Peroxide formers dated

Certain classes of compounds will form potentially explosive peroxide crystals upon extended storage. Common examples of peroxide-forming compounds include isopropyl ether, diethyl ether, tetrahydrofuran, dioxane, potassium metal.

These compounds must be used in a timely manner or tested on a regular basis to ensure peroxide formation is not occurring.

In addition, peroxide formers should be dated upon receipt, again dated upon opening, and stored away from heat and light with tight fitting, nonmetal lids. Expired containers of peroxide- forming chemicals must be immediately disposed of properly through EHS.


  • MSU Chemical Hygiene Plan 3.6.6 OSHA Standard 1910.1450 App A. NPFA 45

Corrective actions:

Organic peroxide means a liquid or a solid organic chemical which contains the bivalent –O-O- structure and is such is considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by oxygen radicals. Organic peroxides are thermally unstable chemicals, which may undergo exothermic self-accelerating decomposition. In addition, they may have one or more of the following properties:

  • Be liable to explosive decomposition.
  • Burn rapidly.
  • Be sensitive to impact or friction.
  • React dangerously with other substances.

Some chemicals can form explosive peroxides when stored; exposure to light and heat increase the rate of peroxide formation. Other chemicals form peroxides that become hazardous when concentrated, such as by distillation.

A list of peroxide-forming compounds can be found here: Chemical Hygiene Plan, Appendix G (PDF)

  1. Date all peroxidizables upon receipt and upon opening. Dispose of or check for peroxide formation after the recommended time; 3-months or one year depending on the chemical. See APPENDIX G.
  2. Do not open any container which has obvious solid formation around the lid.
  3. Addition of an inhibitor to quench the formation of peroxides is recommended.

Peroxide forming compounds that are very old, have obvious container problems, or show visible crystallization inside the bottle or cap require immediate, specialized management. Call MSU EHS directly at 517-355-0153 for immediate assistance. Leave the container in place until MSU EHS arrives.