ALOHA — The Complete Guide: Modelling Toxic Clouds, Fires and Explosions From Hazardous Chemical Releases
ALOHA is software from the US Environmental Protection Agency (EPA) and NOAA, part of the CAMEO suite, for assessing hazardous chemical release scenarios. You enter the chemical, storage conditions, type of release and weather, and get threat zones for a toxic cloud, flammable gas, explosion and fire.
ALOHA
US EPA and NOAA (CAMEO)
Models toxic gas clouds, fires and explosions from a hazardous chemical release and maps the threat zones around it.
Get it from the vendorWhat you get
- Toxic cloud — threat zones by concentration.
- Flammable gas — the area where the cloud could ignite.
- Explosion and fire — overpressure and thermal radiation around the source.
- Map display — through MARPLOT, Google Earth or ArcMap.
- Quick use — a result within minutes, for example in a drill or an emergency.
Licence and limitations
It is free US government software, downloaded directly from the EPA site with no registration; it is not open source. The latest version dates from 2016 and is no longer updated, and the macOS build only supports up to OS X 10.11, so in practice it is a Windows program. It is an approximate model and does not replace a detailed dispersion study.
Related tools
For detailed fire and smoke simulation — FDS and Smokeview. For airflow and contaminants inside buildings — CONTAM. For preparing risk maps and GIS layers — QGIS.
FDS and Smokeview
NIST
Fire and smoke movement simulation in buildings — the world standard in fire safety engineering.
Get it from the vendor
CONTAM
NIST
Airflow and contaminant dispersion inside buildings — ventilation, pressures, smoke and CO2.
Get it from the vendor
QGIS
QGIS.org
Open-source GIS for spatial analysis, layer work and map production.
Get it from the vendorThe bottom line
For process and safety engineers, ALOHA is a fast tool for emergency planning, risk surveys and training — as long as you remember it gives a first estimate.