When a gas or vapor is released, how far downwind is it still dangerous? A Gaussian plume model estimates the concentration footprint and protective action distance.
Hazmat Plume DispersionLive
Gaussian plume · protective action
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A Gaussian plume estimates how a gas or vapor release disperses downwind. Stability class (A unstable to F stable) sets how fast the plume spreads. The dashed line is the protective action distance where concentration falls below your action level. Screening estimate only — use ERG and monitors on scene.
Reading this result: Concentration falls off as the wind stretches and vertical mixing thins the plume — stronger wind and less stable air pull the protective distance in toward the source.
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
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How it works
The Gaussian plume equation predicts pollutant concentration downwind of a continuous release, using Pasquill-Gifford stability classes to capture how atmospheric conditions spread the plume. This is a rapid screening estimate for planning and training — on an actual incident, rely on the Emergency Response Guidebook, air monitoring, and technical specialists.
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The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.
Is this hazmat plume dispersion calculator tool really free?▾
Yes. Hazmat Plume Dispersion runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?▾
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?▾
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?▾
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.