Threat Agent Science: Investigating the Next Generation of Threats


By Dr. Donald Cronce

Threat Agent Science Overview

The mission of Threat Agent Science (TAS) within the US Chemical and Biological Defense Program (CBDP) is to investigate emerging and identified chemical and biological (CB) threat agents, as well as the emerging technologies and processes that make them more accessible to potential State and non-State adversaries. As science and technology continue to advance, to the benefit of people around the world, the role of TAS is to proactively work to understand how these advancements may be used nefariously to produce a new generation of malicious CB threat agents. While seeking to understand these new and emerging threats, TAS only supports defensive Science and Technology (S&T) efforts.

TAS cultivates the foundational knowledge needed by capability developers, decision makers and others to perform the respective activities needed to equip personnel with the tools, equipment and tactics to protect against employed CB agents. Focusing on new and emerging threats (Next Generation Agents, if you will), TAS fills threat knowledge gaps and identifies other issues and characteristics of the new threat that are useful to the larger CB defense community. Similarly, for scientific and technological advancements, TAS seeks to understand the complexities and possibilities of these advancements with respect to the production, procurement and employment of CB agents. Emerging threats are often identified by inputs from the Intelligence Community and technological or market-driven advancements.


TAS takes a very systematic approach to investigate and understand potential new threats, seeking answers to two basic questions: 1. Is the chemical compound or biological pathogen capable of being a legitimate physical or operational threat to the Warfighter? 2. If so, do technologies currently exist that make it easily deployable? If the research indicates that the putative threat agent is viable, studies continue and become more comprehensive in order to understand the extent of the threat possibilities. However, if at any point the research indicates that the purported threat agent is not a significant/realistic threat given current technological, physical or market barriers, the research is concluded and the results documented and reported.

Threat Agent Science Research Thrust Areas

The systematic approach taken by TAS is reflected in how the program is constructed. TAS is organized into five major research thrust areas: 1) Technical Surprise; 2) First Look; 3) Environmental Response; 4) Host Response; and 5) Employment Characterization. The thrust areas represent a continuum of research into chemical and biological threats, from the point where concern about a potential threat is first identified to the point of identifying how it might be used by an adversary against the Joint Forces. Here again, research into a potential threat agent stops if at any point along the way the data demonstrate it not to be currently viable.

Technical Surprise

The first Thrust Area, Technical Surprise, is a proactive effort to identify potential new threats. Horizon Scanning activities are part of this Thrust Area, looking forward to see what technologies and related advancements will come to maturity in the near future. Also included for study in this Thrust Area are technologies that are already being used for legitimate and beneficial purposes but which have the potential for being used maliciously (synthetic biology being an excellent example, as discussed by the US National Academy of Sciences in their 2018 Biodefense in the Age of Synthetic Biology report ( . The emphasis here is on technologies and capabilities that may make traditional, non-traditional or advanced agents more accessible or provide a means by which previously unknown chemical or biological threat agents could be developed by those with malign intent.

First Look

First Look is the initial effort at evaluation of identified potential or emerging threat agents. Potential threats are initially screened by determining fundamental chemical, physical and biological properties as appropriate. Should studies find the potential agent to constitute a viable threat, more complex questions begin to be addressed (for example, ease of synthesis, production, culturing, etc.). Such characterization studies continue unless or until the potential threat is found not to be viable.

Environmental Response

Environmental Response is the next Thrust Area. The research in this thrust investigates how the potential threat interacts with the operational environments in which it might be encountered. Rates of hydrolysis, reactivity with atmospheric pollutants, degradation products, aerosolization ability, and survivability and persistence in various types of soils and surfaces are examples of the types of studies conducted. Understanding environmental effects directly influences protective and decontamination measures that would need to be taken if the potential threat were to ever be employed against US or allied forces.

Host Response

The Host Response Thrust Area investigates the effects of the potential threat on our adversary’s intended target – the human body. Toxicology and predictive toxicology efforts are the primary focus of this Thrust Area. Lethality vs incapacitation, infectivity and virulence and mechanisms of action – all with respect to various routes of exposure – are exemplars of the characteristics determined. Results from these studies contribute to medical countermeasure and personal protection capability development.

Employment Characterization

Employment Characterization is the final Thrust Area. In this thrust, the ability of a potential threat agent to survive known/applicable dissemination methods is investigated. The percentage of the putative agent surviving pyrotechnic or explosive detonation; aerosol and vapor partitioning; particle size; mass distributions and similar factors are evaluated. Additional studies are made for use in hazard assessment models and other decision-making tools. These models help assess whether and to what extent the potential threat is of concern when disseminated in a given scenario.

Using Threat Agent Science

Information generated and provided by the TAS program supports many of the areas of chemical and biological defense R&D. For example, understanding the reactivity of a potential new chemical threat may influence decontamination development; knowing that a biological pathogen has limited survivability outside of a host system may affect protective capability development research priorities; determining that explosive dissemination of a new threat results in the destruction of a specific percentage of the new material could lead to more accurate and precise transport and diffusion hazard assessment models; determining lethal vs. incapacitating dose differences for a new threat may provide data that could change personnel readiness doctrine and policy decisions. TAS is a critical component of the CBDP that both directly and indirectly affects many aspects of chemical and biological defense research, helping to ensure capability developers and others are making well-informed decisions based on a solid scientific foundation.


In summary, TAS investigates known and emerging chemical and biological threat agents, as well as the advancing technologies and processes that make their production and procurement easier. Understanding how these emerging threats and technology advancements might be used nefariously when employed by adversaries against allied forces helps frame all subsequent efforts of protection and mitigation. TAS provides the foundational knowledge needed by capability developers, decision makers and others for them to perform the respective activities needed to defend personnel against employed CB agents, filling identified threat knowledge gaps and identifying characteristics of the new threat that would be useful to the larger CB defense community. Similarly, for scientific and technological advancements, TAS seeks to understand the complexities and possibilities of these advancements with respect to the production, procurement and employment of CB agents. The purely defensive TAS research influences many aspects of CB defense S&T efforts, enabling capability developers and others to make well-informed decisions based on a solid scientific foundation.

About the Author

Dr. Donald Cronce is the Threat Agent Science Lead at the US Defense Threat Reduction Agency, Research and Development Directorate, Chemical and Biological Technologies Department and the Advanced and Emerging Threat Division. He has a Bachelor of Science degree in Chemistry from the University of Wisconsin at Milwaukee and a PhD in Chemistry from The Pennsylvania State University (University Park, PA). Dr. Cronce has authored numerous technical presentations and articles, and holds five US patents in CBRN defense-related areas. He has conducted, managed and/or directed R&D in many areas of CBRN defense for over 30 years, from basic research to advanced development.

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