Materials liable to form peroxides in storage

The following materials may form peroxides in storage, when in contact with air. Once a container is opened, the chemical should be tested for peroxides not less frequently than once every six months using a product such as Merckoquant test paper (available from the Departmental Safety Officer in the PTCL).

A peroxide-containing material always constitutes an explosion risk, but the risk is particularly serious if the material is heated. This is because peroxides are generally less volatile than the compound from which they are formed, (usually having lower vapour pressure because of increased intermolecular forces between the - now strongly polar - peroxide molecules). Distillation therefore leads to progressive concentration of the peroxide. The combination of a concentrated solution of peroxide with heating can result in explosive decomposition.