Draize eye scores and eye irritation thresholds in man combined into one quantitative structure-activity relationship

Draize eye scores (DES) for 37 pure organic liquids have been converted into scores for the corresponding vapours, DES/P degrees, where PO is the liquid vapour pressure in ppm at 298 K. It is shown that there is a constant difference (0.66) between values of log(DES/P degrees) and log(1/EIT) where EIT is the eye irritation threshold in ppm of eight vapours towards human subjects. The 37 log(DES/P degrees) values can be combined with 17 log(1/EIT) values to give one quantitative structure-activity relationship, log SP = -7.918 - 0.482 R-2 + 1.420 pi(2)(H) + 4.025 Sigma alpha(2)(H) + 1.219 Sigma beta(2)(H) + 0.853 log L-16 n = 54, r(2) =0.928, r(cv)(2), = 0.913, sd = 0.36, F = 124 where R-2 is an excess molar refraction, pi(2)(H) is the compound polarizability/dipolarity, Sigma alpha(2)(H) and Sigma beta(2)(H) are the compound hydrogen-bond acidity and basicity, and L-16 is the gas-hexacecane partition coefficient. The number of data points is n, the correlation coefficient is r, the standard deviation is sd, and F is the F-statistic. LogSP is then either [log(DES/P degrees) - 0.66], or log(1/EIT). It is suggested that equation i can be used to predict eye irritation of organic vapours and pure liquids as eye irritation thresholds. (C) 1998 Elsevier Science Ltd. All rightss reserved.