It has already been shown that the deviation in the binary VLE data from the Gibbs-Duhem equation, D, is formulated as D = 2(B - A)Delta x(1)(2) using Margules binary parameters, A and B, representing the VLE data, and an experimental error involved in the liquid phase composition, Delta x(1). In the present investigation, an empirical consistency test is proposed for application to polar binaries using D = 0 holding at Delta x(1) = 0. For that purpose, a polarity exclusion factor, beta = F/vertical bar B - A vertical bar is used, in which F denotes a data deviation from A = B. Using a significant number of the A and B values from the literature reported by different authors using different equipment, it was shown that beta converges to a straight line drawn on a log-log scale, which is called a thermodynamic consistency (TC) line formulated as beta = aP(b) using the system pressure, P. of the constant-pressure data or the average vapor pressure of the constant-temperature data. The proposed empirical TC test uses the deviation from the TC line for determining the uncertainty of the data. Using the same data, it was also shown that beta is a polarity-independent variable. An application of the test to ternary LLE data is demonstrated. (C) 2010 Elsevier B.V. All rights reserved.