Glossary / Physical hazards
Organic peroxide
An organic peroxide is a carbon-containing compound with an oxygen-oxygen bond that makes it thermally unstable and prone to self-accelerating decomposition. Some burn intensely, some are shock-sensitive, and many are used deliberately as initiators in plastics manufacture.
Explanation
The weak oxygen-oxygen bond in these compounds is what makes them useful and dangerous. Industry uses them to start polymerization of plastics and resins, to cure fiberglass and composites, and as bleaching agents. The same chemistry means they can decompose releasing heat and gas, which can lead to fire or explosion in a closed container.
Temperature control is central. Many organic peroxides must be stored below a stated maximum temperature, and some below a control or emergency temperature given by the supplier. If a container warms up, decomposition can speed up and feed itself. Heat sources, direct sun and refrigeration failures are therefore real concerns.
Contamination is another trigger. Metals, accelerators, acids, amines and rust can speed up breakdown, so only clean tools should be used and unused material must never go back into the original container. Spilled product is taken up with inert material rather than sawdust or rags.
Under the GHS, organic peroxides form their own class with types lettered by hazard severity. Their transport rules are covered under their own division in the DOT system. Treat each product on its own SDS rather than assuming it behaves like a similar one.
What to do and watch for
- Store only within the temperature range the supplier states, with a plan for refrigeration failure.
- Keep away from accelerators, metals and acids, and never return unused product to its container.
- Use only the quantity you need and keep it in the original packaging.
Where it appears on an SDS
- Section 7: Handling and storage. Maximum storage temperature, ventilation, and materials that must be kept apart.
- Section 9: Physical and chemical properties. Decomposition temperature information where the supplier provides it.
- Section 10: Stability and reactivity. Conditions leading to hazardous decomposition and incompatible substances.
SDS content and wording vary by supplier. This page is general reference and does not replace the current SDS for your product.
Related terms
- Oxidizer
- Self-reactive substance
- Peroxide former
- Hazardous polymerization
- Explosive
- Incompatible materials