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Interagency Modeling and Atmospheric Assessment Center

The Interagency Modeling and Atmospheric Assessment Center, or IMAAC, provides no-cost, expert support for incidents involving hazardous materials (HAZMAT) or chemical, biological, radiological, nuclear, or explosive (CBRNE) agents. IMAAC supports federal and state, local, tribal, and territorial (SLTT) first responders, emergency managers, public and environmental health practitioners, and other public safety officials by coordinating, developing, and disseminating plume models and other resources intended to support decision-making during HAZMAT/CBRNE emergencies.

Led by FEMA, IMAAC is a partnership between several federal agencies whose missions and capabilities complement one another’s, providing multidisciplinary perspective to CBRNE preparedness and response efforts. These agencies come together and coordinate under IMAAC to provide the singular federal position on HAZMAT/CBRNE incidents. IMAAC is comprised of the following federal entities:

  1. Department of Homeland Security (DHS)
  2. Department of Defense (DoD)
  3. Department of Energy/National Nuclear Security Administration (DOE/NNSA)
  4. Department of Health and Human Services (HHS)
  5. Environmental Protection Agency (EPA)
  6. National Oceanic and Atmospheric Administration (NOAA)
  7. Nuclear Regulatory Commission (NRC)

Engaging IMAAC

Planning, Training, and Exercise Support

IMAAC can provide no-cost HAZMAT/CBRNE planning, training, and exercise support to federal and SLTT government entities. For example, IMAAC can:

  • Provide atmospheric modeling for HAZMAT/CBRNE emergency scenarios to support data-driven planning and preparedness efforts.
  • Facilitate IMAAC training for public safety organizations including, what IMAAC is, what IMAAC’s capabilities are, how IMAAC can be activated, and what types of products IMAAC can produce.
  • Participate in exercises involving HAZMAT/CBRNE emergencies by providing ground truth information through the modeling of the exercise scenario or by activating IMAAC as part of exercise play.

To engage IMAAC for planning , training, and exercise support, please contact the IMAAC Technical Operations Hub by submitting a request through the CBRNResponder IMAAC portal or via email at Please provide as much advanced notice as possible when engaging IMAAC in planning, training, and exercise support.

Real-World Incident Support

IMAAC can also be activated for potential or ongoing real-world incidents involving HAZMAT/CBRNE agents. For instance, IMAAC has activated for:

  • Ground transportation incidents, such as train derailments and semi-trailer motor vehicle accidents involving chemical agents.
  • Chemical releases, fires and explosions at manufacturing and other industrial facilities.
  • Maritime transportation incidents, such as barge fires, with potential for release of HAZMAT into waterways.
  • Numerous other real-world incidents involving the release of HAZMAT/CBRNE agents.

Should you suspect or confirm the occurrence of a HAZMAT/CBRNE incident, do not delay. Activate IMAAC! Call the IMAAC Technical Operations Hub at (877) 240-1187 and be prepared to provide as much incident information as available. This may include but is not limited to:

  • WHO to contact for follow up – name, email address, agency, title, phone number, etc.
  • WHAT was releasedtype of material (chlorine, anthrax), amount of agent released (90-ton rail car, 2 lbs.), form of material (vapor, liquid), etc.
  • WHEN the incident occurred – date, time, time zone, suspected duration of release, etc.
  • WHERE the incident is located – street address, city, state, facility, road intersection, latitude, longitude, etc.
  • WHY you are requesting the productinform protective actions (shelter-in-place, evacuation), protect responder safety (determine appropriate personal protective equipment), inform medical surge, prevent further contamination of environment, determine secondary hazards, etc.
  • HOW the incident happened – type of incident (spill, fire, explosion), etc.

IMAAC Resources


The CBRNResponder Network is a single, secure platform for all chemical, biological, radiological, and nuclear (CBRN) incident data-sharing and multi-hazard event management, integrating multiple federal assets and national-level policy guidance. CBRNResponder includes an IMAAC portal where users can request planning, training, and exercise support; receive and view IMAAC products; and access numerous other resources supporting CBRN preparedness and response. To request a CBRNResponder account, please visit and click on “Request an Account” in the top right corner. For more information on the CBRNResponder IMAAC portal, view the video below.

For more information on how to access the IMAAC portal visit

IMAAC Digital Media Toolkit

IMAAC developed a Digital Media Toolkit to support federal and SLTT partner entities in sharing information about IMAAC with relevant constituents.  The toolkit includes sample social media and newsletter content, graphics, web assets, talking points, and other useful resources. Federal and SLTT entities can use this information to strengthen first responder, emergency management, and public and environmental health awareness of IMAAC, improving future responses to HAZMAT/CBRNE incidents as public safety stakeholders integrate IMAAC products into emergency planning and response.

Person wearing a hazmat suit with text that reads, "Before you suit up, understand the threat. In real-world hazmat emergencies, activate IMAAC 24/7. 877-240-1187"
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IMAAC Training Videos

IMAAC developed a series of thirty brief training videos for use by partner agencies and public safety entities. These three to five minute videos can be found on the FEMA YouTube channel and cover topics related to IMAAC’s capabilities in modeling different CBRNE agents. These videos can be used as part of a larger training curriculum, as just-in-time training for emergency responders, or as refresher training on IMAAC and its capabilities. 

Watch the Videos

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IMAAC Newsletter

IMAAC distributes a quarterly newsletter that provides updates on all things IMAAC. To stay informed of IMAAC’s activations, events IMAAC will be attending, recent engagements with federal and SLTT entities, and other important updates, sign up for the IMAAC newsletter. Sign up for the IMAAC Newsletter.

Interagency Modeling and Atmospheric Assessment Center Newsletter

Contact IMAAC

To contact IMAAC for planning, training, and exercise support or for general inquiries, please contact the IMAAC Technical Operations Hub at (877) 240-1187, email, or submit a request through the CBRNResponder IMAAC Portal.

For real-world HAZMAT/CBRNE incident support, please call the IMAAC Technical Operations Hub upon suspecting or confirming the incident at (877) 240-1187.