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Central Registry Toolbox Code Version(s): V5.4.4
Code Owner: The National Oceanic and Atmospheric Administration (NOAA) Office of Response and Restoration's Emergency Response Division

Description: Areal Locations of Hazardous Atmospheres (ALOHA) is an atmospheric dispersion model maintained by the National Oceanic and Atmospheric Administration (NOAA) Office of Response and Restoration's Emergency Response Division. ALOHA is one of four separate, integrated software applications in the Computer-Aided Management of Emergency Operations (CAMEO) suite, which also includes CAMEO, CAMEO Chemicals, and MARPLOT. CAMEO is a data management tool for keeping track of chemicals stored and transported in local communities. CAMEO Chemicals is a database of hazardous chemical datasheets, and it also includes a tool to predict what hazards might occur if chemicals were mixed together. MARPLOT is a mapping application.

ALOHA is used primarily for the evaluations of the consequences of atmospheric releases of chemical species. In addition to safety analysis applications in the Department of Energy (DOE) Complex, ALOHA is applied for emergency response situations and for training. ALOHA allows the user to estimate the downwind dispersion of a chemical cloud based on the toxicological/physical characteristics of the released chemical, atmospheric conditions, and specific circumstances of the release. Graphical outputs include a "threat zone" that can be plotted on maps with MARPLOT to display the location of other facilities storing hazardous materials and vulnerable locations.

Mark W Miller, at NOAA is the primary contact for ALOHA. The most recent release of ALOHA may be directly downloaded at For previous releases, contact the general CAMEO user email at NOAA,

In May 2004, the DOE performed an evaluation of ALOHA against DOE's safety software quality assurance criteria. A gap analysis report was generated that identifies the strengths and weaknesses based upon ASME NQA-1 criteria. Upon completion of this evaluation, ALOHA V5.2.3 was included in DOE's safety software Central Registry as a safety analysis toolbox code.

In February 2006, ALOHA (V5.4) was released which added the ability to model the hazards associated with fires and explosions. With this major update, users can now estimate the hazards associated with jet fires (flares), pool fires, vapor cloud explosions (VCE), BLEVEs (Boiling Liquid Expanding Vapor Explosions), and flammable regions (flash fires) as well as toxic threats. The help topics and other program documentation were completely updated to include extensive material associated with fires and explosions.

In August 2014, DOE performed and evaluation of ALOHA V5.4 4 against DOE's safety software quality assurance criteria and this version was listed as a Toolbox code in the safety software Central Registry. The evaluation report is posted on the Safety Software Communication Forum (SSCF)
at This is an access controlled password protected site for use by DOE and its contractors.

Reports and publications related to ALOHA:
Note: Non-DOE issued reports and publications are not endorsed for technical content by DOE. These reports are provided on this web site for courtesy to our DOE community.

DOE-EH- Analysis, Software Quality Assurance Improvement Plan: ALOHA Gap Analysis, May 2004.

DOE-EH- Guidance, ALOHA Computer Code Application Guidance for Documented Safety Analysis, June 2004.

Thoman, D. C.; O'Kula, K. R.; Laul, J. C.; Davis, M. W.; and Knecht, K. D.; Comparison of ALOHA and EPIcode for Safety Analysis Applications, Journal of Chemical Health & Safety, Volume 13, Number 6, November/December 2006.