A Review of Modelling and Simulation Methods for Flashover Prediction in Confined Space Fires

Confined space fires are common emergencies in our society. Enclosure size, ventilation, or type and quantity of fuel involved are factors that determine the fire evolution in these situations. In some cases, favourable conditions may give rise to a flashover phenomenon. However, the difficulty of handling this complicated emergency through fire services can have fatal consequences for their staff. Therefore, there is a huge demand for new methods and technologies to tackle this life-threatening emergency. Modelling and simulation techniques have been adopted to conduct research due to the complexity of obtaining a real cases database related to this phenomenon. In this paper, a review of the literature related to the modelling and simulation of enclosure fires with respect to the flashover phenomenon is carried out. Furthermore, the related literature for comparing images from thermal cameras with computed images is reviewed. Finally, the suitability of artificial intelligence (AI) techniques for flashover prediction in enclosed spaces is also surveyed.This work has been partially funded by the Spanish Government TIN2017-89069-R grant supported with Feder funds. This work was supported in part by the Spanish Ministry of Science, Innovation and Universities through the Project ECLIPSE-UA under Grant RTI2018-094283-B-C32 and the Lucentia AGI Grant

Fire safety risk model for a main vertical zone of a large passenger ship

The scope of this thesis is to shed light on the everlasting issue of on-board fires, with a particular focus on large passenger ships, by proposing a fire risk model for a Main Vertical Zone (MVZ). Historically, fire had and always has been a pressing accident type, along with flooding. Despite the regulatory effort, the total loss trend of fire incidents attributes to around 10% of those. Moreover, as per the high-level hazard identification conducted as part of this thesis, it was ascertained that cruise ships dominate the frequency of accidents whereas RoPax dominate the fatalities. The latter could be explained by the fact that numerous RoPax ships operate in less developed countries, where regulation enforcement is questionable and also experience higher transportation work in terms of volume. Conversely with RoPax ships, cruise ships are becoming larger by the day, offering novel designs and pertinent entertainment, which is usually translated into complex designs, in addition to the higher transportation volume in terms of passengers and crew. Various statistical analyses were scrutinised towards understanding how shipborne fires break out, including the one from research project SafePASS, being the most recent one, and having particular focus on all ships carrying passengers. Amongst all samples the frequency of fire events remained the same, highlighting the issue. Passenger ships, which accommodate large capacities of people experience higher fatality rates, underlining the urgency of improved safety measures. Therefore, for the purpose of this thesis focus was given on large passenger ships. On the other hand, the maritime industry and its stakeholders have always had a rather reactive stance towards safety, with the exception of cruise operators where safety is paramount with respect to their business longevity. The most prevalent example of the aforementioned being the birth of Safety of Life at Sea (SOLAS) after the sinking of the RMS Titanic. Accordingly with the high-level hazard identification, the engine room appeared to be the most usual culprit for fire and explosion events on board ships, attributing to more than 50% of such events, which is to be expected as ship’s engine room acts as a process and propulsion plant with inherent fire risks. The most frequent ignition scenario is the release of flammable oil (fuel or lubricating) which comes into contact with a hot surface, which are abundant in an engine room. Furthermore, the current status of the engine room fire safety has been characterised as sub-optimal as it investigates events only prior or next to ignition and has a particular focus on mitigation through various active and passive means (smoke detectors, deluge systems and fire boundaries respectively). Nevertheless, fire events continue to take place, highlighting the need for further research. Irrespective of the commendable research initiatives, such as project SAFEDOR and FIREPROOF, aimed at introducing the risk assessment and risk-based design respectively, the industry still has a focus on events proximate to ignition. Additionally, in line with Safety II and resilience engineering, systemic analysis of safety critical equipment and operations is thought to be the way forward towards a fire free system. Safety barriers have been adequately used in other industries, such as aerospace, oil and gas, and navy ships, but their adoption within the maritime industry is lagging behind. Sensory equipment and data analysis have been historically employed towards inferring safety barrier statuses, particularly that of technical elements. Systemic investigation, on the other hand, necessitates the investigation between the technical system and the asset and the operator, therefore, organisational and operational elements must be taken into account in order to provide a systemic coverage. Consequently, this research proposes a holistic simulation-based Main Vertical Zone (MVZ) fire risk model, specifically designed to demonstrate the efficacy of safety barriers. The fire risk model of the MVZ was stipulated in the form of a risk contribution tree (bow-tie) having preventive measures on the left-hand side and mitigating on the right. Since engine room fires are historically more prevalent compared to other areas, particular focus was given towards establishing a framework for the systemic derivation of a the so termed Release Prevention Barrier (RPB), aimed at averting engine room flammable oil leaks. Focus on flammable oil leaks was given as the author believes that treating hot surfaces is counter-intuitive as the lagging (if necessary by the provisions) may deteriorate over time and improper fitting could almost be guaranteed through repeated maintenance. The proposed framework offers a systemic structured way of establishing the said barrier, with focus on the placement of sensory equipment, which, as per the literature review, is not straightforward whatsoever. The framework is rather generic in the sense that it can be applied on any flammable oil line of any ship, highlighting its applicability. On the right-hand side, mitigating measures from SOLAS and the Fire Safety Systems Code (FSS Code) were deemed to be adequate towards that end, mainly due to their historical contribution in mitigating the effects of fire. Moreover, these have been scrutinised adequately within project FIREPROOF. Full-scale 3D Computational Fluid Dynamics (CFD) simulations were utilised towards assessing the risk of fire within the MVZ. Except for the engine room, passenger cabin and large public space decks are also liable to fire events, following the occupancy trends of such ships. Moreover, engine room fires, although statistically prevalent, do not pose as much risk to passengers as the aforementioned decks. To that effect, fire simulations were conducted on all these decks. To realise the fire simulations and to demonstrate the inherent difficulties posed by the lack of ship-borne fire data, first principle engineering was utilised to the full extent to deterministically assess the risk in way of pyrolysis modelling. For the purpose of the CFD simulations the Fire Dynamic Simulator (FDS) and Pyrosim were utilised, being the industry standard. Thermophysical and chemical data were employed to successfully construct design fires, while the pyrolysis methodology was successfully validated and verified against full-scale experiments, deeming the design fire methodology as suitable for use onboard ships and subsequently assessing the risk within the MVZ. Investigation beyond a MVZ was not sought as it violates the mentality of the MVZ itself, and due to difficulties posed by computational power and respective means necessary to do so. In the case of the engine room fire simulation, a hybrid deterministic approach was stipulated using both first principles and statistical means in way of Monte Carlo simulations. This was performed in an effort to showcase the tremendous difficulties posed by such an endeavour and the reason why deterministic engine room fire simulations are not available.The scope of this thesis is to shed light on the everlasting issue of on-board fires, with a particular focus on large passenger ships, by proposing a fire risk model for a Main Vertical Zone (MVZ). Historically, fire had and always has been a pressing accident type, along with flooding. Despite the regulatory effort, the total loss trend of fire incidents attributes to around 10% of those. Moreover, as per the high-level hazard identification conducted as part of this thesis, it was ascertained that cruise ships dominate the frequency of accidents whereas RoPax dominate the fatalities. The latter could be explained by the fact that numerous RoPax ships operate in less developed countries, where regulation enforcement is questionable and also experience higher transportation work in terms of volume. Conversely with RoPax ships, cruise ships are becoming larger by the day, offering novel designs and pertinent entertainment, which is usually translated into complex designs, in addition to the higher transportation volume in terms of passengers and crew. Various statistical analyses were scrutinised towards understanding how shipborne fires break out, including the one from research project SafePASS, being the most recent one, and having particular focus on all ships carrying passengers. Amongst all samples the frequency of fire events remained the same, highlighting the issue. Passenger ships, which accommodate large capacities of people experience higher fatality rates, underlining the urgency of improved safety measures. Therefore, for the purpose of this thesis focus was given on large passenger ships. On the other hand, the maritime industry and its stakeholders have always had a rather reactive stance towards safety, with the exception of cruise operators where safety is paramount with respect to their business longevity. The most prevalent example of the aforementioned being the birth of Safety of Life at Sea (SOLAS) after the sinking of the RMS Titanic. Accordingly with the high-level hazard identification, the engine room appeared to be the most usual culprit for fire and explosion events on board ships, attributing to more than 50% of such events, which is to be expected as ship’s engine room acts as a process and propulsion plant with inherent fire risks. The most frequent ignition scenario is the release of flammable oil (fuel or lubricating) which comes into contact with a hot surface, which are abundant in an engine room. Furthermore, the current status of the engine room fire safety has been characterised as sub-optimal as it investigates events only prior or next to ignition and has a particular focus on mitigation through various active and passive means (smoke detectors, deluge systems and fire boundaries respectively). Nevertheless, fire events continue to take place, highlighting the need for further research. Irrespective of the commendable research initiatives, such as project SAFEDOR and FIREPROOF, aimed at introducing the risk assessment and risk-based design respectively, the industry still has a focus on events proximate to ignition. Additionally, in line with Safety II and resilience engineering, systemic analysis of safety critical equipment and operations is thought to be the way forward towards a fire free system. Safety barriers have been adequately used in other industries, such as aerospace, oil and gas, and navy ships, but their adoption within the maritime industry is lagging behind. Sensory equipment and data analysis have been historically employed towards inferring safety barrier statuses, particularly that of technical elements. Systemic investigation, on the other hand, necessitates the investigation between the technical system and the asset and the operator, therefore, organisational and operational elements must be taken into account in order to provide a systemic coverage. Consequently, this research proposes a holistic simulation-based Main Vertical Zone (MVZ) fire risk model, specifically designed to demonstrate the efficacy of safety barriers. The fire risk model of the MVZ was stipulated in the form of a risk contribution tree (bow-tie) having preventive measures on the left-hand side and mitigating on the right. Since engine room fires are historically more prevalent compared to other areas, particular focus was given towards establishing a framework for the systemic derivation of a the so termed Release Prevention Barrier (RPB), aimed at averting engine room flammable oil leaks. Focus on flammable oil leaks was given as the author believes that treating hot surfaces is counter-intuitive as the lagging (if necessary by the provisions) may deteriorate over time and improper fitting could almost be guaranteed through repeated maintenance. The proposed framework offers a systemic structured way of establishing the said barrier, with focus on the placement of sensory equipment, which, as per the literature review, is not straightforward whatsoever. The framework is rather generic in the sense that it can be applied on any flammable oil line of any ship, highlighting its applicability. On the right-hand side, mitigating measures from SOLAS and the Fire Safety Systems Code (FSS Code) were deemed to be adequate towards that end, mainly due to their historical contribution in mitigating the effects of fire. Moreover, these have been scrutinised adequately within project FIREPROOF. Full-scale 3D Computational Fluid Dynamics (CFD) simulations were utilised towards assessing the risk of fire within the MVZ. Except for the engine room, passenger cabin and large public space decks are also liable to fire events, following the occupancy trends of such ships. Moreover, engine room fires, although statistically prevalent, do not pose as much risk to passengers as the aforementioned decks. To that effect, fire simulations were conducted on all these decks. To realise the fire simulations and to demonstrate the inherent difficulties posed by the lack of ship-borne fire data, first principle engineering was utilised to the full extent to deterministically assess the risk in way of pyrolysis modelling. For the purpose of the CFD simulations the Fire Dynamic Simulator (FDS) and Pyrosim were utilised, being the industry standard. Thermophysical and chemical data were employed to successfully construct design fires, while the pyrolysis methodology was successfully validated and verified against full-scale experiments, deeming the design fire methodology as suitable for use onboard ships and subsequently assessing the risk within the MVZ. Investigation beyond a MVZ was not sought as it violates the mentality of the MVZ itself, and due to difficulties posed by computational power and respective means necessary to do so. In the case of the engine room fire simulation, a hybrid deterministic approach was stipulated using both first principles and statistical means in way of Monte Carlo simulations. This was performed in an effort to showcase the tremendous difficulties posed by such an endeavour and the reason why deterministic engine room fire simulations are not available

A risk-based fire and rescue management system

This PhD focuses on developing a risk-based fire and rescue model for dwelling fires which importantly, is where most fire deaths occur each year. There are a vast number of variables to consider when modelling dwellings, for example variations will arise in terms of geographical location, fire safety arrangements, characteristics of occupants, activities of occupants, among others. As for the occurrence of fire itself, each incident will be unique in terms of time of day, type of fire, state of occupants, fire cues, etc. What all these variations signify is that the potential magnitude of the next fire event and its consequences are generally unpredictable. Because of complicated scenarios, unpredictability of outcomes, and high frequency of incidents, Fire and Rescue Serices (FRS) have to be both capable and flexible in operation; however finding the optimal way of providing emergency cover and minimizing risk is a complicated task which often results in reasoning and decisions taking place under uncertainty. In order to diminish some of this uncertainty and improve confidence in decision making, an extensive four-part Bayesian Network (BN) model is developed focusing on dwelling fires within the UK. The intention is to model the sequence of events which may occur during a fire from ignition through to extinguishment with the objective of assessing, under specified conditions, fire safety at a given location; this should assist in determining what the most important safety issues are for the purpose of improving fire prevention and mitigating consequences in order to reduce fire risk across residential communities. The model itself is broken down into four parts which can function independently or together as an integrated network. The model parts are as follows: Part I - "Initial fire development". Part II - "Occupancy response and further fire development". Part III - "Advanced fire situation and consequences". Part IV - "Fire response time module". Within the project a risk-based fire and rescue operations management framework is also presented to demonstrate how the BN model could fit into the strategic management of FRS's and how it could link up with other tools and data collection programmes. The BN model may prove to be useful for strategic decision making within FRS's

Sensor and model integration for the rapid prediction of concurrent flow flame spread

Fire Safety Engineering is required at every stage in the life cycle of modern-day buildings. Fire safety design, detection and suppression, and emergency response are all vital components of Structural Fire Safety but are usually perceived as independent issues. Sensor deployment and exploitation is now common place in modern buildings for means such as temperature, air quality and security management. Despite the potential wealth of information these sensors could afford fire fighters, the design of sensor networks within buildings is entirely detached from procedures associated to emergency management. The experiences of Dalmarnock Fire Test Two showed that streams of raw data emerging from sensors lead to a rapid information overload and do little to improve the understanding of the complex phenomenon and likely future events during a real fire. Despite current sensor technology in other fields being far more advanced than that of fire, there is no justification for more complex and expensive sensors in this context. In isolation therefore, sensors are not sufficient to aid emergency response. Fire modelling follows a similar path. Two studies of Dalmarnock Fire Test One demonstrate clearly the current state of the art of fire modelling. A Priori studies by Rein et al. 2009 showed that blind prediction of the evolution of a compartment fire is currently beyond the state of the art of fire modelling practice. A Posteriori studies by Jahn et al. 2007 demonstrated that even with the provision of large quantities of sensor data, video footage, and prior knowledge of the fire; producing a CFD reconstruction was an incredibly difficult, laborious, intuitive and repetitive task. Fire fighting is therefore left as an isolated activity that does not benefit from sensor data or the potential of modelling the event. In isolation sensors and fire modelling are found lacking. Together though they appear to form the perfect compliment. Sensors provide a plethora of information which lacks interpretation. Models provide a method of interpretation but lack the necessary information to make this output robust. Thus a mechanism to achieve accurate, timely predictions by means of theoretical models steered by continuous calibration against sensor measurements is proposed.Issues of accuracy aside, these models demand heavy resources and computational time periods that are far greater than the time associated with the processes being simulated. To be of use to emergency responders, the output would need to be produced faster than the event itself with lead time to enable planning of an intervention strategy. Therefore in isolation, model output is not robust or fast enough to be implemented in an emergency response scenario. The concept of super-real time predictions steered by measurements is studied in the simple yet meaningful scenario of concurrent flow flame spread. Experiments have been conducted with PMMA slabs to feed sensor data into a simple analytical model. Numerous sensing techniques have been adapted to feed a simple algebraic expression from the literature linking flame spread, flame characteristics and pyrolysis evolution in order to model upward flame spread. The measurements are continuously fed to the computations so that projections of the flame spread velocity and flame characteristics can be established at each instant in time, ahead of the real flame. It was observed that as the input parameters in the analytical models were optimised to the scenario, rapid convergence between the evolving experiment and the predictions was attained

Experimental investigation of the smoke explosion phenomenon

One of the essential objectives in fire safety engineering is to safeguard firefighters during operations. A smoke explosion is an unforeseen deflagration that can occur in a compartment fire endangering firefighter safety. In addition to the classical compartment fire development stages, smoke explosions can occur for underventilated conditions while the ventilation openings remain the same. This thesis is focused on the smoke explosion phenomenon to obtain a better understanding of its process. A better understanding of the smoke explosion phenomenon raises firefighters' awareness of its causes and potential consequences. This study starts with a comprehensive review of the previous compartment fire experiments that led to smoke explosions. The effects of the fuel location and the ventilation opening size on the mass loss rate and heat release rate are analysed based on the previous experiments. A novel ventilation factor is introduced for the compartment with two vertical front openings. It is demonstrated that the overall compartment fire behaviour (excluding the possible occurrence of explosions) is nearly independent of the location or the porosity of timber crib fuel for underventilated conditions but depends on the ventilation factor. A preliminary explanation for the occurrence of the smoke explosions is provided, and it was found that the effect of crib porosity on the occurrence of smoke explosions needs further investigation. As part of the study, the flammability limits of the pyrolysate gases produced from thermally decomposed medium density fibreboard (MDF) and plywood are quantified. Finding the flammability limits of the pyrolysate gases is believed to assist in studying the smoke explosion phenomena as the smoke explosion is known to be caused by the gradual transformation of the oxygen and smoke gas mixture to reach a flammable range. An experimental procedure is developed to generate pyrolysis from decomposing thermally thick fuels and measure the flammability of these pyrolysis gases. The flammability characteristics provided fundamental knowledge for understanding the smoke explosion phenomenon in the compartment fires. This study investigates the burning history of medium-density fibre (MDF) cribs in an underventilated compartment with two openings. Such compartment fires are explored before by other researchers and demonstrated that would lead to smoke explosions. A total of 19 compartment fire experiments were completed, five of which led to smoke explosions. A gas conditioning system is designed for the smoke explosion experiments, which includes a flame ionisation detector (FID) for hydrocarbon measurements and an enhanced Phi-meter for equivalence ratio measurements. In addition to these measurements, heat release rate, mass loss rate, temperatures, pressures, and O2, CO2 and CO gas concentrations with the compartment are measured for each experiment. The smoke explosion occurs in a compartment fire when the changes of pyrolysate gases and oxygen concentrations in the compartment make the mixture forms a flammable mixture, i.e., falling within the flammable region of the flammability diagram. The increase of oxygen and pyrolysate gas concentrations to form a flammable mixture occurs following the transition of flaming combustion to smouldering. The averaged equivalence ratio of the compartment immediately before the occurrence of smoke explosions were found between 1.5 to 2.0. The development of fire in severely underventilated compartment fires are described and classified to three different scenarios. These scenarios are: a. flaming combustion from ignition to burnout with no smoke explosion, b. flaming combustion transitioning to smouldering combustion and smouldering combustion continues until the burnout with no smoke explosion, and c. flaming combustion transitioning to smouldering combustion and smoke explosion occurring after the transition to smouldering combustion. The questions raised by the external examiners of the thesis and the authors response to those questions are appended to the thesis

Assessment of Carbon Fiber Electrical Effects

The risks associated with the use of carbon fiber composites in civil aircraft are discussed along with the need for protection of civil aircraft equipment from fire-released carbon fibers. The size and number of carbon fibers released in civil aircraft crash fires, the downwind dissemination of the fibers, their penetration into buildings and equipment, and the vulnerability of electrical/electronic equipment to damage by the fibers are assessed

Experimental Study of Thermal Degradation of Fire Resisting Compartment Partitions in Fires

Fire separations in a building (e.g. walls) are often constructed from combustible materials; those containing wood stud framing, mineral wool insulation, and gypsum board wallcoverings are commonplace in Canadian residential buildings. These construction assemblies degrade under fire exposure, a process involving chemical decomposition as well as physical damage. A fire separation's ability to resist the spread of fire is traditionally assessed by means of a fire resistance test, in which a construction assembly is exposed to an intense furnace fire under prescribed conditions. This method of assessment, while standardized and prescribed in the National Building Code of Canada, can be restrictive to the design process. In contrast, a performance-based approach, in which the adequacy of a fire separation is assessed on the basis of its real-world use, can lead to designs with improved safety, efficiency, and flexibility. Such a design approach requires a specific engineering toolset: models capable of predicting the thermal degradation of construction assemblies under specified fire conditions. Development of the next generation of thermal degradation models requires detailed study of the phenomena occurring at the large-scale, in the context of real fires rather than prescribed exposure conditions, and a controlled means by which to conduct this type of study. Also, a diverse set of experimental data is required for the validation of such models. The objective of the present body of work is to develop a novel large-scale experiment tailored specifically for the study of thermal degradation of construction assemblies in real fires, and to demonstrate the utility of the experimental procedure as applied to the detailed study of thermal degradation phenomena. A selection of relevant experimental techniques were identified, and a new apparatus and method of test were developed for this stated purpose. In this new experiment, one wall of a fire compartment was instrumented and monitored as it was subject to a realistic fire exposure. A novel method for measurement of incident heat flux to a large area in a fire compartment was developed, and used to characterize the conditions of the experiment for a wood crib fire. A series tests were conducted on fire resisting compartment partitions that are used in residential buildings in Canada. In the tests, thermal degradation phenomena were observed and assessed relative to temperatures measured in the degrading walls. The utility of this new approach in the experimental study of thermal degradation of construction assemblies subject to real fire exposures was demonstrated. Furthermore, a relevant set of experimental data was generated that may be used for validation of future models of thermal degradation and integrated fire analysis

Bench and Large-scale assessment of smoke toxicity

The overall goal of the project was to provide evidence to support the regulation of smoke toxicity in order to reduce death and injury in unwanted fires. This entailed the development of a robust methodology for assessing smoke toxicity on a laboratory bench-scale using the steady state tube furnace (SSTF), ISO/TS 19700, and relating it to the toxicity of large-scale fire tests. A review of the literature relating to bench- and large-scale fire toxicity assessment has been undertaken and is reported. Research was conducted on a bench-scale to optimise the methodologies developed and assess the current techniques used in smoke toxicity research. In addition, the formation of the main asphyxiants, carbon monoxide (CO) and hydrogen cyanide (HCN), was investigated under different fire conditions. In most cases, where nitrogen was present in the fuel, the formation of HCN mirrored the formation of CO. HCN and CO formation were found to be steady and relatively consistent starting approximately 5 to 7 min after sample ignition. This research was used to test the assumptions related to steady state burning and sampling times stated in ISO/TS 19700. For smoke toxicity to be regulated as a part of the Construction Product Regulations (CPR), a robust methodology for assessing smoke toxicity for large-scale fires is required as a “reference scenario”. As the current large-scale methods for construction products assess flammability, a revised methodology needed to be developed. In addition, the instrumentation and methodologies for assessing smoke toxicity on a large-scale required development and construction. To measure the smoke toxicity on a large-scale, gas analysers suitable for operating at large-scale test facilities were required. As no such analysers are commercially available, portable analysers were designed and built. The analysers continuously monitor CO, CO2 and O2, with specific sampling of HCN and irritant gases produced during a fire test. The specific sampling was controlled by a mass-flow meter to ensure that equal masses of fire effluent were collected in each sample, and used program-controlled switches for sample collection. To validate the analyser, it was tested alongside the standard SSTF analysers, and used when conducting the research into HCN formation described above. To identify the fire condition of the test in terms of the equivalence ratio, a phi meter was designed and built for this research, based on modifications to the original design. It was smaller and simpler than the original design, increasing portability and performance. The final apparatus was tested and calibrated using the SSTF where the equivalence ratio is controllable and well-defined. The phi meter was used to investigate the effect of sampling location within the SSTF by studying the equivalence ratio at specific locations inside the apparatus. No significant variation of the equivalence ratio with sampling location was found. The phi meter was successfully used to identify the equivalence ratio during the large-scale fire tests. The ISO 9705 room corner test was modified to assess smoke toxicity. The novel methodology used either 1 or 2 L-shaped Single Burning Item (SBI) (EN 13823) test rigs placed on a load cell in the centre of the ISO test room. The measurements specified in the ISO 9705 standard from the exhaust duct were recorded throughout the tests. Fire effluent composition was also monitored using the portable gas analysers in the exhaust duct and the doorway of the test room. To enable future gas yield calculations to be made, McCaffrey probes were used with sensitive pressure transducers to estimate the gas flows in and out of the room. The tests aimed to represent a range of fire conditions, from well-ventilated to under-ventilated flaming. Two methods were investigated to replicate different fire conditions: limiting the ventilation; and increasing fuel loading. Four products, which included non-homogenous and predominantly non-combustible components (plasterboard, OSB, flexible polyurethane foam and electric cables), were burned in the large-scale tests. Under-ventilated flaming occurred in tests with combustible products conducted using two SBI rigs, where well-ventilated flaming had predominated with single SBI rigs. Under-ventilated flaming was not achieved when restricting the ventilation by partially blocking the doorway. These experiments showed that restriction of the ventilation reduced the rate of burning rather than forcing the fire to transition into under-ventilated flaming. This is clearly dependant on the ratio of the heat release from the fuel to the size and heat capacity of the test enclosure. The fire behaviour of the materials was predicted before testing using ConeTools fire modelling software, using test data from cone calorimetry. As ConeTools had not been written for the novel test layout used, the data was used to create heat release predictions for an SBI test and an ISO room test conducted with the product as a standard wall-lining. ConeTools overestimated the heat release predictions compared to previously reported SBI test data. When used to predict the heat release from products in this study, they were underestimated. This research has provided key information and methodologies to support the regulation of smoke toxicity within the CPR. It has provided the revised methodologies which would be necessary for ISO/TS 19700 to become a full standard and provided robust research to reinforce existing methodologies. The methodology of testing smoke toxicity on a large-scale has also been enhanced, including details of specific equipment required to assess specific parameters during a large-scale test