SRC's Henry Program

This program calculates the Henry's Law constant (air/water partition coefficient) using both the group contribution and the bond contribution methods of Hine and Mookerjee [Journal of Organic Chemistry, volume 40, pp 292-8 (1975)]. SRC has updated and expanded the bond and group contribution methods by developing new fragment constants from experimental data. The methodology is described in the following journal article:

Meylan,WM & Howard,PH. 1991. Bond contribution method for estimating Henry's law constants. Environ. Toxicol. Chem. 10: 1283-1293.

Henry version 3 extends the methodology to allow estimation of Henry law constants over a temperature range (0 to 50 deg C). In addition, version 3 includes an experimental database of 1350 compounds.

The newest version of Henry runs under Windows (3.1, 95, 98, NT) making the estimation of Henry's Law constants more convenient and accurate. Methods for chemical structure input now support SMILES notations as well as chemical structures produced in popular chemical drawing programs. Enhanced features of the Windows version include batch-mode data entry and user functions. The Henry program also has a unique function to allow the user to adjust the estimation using an experimental Henry's Law constant from a structurally-related chemical compound.

Example Entry / Results Window (for Toluene)