Consequence Analysis
What is Consequence Modelling? Dispersion, Fire and Explosion Simulation Explained
Vinit Pandey · Published 9 December 2025 · Updated 28 June 2026
In short: Consequence modelling is the quantitative simulation of the physical effects — gas dispersion, fire, and explosion — resulting from a loss-of-containment event, used to determine hazard footprint distances.
- Source Term
- Dispersion / Fire / Explosion Model
- Hazard Footprint Contours
- QRA / Siting / Emergency Planning
Key takeaways
- The source term — release rate, duration, and phase — is the single most influential input
- Light-gas vs heavy-gas dispersion models are chosen based on release density and conditions
- Ignited releases are modelled for thermal radiation (fire) or overpressure (explosion)
- Outputs feed QRA risk integration, HAZID siting, FERA, and emergency response planning
Consequence modelling begins with the source term — the rate, duration, and phase of material released — which is the single most influential input to the accuracy of all downstream modelling.
Depending on the release type, dispersion modelling uses light-gas or heavy-gas (dense cloud) models, accounting for wind speed, atmospheric stability class, and terrain, to predict how a toxic or flammable concentration spreads over distance and time.
If the released material ignites, fire modelling (jet fire, pool fire, flash fire) or explosion modelling (vapour cloud explosion, BLEVE) is used to predict thermal radiation or overpressure contours.
These hazard footprints feed directly into QRA risk integration, HAZID siting decisions, fire and explosion risk assessments, and emergency response planning distances.