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16 Potentially Explosive Chemicals Method 3 Blue-indicating molecular sieve (4—8 mesh, type 4A) is added to containers of peroxidized chemicals and allowed to sit for 1–30 days. An amount equivalent to about 5%–10% (wt/vol) of the peroxidized liquid is used. Alternatively, the mixture can be refluxed, and the reaction occurs within 4 hours. The peroxide is broken down, and the indicator in the sieve is consumed. When run at room temperature, this process is apparently safe, slow, and controlled. Dialkyl peroxides are not efficiently removed, especially from dioxane. This method may be particularly suited to treatment of THF, diisopropyl ethers, and diethyl ethers, which may be decontaminated at room temperature in a couple of days. Other methods for removing higher peroxides including dialkyl peroxides In one suggested procedure, a 10% molar excess of sodium or potassium iodide is dissolved in 70 mL glacial acetic acid. A small quantity of 36% (wt/vol) HCl is added, followed by 0.01 mol of the dialkyl peroxide. The solution is heated to 90°C–100°C on a steam bath over the course of 30 minutes and held at that temperature for 5 hours. Zinc dissolved in acetic or hydrochloric acid has been recommended. Prolonged treatment with ferrous sulfate in 50% sulfuric acid has also been recommended. References Guidelines for Explosive & Potentially Explosive Chemicals – Safe Storage & Handling, Office of Environment, Health and Safety, UC Berkeley (used with permission) Prudent Practices for Disposal of Chemicals from Laboratories, Appendix I, National Academy Press, Washington, DC, 1983, pp. 245-246. Kelly , R.J. “Review of Safety Guidelines for Peroxidizable Organic Chemicals,” American Chemical Society–Chemical Health & Safety, 1996, 4(5), pp. 33-36. Used with permission. Cameron, Mark. “Picric Acid Hazards”, found as PDF document on the Web.