Hazardous Materials Incidents Research Articles

Method development for the evaluation of emergency decontamination protocol effectiveness using an ultraviolet fluorescent aerosol.

After hazardous material incidents, it is important to perform emergency decontamination procedures to remove contamination from the body. As these emergency decontamination procedures are developed, it is important to understand the efficacy of a given protocol. This study discusses a method that was developed to evaluate the efficacy of decontamination procedures by using an ultraviolet fluorescent aerosol and an image analysis protocol. This method involves imaging a mannequin while both unclothed and clothed prior to exposure to the fluorescent aerosol. After exposure, it was imaged again, disrobed, and decontaminated following an unconscious patient wet decontamination method. This work describes in detail the materials and methods used to develop the final methodology. Two clothing types (black cotton and Tyvek) were used to simulate civilian and first responder casualties. Image analysis was used to measure the extent of contamination on the mannequin at each stage of the procedure. These measurements were then compared to determine decontamination efficacy for each step (disrobing, wet decontamination, and total removal). The exposure protocol was shown to provide repeatable deposition of aerosol onto the mannequin. Decontamination was also shown to be repeatable, with no trends toward efficacy changing over time.

Developing a HazMat Decontamination Training Program for a Hospital in Singapore for National Emergency Preparedness.

Introduction:Sengkang General Hospital (SKH) is a part of the national network of hospitals to respond to civil emergencies including hazardous material (Hazmat) incidents in Singapore. The HDS course aims to train our staff on basic knowledge of the effects of hazardous material exposure and the operations of the HDS.Method:HDS course was planned in three phases:Phase one aimed to train all DEM personnel so as to have a critical mass of personnel equipped to operate the HDS upon immediate notice. Phase two involves hospital staff from non-emergency departments. Material and simulations for phase two was simplified to focus on the skills and prompt decontamination. Phase three aims to test out capabilities of HDS and review processes through department simulations and hospital.Results:155 staff have completed HDS training since 2019, amongst them, 23 as instructors. 67.7% found the demonstrations, skills and practices exceeded expectations. 69% were able to apply skills taught during simulation and overall, 71.2% were able to understand topics covered in the modules.SKH was at the forefront of battling Covid-19 and resources were tight. We have resumed trainings to complete Phase two. We aim to train more than 35% of manpower in non-emergency departments to achieve higher recall.Conclusion:Training for national emergencies is challenging. HDS is located right outside the emergency department and has advantages of allowing smooth traffic to decontaminate patients and prompt treatment. However, training can get disrupted with incoming ambulances, patient influx and lack of resources.SKH aims to be well prepared in handling pandemics and still maintain its capabilities in assisting in national emergencies. There are plans for hospital simulation exercises for all relevant stakeholders and internal and external reviews are required to improve decontamination systems and processes. It is important to continue training hospital personnel to support HDS during crises.

Improving Hazardous Material Incident Preparedness for Emergency Medicine Physician Trainees: A Quality Improvement Project

Introduction:Hazardous materials (HazMat) training is not a requirement for accreditation of US Emergency Medicine (EM) residencies, nor for EM board certification by the American Board of Emergency Medicine (ABEM). However, the US Occupational Safety and Health Administration (OSHA) requires hospitals train all personnel expected to deal with contaminated patients. This QI project aimed to develop an EM physician-specific HazMat course and evaluate the physician comfort level with HazMat personal protective equipment (PPE) donning and doffing, triage, procedural skills, and decontamination.Method:A four-hour “HazMat for Docs” course was designed at a large urban academic trauma center and offered to second-year EM residents. Additionally, we performed a quantitative survey of a cohort of 72 current and recently graduated EM residents (classes 2019-2024), some of whom had taken the course in person. Our primary outcome was to measure improvement in comfort level with essential HazMat tasks after completing the course. Our secondary outcome was to evaluate the current or recently graduated EM physician's overall comfort levels with managing a HazMat incident, as well as HazMat skills and knowledge retention.Results:A total of 53 responses (73.6%) were obtained. 45.3% of the respondents were male and 54.7% female. 37.8% of the respondents were recent EM graduates, with 20.8% PGY-4, 13.2% PGY-3, 15.1% PGY-2, 13.2% PGY-1. 16/53 (30.2%) had prior EMS experience. EM Physicians were most comfortable with donning and doffing PPE (4.92 on a 7-point scale) and least comfortable with decontamination procedures (2.98/7). After completing the HazMat course, EM physicians increased their comfort level with HazMat decontamination procedures by 8.6% and with organizing a multi-disciplinary ED HazMat response by 10.5%.Conclusion:EM Physician comfort levels with HazMat procedures are low. Increased training aimed at improving physician knowledge, preparedness, and comfort level for such events is necessary and can be accomplished through a short course.

Chlorine gas hazardous material incident in Karachi, Pakistan: A clinical experience from an emergency department of a tertiary care hospital.

To determine the clinical characteristics, management and outcomes of patients presenting with chlorine gas exposure in an emergency setting. The single-centre, retrospective cross-sectional study was conducted at the emergency department of Aga Khan University Hospital, Karachi, and comprised data of all patients who presented on March 06, 2020, due to acute chlorine gas exposure after a specific industrial accident. Demographic and clinical data was recorded from the medical record files. The association between risk factors and complications was explored. Data was analysed using SPSS 20. There were 51 male patients with a mean age of 33.10±8.37 years. The most commonly affected organ system was respiratory 49(96%), with 43(84.3) having shortness of breath. Eye irritation was found in 44(86.3%) cases and the central nervous system was involved in 14(27.4%). Most of the patients were admitted from the emergency department 36(70%). Regarding treatment, 1(1.9%) patient each required invasive and non-invasive mechanical ventilation. Complications included toxic pneumonitis 3(5.9%) and pneumomediastinum 1(1.7%). No correlation was found between smoking and complications (p>0.05). Most patients showed complete resolution of symptoms after receiving supportive treatment, while complications were rare and there was no mortality.

Exploring pre-hospital healthcare workers' readiness for chemical, biological, radiological, and nuclear threats in the State of Qatar: A cross-sectional study.

BackgroundHazardous Material—Chemical, Biological, Radiological, and Nuclear (HazMat‐CBRN) incidents, though infrequent, are environmentally precarious and perilous to living beings. They can be deliberate or accidental or follow the re‐emergence of highly contagious diseases. Successful management of such incidents in pre‐hospital settings requires having well‐trained and prepared healthcare workers.AimsThis study aimed to explore the reliability and validity of a satisfaction survey, answered by Specialized Emergency Management (SEM) personnel from a national Middle Eastern ambulance service, with a “Hazardous Material Incident Management” course offered to them as a continuing professional development activity and seek their opinion regarding Hamad Medical Corporation Ambulance Service personnel needs for other HazMat‐CBRN related training topics.MethodIn the cross‐sectional study, we conducted an online satisfaction survey for this group of course participants to obtain their feedback as subject matter experts. Aiken's content validity coefficient (CVC) was calculated to assess the content validity. Cronbach's α coefficient was determined to explore the survey's reliability. IBM®‐SPSS® version 26 was utilized to explore the data.ResultsThe SEM satisfaction survey demonstrated important satisfaction with the implemented training with its robust reliability and content validity (Cronbach's α = 0.922 and CVC = 0.952). The participants also recommended additional related topics.ConclusionSustaining and reinforcing the HazMat‐CBRN Incident Management course was strongly recommended, considering the increase of HazMat‐CBRN threats worldwide.

Management of Toxicological Emergencies in the School Setting: An Overview for School Nurses Part 3.

School nurses may encounter a variety of poisoning and overdose scenarios in the school setting. Younger students are more likely to experience unintentional exposures that are usually lower in toxicity, with the risk for harm increasing with age for reasons including substance abuse, self-harm, and exposure to more toxic ingestants. Poison Control Centers are uniquely qualified to assist public and health professionals, including school nurses, with poisoning and overdose incidents and are available 24 hours per day. This article is Part 3 of a series of three articles and focuses on poisonings related to environmental hazards that may be found in the school setting. Information includes expected clinical effects, potential for serious injury, and a reasonable approach to manage exposures for the following substances of potential harm: disinfectants and cleaners, lab accidents and other hazardous material incidents, poisonous mushrooms, and plants differentiating between poisonous, minimally toxic, and nontoxic plants.

Development to Emergency Evacuation Decision Making in Hazardous Materials Incidents Using Machine Learning

Chemical accidents are the biggest factor that hinders the development of the chemical industry. Issuing an emergency evacuation order is one of effective ways to reduce human casualties that may occur due to chemical accidents. The present study proposes a machine learning-based decision making model for faster and more accurate decision making for the issuance of an emergency evacuation order in the event of a chemical accident. To implement the decision making model, supervised learning by the 1-Dimension Convolutional Neural Network based model was carried out using the HSEES and NTSIP data of ATSDR in the United States. An action—victim matrix was devised to determine the validity of emergency evacuation orders and the decision making model was made to learn the matrix so that the decision making model could recommend whether to execute the emergency evacuation orders or not. To make the decision making model learn the chemical accident situations, the embedding technique used in text mining was applied, and weighted learning was carried out considering the fact that learning data are asymmetric. The AUROC value for the results of the decision making by the model is 0.82, which is at a reliable level. Establishing such an emergency response decision making model using the method proposed in the present study in the mitigation stage will help the process. Among the chemical accident emergency management stages, constructing a database for the model, and using the model as a tool for quick decision making for an emergency evacuation order, is also thought to be helpful in the establishment and implementation of emergency response plans for chemical accidents.

Disasters on campus: A cross-sectional survey of college EMS systems' preparedness to respond to mass casualty incidents.

The objective of this study was to assess the training and readiness levels of Collegiate Emergency Medical Service (EMS) providers to respond to mass casualty incidents (MCIs). An anonymous cross-sectional survey of Collegiate EMS providers was performed. Participants were US-based EMS providers affiliated with the National Collegiate Emergency Medical Services Foundation. The main outcome measures were levels of EMS experience and MCI training, subjective readiness levels for responding to various MCI scenarios, and analyzing the effect of the COVID-19 pandemic on MCI response capabilities. Respondents had a median age of 21 years (interquartile range IQR 20, 22), with 86 percent (n = 96/112) being trained to the Emergency Medical Technician-Basic level. Providers reported participating in an average of 1.6 MCI trainings over the last four years (IQR, 1.0, 2.2). Subjective MCI response readiness levels were highest with active assailant attacks followed by large event evacuations, natural disasters, hazardous material (HAZMAT) incidents, targeted automobile ramming attacks, explosions, and finally bioweapons release. Disparate to this, only 18 percent of participants reported training in the fundamentals of tactical and disaster medicine. With respect to the effect of the COVID-19 pandemic on MCI readiness, 27 percent of respondents reported being less prepared, and there was a statistically significant decrease in subjective readiness to respond to HAZMAT incidents. Given low rates of MCI training but high rates of self-assessed MCI preparedness, respondents may overestimate their readiness to adequately respond to the complexity of a real-world MCI. More objective assessment measures are needed to evaluate provider preparedness.

Availability and use of medications by prehospital providers trained to manage medical complications of patients in hazardous materials incidents.

Little is known about prehospital availability and use of medications to treat patients from hazardous materials (hazmat) medical emergencies. The aim of this study was to identify the availability and frequency of use of medications for patients in hazmat incidents by paramedics with advanced training to care for these patients. A prospectively validated survey was distributed to United States paramedics with advanced training in the medical management of patients from hazmat incidents who successfully completed a 16-hour Advanced Hazmat Life Support (AHLS) Provider Course from 1999 to 2017. The survey questioned hazmat medication availability, storage, and frequency of use. Hazmat medications were considered to have been used if administered anytime within the past 5 years. For analyses, medications were grouped into those with hazmat indications only and those with multiple indications. The survey email was opened by 911 course participants and 784 of these completed the survey (86.1 percent). Of these 784 respondents, 279 (35.6 percent) reported carrying dedicated hazmat medication kits, ie, tox-boxes, and 505 (64.4 percent) did not carry tox-boxes. For those medications specifically for hazmat use, hydroxocobalamin was most commonly available, either within or not within a dedicated tox-box. Of the 784 respondents, 313 (39.9 percent) reported carrying hydroxocobalamin and 69 (8.8 percent) reported administering it within the past 5 years. For medications with multiple indications, availability and use varied: for example, of the 784 respondents, albuterol was available to 699 (89.2 percent) and used by 572 (73.0 percent), while calcium gluconate was available to 247 (31.5 percent) and used by 80 (10.2 percent) within the last 5 years. Paramedics with advanced training in the medical management of patients in hazmat incidents reported limited availability and use of medications to treat patients in hazmat incidents.

Development of a Novel Framework for Hazardous Materials Placard Recognition System to Conduct Commodity Flow Studies Using Artificial Intelligence AlexNet Convolutional Neural Network

Conducting hazardous materials (HAZMAT) commodity flow studies (CFS) is crucial for emergency management agencies. Identifying the types and amounts of hazardous materials being transported through a specified geographic area will ensure timely response if a HAZMAT incident takes place. CFS are usually conducted using manual data collection methods, which may expose the personnel to some risks by them being subjected to road traffic and different weather conditions for several hours. On other hand, the quality and accuracy of the collected HAZMAT data are affected by the skill and alertness of the data collectors. This study introduces a framework to collect HAZMAT transportation data exploiting advanced image processing and machine learning techniques on video feed. A promising convolutional neural network (CNN), named AlexNet was used to develop and test the automatic HAZMAT placard recognition framework. A solar-powered mobile video recording system was developed using high-resolution infra-red (IR) cameras, connected to a network video recorder (NVR) mounted on a mobile trailer. The developed system was used as the continuous data collection system. Manual data collection was also conducted at the same locations to calibrate and validate the newly developed system. The results showed that the proposed framework could achieve an accuracy of 95% in identifying HAZMAT placard information. The developed system showed significant benefits in reducing the cost of conducting HAZMAT CFS, as well as eliminating the associated risks that data collection personnel could face.

Equitable routing of rail hazardous materials shipments using CVaR methodology

The low probability – high consequence nature of hazardous materials (hazmat) incidents dictate a risk-averse route planning approach. However, preparing routing plans for multiple hazmat shipments between various origin–destination pairs also raises the question of risk-equity, and not just minimization of hazmat risk. Hence, the objective is to plan an equitable routing plan for different rail hazmat shipments while not only ensuring the safety of citizens but also precluding certain population zones from being subjected to intolerable levels of hazmat risk. To this end, we propose an analytical framework that makes use of a conditional value-at-risk (CVaR) measure of risk to generate minimum risk shipment routes while promoting risk-equity in both the arcs and the yards of the railroad network. While the commercial solver, CPLEX, lacks the ability to generate integer solutions for even small problem instances, a Lagrangian relaxation method aimed at being maximized using the Subgradient optimization algorithm is applied to provide a lower bound. The proposed framework is finally used to study several problem instances using the realistic infrastructure of a railroad operator, and to conclude that risk-equity can be achieved by re-routing, and that the design of train services along with the trade-off between yard-risk and arc-risk determine the number of re-routing and the optimal value of CVaR.

Public Perceptions of the "Remove, Remove, Remove" Information Campaign Before and During a Hazardous Materials Incident: A Survey.

In the event of an incident involving the release of hazardous material (eg, chemical, biological, radiological, or nuclear agents), key actions can be taken to reduce harm and protect the people involved. The quicker actions can be taken, the less harm will occur. Guidance is, therefore, needed to help nonspecialist members of the public to act rapidly before emergency responders arrive. The "Remove, Remove, Remove" campaign includes critical information for anyone who is at or near the immediate scene of a hazardous material release. Using a representative sample of 1,000 members of the UK population, this study examined the impact of the information campaign on knowledge and perceptions both before and during the immediate response to an incident. Findings showed that perceptions of the information were positive, with respondents stating that the information was useful and that the recommended actions would be effective. Respondents also stated they would be willing and able to perform the actions during a real incident. Additionally, the respondents' knowledge and confidence in taking protective actions increased significantly after receiving the campaign information, and they overwhelmingly agreed that they would want to receive this information if it were available before an incident. The findings of the survey support the use of the "Remove, Remove, Remove" information before and during hazardous materials incidents.

Safety and Efficacy of CarbonCool Half-Body Vest for HAZMAT Decontamination Crews Wearing Personal Protective Equipment: A Pilot Study.

Personal protective equipment (PPE) are essential for medical personnel responding to hazardous materials (HAZMAT) incidents. However, their impermeable design causes increased physiological strain and reduced thermoregulation, limiting work times and causing heat-related illnesses (HRI). Use of wearable cooling devices slow heat accumulation and have been shown to reduce thermal and cardiovascular strain in such situations. This was a prospective clinical evaluation to determine the tolerability and effectiveness of the CarbonCool cooling system - a half-body cooling vest - in participants undergoing a HAZMAT decontamination recertification. Physiological measurements (heart rate [HR], weight, temperature, and blood pressure) and participant feedback were obtained. The main outcome of interest was participants' tolerability of the cooling vest. A total of 23 healthy participants were recruited, with 10 randomized to the intervention group and 13 in the control group. Mean age in the control and intervention group was 35.5 years old (SD = 7.8) and 30.0 years old (SD = 6.2), respectively. Qualitative feedback obtained from participants regarding safety, mobility, and cooling efficacy was largely positive. Difference of before-after temperature and HR was 0.3°C (SD = 0.8) and 11.5bpm (SD = 13.6) in the control group compared to 0.0°C (SD = 0.5) and 0.0bpm (SD = 6.4) for the intervention group. This clinical evaluation showed that the CarbonCool cooling vest is safe and tolerable in participants wearing PPE. Further trials with sample size powered to detect physiological outcomes are needed to assess the effect of the cooling vest on a subject's endurance to heat stress.

Analysis of Thermal Runaway Incidents Involving Lithium Batteries in U.S. Commercial Aviation

Thermal runaway incidents involving lithium batteries as cargo, in luggage, or as personal property in the cabin have been associated with fatalities, the destruction of cargo, and even the loss of entire aircraft. This research represents the first examination of the incidence of lithium battery thermal runaway incidents involving a variety of rechargeable lithium-ion and lithium metal batteries on commercial flights in the U.S.A. The objective is to examine the occurrence of these thermal runaway incidents and the circumstances surrounding them from the best available data source, the Pipeline and Hazardous Materials Safety Administration (PHMSA) hazardous material incident database. Using descriptive statistics, the frequency of incidents and the circumstances surrounding these incidents, including incident characteristics, device type, preceding event, activity of device, and location of incident between 1996 and July 2019, are examined. There were records of 274 thermal runaway incidents in U.S. commercial air transportation during the approximately 23-year period., with 76% of these incidents reported since 2015. Fire was the most commonly reported characteristic and loose lithium batteries not otherwise specified were the most common device involved in these thermal runaways. Missing information on the circumstances surrounding incidents among was a common condition, and “Not Specified” represented the largest categorization of preceding events, activity of device and the second largest category of location. The focus of this paper is aviation, but it is expected that some of the insights and lessons learned from incidents in aviation can be extended to other modes of transportation as well.

Designing an integrated reliable model for stochastic lot-sizing and scheduling problem in hazardous materials supply chain under disruption and demand uncertainty

This research addresses the integrated lot-sizing and scheduling problem with complex setup structure in which the required raw materials are hazardous and the inherent risk of hazardous materials (HAZMATs) in case of incidents leads to disruptions and dangerous consequences for the environment and human beings. This paper proposes a reliable model based on mixed-integer programming (MIP) in which the purchasing lot-sizing with all-unit discount and multiple transportation modes, production lot-sizing and scheduling are achieved simultaneously while these decisions are made independently in traditional environments. First, this research examines the maximizing profit with demand choice flexibility in a trade-off with minimizing risk of HAZMAT incidents. Then, the stochastic model with uncertain demand is extended applying the Chance-Constrained Programming (CCP) approach and the results are compared using various datasets. Examinations denote that examples of reasonable sizes in different conditions can be solved in a few seconds. Results show that the deterministic model with demand choice flexibility has a better computational performance than the stochastic model with stochastic demand, but the quality of the stochastic model’s solutions is higher than the other one over the various utilization levels of production lines. Based on the results, with increasing the level of utilization, the total profit decreases, and the total risk increases. Furthermore, the results also prove the impact of discount structure on production and purchasing quantities, revenues, costs, and risks.

Comparing Training Techniques in Personal Protective Equipment Use.

Physicians' management of hazardous material (HAZMAT) incidents requires personal protective equipment (PPE) utilization to ensure the safety of victims, facilities, and providers; therefore, providing effective and accessible training in its use is crucial. While an emphasis has been placed on the importance of PPE, there is debate about the most effective training methods. Circumstances may not allow for a traditional in-person demonstration; an accessible video training may provide a useful alternative. Video training of Emergency Medicine (EM) residents in the donning and doffing of Level C PPE is more effective than in-person training. Video training of EM residents in the donning and doffing of Level C PPE is equally effective compared with in-person training. A randomized, controlled pilot trial was performed with 20 EM residents as part of their annual Emergency Preparedness training. Residents were divided into four groups, with Group 1 and Group 2 viewing a demonstration video developed by the Emergency Preparedness Team (EPT) and Group 3 and Group 4 receiving the standard in-person demonstration training by an EPT member. The groups then separately performed a donning and doffing simulation while blinded evaluators assessed critical tasks utilizing a prepared evaluation tool. At the drill's conclusion, all participants also completed a self-evaluation survey about their subjective interpretations of their respective trainings. Both video and in-person training modalities showed significant overall improvement in participants' confidence in doffing and donning PPE equipment (P <.05). However, no statistically significant difference was found in the number of failed critical tasks in donning or doffing between the training modalities (P >.05). Based on these results, the null hypothesis cannot be rejected. However, these results were limited by the small sample size and the study was not sufficiently powered to show a difference between training modalities. In this pilot study, video and in-person training were equally effective in training for donning and doffing Level C PPE, with similar error rates in both modalities. Further research into this subject with an appropriately powered study is warranted to determine whether this equivalence persists using a larger sample size.

Risk communication infrastructure and community resilience: does involvement in planning build cross-sector planning and response networks?

ABSTRACTThe community resilience needed for effective disaster response and recovery depends in part on robust cross-sector, interorganizational networks, but differences among networked stakeholders can make building community resilience difficult. Local emergency planning committees (LEPCs) may help by acting as risk communication infrastructure. LEPCs help conduct emergency chemical hazards planning and support the public's right-to-know about those hazards. Focusing on an LEPC situated in a major U.S. petrochemical corridor, this study surveyed LEPC stakeholders (N = 171) to investigate their perceptions of a hypothetical hazardous materials (HazMat) incident and their planning and response networks, comparing differences among agency and non-agency stakeholders. Respondents reported being part of robust planning and response networks, indicative of capacity for community resilience. Stakeholders' involvement in planning efforts was associated with their perceptions of the HazMat incident and their networks. This study provides evidence for the efficacy and limits of the LEPC as risk communication infrastructure.

Understanding skin absorption of common aldehyde vapours from exposure during hazardous material incidents.

The toxic release of aldehyde vapours during a hazardous material (HAZMAT) incident primarily results in respiratory concerns for the unprotected public. However, skin absorption may be an important concurrent exposure route that is poorly understood for this scenario. This study provides experimental data on the skin absorption properties of common aldehydes used in industry, including acetaldehyde, acrolein, benzaldehyde and formaldehyde, in gaseous or vapour form using an adapted in vitro technique. Two of the four tested aldehydes were found to penetrate the skin in appreciable amounts following 30-min exposure at HAZMAT relevant atmospheric concentrations: acetaldehyde (5.29 ± 3.24 µg/cm2) and formaldehyde (3.45 ± 2.58 µg/cm2). Whereas only low levels of acrolein (0.480 ± 0.417 µg/cm2) and benzaldehyde (1.46 ± 0.393 µg/cm2) skin penetration was noted. The aldehydes demonstrated differing levels of interaction with fabric. Formaldehyde and acetaldehyde adsorbed strongly to denim, whereas benzaldehyde and acrolein displayed no sink properties. However, denim was shown to be an initial protective barrier and reduced penetration outcomes for all aldehydes. This study provides important information to assist first responders and confirms the relevance of using physicochemical properties (e.g. solubility, molecular weight, partition coefficient) to predict skin permeation potential in the absence of empirical data during HAZMAT incidents involving different types of aldehydes.

Skin permeation of oxides of nitrogen and sulfur from short-term exposure scenarios relevant to hazardous material incidents

Permeation of oxides of nitrogen and sulfur gases through skin and the consequences of dermal exposure are still poorly understood. We measured the penetration profile of three common industrial gases through skin, for short-term exposures relevant to HAZMAT scenarios. Time variations of gas concentration, clothing effects, temperature and humidity on epidermal absorption and penetration were assessed. Fabric off-gassing profiles were also investigated. The results show oxides of nitrogen (NO and NO2) at airborne concentrations up to lethal inhalation levels (e.g. 3000 ppm) have little skin penetration ability. Skin absorption and reservoir effects were noted. Skin exposed to SO2 (3000 ppm/30 min) shows negligible skin absorption or penetration. Fabric on skin marginally increased SO2 absorption and subsequent ventilation did not reduce the absorbed fraction. Increased temperature and humidity had limited additional effect on skin penetration. Importantly, clothing demonstrated sink properties, especially for SO2. Short-term skin exposure relevant to accidents will not significantly contribute to body burden. The greatest concern will likely be off-gassing of chemical-laden fabric for asthma suffers. The risk-based management approach is to avoid potential secondary inhalation from fabric off-gassing by removal of outer layer of bulky clothing. Decontamination and moving into an area of enhanced ventilation may also be advised.

Conditional value-at-risk (CVaR) methodology to optimal train configuration and routing of rail hazmat shipments

Hazardous materials (hazmat) incidents are rare though the consequences could be catastrophic. The low probability–high consequence nature of such events mandate that a risk-averse plan be implemented for routing hazmat shipments. We propose a conditional value-at-risk (CVaR) methodology for routing rail hazmat shipments, using the best train configuration, over a given railroad network using the pre-defined train services such that the transport risk as measured by CVaR is minimized. Freight train derailment records were analyzed to model the behavior of railroad accidents, and to estimate conditional probabilities. The proposed methodology was used to study several problem instances generated using the realistic network of a railroad operator, and to demonstrate that the proposed methodology is superior to other measures for risk-averse routing of hazmat shipments and versatile enough to yield routes based on risk preferences of the decision makers.