Fixed vols. of aq. solns. of surfactants at concns. of 0.01; 0.1; 1; 5 and 10 mmol/L were used to extinguish the samples of cotton and fiberboard according to a std. methods. The mass of the test surfactants sorbed on the cotton and fiberboard surfaces was a measure of their wetting ability. Extinguishing ability of solns. was detd. visually by the operator (fire extinguished or unextinguished). High wetting and extinguishing abilities of surfactants were obsd. for surfactant concns. above 1 and 5 mmol/L, resp.