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Control measure

Cordon control: Oxidising materials

Control measure knowledge

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.

Strategic actions

Fire and rescue services should:
  • Have procedures and support arrangements to identify oxidising materials involved in fire or with the potential to explode

  • Make arrangements to ensure specialist advice on oxidising materials is made available to personnel when required

Tactical actions

Incident commanders should:
  • Establish exclusion zones, inner and outer cordons based on the level of risk from oxidising materials

  • Consider the risk of explosion and implement an appropriate hazard area

  • Request assistance from on-site experts and/or hazardous materials advisers (HMAs) to determine the hazard level of the oxidising material

  • Where Organic Peroxides are present implement appropriate levels of risk control

  • Assess the potential for intensification of fire or explosion from oxidising materials