Classification List of Peroxide Forming Chemicals

Class A - Severe Peroxide Hazard

Spontaneously decompose and become explosive with exposure to air without concentration.

Butadiene (liquid monomer)

Isopropyl ether

Sodium amide (sodamide)

Chloroprene (liquid monomer)

Potassium amide

Tetrafluoroethylene (liquid monomer)

Divinyl ether

Potassium metal

Vinylidene chloride

Bold chemicals constitute the UC Class 1 Settlement Agreement list.

Class B - Concentration Hazard

Require external energy for spontaneous decomposition. Form explosive peroxides when distilled, evaporated or otherwise concentrated.

Acetal

Diethylene glycol dimethyl ether (diglyme)

4-Methyl-2-pentanol

Acetaldehyde

Diethyl ether (ether)

2-Pentanol

Benzyl alcohol

Dioxanes

4-Penten-1-ol

2-Butanol

Ethylene glycol ether acetates (glyme)

1-Phenylethanol

Cumene

Furan

2-Phenylethanol

Cyclohexanol

4-Heptanol

Tetrahydrofuran (THF)

Cyclohexene

2-Hexanol

Tetrahydronaphthalene (tetralin)

2-Cyclohexen-1-ol

Methylacetylene (gas)

Vinyl ethers

Decahydronaphthalene (decalin)

3-Methyl-1-butanol

Other secondary alcohols

Diacetylene (butadine, gas)

Methyl cyclopentane

Dicyclopentadiene

Methyl isobutyl ketone

Bold chemicals constitute the UC Class 2 Settlement Agreement list.

Class C - Shock and Heat Sensitive

Highly reactive and can auto-polymerize as a result of internal peroxide accumulation. The peroxides formed in these reactions are extremely shock- and heat-sensitive.

Acrylic acid

Chlorotrifluoroethylene (gas)

Vinylacetylene (gas)

Acrylonitrile

Methyl methacrylate

Vinyladiene chloride

Butadiene (gas)

Styrene

Vinyl chloride (gas)

Chlorobutadiene

Tetrafluoroethylene (gas)

Vinyl pyridine

Chloroprene

Vinyl acetate

Bold chemicals constitute the UC Class 3 Settlement Agreement list.

Class D - Potential Peroxide Forming Chemicals

May form peroxides but cannot be clearly categorized in Class A, B, or C.

Acrolein

p-Chlorophenetole

4,5-Hexadien-2-yn-1-ol

Allyl ether

Cyclooctene

n-Hexyl ether

Allyl ethyl ether

Cyclopropyl methyl ether

o.p-Iodophenetole

Allyl phenyl ether

Diallyl ether

Isoamyl benzyl ether

p-(n-Amyloxy)benzoyl chloride

p-Di-n-butoxybenzene

Isoamyl ether

n-Amyl ether

1,2-Dibenzyloxyethane

Isobutyl vinyl ether

Benzyl n-butyl ether

p-Dibenzyloxybenzene

Isophorone

Benzyl ether

1,2-Dichloroethyl ethyl ether

b-Isopropoxypropionitrile

Benzyl ethyl ether

2,4-Dichlorophenetole

Isopropyl-2,4,5-trichlorophenoxy acetate

Benzyl methyl ether

Diethoxymethane

n-Methylphenetole

Benzyl-1-naphthyl ether

2,2-Diethoxypropane

2-Methyltetrahydrofuran

1,2-Bis(2-chloroethoxyl)ethane

Diethyl ethoxymethylenemalonate

3-Methoxy-1-butyl acetate

Bis(2-ethoxyethyl)ether

Diethyl fumarate

2-Methoxyethanol

Bis(2-(methoxyethoxy)ethyl) ether

Diethyl acetal

2-Methoxyethyl acetate

Bis(2-chloroethyl) ether

Diethylketene

3-Methoxybutyl acetate

Bis(2-ethoxyethyl) adipate

Diethoxybenzene (m-,o-,p-)

2-Methoxyethyl vinyl ether

Bis(2-methoxyethyl) carbonate

1,2-Diethoxyethane

Methoxy-1,3,5,7-cyclooctatetraene

Bis(2-methoxyethyl) ether

Dimethoxymethane

b-Methoxypropionitrile

Bis(2-methoxyethyl) phthalate

1,1-Dimethoxyethane

m-Nitrophenetole

Bis(2-methoxymethyl) adipate

Di(1-propynl) ether

1-Octene

Bis(2-n-butoxyethyl) phthalate

Di(2-propynl) ether

Oxybis(2-ethyl acetate)

Bis(2-phenoxyethyl) ether

Di-n-propoxymethane

Oxybis(2-ethyl benzoate)

Bis(4-chlorobutyl) ether

1,2-Epoxy-3-isopropoxypropane

b,b-Oxydipropionitrile

Bis(chloromethyl) ether

1,2-Epoxy-3-phenoxypropane

1-Pentene

2-Bromomethyl ethyl ether

p-Ethoxyacetophenone

Phenoxyacetyl chloride

beta-Bromophenetole

1-(2-Ethoxyethoxy)ethyl acetate

a-Phenoxypropionyl chloride

o-Bromophenetole

2-Ethoxyethyl acetate

Phenyl-o-propyl ether

p-Bromophenetole

(2-Ethoxyethyl)-a-benzoyl benzoate

p-Phenylphenetone

3-Bromopropyl phenyl ether

1-Ethoxynaphthalene

n-Propyl ether

tert-Butyl methyl ether

o,p-Ethoxyphenyl isocyanate

n-Propyl isopropyl ether

n-Butyl phenyl ether

1-Ethoxy-2-propyne

Sodium 8-11-14-eicosatetraenoate

n-Butyl vinyl ether

3-Ethoxypropionitrile

Sodium ethoxyacetylide

Chloroacetaldehyde diethylacetal

2-Ethylacrylaldehyde oxime

Tetrahydropyran

2-Chlorobutadiene

2-Ethylbutanol

Triethylene glycol diacetate

1-(2-Chloroethoxy)-2-phenoxyethane

Ethyl-b-ethoxypropionate

Triethylene glycol dipropionate

Chloroethylene

Ethylene glycol monomethyl ether

1,3,3-Trimethoxypropene

Chloromethyl methyl ether

2-Ethylhexanal

1,1,2,3-Tetrachloro-1,3-butadiene

beta-Chlorophenetole

Ethyl vinyl ether

4-Vinyl cyclohexene

o-Chlorophenol

2,5-Hexadiyn-1-ol

Vinylene carbonate