere (impractical). For this reason, it is recommended that all peroxide formers be dated when received. It is prudent practice to maintain only the inventory necessary to complete ongoing work. DO NOT STOCKPILE! The Material Safety Data Sheet is a good source for determining if a material is capable of forming peroxides.

Classes of Chemicals That Can Form Peroxides Upon Aging

Class I

Unsaturated materials, especially those of low molecular weight, may polymerize violently and hazardously due to peroxide initiation.

Acrylic acid
Acrylonitrile
Butadiene
Chlorobutadiene (chloroprene)
Chlorotrifluoroethylene
Methyl methacrylate
Styrene Tetrafluoroethylene
Vinyl acetate
Vinyl acetylene
Vinyl chloride
Vinyl pyridine
Vinylidene chloride

Class II

The following chemicals are a peroxide hazard upon concentration (distillation/ evaporation). A test for peroxide should be performed if concentration is intended or suspected.

Acetal
Cumene
Cyclohexene
Cyclooctene
Cyclopentene
Diacetylene
Dicyclopentadiene
Diethylene glycol dimethyl ether (diglyme)
Diethyl ether (ether)
Vinyl ethers Dioxane (r-dioxane)
Ethylene glycol dimethyl ether (glyme)
Furan
Methyl acetylene
Methyl cyclopentane
Methyl-i-butyl ketone
Tetrahydrofuran
Tetrahydronaphthalene

Class III

Peroxides derived from the following compounds may explode without concentration.

Organic

Divinyl ether
Divinyl acetylene
Isopropyl ether

Inorganic

Vinylidene chloride
Potassium metal
Potassium amide
Sodium amide (sodamide)

NOTE: Lists are illustrative but not exhaustive.
Source: Prudent Practices in the Laboratory