Potentially Unstable Wastes
Many commonly-used reagents in research laboratories have the tendency over time to chemically decompose, resulting in highly flammable or sometimes even shock-sensitive compounds. If left for a long enough time, these unstable wastes can decompose to the point where they present significant personnel dangers. For this reason, the University of Florida has the following policies regarding the storage of these chemicals:
Dinitro- and trinitro- compounds, such as picric acid (trinitrophenol), should be disposed of through EH&S as hazardous waste once the compound is noted to be undergoing physical change. These compounds are often supplied as a thick, yellow liquid; once that liquid begins to crystallize, the physical change is taking place and the remainder of the reagent should be disposed of. If the compound is supplied in a paste form, it must be disposed of once the moisture is observed to be “leaving” the paste (i.e. the paste begins to become dry and crumbly).
Peroxide Forming Chemicals- many common organic chemicals and some common inorganic chemicals can form potentially explosive peroxides during storage. The table below is a reference for some of the more common peroxide forming chemicals. This table is not all-inclusive and is meant to serve as a reference for the most commonly-encountered peroxide forming chemicals.
Peroxide formation is accelerated by exposure to air, heat, and light. To minimize peroxide formation these chemicals should be stored in a tightly sealed container away from light and heat. Never move a product container that is suspected of having formed peroxides upon storage. Always be sure to check solvents for peroxides prior to distillation of the solvent in question. Consult the MSDS before working with any peroxide forming chemical.
The following peroxide-forming compounds should be dated upon receipt of the chemical from the manufacturer/supplier, and dated again upon opening.
|Chemicals that form explosive levels of peroxides without concentration-
Dispose of within 3 months of opening
|Butadiene a||Divinylacetylene||Tetrafluoroethylene a||Sodium Amide|
|Chloroprene a||Isopropyl Ether||Vinylidine chloride||Potassium metal|
|Chemicals that form explosive levels of peroxides on concentration-
Dispose of within 6 months of opening
|Chlorofluoroethylene||Diethylene glycol dimethyl ether (diglyme)||Methyl isobutyl ketone||Vinyl Ethers|
|Cumene||Dioxanes||4-Methyl-2-pentanol||Other secondary alcohols|
|Cyclohexanol||Ethylene glycol dimethyl ether (glyme)||2-Pentanol|
|Chemicals that may autopolymerize due to peroxide formation-
Dispose of within 12 months/immediately *
|Acrylic acid||Chlortrifluoroethylene||Vinyl acetate||Vinyladiene chloride|
|*- inhibited chemicals can be stored for 12 months, uninhibited should be disposed of immediately.|
|a- when stored as a liquid monomer|
|Information adapted from “Review of Safety Guidelines for Peroxidizable Organic Chemicals” by Richard J. Kelley|