Which method would be ineffective in extinguishing a fire involving self-oxidizing materials?

Blanketing is an ineffective method for extinguishing a fire involving self-oxidizing materials because it relies on covering the fire to deprive it of oxygen. However, self-oxidizing materials, by their nature, generate their own oxygen, making it impossible to smother the fire effectively using a blanket approach. These materials can release oxygen during decomposition, thereby sustaining combustion despite the lack of external oxygen.

Using a cooling agent to absorb heat can be effective as it lowers the temperature of the materials involved, potentially bringing them below their ignition point. Stopping the flow of gases or liquids can be advantageous because it prevents the availability of fuel for the fire. Interrupting the chemical reaction is also a viable method, as it targets the combustion process directly, disrupting the chain reaction necessary for fire.

In summary, while methods like cooling, stopping fuel flow, or interrupting the reaction can effectively manage fires in a variety of contexts, blanketing is ineffective against fires involving self-oxidizing materials due to their intrinsic ability to produce oxygen.