Environmentally-clean wildfire inhibitor liquid biochemical solutions produced from an aqueous mixture of alkali metal salt derived from a non-polymerized saturated carboxylic acid such as oxalic acid, and dissolved in water along with a dispersing and coalescing agent, realized as an ester of a non-polymerized saturated carboxylic acid, and dissolved in the water to provide a liquid fire inhibitor solution that can be sprayed on combustible surfaces to form thin alkali metal salt crystalline coatings on the combustible surfaces when and as water molecules in the liquid fire inhibitor evaporate to the environment during drying operations, to inhibit fire ignition, flame spread and smoke development.

The disclosure relates to firefighting measures, and in particular, to firefighting compositions for preventing, retarding and extinguishing fire in a combustion zone that comprises a combination of at least one cooling component, at least one fire-isolation component comprising, at least one oxidizer diluting component, and at least one flame retarding component.

A forest fire retardant composition contains a retardant compound that includes a halide salt, a non-halide salt, a metal oxide, a metal hydroxide, a sulfate salt, or combinations thereof. The forest fire retardant composition may include at least one anhydrous salt and at least one hydrate salt. The sulfate salt may be magnesium sulfate. The magnesium sulfate hydrate has a formula MgSO.sub.4(H.sub.2O).sub.x, where x is about 1 to about 11. For example, x may be equal to at least one of 1, 2, 3, 4, 5, 6, 7, 9, 10 or 11. The composition may be in the form of a dry concentrate, a liquid concentrate, or a final diluted product. The final diluted product is effective in suppressing, retarding, and controlling forest fires while exhibiting corrosion resistance and low toxicity.