Environmental, Health and Safety Services

Peroxide-Forming Chemicals

  • Containers should be dated upon receipt and again upon opening. Laboratory workers must remain aware of these dates and arrange for disposal before expiration.
  • Peroxide-forming chemicals are to be used or disposed of within six months of the posted opening date.
  • Never attempt to force open a rusted or stuck cap on a container of a peroxide-forming chemical.
  • Manufacturers of lower-purity solvents add a peroxide inhibitor to some of their peroxide-forming chemicals. The expiration date of these preserved ethers may be up to two years from the date of receipt; however, once opened, the material should be used or disposed of within six months.
  • Keep only a minimal working inventory of peroxide-forming chemicals in the lab.
  • Never distill potential peroxide-formers to dryness. Always leave at least 10% of the original liquid volume. When preparing to distill or evaporate compounds listed as peroxide-formers, always test for peroxides first.
  • Immediately dispose of any rusted, damaged, undated, or suspicious-appearing containers of peroxide-forming chemicals through EHSS.
  • Do not use any peroxide-forming chemicals if a precipitate has formed or an oily viscous layer has appeared. Contact EHSS immediately.