Fluorine-free firefighting foams containing one or more biopolymers

A fire-fighting foam composition for fighting a Class B fire, the composition comprising:

• a plurality of biopolymers comprising diutan gum, guar gum, and xanthan gum, wherein the combined proportion of the plurality of biopolymers is from about 2 wt % to about 2.5 wt % of the composition;
• an anionic surfactant, wherein the anionic surfactant is selected from the group consisting of alkyl sulfates, alkyl ether sulfates, sulfosuccinates and combinations thereof;
• and
• an organic solvent, wherein the organic solvent is selected from the group consisting of glycols, alcohols, glycol ethers and combinations thereof;
• wherein:
• the weight ratio of the anionic surfactant to the plurality of biopolymers is from about 7:1 to about 11:1;
• the weight ratio of the plurality of biopolymers to organic solvent is from about 1:1 to about 1:12, and
• the composition is free of fluorinated surfactants and fluorine-containing polymers.