Peroxide Forming Chemicals

Certain chemicals can form dangerous peroxides on exposure to air and light. Since they are sometimes packaged in an atmosphere of air, peroxides can form even though the containers have not been opened. Peroxides may detonate with extreme violence when concentrated by evaporation or distillation, when combined with other compounds, or when disturbed by unusual heat, shock or friction. Formation of peroxides in ethers is accelerated in opened and partially emptied containers. Refrigeration will not prevent peroxide formation and stabilizers will only retard formation.

Peroxide formation may be detected by visual inspection for crystalline solids or viscous liquids, or by using chemical methods or specialized kits for quantitative or qualitative analysis. If it is suspected that peroxides have formed, the container should not be opened, even to test as any peroxides deposited on the threads of the cap could detonate. Call EHS (5512) for management/disposal of these containers.

As chemicals with the potential to form peroxides have limited shelf lives, prudent practice would be to purchase very small amounts for delivery as close to time of intended use as possible. Containers should be labeled with date of arrival on campus. The date of opening the container and the date for disposal, based on the following table, should be added at the time the container is opened.

Examples of Peroxidizable Compounds


Discard after Three Months (Peroxide Hazard simply as a result of Storage)

        Divinyl acetylene

        Divinyl ether

        Isopropyl ether

        Potassium metal

        Sodium amide

        Vinylidene chloride


Discard after One Year (Peroxide Hazard as a result of Concentration)








        Diethyl ether

        Diethylene glycol dimethyl ether (diglyme)


        Ethylene glycol dimethyl ether (glyme)


        Methyl acetylene


        Methyl isobutyl ketone (MIBK)

        Tetrahydronaphtalene (Tetralin)


        Vinyl ethers


Discard after one year (Peroxide Hazard as a result of Polymerization*)

        Acrylic Acid





        Methyl methacrylate



        Vinyl acetylene

        Vinyl acetate

        Vinyl chloride

        Vinyl pyridine

* Under storage conditions in the liquid state the peroxide-forming potential increases and certain of these monomers (especially butadiene, chloroprene, and tetrafluoroethylene) should be discarded after three months.

Chemicals with similar sounding names that are not identified as peroxide formers: