Patent ID: 8409478

Claim:
A flame retardant composition for aerial fire fighting, comprising a liquid ammonium polyphosphate and ammonium polyphosphate in powder form in suspension; wherein: the liquid ammonium polyphosphate has a chain length with a value of n, where n is 1 to 5, n being the number of condensation groups; the ammonium polyphosphate in powder form has a chain length with a value of n, where n is 900 to 1500, n being the number of condensation groups; the composition comprises at least one metal salt of the orthophosphoric acid as a corrosion inhibitor for alloys of aluminium, steel, bronze and magnesium, wherein the metal salt comprises a zinc orthophosphate salt; wherein the liquid ammonium polyphosphate content is 70% to 95% by weight of the total weight of the flame retardant composition; the ammonium polyphosphate in powder form is 5% to 13% by weight of the total weight of the flame retardant composition and the zinc orthophosphate salt is 0.01% to 5% by weight of the total weight of the flame retardant composition.