HEGADAS is a far-field heavy gas dispersion model, available for both steady- state (HEGADAS-S) and transient releases (HEGADAS-T). HEGADAS can be used as a stand-alone model, but will usually be run in conjunction with one of the near-field models. HEGADAS includes both HF and multi-component thermodynamic descriptions.

To run HEGADAS chemical information relevant to the system of interest should be incorporated into the DATAPROP data base.