- 2018 Hungarian Meteorological Service. All Rights Reserved. Administration or non-process buildings, which are located in industrial facilities often have a large number of occupants. In the unlike event of a toxic gas release, large amounts of pollutants can penetrate into the building shell through openings and cracks and could lead to serious consequences for the health of people and the environment. Lethal dosages can be reached indoors because of the gas ingress and its entrapment. A multi-scale modelling methodology is presented for a H2S release affecting an administration building. The proposed methodology extends ordinary numerical modelling approaches one step further by using evacuation models for better understanding, protecting and mitigating the vulnerability of the building occupants during their evacuation to safer places.