Methods and compositions for extinguishing fires

A method of extinguishing a fire of a flammable substance which comprises applying to the burning area of said substance a fire extinguishing composition comprising a particulate combustible high molecular weight thermoplastic polymer, the particles of said polymer arranged in intimate association with a sufficient quantity of a chemical extinguishing agent to protect said polymer particles during transit through a flame and onto the surface of said burning substance.

A method for extinguishing a fire of a flammable liquid and preventing its reignition which comprises applying particles of a thermoplastic polymer to the burning area of said liquid, said polymer being soluble in said liquid, said polymer particles having associated therewith one or more chemical fire extinguishing agents arranged to protect the polymer particles during transit through a flame to said burning area.

A method for making a flammable liquid resistant to burning which comprises adding to said liquid particles of a high molecular weight polymer together with a powdered dry chemical fire extinguishing agent, the molecular weight of said polymer sufficient to gel said flammable liquid upon dissolving therein and the concentration of dry chemical extinguishing agent in said liquid at an exposed surface thereof being sufficient to quench flame.

A composition for extinguishing fires comprising a particulate combustible high molecular weight thermoplastic polymer, the particles of said polymer coated with multiple layers of at least two different chemical extinguishing agents, a first chemical extinguishing agent forming a first layer around the polymer particles and a second chemical extinguishing agent forming a second layer about said first layer, the quantity of said chemical extinguishing agents making up the multiple layers being sufficient to protect said polymer particles during transit through a flame and onto the surface of a burning substance.