Firefighting foam composition

A firefighting foam composition comprising:

• (a) about 0.5% to about 12% by weight of the composition of a surfactant blend comprising
• (i) a cationic surfactant having the general formula:
• where R1 is a straight or branched, saturated or unsaturated, alkyl or alkene chain having an average chain length of 8 to 10 carbon atoms;
• R2 is H or a straight or branched, saturated or unsaturated, alkyl or alkene chain having from 1 to 10 carbon atoms;
• R3 is H, methyl, or ethyl;
• R4 is H, methyl, or ethyl;
• and
• X− is a monovalent anionic counterion, preferably a halide, most preferably Cl− or Br−;
• (ii) an alkyl amine oxide nonionic surfactant having an alkyl moiety with an average carbon chain length of 8 to 10 carbon atoms;
• (iii) an anionic surfactant having the general formula:
• where R′ is a straight or branched, saturated or unsaturated, alkyl or alkene chain having an average chain length of 8 to 10 carbon atoms, X2− is a sulfate group, and Y+ is a cationic counter ion preferably selected from the group consisting of sodium, potassium, ammonium, and substituted ammonium;
• wherein the cationic surfactant, the nonionic surfactant, and the anionic surfactant are present in the surfactant blend in a molar ratio of about 0.25-1.0:0.25-1.0:0.25-1.0;
• (b) at least one additive selected from the group consisting of thickeners, foam stabilizers, and polymers;
• and
• (c) water to total 100% by weight of the composition.

A method for fighting a fire comprising:

• (a) aerating a firefighting foam composition to form an aerated firefighting foam;
• and
• (b) applying the aerated firefighting foam to a fire, or to a surface of a volatile flammable liquid, wherein the firefighting foam composition comprises water and about 0.5% to about 12% by weight of the composition of a surfactant blend comprising:
• (i) a cationic surfactant having the general formula:
• where R1 is a straight or branched, saturated or unsaturated, alkyl or alkene chain having an average chain length of 8 to 10 carbon atoms;
• R2 is H or a straight or branched, saturated or unsaturated, alkyl or alkene chain having from 1 to 10 carbon atoms;
• R3 is H, methyl, or ethyl;
• R4 is H, methyl, or ethyl;
• and
• X− is a monovalent anionic counterion, preferably a halide, most preferably Cl− or Br−;
• (ii) an alkyl amine oxide nonionic surfactant having an alkyl moiety with an average carbon chain length of 8 to 10 carbon atoms;
• and
• (iii) an anionic surfactant having the general formula:
• where R′ is a straight or branched, saturated or unsaturated, alkyl or alkene chain having an average chain length of 8 to 10 carbon atoms, X2− is a sulfate group, and Y+ is a cationic counter ion preferably selected from the group consisting of sodium, potassium, ammonium, and substituted ammonium;
• wherein the cationic surfactant, the nonionic surfactant, and the anionic surfactant are present in the surfactant blend in a molar ratio of about 0.25-1.0:0.25-1.0:0.25-1.0.