Abstract Minimum extinguishing concentrations of mixtures of organophosphorus and iodine-containing compounds and inert diluents were measured using the cup-burner and cylinder techniques. The results of these measurements were used to develop and test new effective fire-suppression compositions whose components exhibit a synergetic effect and to estimate the lower temperature limit of their application. The results of laboratory experiments were verified by full-scale tests in which two types of model fire sources were extinguished by salt solution aerosols. The tests demonstrated that short-term action of an aerosol cloud of an aqueous solution of potassium ferrocyanide K3[Fe(CN)6] on the flame front of a surface forest fire led to suppression of gas-phase combustion, and in the case of wood burning, to complete flame extinction. The minimum extinguishing mass concentration of K3[Fe(CN)6] in these experiments was 4.5 g/m3, which is close to that measured in laboratory experiments. In fire suppression by the aerosol, the volumetric flow rate of this fire suppressant was found to be 30 times lower than the standard flow rate of pure water from a fire hose.