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The Environmental Impacts of Fire-Fighting Foams Extinguishing foams are commonly used for extinguishing the fire of flammable liquids, whereby their insulating, choking and quenching effects are exploited. The purpose of the paper is to consider and compare the foams currently used in fire departments, regarding mainly their high extinguishing effect (capability of faster aborted burning on the large surface at low foam consumption), but also their impact on the environment in each stage of their life cycle.

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Four polysaccharide samples related to (4-O-methyl-D-glucurono)-D-xylan were analyzed by thermogravimetry (TG) and differential scanning calorimetry (DSC) in nitrogen and oxygen environments. The calculated difference in the measured fG-residues run in different environments and obtained at temperatures close to 300 °C by a dynamic experiment indicate the action of oxygen on the formation of gaseous products. The rats constants and activation energies of the degradation process in both environments indicate the increase in stability due to the protection of hydroxyls by acetylation. In an inert environment xylans have one broad multicomponent exotherm, as determined by dynamic DSC measurement. In an oxygen environment two or three independent exotherms are observed. The pretreatment of xylan with trifluoroacetic acid (solvent used for acetylation) and acetylation lowers the exothermic effect of both the thermolysis and thermooxidation. The recycling of the acetylated xylan to Na + -salt form leads to a greater exothermic effect of the degradation in both environments.

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