Visual Accident Perimeter

Visual Accident Perimeter, or short VAP, is a tool developed by BIG to allow for a quick assessment of the dispersion of a substance in case of an incident.

The tool provides two commonly used dispersion models: the ERG model (model described in the Emergency Response Guidebook) or the Gaussian Plume model. This model contains six layers that visualise the calculated dispersion model together with the odour limit, occupational threshold limits and explosion limits on a geographic map.

If the device is equipped with an orientation sensor and a GPS it can also determine the viewpoint and your current location on the map.

The application runs on Windows 10 on as well mobile devices as desktops and on Android and iOS mobile devices. Depending on the hardware (Orientation sensor, GPS, internet connection) different functionalities are available. When the link to the BIG Kaleidos Mobile is activated, the data of the searched substance can be used in the selected dispersion model.


The Visual Accident Perimeter app can be found on Google Play Store.

Download from Google Play Store


The Visual Accident Perimeter app can be found in the Windows Store.
Download from Windows Store


The Kaleidos Mobile app can be found on iTunes.

Download from iTunes


The application runs on all mobile or desktop devices with Windows 10-operating systems and mobile devices running on Android 7.0 or iOS 10.0 or higher.

Some functionalities of the application are not accessible due to hardware availability on the device:


If you experience problems with the installation/activation of the Visual Accident Perimeter app,
please contact our Support service at +32 (0)14 58 45 47 or via mail (