Environmental Health & Safety
An old chemical was discovered in an University chemical storeroom. Explosives experts reported that the explosive potential of the rusty can of polyvinyl ether was equivalent to eight sticks of dynamite because of the formation of peroxides. This can bulged at the top and bottom as a result of moving it off the shelf. A two-man team of suited explosive experts spent two hours chemically treating the peroxides. At one point, the controlled reaction almost set off an explosion. We were fortunate that a disaster was averted, and in the process we learned that we have the potential for a repeat performance in many other laboratories.
There are several classes of chemical compounds that form peroxides under normal storage conditions when allowed access to air. The list of peroxidizable compounds is long. Some broad classes of problem chemicals include ethers, vinyl monomers, alkali metals and dienes. Specifically, isopropyl ether, ethyl ether, dioxane, vinyl ether, and tetrahydrofuran are commonly found in the University. Environmental Safety, upon request, can provide you with a list of peroxidizable chemicals and a data sheet from the National Safety Council.
A single opening of a container will introduce sufficient air to initiate autoxidation - the process of peroxide formation from the reaction of the compound with molecular oxygen. The resulting bivalent O-O group is a strong oxidizing agent. In solution at low concentrations, peroxides can be safely treated and disposed. However, if crystals form, the container is sensitive to thermal and shock hazards. Heating the solution or moving the container can cause an explosion. There is a special hazard if distillation of these compounds is attempted.
To prevent accidents from peroxidizable compounds, laboratories should implement a program for their recognition and safe handling. The program should include:
- Identification of all chemicals in storage that may form peroxides.
- Use of warning labels on these chemicals that record date opened.
- Ordering of the smallest practicable container size.
- Testing for peroxides periodically. (Test strips are available from VWR Scientific, Cat. No. EM-10011-1)
Refer to the Chemical Hygiene Program for the University for additional information.
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This page last updated 11/24/2010. Disclaimer.