BACKGROUND Although certain pollutants are prohibited or heavily regulated, particularly in Europe and the USA, contaminated sites still represent a serious threat to the environment and health. The physical and chemical properties of 'dense non-aqueous phase liquid' (DNAPL) pollutants such as trichloroethylene (TCE), including their low solubility, high specific density and tendency to remain adsorbed to organic materials, make their removal from polluted sites extremely difficult. RESULTS This study tested the ability of a series of commercial fatty alcohol ethoxylated surfactants of CiEj type (i = number of carbons in the alkyl chain; j = number of ethylene oxide (EO) units), known to be biodegradable and low-cost, to improve the solubility of TCE in water; this would make its removal from contaminated sites more effective. The solubility of TCE in Synperonic (TM) 91/5 (C10E5), 91/6 (C10E6), 91/8 (C10E8), 91/10 (C10E10) and 13/8 (C13E8) aqueous solutions was evaluated and the solubilization performances were reported as molar and weight solubilization ratios (MSR and WSR). Solubility was measured above the critical micelle concentration (CMC) up to 0.7 mol L-1 at 5, 20 and 30 degrees C to assess the feasibility of the approach for TCE removal from sites located in different climatic areas. Increasing EO units contributed to improved TCE solubility (at constant alkyl chain length). CONCLUSION The best surfactant was Synperonic (TM) 91/10 with an MSR of 3.54 at 19 degrees C. The results show that an optimal combination of EO units and alkyl chain length, and not only the hydrophilic-lipophilic balance (HLB) value, is key for the design of effective TCE remediation systems from groundwater. (c) 2019 Society of Chemical Industry