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Chemical Security Analysis Center

CSAC Chemical Security Analysis CenterLocation: Aberdeen Proving Ground, MD

In 2006, by Presidential Directive, the Department of Homeland Security (DHS) established the Chemical Security Analysis Center (CSAC) to identify and assess chemical threats and vulnerabilities in the United States and develop the best responses to potential chemical hazards. Overseen by the DHS Science and Technology Directorate (S&T), CSAC supports the homeland security community by providing a crucial knowledge repository of chemical threat information, design and execution of laboratory and field tests, and a science-based threat and risk analysis capability, among other services. CSAC’s presence on the Edgewood Area of U.S. Army Aberdeen Proving Ground, Maryland allows close collaboration with Army scientists and engineers.

Offering Technical Assistance Capabilities in Response to Investigations and Crises

For inquiries related to chemical threats and chemical hazards, the CSAC offers a 24-hour, seven-days-a-week informational response capability, known as “CSAC Technical Assistance,” to federal, state, local, territorial, and first responder agencies. CSAC Technical Assistance is a key resource for the National Operations Center. CSAC Technical Assistance typically responds to 70 to 80 requests per year. Key customers include the Department of Health and Human Services, Environmental Protection Agency, Federal Bureau of Investigation and many other agencies and industry stakeholders.

Supporting S&T’s Efforts to Address National Hazards, Threats and Risks

CSAC applied previously developed and validated multi-zone models for chemical contamination in aircraft to understand the transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) on commercial aircraft. These models were developed in conjunction with the United Kingdom (UK) Centre for the Protection of National Infrastructure, the UK Department for Transport, TSA, and CTTSO, using the National Institute of Standards and Technology CONTAM software. Select potential mitigation measures such as the use of High Efficiency Particulate Air filtration, adjustment of air flow exchange rates, and universal mask wearing were evaluated for the impact on passenger exposure given a single contagious passenger and multiple contagious passengers on a flight.

Through the DHS S&T Probabilistic Assessment of National Threats Hazards and Risks (PANTHR) program and the DHS S&T Hazard Awareness Characterization Technology Center (HAC-TC), key parameters such as the rate of viral shedding and the particle size distribution for common activities such as breathing, talking, and coughing were estimated based on an extensive literature review. The study included estimates for the emission of both small aerosols, which are most useful for characterizing the airborne hazard and impact of filtration systems, and larger droplets, which are most important for characterizing surface contamination. The results of this study have been used to evaluate potential mitigation measures to help decrease the risk of pathogen transmission during air travel.

Project Jack Rabbit—Helping DHS and its Partners Reduce the Risk of Large-Scale Toxic Inhalation Hazard Chemical Releases

Each year, hundreds of millions of tons of chemicals like chlorine and ammonia are transported through U.S. population centers. Although these chemicals are essential, they are toxic and pose a risk to the public through accidental release or an act of terrorism. To better understand and address this risk, CSAC conducted Project Jack Rabbit in 2010 followed by the Jack Rabbit II Program Fact Sheet program in 2015-2016.

Jack Rabbit I involved a series of 1- to 2-ton outdoor chlorine and ammonia release trials involving a team of stakeholders from government, industry, and academia.

Scientist testing chemicalsJack Rabbit II continued where Jack Rabbit I left off, with release trials of up to 20 tons. These experiments were unprecedented and filled crucial knowledge and data gaps. Prior to Jack Rabbit I and II, large-scale chlorine releases had never been tested at volumes representative of rail cars, tanker trucks, barges or bulk storage tanks. Jack Rabbit improved hazard prediction modeling, emergency planning, and response and mitigation strategies, as well as the United States' resilience against chemical release incidents.

Final and follow-on test reports of S&T CSAC’s Jack Rabbit I and II Programs have been approved for public release. The JR II Program Final Test Report documents the large-scale outdoor chlorine release trials conducted at U.S. Army Dugway Proving Ground, Utah, made possible by direct support from the U.S. Defense Threat Reduction Agency, Transport Canada (TC), and Defence Research and Development Canada (DRDC). The Chlorine Reactivity with Environmental Materials in Atmospheric Dispersion Models report describes kinetic measurements and maximum deposition effects of select vegetation exposed to toxic gas, capturing work performed in partnership and collaboration with University of Arkansas and TC/DRDC.

Jack Rabbit III, a continuum endeavor, will consist of laboratory, chamber, and field experiments to gather scientific data and identify technologies to fill critical data gaps. The Jack Rabbit III focus is to build security, safety, and resilience in the chemical supply chain through experimentation over the next five years. Jack Rabbit III involves the work of a collaborative team of partners and cosponsors from government, industry, and academia to identify and prioritize critical data gaps for toxic inhalation hazard (TIH) chemical release atmospheric dispersion modeling; emergency preparedness and response; and hazard and risk mitigation procedures.

Our Impact

Did You Know?

In 2019, S&T CSAC responded to a DHS National Operations Center (NOC) request for information regarding Hurricane Dorian to provide critical chemical facility information and analysis of the toxic chemical hazards and risks within the potential hurricane effect zones. Hurricanes pose a significant risk to even the most secure chemical facilities, with storm-driven power outages, high winds, and flooding potentially leading to chemical leaks, explosions, or fires. S&T CSAC analysis documented the chemical type and the amount being stored at more than 2,000 chem­ical facilities in the southeastern United States, Puerto Rico, and the Bahamas.

Fact Sheets


We would like to hear from you! Contact us at: csacinfo@st.dhs.gov

Last Updated: 08/02/2023
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