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Oxidisers contaminated with combustibles

Hazard Knowledge

Contamination of an oxidising agent with a fuel (or vice versa) will result in an oxidation reaction between the two substances. This reaction may start slowly, but it will be an exothermic reaction that results in an increase in the temperature of the mixture. This in turn will increase the rate of the reaction, which will generate more heat and further increase the rate at which the reaction occurs. As this process continues it is possible that the temperature of the fuel will continue to rise to the ignition temperature for the fuel. Combustion will then occur instantly.

In other cases, the reaction between the oxidising agent and the fuel may not create sufficient heat to initiate instant combustion. However, for these mixtures, where an ignition source does lead to a fire involving the mixture, the oxidising agent will react in a way that yields oxygen. The fire is therefore no longer dependant on only oxygen from the atmosphere. This will lead to a more fierce fire that can continue even when the level of atmospheric oxygen is reduced.

Organic peroxides contain both an oxygen source and a fuel element. Therefore, the substances include two elements of the fire triangle. In this case, only energy is required to initiate a fire involving an organic peroxide. This may be provided through an increase in temperature, shock, friction or through an exothermic reaction as a result of contamination.