CHARM® Software - When Realism Counts
The potential for accidental release of hazardous chemicals (air dispersion and transport), fires (BLEVE, pool fire, and jet fire), and explosions (mechanical failure and air dispersion and transport followed by vapor cloud explosion), poses a risk
that must be addressed on several levels. The EPA Risk Management Program (RMP, Rule 112r)
requires hazard assessment and emergency response programs. To assure that you have
adequate resources and that plans are well organized for any contingency, you need to plan
for emergency response. Should such an accident occur, you need real-time data to guide the
response activities. CHARM software helps you meet all of these needs.
There are two versions of the CHARM software available; One assumes a single source in flat
terrain. The second version allows for multiple sources in complex terrain but requires more
input than the first. Both versions are available for downloading for a two week evaluation
period on the Downloads page. Registration is required for trial version downloads - no financial information is required or requested if checkout is directly from Your Cart. They both provide calculations of air transport and dispersion, mechanical and vapor cloud explosions, and BLEVE, jet fire, and pool fire radiation.
See the Examples
page for representative impact results of scenarios calculated using the complex terrain version.
The flat terrain version is also available as a web application, which can be accessed through a browser on the Internet and requires no special software to be loaded on the browser’s computer.
Both versions of CHARM can be used to estimate impacts from the use of chemical
WMDs. The expected species that may be used (e.g. chlorine, mustard gas, sarin, soman, and
VX) are in both databases. The complex terrain version can do an even more
complete simulation. Many chemicals used for WMD are released as aerosol. The
complex terrain version of CHARM is capable of simulating all major processes
affecting aerosol. Some estimate of the size distribution of the aerosol in the
released chemical is needed. After the release has occurred, CHARM can calculate
the changes in the size distribution due to coagulation,
condensation/evaporation, and deposition.
The aerosol capabilities of the complex terrain version of CHARM also allows
impacts from biological WMDs (e.g. anthrax) to be estimated. The impacts can be
given as air concentrations or surface deposition.
Nuclear Radiation impacts have been added in the Complex Terrain version. Radionuclides can be included in an emission. Radiation rates and doses are calculated - 2D, 3D, and table displays.
Complex Terrain version can use multi-processor chips. Faster results!
The list with the changes made to the Flat and Complex Terrain versions of CHARM is available here
WebCHARM takes the power of CHARM and delivers it right to the web browser of your choice, no matter where you are. We understand that in many situations, especially in the field of accidental releases, you cannot always be by a computer with the proper software loaded. Because WebCHARM is hosted entirely through the web with no software to download, you are always just a few clicks away from conducting your
If you have already purchased a license, go to WebCHARM
Descriptions and Sample Screens
Plume affected by terrain and buildings