The goal of the sixth industrial fluid properties simulation challenge was to assess the capability of molecular modeling and simulation methods and force fields to accurately predict liquid-liquid phase equilibria for practically relevant and moderately complex chemical systems. The contestants were challenged to predict mutual solubilities in liquid-liquid equilibria (LLE) for the PROGLYDE DMM (TM)(1) + water system at various temperatures and atmospheric pressure. The benchmark data that were used to judge the challenge were measured at The Dow Chemical Company. (C) 2011 Elsevier B.V. All rights reserved.