3.2. Response Phases

Each phase of the FGA scenario exercise required site-specific decisions. During each stage, the possible exposure to the general public and response workers was monitored using field screening and expedited on-site and off-site laboratory analysis.

3.2.1. PHASES 2A&B

• Notification: The local authorities notified appropriate agencies, including local hazardous materials (HAZMAT), police, fire, and possible property stakeholders. Local authorities notified the local FBI office, which deployed their Weapons of Mass Destruction (WMD) coordinator for forensic sampling to identify the hazardous chemical and criminal investigation activities. The FBI collected all available data from local responders. Unified Command was set up and included local, state, and federal response assets. A coordinated information stream was set up.

• First Response: Local HAZMAT-capable hospitals were alerted for the arrival of patients with cholinesterase inhibition, respiratory distress, and other symptoms of SLUDGE– (Salivation, Lacrimation, Urination, Diarrhea, Gastrointestinal cramps, Emesis) and DUMBBELS (Defecation, Urination, Miosis/Muscle weakness, Bronchospasm/Bronchorrhea, Bradycardia, Emesis, Lacrimation, Salivation/Sweating), which may be indicative of a nerve agent exposure. Diagnostics of cholinesterase suppression were employed by hospital laboratories. Portable diagnostics, such as EQM Research’s Test-mate system, were also employed in a field laboratory under the umbrella of an extended Clinical Laboratory Improvement Amendments (CLIA) certificate. The public was notified about the incident and provided with instructions for reporting to public decontamination facilities. These facilities were set up for people who thought they might have been potentially exposed. Response workers utilized modified Level B (SCBA and a hooded chemical-resistant suit that protects against FGA with no exposed skin, i.e., taped or encapsulated B).

Local authorities ordered the four different locations (restaurant, bar, park, and home) to be evacuated, and the car impounded. Evacuees were notified on the reason to leave the sites based on the possible high risk of exposure. Evacuees were also informed to monitor themselves for signs and symptoms (SLUGDE, DUMBBELS) and report themselves with such signs to a hospital. Under UC, a Joint Information Center was established, who provided routinely scheduled notifications to the local health department. A shelter-in-place was recommended for outlying areas on a case-by-case basis. State and local police enforced an evacuation/shelter-in-place. The EPA deployed federal assets for air monitoring but faced challenges. Any positive results on handheld screening meters (MX908, Proengin’s AP4C, etc.) or M8 paper from surfaces were considered indicative of FGA presence. The data were sent to the UC to advise the local Health Department on evacuation and shelter-in-place actions.

3.2.2. PHASE 2C

• Characterization: UC tasked the Planning Section Chief to develop an Incident Action Plan, Sampling and Analysis Plan, Health and Safety Plan, and an Ambient Air Monitoring Plan. EPA deployed their VIPER¹⁴⁰ interface to network all monitoring instruments around the targeted areas. EPA’s PHILIS (Portable High-Throughput Integrated Laboratory Identification System) units were mobilized to the site for sample analysis during the characterization and clearance phases. Several MINICAM™ portable gas chromatographs were obtained from the Army for near-real-time air monitoring but faced a challenge due to the extremely low volatility of FGAs. As such, air monitoring was discontinued. Additionally, the National Guard WMD-Civil Support Teams responding leveraged point detectors and bench-top analytical equipment, with results indicating an FGA. Surface wipes were taken to determine the contaminated area’s extent, with responders collecting additional soil and bulk samples (carpet, stained areas) and analyzed on-site by the PHILIS mobile labs. Excess samples, which were unable to be analyzed on-site, were sent to Chemical Biological Application and Risk Reduction (CBARR), National Reference Labs, and the EPA Environmental Response Laboratory Network laboratories for FGA analysis.

• Remediation (Cleanup): Characterization results indicated that four locations were contaminated. The RAP addressed the complexity of decontaminating all sites simultaneously. UC tasked the Planning Section Chief to develop a RAP, waste disposal plan, and select a decontamination strategy for cleanup. EPA Office of Research and Development (ORD)/Center for Environmental Solutions and Emergency Response (CESER) provided research data to support various decontamination strategies and waste staging locations. EPA provided a waste disposal matrix to assist with transportation and disposal requirements. The sites were divided into separate operable units (OUs). Each OU was managed by a task force, which coordinated all sampling and analysis, decontamination, and health and safety issues for that specific unit. EPA, CDC, FEMA, state, local, tribal, and other stakeholders were selected to participate in the TWG. The decontamination of critical items, sensitive equipment, and other “special” items was considered in the overall plan. The TWG selected to dispose of certain media that are difficult to decontaminate, such as porous, permeable materials, and easy to remove items (carpet, chairs, tables, etc.). The group recommended the scabbling of concrete or complete removal where cleanup goals could not be achieved. Jurisdictional issues complicated transportation and disposal of the waste. The UC resolved the problems at a federal level by obtaining a certified hazardous materials incinerator's service.

• Clearance: The Planning Section was tasked to develop the Clearance Sampling Plan using the clearance decision levels agreed upon by the TWG. Sampling and analysis continued to verify each OU's decontamination efficacy; the UC cleared each OU via the Environmental Clearance Committee.

• Phase 3: Restoration/Recovery: The UC (including public health professionals) cleared the last remaining OU, indicating that the entire site was cleared for resumed use/re-occupancy. All sampling media had FGA concentrations that met the clearance decisions. Local and state Departments of Environmental Protection discontinued ambient air sampling because concentrations remained below risk-based levels established by the TWG. The Public Information Officer continued to be in place to address public concerns.

3.2.3. APPLICABLE TOXICITY VALUES FOR DECISION-MAKING

Although site-specific information would be developed for any contamination event, Table B-3 shows a comparison of median lethal concentration and dose for FGA and other nerve agents that could be used to inform the decision-making process for clearance.

Table B-3: Overview of the gradual increase in the toxicity of CWA. LCt50, median lethal concentration; LD50, median lethal dose

Due to the lack of established occupational exposure limits for FGAs, extreme precautions must be taken to prevent any exposure. This guidance document's recommendations are based on the reported toxicity and the chemical and physical properties of FGAs.

3.2.4. EXPOSURE ROUTES

FGAs are low-volatility nerve agents, and like VX do not volatilize or evaporate readily. They will mostly be encountered as a bulk liquid or as a low-visibility liquid film on a surface. The most likely exposure route is skin contact, but FGAs may be absorbed by inhalation, mucous membrane contact (eyes, nose, mouth), or ingestion. After exposure, symptoms may occur within minutes to hours or up to three days. In general, the latent period between dermal exposure and symptom onset may be longer for FGAs than for VX. Inhalation, ingestion, or large dermal exposures will have shorter latent periods. Prompt administration of decontamination procedures and medical evaluation is critical. Personnel decontamination procedures should include a reactive decontaminant such as RSDL if dermal exposure is suspected. Additionally, due to the relatively long latent period, a post-decontamination monitoring protocol using serial acetylcholinesterase activity diagnostic measurements should be implemented with any individual suspected of dermal exposure to FGA.