Abstract. Extinguishing forest fires is a critical issue for fire brigades; fire can spread throughout vast areas in a relatively short period of time. The studies presented in this paper describe the results of laboratory and field tests of new compositions of wetting agents for extinguishing wildland fires. The studies assessed the ability to penetrate surface fuels using 0.5 and 1% solution of wetting compositions. The penetration of the liquid through the layer of the loose rotting wood with solutions of obtained wetting agents was up to 68 times faster than with water. The absorption of water droplet was even 40 times slower in comparison to wetting agent solutions. Based on laboratory research, compositions that exhibit the best wetting properties were analysed in real conditions in field tests to assess their capacity to penetrate in surface fuels, their ability to make fire barriers and their efficiency in suppressing fires of soil cover and thickets. In tests performed in 4 m 2 plots, the wetting compositions hold the flames from crossing a thin firebreak for up to three times longer periods than water. The results of the studies confirmed a significant increase in efficiency when new biodegradable wetting agents are employed to extinguish forest fires.

During rescue operations related to the elimination of the effects of industrial accidents or natural disasters, extinguishing agents are used that affect the migration and transformation of contamination in the environment. Firefighting foam sprayed onto an oil spill slowly drains to an aqueous solution and penetrates the soil. The role of surfactants in the removal of petroleum derivatives is well known, but such extinguishing agents also contain solvents, preservatives, corrosion inhibitors and other ingredients that can reduce the beneficial effect of surfactants on soil remediation. The article presents the results of research on the remediation of soil contaminated with diesel fuel and enhanced with firefighting agents used to extinguish fires or remove oil spills on the road. The obtained results of biodegradation and leaching studies indicate differences in the efficiency of diesel fuel removal from soils. It was also found that Wet 1% reduces the amount of polycyclic aromatic hydrocarbons (PAHs) in the soil compared to oily samples not wetted with extinguishing solutions. Chromatographic analyses have shown both the hydrocarbons degradation and the possibility of their transformation into more hazardous compounds. The effectiveness of soil remediation depends on the chemical composition of the extinguishing agent used on the contaminated soil.

The aim of this study was to compare the concentrations of particulate matter (PM) and PM-bound polycyclic aromatic hydrocarbons (PAHs) during the combustion of various types of materials (i.e., oak, beech, and pine wood, polypropylene, polyurethane, paper, cotton, and oriented strand board (OSB)), and to compare the carcinogenic, mutagenic, and toxic potential of the emissions during the burning of these materials. Personal portable sampling devices were used to collect samples and to determine concentrations of PM4, total suspended particles (TSPs), PM-bound PAHs. The samples were collected during controlled fires under laboratory conditions. The highest PM concentration was recorded during the burning of polyurethane (PM4-1818 mg/m3, TSP-2800 mg/m3), while the highest concentration of PAH mixture was recorded when burning OSB (628.5 µg/m3 PM4-bound; 791.2 µg/m3 TSP-bound PAHs). Thus, the highest carcinogenic (85.5 µg/m3), mutagenic (68.2 µg/m3) and toxic equivalents (26.4 ng/m3) of the PAH mixture were noted during OSB combustion. Carcinogenic potential (CP) of PAH group was determined mainly by phenanthrene (CP on average 21.6%) and pyrene concentrations (13.3%). The results of the study express possible adverse effects from PM-bound PAHs released during combustion for firefighters and other people staying near a fire site.

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The results of research into obtaining an ecological wetting agent for wildfires are presented. First, measurements of the equilibrium and dynamic surface tension for anionic and non-ionic commercial surfactants and their binary mixtures were conducted. Next, the parameters of adsorption facilitating a quantitative description of the process in both binary systems as well as single-component solutions were estimated. In addition, the static and dynamic contact angles on model surfaces with different hydrophobicity were studied (glass, polyethylene, pressed peat). In a few mixed systems, a synergism in reducing the critical micelle concentration and/or a synergy of the ability to wetting model surfaces was identified. Next, research into the sorptivity and wettability of peat (loose and pressed) was conducted. It was found that non-ionic and anionic surfactants exhibit different abilities in respect of foaming and moistening of peat. From an analysis of the preliminary results, the surface-active components were selected to obtain a wetting agent composition. The wettability and adsorption characteristics and an evaluation of the foaming ability using solutions of the prepared compositions were tested. The effectiveness of the wetting composition thus obtained was confirmed in the laboratory and in field firefighting. The test results confirmed the better wettability and sorptivity on peat and the effectivity for combating wildfires, compared with some typical commercial products.