Fire Scene Research Articles

Evaluating the performance of surfactant and charcoal-based cleaning products to effectively remove PAHs from firefighter gear

Firefighters regularly respond to fire scenes where a mixture of chemicals including volatile, semi-volatile, and nonvolatile compounds are present in smoke and soot. Polycyclic aromatic hydrocarbons (PAHs) are common contaminants at fire scenes that may be deposited on the gear and the individual firefighter. Laundering is a common approach for the decontamination of contaminated gear. Surfactants are widely used by firefighters during laundering to remove PAHs as they are generally non-toxic and biodegradable. The removal of PAHs depends on the surfactant types, chemistries, and concentrations. This study evaluated the effect of surfactant concentrations to remove persistent contaminants like PAHs from turnout gear. The cleaning performance of different types of surfactants was also evaluated. Outer shell fabrics were contaminated with a standard mixture of 16 PAH compounds, and two commercial detergents were used at different concentrations. Additionally, the cleaning efficacy of eight commercially available regular and charcoal-based cleaning products was also determined against PAHs at a single surfactant concentration. For the decontamination method, a bench-scale washing procedure simulating the National Fire Protection Assocation 1851 laundering process was used. The removal efficacy of high molecular weight (HMW) PAHs were found to be lower compared to the low molecular weight PAHs for any type or any concentration of detergent. Our research also showed that the recommended surfactant concentrations provided by detergent manufacturers can be ineffective at removing the HMW PAHs from heavily contaminated fabric. With 1 mL of detergent in a 100-mL bath, which is multiple times higher than recommended amount, only 40% of HMW PAHs were removed. The cleaning efficacy can be increased to above 90% by using higher concentrations of detergents. This research shows that firefighters may need to use a higher concentration of detergent than the recommended amount to effectively remove PAHs from the gear. All the regular and charcoal-based detergents were able to remove PAHs effectively from contaminated fabrics when a higher concentration of detergent was used.

136 Occupational Exposure to Asbestos

Abstract Asbestos containing materials (ACMs) are still found in many buildings even though the use of asbestos in building materials has been prohibited in Norway since 1985. Employees that may be at risk of exposure to airborne fibers are workers within the construction industry. However, firefighters and workers investigating fires may also encounter asbestos fibers in their work. The aim of this study was to investigate the airborne fiber concentration during abatement of various ACMs. A comparison of counting results from scanning electron microscope (SEM) and phase-contrast microscope (PCM) were performed for these measurements. A separate part of the study focused on thermal transformation of fibers during fires. Parallel personal air samples were collected during asbestos abatement of different building materials and analyzed with SEM and PCM, respectively. Material samples from abatement sites and from fire scenes were investigated in SEM. The highest fiber concentrations were measured during interior wall removal (1.5-4.5 fibers/cm3 (f/cm3)). Thin fibers (<0.2 µm in width) constituted up to 50% of the total fiber concentration for some ACMs. Asbestos fibers observed in ACMs after fire may show a thermal transformation, however, in many cases the fibers are unchanged. For ACMs investigated in this study, there seem to be a good correlation between samples analyzed by SEM and PCM if the only dominant fiber type present is asbestos fibers. Thin fibers may constitute a large fraction of the total fiber concentration released and counting these fibers are therefore important for an adequate risk and exposure assessments.

Camille—Virtual Production Case Studies Considerations for Working With LED Walls for Independent Filmmakers

Camille is a short research and development (R&D) film created with the intent to share learnings with other filmmakers. By design, the film references Terrence Malick’s “Days of Heaven” and paintings by Andrew Wyeth. The director was interested in exploring ways to create naturalistic images and verité camera work using light-emitting diode (LED) volumes to prove that it is possible to capture supporting visual effects in-camera that add value to a project (even on an independent budget). Key reasons for using LED wall technology were: 1) no time or budget to travel crew to a real location; 2) no budget for permits, fire crew, and safety to execute a fire scene; and 3) to create extreme weather systems that could be art directed and scheduled around actors’ availability. This article outlines key case studies that demonstrate how the creative team incorporated realtime workflows, a new department and display technology into the filmmaking process, revealing both successes and pivots in the process.

Fire modelling framework for investigating tall building fire: A case study of the Plasco Building

Fire can damage structures severely and even cause the building collapse. Structural and fire engineers must carry out a comprehensive forensic investigation of major structural failures in the same rigorous and meticulous manner the airline industry investigates air crashes. The forensic assessment should identify the cause, fire spread scenario, fire behaviour patterns from its growth to decay, de-compartmentation, the performance of fire protection systems, and firefighting management. Using the available tools and data, the current paper proposes a methodology to reconstruct the fire for the forensic assessment of tall buildings. This is done by first organising observed data into a coherent timeline and presenting the actual fire spread obtained from the visual evidence. The total fire spread within the building is estimated based on fire dynamics principles and observed fire scenes that can be verified with a calibrated CFD model. The collapse of the Plasco Building is assessed by employing the proposed framework. The rise in construction of the tall buildings increases the risk of the occupants’ safety from the fire induced structural failure or collapse. The framework presented in this paper can guide engineers to improve the building resilience designs and reduce the fire accidents related risks.

Influence of Firefighting Intervention on Fire Spread Characteristics in Ship Engine Room

The purpose of this paper is to investigate and evaluate the ship engine room fire spreading characteristics based on the effect of firefighting interventions. The large eddy simulation (LES) and theoretical models are employed to simulate a fire scene in the engine room. The fire spreading characteristics and the mechanism of the use of a fine water mist are obtained by varying the ventilation conditions and parameters of the water sprinkler. The results show that the reason why a pool fire can be more easily extinguished as the spray speed increases is because the water mist with a higher spray speed has a larger spray area. Meanwhile, the temperature in the engine room would drop more rapidly with the increasing spray area due to the higher evaporation rate. Furthermore, the arrangement of the ventilation conditions had an obvious effect on the fire spreading characteristics, as the depletion of the combustion medium affects the combustion situation.

Technical Appraisal Method of Circuit Breaker Material Evidence in Fire

Circuit breaker is an important electrical control on and off in the electrical line, which refers to the switch device that can close, load and break the current under normal loop conditions, and can close, load and break the current under abnormal loop conditions in the specified time. Circuit breakers are divided into high voltage circuit breakers and low voltage circuit breakers according to their range of use. Low voltage circuit breakers are common to molded case circuit breakers. Play a protective role in the safety of electrical lines and electrical appliances. When a fire occurs, the action of the circuit breaker plays a vital role in the occurrence and development of the fire. Therefore, the circuit breaker is an important material evidence in the investigation of the cause of electrical fire, and it will play an irreplaceable role in the investigation of the cause. In particular, the plastic case circuit breaker is the most commonly used type in life. The plastic case circuit breaker extracted from the fire scene, according to the appearance characteristics or internal structure characteristics, identify its working state in a period of time before and after the fire, and can judge the relationship between the physical evidence and the cause of fire.

Application of Secondary Short Circuit Fuse Mark in Fire Cause Investigation

Metallographic analysis technology holds an important place in the fire material evidence identification, especially in the cause of the electrical fire scene investigation process, indispensable metallographic method, through the analysis of the microstructure of metal material evidence, can judge the melting properties of material evidence, namely the formation of physical evidence logic relationship with the occurrence of fire in time, Thus provide the most direct evidence for the fire scene investigation. There are many kinds of fusion marks extracted from fire scene, common ones are fire fusion mark, primary short circuit fusion mark, secondary short circuit fusion mark, etc. [1]. The relationship between the formation of secondary short circuit fuse mark and the electrical circuit is complicated, and its characteristics are different from those of fire fuse mark and primary short circuit fuse mark.

Intelligent fire information system based on 3D GIS

BackgroundThis work aims to build a comprehensive and effective fire emergency management system based on the Internet of Things (IoT) and achieve an actual intelligent fire rescue. A smart fire protection information system was designed based on the IoT. A detailed analysis was conducted on the problem of rescue vehicle scheduling and the evacuation of trapped persons in the process of fire rescue. MethodsThe intelligent fire visualization platform based on the three-dimensional (3D) Geographic Information Science (GIS) covers project overview, equipment status, equipment classification, equipment alarm information, alarm classification, alarm statistics, equipment account information, and other modules. The live video accessed through the visual interface can clearly identify the stage of the fire, which facilitates the arrangement of rescue equipment and personnel. The vehicle scheduling model in the system primarily used two objective functions to solve the Pareto Non-Dominated Solution Set Optimization: emergency rescue time and the number of vehicles. In addition, an evacuation path optimization method based on the Improved Ant Colony (IAC) algorithm was designed to realize the dynamic optimization of building fire evacuation paths. ResultsThe experimental results indicate that all the values of detection signals were significantly larger in the smoldering fire scene at t=17s than the initial value. In addition, the probability of smoldering fire and the probability of open fire were relatively large according to the probability function of the corresponding fire situation, demonstrating that this model could detect fire. ConclusionsThe IAC algorithm reported here avoided the passages near the fire and spreading areas as much as possible and took the safety of the trapped persons as the premise when planning the evacuation route. Therefore, the IoT-based fire information system has important value for ensuring fire safety and carrying out emergency rescue and is worthy of popularization and application.

Scheme design of the optimal background clutter suppression for impulse radio ultrawide band radar in complex fire environment: a simulation and experimental study

Impulse radio ultrawide band (IR-UWB) radar possesses several advantages, such as heat flow insensitivity, high resolution, great penetration, good mobility, and lightweight, making it a promising technology for detecting and rescuing individuals trapped in fire scenarios. However, reliable detection and extraction of vital signs of trapped people in the presence of complex fire environment, such as water droplets, smoke, wall occlusions, and reflections, require an optimal background clutter suppression scheme designed specifically for fire scenarios. This study comprehensively evaluates 20 background noise suppression schemes using an exhaustive approach that involves constructing radar echo simulation signals and designing an evaluation method for algorithms. The practical applicability of the improved design solutions was evaluated by conducting small-scale fire experiments in an acrylic chamber. The results indicate that the designed scheme is effective in overcoming the background interference from the combustion environment and is capable of supporting subsequent trajectory identification and vital sign extraction in the fire scene environment.

Firefighters' exposure to per-and polyfluoroalkyl substances (PFAS) as an occupational hazard: A review.

The term "firefighter" and "cancer" have become so intertwined in the past decade that they are now nearly inseparable. Occupational exposure of firefighters to carcinogenic chemicals may increase their risk of developing different types of cancer. PFAS are one of the major classes of carcinogenic chemicals that firefighters are exposed to as occupational hazard. Elevated levels of PFAS have been observed in firefighters' blood serum in recent studies. Possible sources of occupational exposure to PFAS include turnout gear, aqueous film-forming foam, and air and dust at both the fire scene and fire station. Preliminary discussion on PFAS includes definition, classification, and chemical structure. The review is then followed by identifying the sources of PFAS that firefighters may encounter as an occupational hazard. The structural properties of the PFAS used in identified sources, their degradation, and exposure pathways are reviewed. The elevated level of PFAS in the blood serum and how this might associate with an increased risk of cancer is discussed. Our review shows a significant amount of PFAS on turnout gear and their migration to untreated layers, and how turnout gear itself might be a potential source of PFAS exposure. PFAS from aqueous film-forming foams (AFFF), air, and dust of fire stations have been already established as potential exposure sources. Studies on firefighters' cancer suggest that firefighters have a higher cancer risk compared to the general population. This review suggests that increased exposure to PFAS as an occupational hazard could be a potential cancer risk for firefighters.

Smart prediction for tunnel fire state evolution based on an improved fire simulation curve through particle swarm optimization algorithm

Tunnel fires have received significant attention because they can cause large economic losses every year. To estimate the fire development and realize a prompt response to the fire disaster are thus crucial to tackle the above issue. Here, a smart prediction method for fire state evolution is developed based on an improved fire simulation curve through the particle swarm optimization algorithm. The improved fire simulation curve is established by supplementing the stable stage during the tunnel fire based on a fire curve proposed in 2002. Experimental results from a prototypical tunnel fire test indicate that the proposed method can effectively portray the behavior of a typical tunnel fire development. Moreover, it is accurate over a wide range of conditions, including different heat release rates, different measurement noises, different sampling intervals, and different prior durations. Particularly, the fluctuation range of estimation results is becoming larger with the increasing noise level. The influence of the sampling interval is mainly reflected in the calculation time. Prior duration is the most important factor of the prediction accuracy, the longer prior duration corresponds to the more precise results. 200s and 300s can be regarded as the critical duration by considering the estimation error of the whole-time domain and the preliminary stage, respectively. The proposed method has a broad application prospect, it can avoid complicated temperature spreading mechanisms, the additional workload for prior information, and the limitation of the specific fire scene.

딥러닝 기반의 열화상 카메라를 이용한 화점 추적 팬-틸트 시스템 구현

There have been frequent fatal accidents of firefighters at fire scenes. A firefighting robot can be an alternative to humans at a fire scene to reduce accidents. As a critical function of the firefighting robot, it is mandatory to autonomously detect a fire spot and shoot water. In this research, a deep learning model called YOLOv7 was employed based on thermal images to recognize the shape and temperature information of the fire. Based on the results of the test images, which were not used for learning purposes, a recognition rate of 99% was obtained. To track the recognized fire spot, a 2-DOF pan-tilt actuation system with cameras was developed. By using the developed system, a moving target can be tracked with an error of 5%, and a variable target tracking test by alternately covering two target braziers showed that it takes about 1.5 seconds to track changing targets. Through extinguishment experiments with a water spray mounted on the pan-tilt system, it was observed that the temperature of the brazier dropped from 600 degrees to 13 degrees. Based on the obtained data, the feasibility of a robotic firefighting system using image recognition was confirmed.

A multiple back propagation neural network fusion algorithm for ceiling temperature prediction in tunnel fires

This study presents a multiple back propagation neural network (BPNN) fusion algorithm to predict the ceiling temperature distribution and the maximum ceiling temperature in tunnel fires for better firefighting decision-making. The algorithm belongs to a kind of data-driven artificial intelligence methods, which is not limited to the special tunnel fire scenes. To improve the prediction precision, a strong multiple BPNN including some sub-BPNNs and an additional external iteration procedure are used in the algorithm. Large-scale pool fire experiments under different ventilation conditions were carried out to investigate the ceiling temperature character of tunnel fires and verify the algorithm. The results show that the algorithm can predict well the ceiling temperature distribution and the maximum ceiling temperature under different ventilation conditions, which has a higher prediction precision than the traditional single BPNN algorithm and some developed theoretical models.

Microstructural Examination of Molten Marks on Copper Wire for Fire Investigation

Fire investigators have attempted to study fire behaviors through microstructural examination of molten marks on copper wire. However, there have not been many studies on the metallurgical examination of real-world cases. This research examined the surface morphology and microstructure in the longitudinal section of molten marks on copper wire from various fire scenes to explain how they formed and identify the surrounding materials. The results show that the foreign elements discovered via EDS on the surface of molten marks vary depending on their environment. Molten mark microstructures differed even if they were collected from the same fire scene; a distinct microstructure implies different molten mark formations. Moreover, the presence of residual elements in the microstructure indicates the existence of surrounding materials during formation in a fire. Therefore, microstructural diversity and the presence of residual elements may guide fire investigators in explaining the formation of molten marks and the fire environment for fire investigation.

Analysis of solid combustion products to establish a theoretical model of the causes of thermal runaway of ternary lithium-ion battery overcharge and heating

It is difficult to determine whether ternary lithium-ion batteries (t-LIBs) were the “source” of the actual fire scene because of the little available direct evidence left after thermal runaway combustion of lithium-ion batteries (LIBs) and the lack of relevant analytical methods for t-LIBs after complete combustion. As a result, a large number of fires involving t-LIBs are controversially identified as the cause every year. In this paper, we conducted experiments on the two most common thermal runaway types of t-LIBs to investigate the correlation model between their combustion products and thermal runaway types. In the case of overcharge, the combustion products (black powder) of t-LIBs contain aluminum elements, which may be due to the thermal reaction of aluminum. In contrast, in the case of heating, the combustion products of t-LIBs have almost no detectable elemental aluminum. The reason may be due to the ability of the electrode material to continuously decompose and precipitate a large amount of metal oxides under the overcharge condition, which constitutes the condition for the occurrence of the aluminum thermal reaction, making the presence of Al2O3 in the combustion products. However, the lack of continuous current action under the heating condition prevents the generation of the aluminum thermal reaction.

Detection and Characterization of Gasoline based Polycyclic Aromatic Hydrocarbons on Different Materials by Gas Chromatography-Mass Spectrometry

Polycyclic aromatic hydrocarbons (PAHs) profile by gas-chromatography-mass spectrometry were recently used for the identification of sources of contamination in environmental forensic investigations. In present study, an effort is given to utilize gas chromatography-mass spectroscopy to obtain PAHs profile that could help forensic scientist in selection of evidence at the scene of fire. In forensic laboratories, the main evidence received in fire burning cases are fire debris which consists of soil, wood, paper, cloth etc. as a piece of individual evidence or mixture. In fire investigation, the type of material collected from the crime scene affects the investigation hence present study focused on which type of material is more suitable while utilizing a polycyclic aromatic hydrocarbon as a source identifier. Total of nine different materials like paper, cardboard, foam, cloth, metal, hair, soil, meat and wood were selected and these are burned with gasoline in partial burning and complete burning conditions. Debris obtained sonicated at room temperature and concentration of 18 PAHs were determined with gas chromatography-mass spectrometry. Results obtained were analyzed with the Principal Component Analysis (PCA) technique to generate a profile of PAHs. It is concluded that partially burned samples provide more information about the use of ignitable liquid to commit the crime as compared to completely burned samples. The meat, hair, metal and soil material provide more information about the presence of ignitable liquid based on the 18 PAHs concentration profile.

Аналитическая оценка радиуса действия пожарного резервуара и пожарного водоёма

PURPOSE. Draft amendments and addendums to code 8.13130.2020 “Fire protection systems. Outdoor fire-fighting water supply. Fire safety requirements”, according to which it is proposed to increase working radius of fire tanks and fire reservoirs to 400 m are analyzed. Regulatory documents regarding outdoor fire-fighting water supply for the period from 1947 to the present are examined. The authors analyzed aspects related to determining operating range of a fire tank and an artificial fire reservoir, depending on the capabilities of fire departments and fire-fighting equipment. Such aspects include level of equipping main fire trucks and technical capabilities of pumping equipment for using water sources located at a distance of up to 400 m from the fire site, as well as the number of combat crews arriving at the fire scene. METHODS. System and structural analysis, mathematical statistics, descriptive analysis were used. FINDINGS. The authors proposed and analyzed possible schemes for using water sources located at a distance of more than 200 m from protected objects; analytical characteristics of pump-hose systems for the proposed schemes were obtained; the operating characteristics of a fire pump and pump-hose systems were constructed in the same coordinate systems. RESEARCH APPLICATION FIELD. The results can be used when making a final decision to increase the operating range of fire tanks and fire reservoirs. CONCLUSIONS. With working radius of buildings and structures with fire tanks and artificial reservoirs, the value of which will exceed 200 m, the time of emergency rescue services deployment and free fire development will increase; operational capabilities of fire department to solve related tasks will be reduced; water supply for firefighting will be provided by at least two medium or heavy class fire trucks; organizing water supply into pumping with sequential operation of fire truck pumps will be required.

Study on Smoke Propagation Characteristics for a Train Carriage Fire in a Subway Tunnel

The most serious fire scene in a subway system is that a train catching on fire has to stop in the tunnel. The objective of this paper is to discuss safety evacuation of this scenario. A subway tunnel in Beijing was selecting as research object, and adopting numerical simulation methods to analyze smoke propagation in the tunnel and train carriage. In addition, the influence of train carriage door opening on the smoke spread was studied in the double narrow space formed by the carriage and tunnel. Results show that the opening method of door would affect the smoke spreading path, and the range of high temperature area. For a fire occurred in train carriage, opening of the end door of train can effectively enhance diffusion of smoke into the tunnel. This research is not only helpful to guide the cabin crew to evacuate efficiently and orderly, but also provide guidance for the planning of subway tunnels.

A review of forest visualization and forest fire simulation technology research

A review of forest visualization and forest fire simulation technology research

Очерёдность привлечения пожарно-спасательных подразделений по повышенным рангам пожаров

PURPOSE. The order and priority of involving fire and rescue units in fires that have already been burning and in potential ones of higher ranks according to the units departure schedule of territorial fire and rescue garrison to extinguish fires and perform emergency rescue operations using as the example Moscow city are considered. METHODS. A comparative analysis of involving fire and rescue units in fires of higher ranks using geographic information systems has been carried out. The research results have been summarized and extrapolated to potential fires. FINDINGS. The results of comparing fire and rescue units involvement in fighting higher ranks potential fires and fires that have already occurred demonstrate different priority options of units dispatch. Priority options for fire and rescue units involvement are determined by the location of burning facility and possible routes to the fire scene. These conditions cannot be taken into account in the departure schedule. The study has made it possible to determine that the sequential order of fire and rescue units involvement has an impact on the total concentration time of units for certain fire ranks. An algorithm has been developed that, by geographic information systems, alternately determines the involvement of the nearest fire and rescue units to potential fires of higher ranks. RESEARCH APPLICATION FIELD. The article is of a theoretical nature and is aimed at improving the functioning of fire and rescue garrisons. In the future, the findings of the research will make it possible to improve the existing automated management systems for fire and rescue garrisons, as well as simulation systems of their functioning. CONCLUSIONS. The presented algorithm will enable the rapid concentration of fire and rescue units at a higher rank fire scene, as well as reduce possible casualties and property damage. At the same time, the algorithm will allow the management and dispatch staff of fire and rescue garrisons to minimize time necessary for making managerial decisions, ensure control over fuels and lubricants consumption and reduce the depreciation of fire appliances.