Chemical Warfare Agents

The Chemical, Biological, Radiological, and Nuclear (CBRN) Consequence Management Advisory Team (CMAT) provides chemical subject matter expert support to the 10 EPA Regions and other EPA program offices. CBRN CMAT has developed critical key partnerships with the stakeholders involved in CBRN responses and maintains an excellent rapport with federal, state, local, Tribal, and academic partners.

Chemical Agent Primer | Chemical Agent Experts | Assets and Equipment | Workgroups

What are Chemical Warfare Agents?

The Chemical Weapons Convention and the Organisation for the Prohibition of Chemical Weapons (OPCW) defines a chemical weapon as, “a chemical used to cause intentional death or harm through its toxic properties. Munitions, devices and other equipment specifically designed to weaponize toxic chemicals also fall under the definition of chemical weapons.” This definition includes toxic chemicals and their precursors.

Chemical agents fall into four categories: choking agents, blister agents, blood agents, and nerve agents.

Choking agents irritate the nose, throat, and lungs when inhaled and include Chlorine (Cl), Chloropicrin (PS), Diphosgene (DP), and Phosgene (CG).
Blister agents affect the eyes, respiratory tract, and skin and include Sulfur Mustard (H, HD), Nitrogen Mustard (HN), Lewisite (L), and Phosgene oxime (CX).
Blood agents inhibit the ability of cells to use oxygen and include Hydrogen Cyanide (AC), Cyanogen Chloride (CK), and Arsine (SA).
Nerve agents block the Acetylcholinesterase (AChE) enzyme in the nervous system, which causes hyper-stimulation of muscles. The nerve agent category include: Tabun (GA), Sarin (GB), Soman (GD), Cyclosarin (GF), and venomous agent X (VX).

Fourth-Generation Chemical Warfare Agents

A new category of chemical warfare nerve agents was reportedly developed in the former Soviet Union in the 1970s to 1990s. This class of agent was developed to be highly toxic, untraceable, and undetectable. The so-called fourth generation agents (FGAs), also known as Novichoks or non-traditional agents, are low volatility nerve agents that evaporate even less readily than VX. FGAs are at least as potent as VX; it takes a lower, or a similar, dose of an FGA compared to VX to cause adverse health effects or death. In 2020, the OPCW added two chemical families, including the chemical family of the Novichok nerve agent involved in the UK assassination attempts of Sergei Skripal in 2018 as well as a closely-related family of chemicals, to Schedule 1 of the Chemical Weapons Convention’s Annex on Chemicals.

CBRN CMAT Chemical Agent Experts

CBRN CMAT chemical subject matter experts have experience and training in the areas of chemical agent environmental sampling, decontamination of indoor and outdoor spaces, personnel decontamination, sample analysis, appropriate medical countermeasures in the event of exposures, generating site-specific clearance values, waste characterization, and waste management (transportation, staging, disposal).

CBRN CMAT supports the local, state, and federal consequence management response to chemical agent incidents and utilizes threat awareness to inform the requirements for decontamination equipment and approaches for protecting communities. Our subject matter experts are available for both consultations and on-site assistance.

CBRN CMAT Chemical Response Assets and Equipment

PHILIS (Portable High-throughput Integrated Laboratory Identification System) – a mobile laboratory for on-site analysis of environmental samples contaminated with chemical warfare agents and toxic industrial compounds. PHILIS mobile labs:

Reduce turn-around time for data.
Enhance on-site decisions.
Provide reliable on-site data for facility clearance decisions.
Eliminate the need to ship/analyze samples off-site.

ASPECT (Airborne Spectral Photometric Environmental Collection Technology) – EPA's airborne real-time chemical and radiological detection, infrared and photographic imagery platform. Based near Dallas, Texas, and able to deploy within one hour, ASPECT is available to assist local, national, and international agencies supporting hazardous substance response and radiological incidents.

Environmental Response Laboratory Network (ERLN) – The ERLN is a comprehensive, all-hazard/all-environmental media laboratory network that can be activated as needed to provide analytical data of known quality in support of environmental emergency response and recovery actions. The ERLN integrates the capabilities of public sector laboratories with accredited private sector laboratories and can be used to support incidents of any scale during the preparedness, response, and remediation phases.

EPA Chemical Warfare Agent Workgroups

EPA Chemical Warfare Agent Preparedness Workgroup

CBRN CMAT’s chemical subject matter experts manage and co-chair EPA’s Chemical Warfare Agent Preparedness Workgroup, a cross-agency workgroup made up of representatives from each of the 10 EPA Regions, Special Teams, EPA’s Office of Research and Development, and several EPA Program Offices.

NRT Chemical Warfare Agent Quick Reference Guide Workgroup

CBRN CMAT’s Chemical SMEs also chair the National Response Team Chemical Quick Reference Guide (QRG) Workgroup. The workgroup is made up of members from across the federal government, including EPA, U.S. Coast Guard, U.S. Department of State, U.S. Department of Defense, Federal Emergency Management Agency, U.S. Department of Agriculture, U.S. Department of Health and Human Services, and U.S. Department of Transportation, who collaborate to draft and update agent-specific reference guides intended for use by EPA or Coast Guard responders in the first 24-48 hours of a chemical agent incident or release.

To access the Chemical QRGs, see the EPA CBRN Quick Reference Guides webpage or the NRT Chemical QRG webpage.