New reproducible method for investigation of ethanol permeability of polymeric membranes in alkali media has been developed. Using the developed method ethanol crossover through KOH doped poly[2,2'-(4,4'-diphenylether)-5,5'-bibenzimidazole] (DOPBI) has been investigated with respect to alkali concentration. The permeability value, obtained in 3 M KOH was 8.6 x 10(-8) cm(2) s(-1), which further decreased with the raise of alkali concentration. Preliminary modeled estimation showed that ethanol crossover would drop by a factor of 4 if discharge current of the cell raised by approximately 1 mA cm(-2). The developed method can be expanded to measuring polymeric membrane permeability to alcohols in acidic conditions and various aqueous solutions. (c) 2008 Elsevier B.V. All rights reserved.