An oxidising material involved in a fire indicates that the fire will be more intense than if the fuel were to combust with the atmosphere providing the only source of oxygen. Oxidising substances can behave unpredictably and react with sufficient speed and energy to create an explosion. This can be caused by a spontaneous reaction of the oxidising material itself, as can be seen with organic peroxides or because of a reaction between an oxidising material and a fuel source such as ammonium nitrate or a fuel source such as diesel, oil or petrol. Identifying the exact oxidising material involved will indicate the potential for an explosion to occur.
If it is known or suspected that an organic peroxide is involved in a fire, personnel should withdraw to a safe distance. Hazardous materials advisers (HMAs) or on-site experts should be consulted to provide advice on the substances involved, their possible impacts and an appropriate cordon distance based on the level of risk.
Organic peroxides contain a source of oxygen and fuel. Therefore, any energy supplied to the substance, either by heating or through shock/friction caused by moving the product, can initiate decomposition of an organic peroxide and lead to an explosion or initiate/intensify a fire.
See Control measure – Recognise and manage ammonium nitrate fertiliser mixtures with the potential to explode.