Applying cooling to a contaminated oxidising agent is the most effective measure to avoid a fire starting. Where a fuel source and an oxidiser have already mixed, or a spontaneously combustible oxidising material has become unstable, two sides of the fire triangle – oxygen and fuel – are already in place. Therefore, reducing heat is the main option for avoiding fire.
Where the contaminated oxidising material will react with water, take advice from the on-site specialist or hazardous materials adviser (HMA) regarding other possible tactics. Containers can be cooled where the risk of water ingress is low, but the run-off and steam created will need to be considered. Refer to  Separate oxidising materials from fuel sources. In these cases, undertaking a controlled burn may be the most appropriate tactic. Refer to Environmental protection – Controlled burning.