Environmental Health & Safety
CHEMICAL HYGIENE PROGRAM
Printable files are available in three parts with Adobe Acrobat Reader:
- PDF Version of Chemical Hygiene Program
- PDF Version of Appendices 1 through 11
- PDF Version of Appendices 12 through 16
Organic peroxides are considered low-power explosives that are sensitive to shock, sparks, and other accidental ignition. Several compounds that may be found in labs present a similar hazard because they can undergo auto-oxidization to form organic hydroperoxides and/or peroxides when exposed to oxygen in air. Ultraviolet light may cause a free-radical chain mechanism. Oxygen may be added resulting in the formation of the peroxy radical.
Actions can be taken to reduce the formation of peroxides. Storing the chemical under inert atmosphere (N2 or argon) or under vacuum can increase the safe storage lifetime. Also, chemical manufacturers add stabilizers or inhibitors to inhibit peroxide formation.
Prudent Practices in the Laboratory, Handling and Management of Chemical Hazards, 2011 edition, provides useful test methods to determine if peroxide formation has occurred. Routine testing should be done prior to the expiration date on the container. The following three tests methods can be used to check for peroxy and hydroperoxide formation:
- Peroxide test strips: These turn to an indicative color in the presence of peroxides. NOTE: When used, the strip must be air dried until the solvent evaporates and exposed to moisture for proper indication and quantitation.
- Add 1 to 3 ml of the liquid to be tested to an equal volume of acetic acid, add a few drops of 5% aqueous potassium iodide solution, and shake. The appearance of a yellow to brown color indicates the presence of peroxides. Alternately, addition of 1 ml of a freshly prepared 10% solution of potassium iodide to 10 ml of the organic liquid in a 25 ml glass cylinder produces a yellow color of peroxide is present.
- Add 0.5 ml of the liquid to be tested to a mixture of 1 ml of 10% aqueous potassium iodide solution and 0.5 ml of dilute hydrochloric acid to which has been added a few drops of starch solution just prior to the test. The appearance of a blue or blue-black color within 1 minute indicated the presence of peroxides.
Class A: Chemicals posing peroxide hazard without concentration
| Butadiene | Isopropyl ether | Tetrafluoroethlene |
| Chlorobutadiene (chloroprene) | Potassium amide | Vinylidene chloride |
| Divinyl acetylene | Potassium metal | |
| Divinyl ether | Sodium amide (sodamide) |
If a container of a Class A peroxidable is past its expiration date, or if the presence of peroxides is suspected or proven, DO NOT ATTEMPT TO OPEN THE CONTAINER!
Class B: Chemicals posing peroxide hazard upon concentration (distillation or evaporation)
| Acetal | Dicyclopentadiene | Methyl acetylene |
| Cumene | Diethylene glycol dimethyl ether (diglyme) | Methyl cyclopentane |
| Cyclohexene | Diethyl ether | Methyl isobutyl ketone |
| Cyclooctene | Dioxane (p-dioxane) | Tetrahydrofuran |
| Cyclopentene | Ethylene glycol dimethyl ether (glyme) | Tetrahydronaphtalene |
| Diacetylene | Furan | Vinyl ethers |
A test for peroxide should be performed.
Class C: Unsaturated materials that may autopolymerize as a result of peroxide accumulation if inhibitors have been removed or are depleted.
| Acrylic acid | Ethyl acrylate | Vinyl acetylene |
| Acrylonitrile | Methyl methacrylate | Vinyl chloride |
| Butadiene | Styrene | Vinyl pyridine |
| Chlorotrifluoroethylene | Vinyl acetate |
NOTE: These lists are illustrative but are not exhaustive
QUESTIONS or COMMENTS? Contact EH&S at (585) 275-3241 or e-mail EH&S Questions.
This page last updated 7/30/2015. Disclaimer.
