Chemical Incidents Research Articles

Preparedness as a key factor for human biomonitoring programs after chemical incidents.

Human biomonitoring (HBM) has been repeatedly recommended for and applied to post-incident chemical exposure assessment. The applicability of HBM and the validity of its results, however, closely depend on the existence and quality of preparatory measures such as information and instruction materials, sampling procedures, transport and storage facilities, and on the selection of appropriate biomarkers, sampling time, transport and storage conditions. To establish a standardized HBM program for emergency responders of a large chemical production site, considering the aforementioned aspects. An HBM program based on a comprehensive questionnaire, information and training of emergency responders, and availability of sampling material was established. The quantitative determination of metabolites of hazardous substances was carried out based on quality-controlled analytical methods. The use of HBM after emergency operations was significantly increased immediately after the implementation of the program. Only in single cases, however, established HBM assessment values were exceeded. After one major incident, an increased exposure to benzene exceeding the internal action value was observed after firefighting and safeguarding. The experience with several minor and one major incident at a chemical production site suggests that the implementation of easily accessible and applicable routines is one paramount prerequisite for the success of HBM programs after chemical incidents.

Mass Casualty Decontamination for Chemical Incidents: Research Outcomes and Future Priorities.

Planning for major incidents involving the release of hazardous chemicals has been informed by a multi-disciplinary research agenda which has sought to inform all aspects of emergency response, but with a focus in recent years on mass casualty decontamination. In vitro and human volunteer studies have established the relative effectiveness of different decontamination protocols for a range of chemical agents. In parallel, a programme of research has focused on communicating with and managing large numbers of contaminated casualties at the scene of an incident. We present an accessible overview of the evidence underpinning current casualty decontamination strategies. We highlight where research outcomes can directly inform response planning, including the critical importance of beginning the decontamination process as soon as possible, the benefits of early removal of contaminated clothing, the evidence under-pinning dry and wet decontamination and how effective communication is essential to any decontamination response. We identify a range of priority areas for future research including establishing the significance of the ‘wash-in’ effect and developing effective strategies for the decontamination of hair. We also highlight several areas of future methodological development, such as the need for novel chemical simulants. Whilst considerable progress has been made towards incorporating research outcomes into operational policy and practice, we outline how this developing evidence-base might be used to inform future iterations of mass casualty decontamination guidance.

Study on Improvements to Domestic Marine HNS Training Curricula through a Case Analysis of Marine Chemical Incidents

Study on Improvements to Domestic Marine HNS Training Curricula through a Case Analysis of Marine Chemical Incidents

What can the trove of CSB incident investigations teach us? A detailed analysis of information characteristics among chemical process incidents investigated by the CSB

Understanding the commonalities among previous chemical process incidents can help mitigate recurring incidents in the chemical process industry and will be useful background knowledge for designers intending to foster inherent safety. The U.S. Chemical Safety and Hazard Investigation Board (CSB) reports provide detailed and vital incident information that can be used to identify possible commonalities. This study aims to develop a systematic approach for extracting data from the CSB reports with the objective of establishing these commonalities. Data were extracted based on three categories: attributed incident causes, scenarios, and consequences. Seventeen causal factors were classified as chemical indicators or process indicators. Twelve chemical indicators are associated with the hazards of the chemicals involved in the incidents, whereas five process indicators account for the hazards presented by process conditions at the time of the incident. Seven scenario factors represent incident sequences, equipment types, operating modes, process units, domino effects, detonation likelihood for explosion incidents, and population densities. Finally, three consequence factors were selected based on types of chemical incidents, casualties, population densities, and economic losses. Data from 87 CSB reports covering 94 incidents were extracted and analyzed according to the proposed approach. Based on these findings, the study proposes guidelines for future collection of information to provide valuable resources for prediction and risk reduction of future incidents.

Analysis of Safety Culture Weaknesses in Chemical Safety Board Investigation Reports

The U.S. Chemical Safety Board (CSB), an independent, non-regulatory federal agency that investigates the root causes of major chemical incidents, has firstly analyzed safety culture as an important element to maintain process safety in the investigation report of “BP America Refinery Explosion” in 2007. On the same year, the Center for Chemical Process Safety (CCPS) published Risk Based Process Safety (RBPS) in which process safety culture was newly added as an element. The author found six CSB reports which analyzed the weaknesses of safety culture and related them to the essential features of process safety culture in RBPS. Discussions are made on the results of the relations.

Сучасна модель навчально-тренінгового центру з підготовки експертів у сфері хімічної, біологічної, радіаційної та ядерної безпеки (Результати першого тренінгу з хімічної безпеки в рамках Проекту 57: Посилення існуючих експертно-криміналістичних можливостей при розслідуванні ХБРЯ інцидентів. Україна, Київ, липень 2019 р.)

Minimizing the effects of chemical, biological, radiation and nuclear (CBRN) incidents requires the simultaneous efforts of different specialists not only within one state, so recently international projects have been chosen for the purpose of developing and implementing not only national measures to minimize CBRN threats, but also coordination at the international level. The Aim of the Research. Substantiation of the relevance of a permanent international training center organization for the training of specialists in the field of CBRN security (direction — chemical security) for the needs of the power and special structures of Ukraine. Methods. Results of the instruction and trainings conducted within the framework of the project on the establishment of a network of training centers for minimizing the risks related to the CBRN threats in the countries of the region of Southeast and Eastern Europe, held on the basis of State Enterprise “Research Centre of Preventive Toxicology, Food and Chemical Safety named after L. I. Medved”, Ministry of Healthcare of Ukraine” (Science Center) in July 2019. Results and Discussion. Project 57: Strengthening the crime scene forensics capabilities in investigating CBRN incidents in the South East and Eastern Europe Centers of Excellence Region (Ref: Europe Aid / IFS / 2016/374993) came into action in 2019. The objective of Project 57 is to introduce a system of trainings on the investigation of CBRN incidents and the gradual formation of relationships between forensic experts and organizations with experience in the field of CBRN materials at the national level. Successful fulfillment of the tasks of investigating CBRN incidents requires constant professional improvement of specialists in various fields and development of the system of communication and interaction at the interdisciplinary level. Project 57 from Ukraine involved Ukrainian experts instructed and trained in EU countries as national forensic trainers in crime scene investigations. These candidates, after conducting the relevant exercises, were involved in conducting trainings on raising the level of knowledge of law enforcement officers of Ukraine. In July 2019, a team-based training (July 5) and national exercises (July 22–25) were held under Project 57 at the Science Center. Law enforcement experts from Ukraine and Moldova participated in the team and staff training. Exercises were performed in groups, and the results of the work were demonstrated and discussed via Skype conference mode. National exercises were conducted in the form of practical exercises in a specially prepared territory of the Science Center. The participants of the training worked with imitation material evidence in protective suits using technical means in real-time situations. In addition to the acquisition of practical skills, there was an exchange of knowledge and experience between the various agencies involved in the field of chemical threat. The participants gained experience that will help to improve management skills and improve coordination and communication between the actors involved in the response to the CBRN incidents. Conclusions. The conducted trainings proved the necessity of introducing a system of continuous professional instruction and advanced training of the staff of special and security structures of Ukraine involved in the investigation of CBRN incidents. Key Words: chemical, biological, radiation and nuclear safety, continuous professional development.

Clinical Presentations and Outcomes of Industrial Chlorine Gas Exposure Incidence in Oman.

The main objective was to study different clinical presentations and outcomes of patients after acute industrial chlorine gas exposure in Oman with evaluation of overall incident management to help develop a chemical exposure incident protocol. This was a retrospective observational study of 15 patients exposed to chlorine gas after an accidental chlorine gas leak in a metal melting factory in Oman. Six (40%) patients were admitted and nine (60%) patients were discharged from the emergency department (ED) after initial management. The important post-chlorine gas exposure clinical symptoms were eye irritation (66.6%), cough (73.3%), shortness of breath (40.0%), chest discomfort (66.6%), rhinorrhea (66.6%), dizziness (40.0%), vomiting (46.6%), sore throat (13.3%), and stridor (53.3%). Important signs included tachycardia (40.0%), tachypnea (40.0%), wheeze (20.0%), and use of accessory muscles for breathing (20.0%). Signs and symptoms of eye irritation, rhinorrhea, tachycardia, tachypnea, wheeze, and use of accessory muscles for breathing have shown significant correlation with outcome (admission) having P value of <.05. In the presented acute chlorine gas exposure incidence, 15 exposed persons were brought to the ED, out of which six were admitted and nine were discharged after symptomatic treatment. Signs and symptoms of eye irritation, rhinorrhea, tachycardia, tachypnea, wheeze, and use of accessory muscles of breathing show significant relation with the outcome of admission.

A controlled cross-over study to evaluate the efficacy of improvised dry and wet emergency decontamination protocols for chemical incidents.

The UK Initial Operational Response (IOR) to chemical incidents includes improvised decontamination procedures, which use readily available materials to rapidly reduce risk to potentially exposed persons. A controlled, cross-over human volunteer study was conducted to investigate the effectiveness of improvised dry and wet decontamination procedures on skin, both alone, and in sequence. A simulant contaminant, methyl salicylate (MeS) in vegetable oil with a fluorophore was applied to three locations (shoulder, leg, arm). Participants then received no decontamination (control) or attempted to remove the simulant using one of three improvised protocols (dry decontamination; wet decontamination; combined dry and wet decontamination). Simulant remaining on the skin following decontamination was quantified using both Gas Chromatography Tandem Mass Spectrometry (GC-MSMS) for analysis of MeS and UV imaging to detect fluorophores. Additionally, urine samples were collected for 24 hours following application for analysis of MeS. Significantly less simulant was recovered from skin following each improvised decontamination protocol, compared to the no decontamination control. Further, combined dry and wet decontamination resulted in lower recovery of simulant when compared to either dry or wet decontamination alone. Irrespective of decontamination protocol, significantly more simulant remained on the shoulders compared to either the arms or legs, suggesting that improvised decontamination procedures are less effective for difficult to reach areas of the body. There was no effect of decontamination on excreted MeS in urine over 24 hours. Overall, findings indicate that improvised decontamination is an effective means of rapidly removing contaminants from skin, and combinations of improvised approaches can increase effectiveness in the early stages of decontamination and in the absence of specialist resources at an incident scene. However, the variable control and consistency of improvised decontamination techniques means that further intervention is likely to be needed, particularly for less accessible areas of the body.

Emergency Healthcare Providers' Perceptions of Preparedness and Willingness to Work during Disasters and Public Health Emergencies.

This study evaluates the perceptions of preparedness and willingness to work during disasters and public health emergencies among 213 healthcare workers at hospitals in the southern region of Saudi Arabia by using a quantitative survey (Fight or Flight). The results showed that participants’ willingness to work unconditionally during disasters and emergencies varied based on the type of condition: natural disasters (61.97%), seasonal influenza pandemic (52.58%), smallpox pandemic (47.89%), SARS/COVID-19 pandemic (43.56%), special flu pandemic (36.15%), mass shooting (37.56%), chemical incident and bombing threats (31.92%), biological events (28.17%), Ebola outbreaks (27.7%), and nuclear incident (24.88%). A lack of confidence and the absence of safety assurance for healthcare workers and their family members were the most important reasons cited. The co-variation between age and education versus risk and danger by Spearman’s rho confirmed a small negative correlation between education and danger at a 95% level of significance, meaning that educated healthcare workers have less fear to work under dangerous events. Although the causes of unsuccessful management of disasters and emergencies may vary, individuals’ characteristics, such as lack of confidence and emotional distractions because of uncertainty about the safety issues, may also play a significant role. Besides educational initiatives, other measures, which guarantee the safety of healthcare providers and their family members, should be established and implemented.

Guidelines for first responders based on results from deploying a mockup radiological dispersal device

During the past 7th Security Framework Program the European Commission funded a research project called CATO (CBRN Crisis management, Architectures, Technologies and Operational procedures) to develop a prototype decision support system for crisis management in addition to providing a suite of guidelines for first responders and incident commanders when dealing with chemical, biological, radiological or nuclear incidents. In order to derive these guidelines a proof-of-concept experiment was setup during which several passive agent (Stable CsCl) dispersions with improvised explosive devices and vehicle-borne improvised explosive devices were carried out. Each dispersion was thoroughly characterised by a number of monitoring devices, including high-volume air samplers and size-segregated air samplers. All environmental and forensic samples were collected by the UK counter terrorism police, following strict labelling and chain-of-custody protocols. The samples were analysed at the Belgian Nuclear Research Center suing the k0 method for instrumental neutron activation technique. A full consequence assessment analysis was carried out assuming that the observed concentration of Cs-133 in samples was Cs-137 instead and use was made of the specific activity of Cs-137. Due to the sensitivity of the information the European Commission classified this research. The resulted reported on in this work have been unclassified and are released to assist emergency planners and first responders to take the necessary precautions. The results indicate that, up to distances of 50 m from ground zero radiation levels will be considerable and therefore live-saving actions must be performed by fire/rescue wearing full protective gear. In addition, low-wind conditions will favor a long airborne residence time and therefore the use of full-face protective gear is a must. In order to protect first responders, a radiation protection specialist is to determine how long people can enter and remain in the contaminated area. The recovery of evidence in the case of a car-bomb will be hard or even impossible due to the high level of radioactive material remaining inside the vehicle.

Civil legal aspects of remote consulting in the event of a hazardous chemical incident: the good Samaritan law

Резюме. В Украине при отсутствии специализированных токсикологических центров консультативная помощь в случае химического инцидента предоставляется специалистами оперативно-диспетчерской службы центров экстренной медицинской помощи и медицины катастроф. Сегодня в отдельных странах оперативно-диспетчерская служба использует­ положения «закона доброго самаритянина». Цель исследования — анализ опыта отдельных стран в вопросах регистрации телефонного сообщения об опасном химическом инциденте на основе «закона доброго самаритянина». Методы исследования: контент-анализ, сравнительный анализ. Результаты. В начале 2020 г. сеть консультативных токсикологических центров в мире была представлена 313 учреждениями в >150 странах. За последние 20 лет в работе центров увеличился спрос в телефонных консультациях, интернет-ресурсах, в частности социальных сетях, содержащих информацию о потенциальных ядах (наркотиках, алкоголе, лекарствах, пестицидах, агрохимикатах, товарах бытовой химии и т.п.). Важным аспектом в коммуникациях между оператором и абонентом является гражданско-правовая ответственность за сообщение об инциденте, который связан с действием опасных химических веществ (наркотических, токсических, взрывоопасных и др.), которая предусмотрена «законом доброго самаритянина». В статье продемонстрированы данные о положительных результатах имплементации закона в работу экстренных служб США и других стран. Выводы. Юридическое закрепление «закона доброго самаритянина» в сфере консультативной медицинской помощи позволяет во многих странах мира ежегодно сохранить от преждевременной смерти сотни жизней, поэтому имплементация этих положений в законодательство Украины в сфере здравоохранения является актуальным вопросом для профильного министерства и профессиональных медицинских ассоциаций.

Effects of threat and efficacy messages on expected adherence to decontamination protocols in an immersive simulated chemical incident: A randomized controlled experiment

AbstractThe UK’s Initial Operational Response (IOR) decontamination protocol requires that chemically contaminated casualties remove contaminated clothing (disrobe) and then apply water or absorbent materials to skin. The health‐protective efficacy of the protocol is predicated on casualties quickly accepting both the need to act and the fact that this protocol is an effective action. The aim of this study was to test whether adherence is affected by the presentation of information by first responders about the severity and likelihood of contamination (Threat) and the health‐protective efficacy of IOR procedures (efficacy). A double‐blind randomized controlled experiment (N = 132) with a 3x2 independent measures design (registration number: ISRCTN17886859) was used to assess the effects of threat and efficacy on behavioural expectations during a simulated chemical incident, presented as an immersive video. Results indicated that addressing the threat of contamination made participants more likely to expect themselves to disrobe were the situation real. Emphasizing the efficacy of protective action made participants more likely to expect themselves to apply absorbent materials to skin and had an indirect positive effect on disrobing expectations, mediated by efficacy perceptions. We recommend that first responders explicitly address the threat of contamination and efficacy of decontamination when communicating with chemically contaminated casualties.

Lack of Alignment in Emergency Response by Systems and the Public: A Dutch Disaster Health Literacy Case Study.

Disaster health literacy is vital for emergency medicine and public health preparedness. Conversely, how health and safety information is communicated has a significant impact on disaster health literacy. A lack of alignment between the disaster response and the public's reaction was apparent during a Dutch chemical incident. This case study aims to provide insights into why that misalignment occurred. The case study used readily available Twitter data. The tweets represented both the public and the authorities. The tweets were coded, thematically categorised, analysed, and synthesised to generate an explanatory framework describing the obstacles experienced during the emergency. The analysis identified four areas of concern with regards to the lack of alignment between the authorities and the public: the alert of the chemical incident, the inadequate communication, the problematic disaster management, and the insufficient disaster health literacy. The case study showed shortcomings in communication and a lack of alignment in the emergency response of the authorities as well as the public's disaster health literacy. Immediate action points were apparent, and a more profound evaluation is recommended to avoid further escalation of an emergency in the future. Trust needs to be built before the next incident strikes.

Big data-based applied research on hazardous chemical safety regulation

With the rapid development of modern industry in China, a large number of hazardous chemicals are put into the production and use of chemical enterprises, increasing the probability of hazardous chemical accidents to a certain extent. Because hazardous chemicals are extremely dangerous and destructive, timely and efficient regulation of hazardous chemical safety is of particular importance. The application of China’s Beidou satellite navigation system for safety supervision is of great significance, with its advantages of high accuracy and allweather weather, and the rapid development of related technologies and applications in recent years, has been widely applied in the field of safety monitoring of bridges, earthquakes, dams and other areas. Based on the investigation and analysis of emergency management of critical chemical enterprises, this paper explores the construction of an innovative application system for the safety supervision of critical chemicals based on big data of Beidou positioning system, including a platform for dynamic supervision and traceability of the whole process of critical chemicals based on big data, a platform for dynamic supervision of critical chemical transport safety based on big data, a prediction and early warning application of social public bg data in the critical chemical industry, and a platform for emergency information mining and analysis of critical chemical incidents based on social media big data to form a more scientific safety supervision system for critical chemicals.

Modeling Terrorist Attack Cycles as a Stochastic Process: Analyzing Chemical, Biological, Radiological, and Nuclear (CBRN) Incidents

To further the research agenda on chemical, biological, radiological, and nuclear (CBRN) attacks, we present a novel methodology for modeling a CBRN terrorist attack cycle as a stochastic process. With this model, we can investigate the following questions: Given an adversary’s intent to pursue unconventional weapons, what agents do different perpetrator types pursue? What is the likelihood of a CBRN adversary acquiring or deploying a weapon? At what stage is an adversary most likely to abort their planned attack or be interdicted by law enforcement? Our model successfully identifies correlations between perpetrator type, weapon type, and outcome.

Effective Parameters on Chemical Accidents Occurrence: Findings from a Systematic Review

Chemical accidents have had an increasing trend both in developed and developing countries in the two recent decades. Inappropriate infrastructures make developing countries more vulnerable to chemical accidents. Assessing chemical risks and defining the relevant causes as well as variables are necessary for reducing the injuries and causalities of such chemical incidents. The aim of this study was to explore the causes and parameters affecting occurrence of chemical accidents. The study was performed in 2018. The systematic review adopted in this paper was based on a step-wise process including framing questions, identifying relevant works, assessing the quality of studies, summarizing the evidence and lastly discussing methods, results, and findings. It used bibliographies, citation databases such as PubMed, Web of Science, Scopus, and Google Scholar, and other available records to find an answer to the question of what the effective parameters are on the chemical accident occurrence. Descriptive and thematic analyses were performed to find the articles. The written manuscript was evaluated by PRISMA checklist. It examined 24 peer-reviewed English papers, four reports, and one guideline. It found 39 variables mostly contributing to the occurrence of chemical accidents during this systematic review study. These variables were classified into three main causes and four categories. The main causes included direct/immediate factors, indirect/external/environmental factors, and root parameters. Prevention and mitigation chemical action plans are required to establish chemical safety and preparedness against chemical incidents. Further studies are needed to make the causes, categories and variables more valid, specific, and detailed based on the characteristics of production, storage, transportation, and chemical disposal activities.

Analysis of Chemical Simulants in Urine: A Useful Tool for Assessing Emergency Decontamination Efficacy in Human Volunteer Studies.

To date, all human studies of mass-casualty decontamination for chemical incidents have relied on the collection and analysis of external samples, including skin and hair, to determine decontamination efficacy. The removal of a simulant contaminant from the surface of the body with the assumption that this translates to reduced systemic exposure and reduced risk of secondary contamination has been the main outcome measure of these studies. Some studies have investigated systemic exposure through urinary levels of simulant metabolites. The data obtained in these studies were confounded by high background concentrations from dietary sources. The unmetabolized simulants have never been analyzed in urine for the purposes of decontamination efficacy assessment. Urinary simulant analysis could obviate the need to collect skin or hair samples during decontamination trials and provide a better estimate of both decontamination efficacy and systemic exposure. The study objective therefore was to determine whether gross skin contamination as part of a decontamination study would yield urine levels of simulants sufficient to evaluate systemic availability free from dietary confounders. In this study, a gas chromatography-tandem mass spectrometry method was developed for the analysis of two chemical simulants, methyl salicylate (MeS) and benzyl salicylate (BeS), in urine. An extraction and sample clean-up method was validated, enabling quantitation of these simulants in urine. The method was then applied to urine collected over a 24-hour period following simulant application to the skin of volunteers. Both MeS and BeS were present in all urine samples and were significantly increased in all post-application samples. The MeS levels peaked one hour after skin application. The remaining urinary levels were variable, possibly due to additional MeS exposures such as inhalation. In contrast, the urinary excretion pattern for BeS was more typical for urinary excretion curves, increasing clearly above baseline from four hours post-dose and peaking between 12.5 and 21 hours, a pattern consistent with dermal absorption and rapid excretion. The authors propose BeS is a useful simulant for use in decontamination studies and that its measurement in urine can be used to model systemic exposures following skin application and therefore likely health consequences.

Chemical incident surveillance launch in Lebanon

Background: The International Health Regulations (2005) require that countries develop preparedness plans for chemical threats. Little information is available in Lebanon on chemical incidents. Therefore, there was a need to establish a chemical exposure surveillance system in Lebanon.

Application of Evolutionary Game Theory in Safety Management of Chemical Production

The chemical industry is essential in the social economy, and the issue of production safety has aroused widespread concern. Chemical safety incidents occupy the headlines from time to time, and chemical production safety management is particularly important. This paper presents an application model based on evolutionary game theory in the assessment and analysis of chemical production safety management. The model uses evolutionary game theory to construct a strategic interactive payoff matrix between the management department of a chemical plant and the chemical plant using a replicated dynamic equation to analyze their strategic interaction and to reveal the evolution of behavioral strategy selection. The evolution results were verified and simulated. The application of this model provides an effective safety management basis and recommendations for the management of chemical plants, providing a foundation for the safe production and healthy development of chemical plants.

Phenobarbital as alternate anticonvulsant for organophosphate-induced benzodiazepine-refractory status epilepticus and neuronal injury.

ObjectiveOrganophosphates (OPs) such as diisopropylfluorophosphate (DFP) and soman are lethal chemical agents that can produce seizures, refractory status epilepticus (SE), and brain damage. There are few optimal treatments for late or refractory SE. Phenobarbital is a second‐line drug for SE, usually after lorazepam, diazepam, or midazolam have failed to stop SE. Practically, 40 minutes or less is often necessary for first responders to arrive and assist in a chemical incident. However, it remains unclear whether administration of phenobarbital 40 minutes after OP intoxication is still effective. Here, we investigated the efficacy of phenobarbital treatment at 40 minutes postexposure to OP intoxication.MethodsAcute refractory SE was induced in rats by DFP injection as per a standard paradigm. After 40 minutes, subjects were given phenobarbital intramuscularly (30‐100 mg/kg) and progression of seizure activity was monitored by video‐EEG recording. The extent of brain damage was assessed 3 days after DFP injections by neuropathology analysis of neurodegeneration and neuronal injury by unbiased stereology.ResultsPhenobarbital produced a dose‐dependent seizure protection. A substantial decrease in SE was evident at 30 and 60 mg/kg, and a complete seizure termination was noted at 100 mg/kg within 40 minutes after treatment. Neuropathology findings showed significant neuroprotection in 100 mg/kg cohorts in brain regions associated with SE. Although higher doses resulted in greater protection against refractory SE and neuronal damage, they did not positively correlate with improved survival rate. Moreover, phenobarbital caused serious adverse effects including anesthetic or comatose state and even death.SignificancePhenobarbital appears as an alternate anticonvulsant for OP‐induced refractive SE in hospital settings. A careful risk‐benefit analysis is required because of negative outcomes on survival and cardio‐respiratory function. However, the need for sophisticated support and critical monitoring in hospital may preclude its use as medical countermeasure in mass casualty situations.