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Chemical and Biological Defense

ChemistryThe Department of Homeland Security (DHS) Science and Technology Directorate (S&T) chemical and biological defense program increases the nation’s preparedness against chemical and biological threats through improved threat awareness, advanced surveillance and detection, and responsive countermeasures. S&T works with the DHS component activities and other U. S. government agencies to increase public and governmental awareness of potential chemical and biological threats and to strengthen the nation's response against these threats.


Chemical and biological attacks pose a significant threat to our nation’s population, infrastructure, economy and security. Protection of the public, emergency responders, agricultural resources and critical infrastructure is a national priority. S&T addresses these threats through comprehensive research, development, testing and evaluation efforts.

S&T is supported by a strong and diverse group of scientists, engineers, program managers and analysts. Working with industry, academic, national laboratory and federal partners, S&T develops technologies, systems, and knowledge products to increase national preparedness in two focus areas:

Biological Defense

S&Ts focus in biological defense encompasses risk-based biological threat countermeasure development programs including threat characterization and development and transition of new and improved technologies, strategies, and procedures. These programs support multi-layered defense capabilities – threat awareness, prevention, surveillance and detection, forensics, and response and recovery – that address intentional or accidental introduction of biological agents that threaten the nation’s human national security. Hazards to the population through inhalation, dermal exposure and ingestion are within this mission.

Chemical Defense

S&T’s chemical defense work focuses on risk-based chemical countermeasures development programs which seek to characterize the threat and develop and transition new and improved prototype technologies, strategies and procedures for the interdiction, detection, response and recovery from use of toxic chemical threat agents in intentional attacks or from major accidental releases that present acute hazards to the health of the nation’s population. Hazards to the population through inhalation, dermal exposure and ingestion are addressed within this mission.

To learn about similar work S&T is doing in this area visit: Probabilistic Analysis for National Threats Hazards and Risks (PANTHR) program webpage.






Last Updated: 01/12/2023
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