Fire Investigation Research Articles

Application of investigation techniques to identify an arson fire

Determining the cause of an arson fire is the most difficult part of fire investigation. In this study, the researcher used various clues and several pieces of fire debris collected from the actual fire site to conduct a series of experiments and analyses in sequence, starting from metallographic analysis to inductively coupled plasma optical emission spectrometry and then a thermal analysis experiment to determine the cause of a fire. It was found that when the temperature was elevated at a rate of 2 °C/min, polyurethane (PU) foam, a structural component of refrigerators, started thermal decomposition. At about 130 °C, the thermal decomposition accelerated, and eventually at 384 °C, about 4883.33 J/g of maximum heat was released. In the end, remaining debris was about 4.96%. Therefore, the combustion of PU foam is an ultrafast type of combustion reaction. The content as well as the experimental procedure of the study is useful for fire investigators in determining the cause of arson fires.

A thermoanalytical, X-ray diffraction and petrographic approach to the forensic assessment of fire affected concrete in the United Arab Emirates

For most fires, forensic investigation takes place well after building materials have cooled and knowledge of the structural damage due to heat exposure can reveal the temperature reached during an incident. Recently, there have been significant changes in the types and hence characteristics of cementitious materials used in the United Arab Emirates. Few studies focus on the application of thermo-analytical, X-ray diffraction and petrographic techniques on newly developed structures and this work aims to address this deficiency by utilising a series of parametric laboratory-based tests to assess the effects of heat on hardened concrete. Specimens were made with a design mix typically used for low-rise residential homes and storage facilities. The key constituents were: Portland cement (PC), crushed gabbro stone and dune sand with water/cement ratios of 0.4–0.5. Portland cement substitutes included ground granulated blast-furnace slag (GGBS), and silica fume (SF) at replacement percentages of up to 50% and 4%, respectively. The concrete cubes of 100-mm size were produced and standard cured to 28 days and then exposed to heat inside an electric furnace with pre-determined temperature regimes of 150°C, 300°C, 600°C and 900°C. Petrographic examination was utilised to compare the discolouration of the cooled concrete. Data derived from thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are reported in order to assess the usefulness of these techniques in fire scene investigation to differentiate between these temperature regimes. The results from the TGA indicate that the majority of the percentage weight loss for all the mixtures occurred in the range 650–700°C, which corresponds to the decarbonation of calcium carbonate, mainly from the aggregates. The endothermic DSC peak at 70–120°C relates to the loss of evaporable water. Since both of these reactions are irreversible, this information can help fire investigators estimate the temperature history of concrete after exposure to fire. On the other hand, the portlandite in the cement matrix dehydroxylates at 450–550°C but then reforms as the concrete cools. The onset temperature for the dehydroxylation of the reformed mineral is always lower than in virgin samples and its enthalpy furthermore depends strongly on the thermal history of the portlandite. Thus, this feature can be used to establish the temperature to which the material was exposed to during a fire incident.

The Research of Targeting Object in Fire Investigation

In the practice of the law we become more and more aware of the importance of this legal terminology: targeting object. During the process of proof on the case facts, facts prove, the targeting objects are usually very complicated, there are not explicit specifications on the targeting object during all kinds of legal proceedings. In the fire investigations, the targeting object is the main destination of the whole proof process, without it, the rule of relevant proof responsibility and standard will be hard to establish. In order to find out the cause of the fire, fire accident and fire loss statistics, we should collect the fire evidence objectively and carefully. And the research of targeting object in the fire investigation is the base of fire investigation. So in this paper, aiming at the fire targeting object in the fire administrative procedures, criminal fire procedures and in the accidental fire procedures, the relevant specific content will be analyzed carefully. Through the elaborate and summary of the specific content on the targeting object, we can be more clear of the evidences we should take in the fire, so as to improve the timeliness and accuracy of the fire cases.

Research on Application of Abduction to Fire Investigation

To solve the problem of fire investigation caused by lack of exacting logical reasoning, it is of significance in helping that abduction, an important logical thinking should be introduced to the field of fire investigation. This paper first analyzes the fundamental reasoning forms of abduction as well as its general situation of application. Combined with practical work experience, the mode of application of abduction to fire investigation is put forward. The author shows it in detail by analyzing a real fire case. It is north noting that some matters needing attention in application are presented in the end. This paper will be conductive to constructing the right logical reasoning model in fire investigation.

Investigation and Identification of Fire Caused by Setting off Fireworks

Investigation and identification of fire caused by setting off fireworks for fire investigator is a great challenge. Combined with fire cases, this paper analyzed the characteristics of fire caused by setting off fireworks. Fire more happened during the festivals and other important events. Building burning loses more serious external than internal, upper than lower. Many witnesses exist in the fire. Fire scene may have many fireworks residue. Then the paper proposed content of fire inspection and interrogation, inspection on the fire building outside ground, monitoring video equipment, recognition the location of fire origin and combustible in fire origin, obtain evidence of fireworks flying objects arriving fire origin and carry out fire scene experiment, interrogation about festival or other important events, fireworks and its display, children around the fire scene, meteorological condition. At last, the paper summarized identification factors of fire caused by setting off fireworks. Fireworks are setting off before the fire. Firework flying object can reach fire origin. Fire origin has combustible; combustible can be ignited by flying object of fireworks. The mode of fire and fire caused by setting off fireworks is consistent. Fire origin has the condition of fire spread. The paper will help for fire investigator to investigation and identification of fire caused by setting off fireworks.

Fire investigation on a car park

This work deals with the numerical back analysis of a fire developed in a pilotis floor on the ground level of a multi-storey residential building. Several parked cars were burned and the building was significantly damaged. The most probable cause of the fire was the ignition of a car due to arson, and since the ceiling was covered by polystyrene, the fire quickly spread laterally and transmitted the heat to the other cars. Fire investigation was devoted to ascertain whether the fire was due to fault or arson and, in case of arson, if the fire started from one or more cars. The reconstruction of the fire presented herein is based on both results of tests made on polystyrene panels of the pilotis floor, and fire dynamics sub-models. The combination of tests and fire dynamics made possible a plausible back analysis of the event.

Ultrastructural Analysis of Incinerated Teeth by Scanning Electron Microscope – A Short Study

In forensic context precise knowledge on physical and histological changes of teeth subjected to high temperatures is of great importance. Preserving fragile incinerated teeth for physical, histological and ultra structural examinations is essential in fire investigations involving the origin of fire, its cause as well as the identification of victims which relies on a thorough understanding of the structural changes in dental tissues subjected to heat. The study was conducted to evaluate the physical and ultrastructural changes seen in freshly extracted teeth when subjected to gradual heating at different temperatures using Scanning Electron Microscope (SEM). Freshly extracted teeth collected from subjects of different age groups were subjected to different temperatures using laboratory furnace and findings were correlated to the temperature. The study was conducted on 60 healthy freshly extracted teeth belonging to age group between 20-30 years. Group A comprised of control group which included teeth that were not subjected to heat whereas Group B, C and D comprised of teeth that were subjected to different temperatures i.e., 100(o)C, 300(o)C and 600(o)C respectively for a time of fifteen minutes in laboratory furnace, after which they were processed for SEM examination. Each group included 15 teeth; 5 anteriors, 5 premolars and 5 molars. Examination under SEM revealed definite ultra structural changes which were explicitly seen at particular temperatures (100(o)C, 300(o)C and 600(o)C). The samples showed cracks and charring of the tooth structure with ultra structural findings such as pebbles, granules, dots on enamel surface; and soap bubble pattern, honey comb pattern and snail track pattern on cementum surface. Because of the consistency of morphological changes and the ultra structural patterns at various temperatures, evaluation of incinerated dental remains using SEM can provide additional investigative avenues in victim identification and in the areas of forensic fire investigations.

Design and Development of Fire Gridding Platform Based on Internet of Things

This article describes the construction background about fire gridding platform, reviews the research and progress in fire Internet of Things and fire gridding. The platform includes perception / execution layer, field control layer, network layer, center platform layer and application layer, which provide a good bonding about site control and remote monitoring. This article supplies a detail design for the main functions of application and task flow of fire hazard investigation. At the same time, a digital management platform was developed.

The analysis of fire losses and characteristics of residential fires based on investigation data in Selangor, 2012-2014

This is a research in progress where authors seek to investigate the factors of residential fires. As part of the research, this paper aims to analyse the fire problems faced by the community of Malaysia. Data regarding residential fires between 2012 and 2014 was collected from fire investigation reports prepared by the Selangor Fire and Rescue Department. Descriptive analysis is conducted to summarize the data collected and describe the common phenomenon of residential fires. The distributions of the fire characteristics suggested that residential fires are commonly occurred during daytime, confined within the room of fire origin, caused by electrical failure and cooking negligence, started from kitchen, and occurred in multi-units housing. Further analysis will be conducted in order to investigate the relationships between the characteristics and residential fires.

Study on Metallographic Structure of Melted Breakpoint mark for Copper Wire Current Overloading

As a common electrical fault causing fire, current overload results in some trace evidences on the wire. However, most of relative evidences, such as insulating layer, metal core, are likely to be destroyed or disturbed by fire. The majority of wire evidences from fire are asked to test melted breakpoints marks of the wire. Thus, it is significant to clearly reveal the metallographic features of melted breakpoint mark for wire overloading for fire investigators. This paper selected two kinds, single-core and multi-cores, 1.5mm2 copper wires to make melted breakpoints with 100A current overload. Then, this paper did some research on the fire heat influence on the microstructure of melted breakpoints. Experimental results indicated that the metallographic structure of the melted breakpoint mark caused by current overload was significantly different from that of melted mark caused by fire and short circuited melted mark. As for melted breakpoint marks of copper wire overloading, the most distinctive feature of the metallographic structure was dendritic segregations existing.

Quantitative Relationship Between Concrete Neutralization Depth and Its Influence Factors

The concrete is a very common building material. It is widely used because of its good fire safety, low cost, convenient production process and no pollution to the environment. According to the pyrolysis process and mechanism of concrete, muffle furnace experiments were conducted. By studying the quantitative relationship of concrete's neutralization depth and its influence factors the paper establishes a mathmatical model of calculation neutralization depth, hoping to provide a reference for future fire investigation.

Study on the Splashing Short-circuited Beads’ Characteristics in Fire Scenes by Density Methods

In fire scene, the reasons for the formation of splashing melted beads are confirmed difficultly for investigators. The paper is studying density distribution characteristics of the splashing melted beads in fire scene. The splashing PSCMB and SSCMB are gotten from experimental lab. After meaturing density of the splashing PSCMB and SSCMB, SPSS analysis software was used for the analyzing density data of the splashing PSCMB and the splashing SSCMB. This results showed that the density value of splashing PSCMB and splashing SSCMB have a little degree of overlapping. The overlapping scope is 6.7-6.9. So within the scope, there are 3 PSCMB and there are 2 SSCMB. The ratio is respectively 10% and 6.67%. it is a good discrimination. The results could be used for helping fire investigators distinguishing the shaping reasons of splashing melted beads from fire scenes. This method can be the supplement for the existing appraisal method (ep. Metallographic analysis). And it is practical and effective for distinguishing from the splashing PSCMB and SSCMB.

Research on Burn Pattern Characteristics of Two Typical Flooring Materials Loaded by Gasoline

Gasoline, as one of the flammable liquids, is used commonly in arson. Due to its typical fluidity and permeability, particular burn patterns can be formed in fire scene. In order to provide references for fire investigators to collect trace evidences and identify fire cause accurately, the burn patterns on different flooring materials are investigated in this paper. Two new kinds of flooring materials (Rubber pad and EVA mosaic floor) were selected in the experiments to study the burn pattern characteristics by simulating the fire scene. By comparing the difference of the burning pattern with and without gasoline, rules of pattern characteristics on different material surface have been summarized. Meanwhile, fire extinguishing style was considered in this work. The results show that the burn pattern characteristics become remarkably different when the flooring materials loaded by gasoline. In addition, fire extinguishing style has a great impact on the burn patterns, such as the carbonized degree, the residual shape and the fire traces. It is believed that the results in this paper would provide important guidance for investigation on arson which applied gasoline as the combustion improver.

Review of the Research on the Identification of Electrical Fire Trace Evidence

In this paper, we review the research results about the identification of the electrical fire trace evidence and the fire reason recognition. We point out the existing problems and put forward the corresponding suggestions to promote the development of the cause of the fire investigation and make it better to serve for the work of fire investigation.

Research on Burn Pattern Characteristics of Polypropylene fiber and Polyvinyl chloride coil Flooring Materials Loaded By Gasoline

Gasoline, as one of the flammable liquids, is used commonly in arson. Due to its typical fluidity and permeability, particular burn patterns can be formed in fire scene. In order to provide references for fire investigators to collect trace evidences and identify fire cause accurately, the burn patterns on different flooring materials are investigated in this paper. Two polymer flooring materials (Polypropylene fiber and Polyvinyl chloride coil) were selected in the experiments to study the burn pattern characteristics by simulating the fire scene. By comparing the difference of the burning pattern with and without gasoline, rules of pattern characteristics on different material surface have been summarized. Meanwhile, fire extinguishing style was considered in this work. The results show that the burn pattern characteristics become remarkably different when the flooring materials loaded by gasoline. In addition, fire extinguishing style has a great impact on the burn patterns, such as the carbonized degree, the residual shape and the fire traces. It is believed that the results in this paper would provide important guidance for investigation on arson which applied gasoline as the combustion improver.

Study on the Ignition Capability of Welding Slag to B2 Grade Polystyrene Extruded Board

In order to study the ignition capability of welding slag to polystyrene extruded board of B2 grade, the ignition process was simulated by changing the splash direction of welding slag, the initial distance between the extruded board surface and triangular iron, as well as the shape of extruded board. The results show that the ignition capability of horizontal and vertical welding slag at the distance of less than 6cm are similar, while at the distance of 6cm, the ignition capability of vertical welding slag is higher than that of horizontal welding slag. The shape of the extruded board (blocks or chippings) has little influence on the ignition capability of vertical welding slag within the range of 6cm. It is believed that the conclusions of this study can provide some references for fire investigation related to the ignition capability of welding slag to polystyrene extruded board.

Investigation of a pyrophoric iron fire in a Visbreaker fractionation column provides better cleaning work procedure

An unexpected ignition of pyrophoric iron sulphide deposits took place in the fractionator of a Visbreaker unit. The distillation column had been chemically decontaminated prior to the event. The investigation of the event leads to conclusions concerning chemical decontamination limitations in vessels in coking service. Based on the lessons learned from this case, a prioritization of manual vessel cleaning works in coking service is proposed.

An assessment of hot metal fragments from heavy mechanical equipment as a potential ignition source for forest litter

The presence of metal particles, produced by rock strikes with heavy mechanical equipment, has come to be considered as evidence of fire causation in the investigation of forest fires. I report here the results of a series of experiments where direct thermographic measurements were made of the temperatures of the fragments that are created by repeatedly driving a bulldozer over rocks under extreme conditions. It is apparent, from these experimental determinations, a theoretical evaluation of the process that gives rise to them and comparison with published data, including the ignition of cellulose fuel beds by steel particles, that the minimum requirements for the ignition of kindling are not being met and that such fragments are not in fact a viable source of ignition for forest litter.

Influence of fire accelerant on the thermal degradation and ignition of wood chip

It is important in fire investigation and forensic science to understand how a fire accelerant can influence the combustible material in the fire process. In this paper, thermogravimetric analysis and burning tests have been conducted to study the effect of gasoline on the decomposition and ignition of camphorwood. The results have shown that the major effect of gasoline during the wood's decomposition takes place in the stage of dehydration (30~150℃) and major decomposition reaction (250~400℃). The Coats-Redfern integral method has been applied for the degradation in nitrogen, indicating the overall activation energy for the degradation has been decreased with the addition of gasoline to wood. The ignition time has been shortened and the ignition temperature has been reduced with the increase of gasoline volume, and the largest reduced range is 86.3% and 69.5% respectively, but with a limit for saturation. The ignition temperatures dropped with the increase of heat flux for wood with 1 mL of gasoline and, at the lower value of heat flux, the change of ignition temperature and time is more sensitive. The results could help better understand of the effect of fire accelerants in investigations into the cause of fires.

CSB investigation of Chevron Richmond refinery pipe rupture and fire

The U.S. Chemical Safety and Hazard Investigation Board (CSB) investigated a pipe rupture of a high temperature light gas oil line at the Chevron Richmond Refinery in Richmond, CA. The CSB found technical, regulatory, and Chevron organizational factors causal to the incident. This article is a summary of the technical and organizational analysis presented in the CSB final investigation report on the Chevron Richmond Refinery incident. © 2015 American Institute of Chemical Engineers Process Saf Prog 34: 355–359, 2015