HGSYSTEM 1.0 (also known as version Nov'90) arose initially from the need for a Hydrogen Fluoride (HF) gas dispersion modelling tool for assessing the consequence of HF spills. This work was sponsored by a group of about 20 companies from the chemical and petroleum industries in order to provide an openly available tool for carrying out HF and hydrocarbon dispersion assessments. HGSYSTEM 1.0 (and a later version 1.1 which contained no extra modelling capability) was distributed within the sponsoring companies and, for other parties.

HGSYSTEM version 3.0 has added a significant number of new capabilities compared with version 1.0(1.1) and these are described in this WEB page. It is again intended that the use of the programs is not restricted to the sponsoring companies and that they are openly available for carrying out dispersion assessments. (It should be noted that there were no released versions of HGSYSTEM numbered 2.n).

HGSYSTEM version 3.1 has some updates to the officially released version of HGSYSTEM v3.0. However it is not deemed as an official release because version 1.0 and 3.0 have been independently reviewed and thus have a particular regulatory status. The last review we know of was conducted for the US DoE on version 3.0. Further details of version 3.1 can be found here