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Policy: Dating/Disposal of Peroxide Formers

Purpose - To limit the explosion potential created by peroxide formation in ethers and similar compounds, the following requirements must be satisfied:

a.  Container labeling - In addition to the original manufacture label or secondary label, the container for all peroxide-formers (Class I, II and III as listed below) shall be labeled with the following

         (links to label examples -  ppt    jpeg    pdf 9
  • date of purchase,
  • open date (date of first opening) and
  • required discard date (date that chemical must be disposed by), based on the following requirements

b.  Disposal Requirements - by group

Class III Group - High hazard - (3 month storage after opening) - These chemicals form explosive levels of peroxides without concentration and are severe hazard after prolonged storage, especially after exposure to air.  All have been responsible for fatalities.

Test for peroxide formation (see testing section) or discard after three (3) months from open date.  If peroxides are not present, the discard date can be reset as per Class III schedule (otherwise discard promptly via EH&S). This group includes the following compounds:

divinely acetylene isopropyl (diisopropyl) ether potassium amide
potassium metal sodium amide vinylidene chloride six
Butadiene *1 Chloroprene *1 Tetrafluoroethylene *1

*1 - when stored as a liquid monomer

Class II Group - Concentration peroxides - (12 month storage after opening) - These are a peroxide hazard upon concentration (distillation or evaporation). Test for peroxide before distillation, evaporation or if concentration is suspected.

Test for peroxide formation or discard after 12 month from open date.   If test shows peroxides are not present, the discard date can be reset to 6 months from test date (otherwise discard promptly via EH&S).  This group includes the following:

Acetal Acetaldehyde Benzyl alcohol
Butadiyne (butadiene) 2-Butanol Cellosolves
Chlorofluoroethylene Cumene Cyclohexene
Cyclohexanol 2-Cyclohexen-1-ol Cyclopentene
Decahydronaphthalene Decalin Diacetylene (butadiene)
Dicyclopentadiene Diethyl ether Diethylene glycol dimethyl ether
Diglyme Dioxanes Ethyl ether
Ethylene glycol dimethyl ether Ethylene glycol ether acetate Furan
Glyme 4-Heptanol 2-Hexanol
Isopropyl alcohol Isopropyl benzene Methyl acetylene
3-Methyl-1-butanol Methylcyclopentane Methyl isobutyl ketone
4-Methyl-2-Pentanol 4-Methyl-2-Pentanone 2-Pentanol
4-Penten-1-ol 1-Phenylethanol 2-Phenylethanol
2-Propanol Tetrahydrofuran Tetrahydronaphthalene
Tetralin Vinyl ethers (Other Secondary Alcohols)

Class I Group - Autopolymerizers - (12 month storage after opening) - These peroxide former are unsaturated materials, especially those of low molecular weight, which may autopolymerize violently and hazardously due to peroxide initiation.  These should not be stored under inert atmosphere after opening.

Test inhibited chemicals*2 for peroxide formation (see test procedure) or discard after 12 month from open date.   If test shows peroxides are not present, the discard date can be reset to 12 months from test date (otherwise discard promptly via EH&S). This group includes the following:

acrylic acid acrylonitrile 1,3-butadiene*3
2-chloro-1, 3-butadiene chloroprene *3 chlorotrifluoroethylene
dibenzocyclopentadiene 9,10-dihydroanthracene indene
methyl methacrylate styrene tetrafluoroethylene*3
vinyl acetate vinyl acetylene vinyl chloride
vinylidene chloride vinyl pyridine  

*2 - Uninhibited autopolymerizers should not be stored over 24 hours (add polymerizer inhibitor).
*3 - When stored as a gas

c. Testing for peroxides

The recommended way to test for peroxides is through semi-quantitative analysis using peroxide detection dip strips which are available from most lab equipment supply companies.   If the test strip indicates a concentration above 10 ppm, the chemical can not be used and it should promptly sent for disposal through EH&S.  Chemical that show no peroxides can be reset as per their group schedule.  Those that show the presence of peroxides but below 10 ppm should be re-tested after 6 month or per their group schedule whichever is the shorter time period.  (additional details for testing and supply source are given in the SOP documentation - link below)

d.  Additional information - Standard Operating Procedure (SOP) for Explosive Chemicals

The above policy is summarized from the EH&S Standard Operating Procedures (SOP) for managing explosive chemicals. This SOP was compiled from many sources and takes a strong conservative approach in the interest of health and safety of those that work with and dispose of these chemicals.  

Additional details and information on other potentially explosive materials can be reviewed by downloading the Standard Operating Procedure (SOP) for peroxide formers and explosive chemicals

Chemical Safety


Lab Safety
Table of Contents

Hazardous Waste Manual
Table of Contents

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Contact Information 
 Environmental Health& Safety: MSC-3578, P.O. Box 30001, Academic Research Bldg. C, Rm. 109
    Street delivery address: NMSU, 1620 Standley Dr., Academic Research Bldg. C, Las Cruces, NM 88003
    Training Office: Academic Research Unit C, rm110 (see map ), 
    Telephone: 575-646-3327; FAX: 575-646-7898. Website - http://www.nmsu.edu/safety
    Send email to David Shearer, EH&S (click here) with questions or comments about this web site. 
    This page was last updated on 08/22/2008