Fire Rate Research Articles

Fire Safety Assessment of a Typical Sports Hall Building Based on Fire Dynamics and Crowd Movement Models

Fire risk analysis is one of the essential components of building design to ensure the safety of occupants and properties in case of fires. Currently, the Ministry of Public Works and Housing Regulation No. 20/PRT/M/2009 provides guidelines for conducting a fire risk analysis, however, without a clear consideration of fire dynamics in the estimation of the fire risk level. In this work, we investigate the fire safety aspects of a typical sports hall buildings by a fire dynamics deterministic model (Fire Dynamics Simulator (FDS) of the National Institute of Science and Technology, USA) and crowd movement model for occupant evacuation (Pathfinder of Thunderhead Engineering). Systematic investigations were made on the effects of the fire growth category and smoke extraction system on the Available Safe Egress Time (ASET). The results of ASET were then compared to the Required Safe Egress Time (RSET) which is obtained from the evacuation model. Our results suggest that ASET decreases exponentially with fire growth rate, especially from slow to medium growth rate. The fire growth rate significantly affects the acceptable fire risk of ASET longer than RSET. Occupant capacity, fire management systems, and smoke extraction systems play important roles in reducing fire risk. However, as the fire growth rate increases, the effects of smoke extraction in maintaining safe conditions diminish. This study provides recommendations to reduce risks to the occupants in case of fire, contributing to the considerations of the design and management of a typical sports hall building.

Experimental investigation on maximum ceiling temperature and longitudinal attenuation in a closed tunnel with an inclined shaft

For tunnel fires with open and closed tunnel ends, the smoke flow pattern and air supply conditions vary considerably, resulting in different maximum excess ceiling temperature (ΔTmax) and its longitudinal distribution (ΔTx). However, few studies have focused on the tunnel closed at both ends with an inclined shaft (typical tunnel structure during construction). Hence, tunnel model 1 (tunnel closed at both ends with an inclined shaft) and tunnel model 2 (tunnel open at both ends) are built for comparison and analysis. The results show that tunnel model 1 has higher ceiling temperatures and slower attenuation than tunnel model 2. Therefore, the ΔTx in tunnel model 1 needs to be re-analyzed in detail. Different inclined shaft slopes, fire heat release rates, longitudinal and vertical fire positions are considered. In tunnel model 1, for h (lifting height of burner surface) = 0, the ΔTmax value tends to be constant for the same heat release rate, irrespective of the longitudinal fire position. For h = 5 cm, the ΔTmax value takes on a rising trend with the fire moving downstream. Moreover, the inclined shaft slope within this study has little influence on ΔTx. As the fire moves downstream, the downstream ΔTx/ΔTmax value decreases more rapidly. From h = 0 to h = 5 cm, the value of ΔTx/ΔTmax drops slightly faster, but the gap is small and can be ignored. Finally, the experimental correlations are proposed to estimate the longitudinal ceiling temperature distribution in a closed tunnel with an inclined shaft.

Numerical Study on the Influence of the Slope Composition of the Asymmetric V-Shaped Tunnel on Smoke Spread in Tunnel Fire

Asymmetrical V-shaped tunnels often appear in tunnels crossing the river or urban underground road tunnels. The smoke flow inside is affected by a lot of factors. A full understanding of the smoke flow in this kind of tunnel is the basis of the smoke control. In this study, the effects of slope composition and fire heat release rate (HRR) on the longitudinal induced airflow velocity, the smoke back-layering length at the small slope side, and the maximum ceiling temperature were studied by the numerical method. The results show that when the fire occurs at the slope change point of the V-shaped tunnel, the maximum ceiling temperature decreases with the increase in the slope of the large-slope side tunnel. The longitudinally induced velocity is primarily related to the slope of the large-slope side tunnel and the fire HRR. When the slope difference between the side tunnels or the slope of the large-slope side tunnel is large, the smoke in the small-slope side tunnel flows back toward the fire source after reaching its maximum dispersion distance and then reaches a quasi-steady state. The smoke back-layering length is mainly affected by the slope and length of the large-slope side tunnel. When the slope of the large-slope side tunnel is 9%, the induced airflow velocity from the small-slope side can prevent the spread of smoke. The empirical models of the smoke back-layering length and the longitudinal induced airflow velocity in the small-slope side tunnel are drawn, respectively, by the theoretical analysis and the numerical results. This study can provide technical support for the design and operation of smoke control systems in V-shaped tunnels.

Optimised prediction of tunnel fire heat release rate using the ResNet18_2CLSTM model with bagging for multimodal data

Accurate predictions of HRR will improve preparedness and response strategies, enhance safety, and minimise damage in tunnel fires. In this study, a deep learning prediction model for HRR under multimodal data fusion is proposed. A multimodal dataset is first established to obtain flame images and flue gas time series data through model-scale tunnel fire experiments. During the model training process, ResNet18 was used to extract features from the flame image, and 2CLSTM was employed to understand the time series of the flame image features and flue gas features to establish the correlation with the HRR. It was evaluated that the error analyses of the measured and predicted values of the validation set yielded R2 greater than 0.85, with errors and standard deviations less than 4 kW. And the model predicted better in the flame growth and decay phases. However, there is some deviation in the predictions near the peak HRR. To address this issue, the Bagging algorithm was introduced to optimise the model. The results show that the ResNet18_2CLSTM model with Bagging reduces the RMSE by 20.47 % and increases the R2 by 4.64 % compared to the original model, and the accuracy is greatly improved.

Effect of ambient pressure on the fire characteristics of lithium-ion battery energy storage container

As lithium-ion battery energy storage gains popularity and application at high altitudes, the evolution of fire risk in storage containers remains uncertain. In this study, numerical simulation is employed to investigate the fire characteristics of lithium-ion battery storage container under varying ambient pressures. The findings reveal that the peak heat release rate of fires at normal pressure is significantly higher than at lower pressure. Specifically, the heat release rate at 100 kPa is 9215 kW, exceeding the value at 40 kPa by 42%, which is only 3900 kW. This peak heat release rate also demonstrates a power function relationship with ambient pressure. In addition, fires tend to last longer in lower pressure, where high-temperature areas expand and spread rates increase. Moreover, higher pressures produce elevated peak concentrations of CO and CO2, while smoke spreads faster in lower pressure, despite lower peak smoke concentrations. The study findings can serve as a foundation for assessing the fire hazards and designing fire protection measures for lithium-ion battery storage containers exposed to varying ambient pressures.

Forest management with fire simulation

In this work, we address a forest management problem for timber production with fire concerns, employing a novel simulation-based optimization approach wherein forest management is iteratively guided by the feedback from fire spread simulations.The forest management problem involves selecting an alternative prescription for each stand, subject to various restrictions (e.g. bounds on ecosystems services), to maximize the net present value. For each stand, prescriptions involve projecting forest conditions and outcomes using species-specific growth and yield models, combined with different fuel treatment scenarios. In each iteration, the optimization problem is solved. Fire travel times between adjacent points in a grid representing the forest are calculated, based on fuel models associated with the selected prescriptions and other conditions as wind and slopes. Fire spread is simulated for all potential ignitions. Fire paths with a rate of spread greater than a given threshold are identified and constraints are added to the forestry problem to exclude their associated prescriptions to be jointly selected. This problem is re-optimized and the process is repeated until there are no such paths.We describe computational experiments in a Portuguese forest showing how trade-offs between the net present value and the maximum fire rate of spread can be obtained. When too restrictive conditions are imposed on fire, the approach suggests a set of stands to become fire breaks. We also conducted experiments to demonstrate how the impact of the forest surroundings, as well as bounds on ecosystem services, can be evaluated with respect to these trade-offs.

Experimental study on the burning rate and flame dynamics of oil reservoir pool fire under cross-wind: Effect of lip height

The study of combustion characteristics and heat feedback mechanisms of liquid fuels is important for fire safety engineering, particularly in the context of energy utilization. In thiswork, the effect of lip height on the evolution of n-heptane pool fire burning rates and flame heights, as well as the thermal feedback control mechanism, were investigated in a series of experiments in the presence of cross-wind. The results showed that the lip height of pool and cross-wind speed have a significant effect on the flame characteristics and heat feedback mechanism. For a given wind speed condition, the radiative feedback fraction and the convective feedback fraction showed non-monotonic changes with an increase in the lip height of pool. With the increase of lip height and cross-wind speed, the lift off phenomenon gradually appeared inside the oil pool, while the flame height outside the oil pool gradually decreased. A new correlation is proposed, which can well describle the relationship between the flame height and the ratio of the air entrainment caused by the cross airflow to that caused by the flame buoyancy, which can provide references for the utilization and management of energy storage strategies nowadays.

Сombat operations model of a single self-propelled artillery system for the computer game ARMA 3

Military computer games are an important segment of the world media culture and media business. In addition to the entertainment aspect, military simulators play an important role in the training of future military specialists. However, quite often the scenario component of military gaming lags behind the rapid development of real military equipment. World experience of military conflicts of the 21st century shows that the most intensively developing segment of ground forces weapons is its artillery component. In this paper, a model of combat use of a new generation artillery system is developed. The model is intended for modification of the military game ARMA 3. The new generation artillery system is a large-caliber gun with a high level of automation. It has a high rate of fire, maneuverability, and shooting accuracy. Due to these qualities, the new generation artillery system is comparable in combat power to a unit of traditional guns and can carry out combat operations in single mode. A technique has been developed for dynamically assessing the current combat capability of an artillery system, taking into account the resource costs during fire activity, including indirect hits by the enemy. It is shown that in addition to traditional tactical counter-battery tasks, an artillery system can be used to destroy a suddenly emerging high-risk target. A high-risk target is a non-artillery system capable of causing very large damage in a short period of time. Based on the method of dynamically assessing the current combat capability, a tree of artillery system states is constructed. It includes the most probable states of the artillery system and the corresponding design parameters. A ratio is obtained that allows, for a known state of the artillery system, to estimate the number of shots needed to hit the target with the required guaranteed probability. Calculated examples show that a new-generation artillery system is capable of destroying a high-risk target, sometimes even at the cost of its own loss. The developed model is implemented and is being tested as a mod for the war game ARMA 3.

Sustainable lignosulfonate-modified PA6.6 fabrics to improve durable flame retardancy, hydrophilicity and mechanical performance

Creating durable flame retardancy, enhanced mechanical performance, and hydrophilic polyamide 6.6 (PA6.6) textiles via cost-effectiveness from sustainable renewable sources is a considerable challenge. This study introduces a pretreatment process involving the application of sodium lignosulfonate (LS) to the surface of PA6.6 fabrics, thereby enhancing their hydrophilic and flame-retardant properties. Subsequently, a layer-by-layer (LbL) nanocoating treatment is employed, utilizing renewable polyelectrolytes—chitosan (CS), LS, and poly (sodium phosphate) (PSP)—to create 8-bilayer (BL) and 4-quarda layer (QL) structures that further improve the hydrophilicity and durable flame resistance of PA6.6 fabrics. The combined LS-modified and LbL coatings notably increased the limiting oxygen index (LOI) values from 19.5 % to 22.5 %, eliminated melt dripping, and secured a V-1 rating in the vertical burning (UL-94) tests. Moreover, the treated fabrics exhibited a 43 % reduction in the peak heat release rate (PHRR) and a lower fire growth rate (FGR) of 0.84 W/g·s, with a significant increase in char yield% in both air and nitrogen (N2) atmospheres. A cross-linked network structure is responsible for the superior hydrophilicity, enhanced tensile strength, and fabric softening properties. The self-crosslinking of sulfur-containing radicals with amide units ensures an anti-dripping performance that can withstand up to 30 home laundering cycles, demonstrating remarkable washing durability. However, a convincing approach has been developed for sustainable and high-performance materials for the textile industry, and a simple LbL technique using renewable polyelectrolytes that have traditionally been utilized in water treatment and food processing has been developed.

Preparation of biobased guar gum polyelectrolyte complex coatings by sol‐gel method for improving the flame retardancy of ramie fabrics

AbstractIn this study, to improve the flame‐retardant properties of ramie fabrics (RFs), a polyelectrolyte complex (PEC) was prepared in a one‐step process using biobased guar gum (GG), polyethyleneimine (PEI), and ammonium polyphosphate (APP) and deposited on the surface of the RF to construct an intumescent flame‐retardant coating. Fabrics treated with PEC coatings exhibited excellent flame‐retardant properties. Specifically, the cone calorimeter test results revealed that an increase in sample weight of only 13.23 wt% resulted in significant reductions in the peak heat release rate (pHRR), total heat release (THR), and fire growth rate (FGR) of 91.37%, 65.12%, and 95.28%, respectively. Additionally, the limiting oxygen index (LOI) increased from 19.4% to 33.5%, and the fabrics self‐extinguished immediately after the ignition source was removed during the UL‐94 test. Scanning electron microscopy (SEM) of the char residue revealed expansion bubbles on the surface, suggesting that the PEC coating provides flame retardancy through a synergistic effect involving both the gas phase and the condensed phase. This study provides a simple and convenient solution for realizing green and efficient flame‐retardant coatings on RF.

Flame Retarded Adhesive Tapes and Their Influence on the Fire Behavior of Bonded Parts

AbstractPressure-sensitive adhesive tapes are used in automotives, railway vehicles and construction, where flame retardancy is of major importance. This is why industrial applicants often buy, and industrial tape manufacturers often produce, flame-retardant adhesive tapes, advertised for their good flammability characteristics. Yet, how flame-retardant tapes influence the fire behavior of bonded materials is a rather open question. To investigate this issue, three different substrates were bonded, using eight double-sided adhesive tapes containing two different carriers and two different flame retardants. The bonded substrates were compared to their monolithic counterparts in terms of flammability, fire behavior and fire stability. The fire behavior of adhesive tape bonded materials differed significantly from the monolithic substrates. The usage of different adhesive tapes let to different burning behavior of the bonded materials mainly due to different carrier systems. In contrast, the implementation of flame retardant into the adhesive had rather minor or no effect on the burning behavior of the bonded substrates despite their positive effect on the flammability of the free-standing tape. The carrier changed the HRR curve in the cone calorimeter and was able to both, reduce and increase fire hazards. Using the carrier with the better fire performance can lower the fire growth rate by 20%, the peak of heat release rate by 27%, and the maximum average rate of heat emission by 30% in cone calorimeter tests. Overall, the fire behavior of bonded materials is a complex interaction between substrate, adhesive, and carrier, and depends on the fire scenario the materials are exposed to.

Impinging ceiling flame behaviors induced by wall-attached gaseous fuel fires at one end in a narrow building corridor: Different phases and generalized correlations

This work investigated the flame extension behavior after impinging upon a ceiling induced by wall-attached fires at the closed end in a narrow building corridor. Experiments were conducted in a reduced scale corridor with one end closed and the other opened, under various fire heat release rates and source-ceiling heights (from 0.05 m to 0.50 m) of totally 353 test conditions. The flame morphological characteristic parameters involving the flame extension length in the center of the ceiling and in the two sides were measured and analyzed comprehensively. By a careful observation, it was found that, as the fire heat release rate increased or the source-ceiling height decreased, the ceiling flame extension behavior can be divided into different behavior phases: the flame spreads to the two sides after impinging the narrow building ceiling; flame extends longitudinally after reaching side walls, presenting a semi-elliptical shape; flame in the two sides extends farther than that in the center of the ceiling, presenting a “U” shape; and flame presents a cellular structure (the fire source is near the building ceiling). The dimensionless critical fire heat release rates for the transition of these phases were identified, and non-dimensional correlations were obtained for the prediction of flame extension lengths of different phases. This work provides new observations of different phases and generalized correlations for impinging ceiling flame behaviors induced by wall-attached gaseous fuel fires at one end in a corridor.

Modelling the maximum ceiling temperature with bifurcated plume in tunnel fires

Evaluation of the temperature profile induced by tunnel fire is of great significance for fire detection and structural damage assessment. In this work, a special plume model, namely, the “plume bifurcation” is introduced, and its impact on the temperature distribution is analysed theoretically. Full-scale tunnel fire experiments and numerical simulations are conducted to investigate the plume evolution under various heat release rates and ventilation conditions. Results show that the plume will sperate into two sub-streams under strong ventilation condition, resulting in the multi-dimensional plume movement pattern when rising. The sub-plume impingement point location, quantified by the longitudinal vertical deflection angle θv and horizontal bifurcation angle θh, is correlated with the fire heat release rate and ventilation condition. The plume bifurcation angle is 0 when the dimensionless ventilation velocity V′≤0.33, marking a single-stream plume; and rapidly increase and then slowly decrease with V′ when V′>0.33, representing the sudden occurrence and decay trend of plume bifurcation with the ventilation velocity. Finally, a novel bifurcated plume-based model to estimate the maximum ceiling temperature is proposed. This study reveals the role of multi-dimensional smoke movement in reshaping the temperature field, providing new perspectives for a deeper understanding of the smoke transport behaviour in longitudinally ventilated tunnel fires.

An experimental study of fire development under varying ventilation conditions during the depressurization process in pressurized buildings

Hermetic pressurized buildings are a new type of building in high-altitude areas that efficiently addresses issues such as high-altitude reactions. The indoor pressure is higher than the external pressure under working conditions, and pressure relief must be carried out first during emergencies. The emergency pressure relief process during a fire may lead to complex fire behavior that is different from that in regular buildings. In this study, we focus on the impact of ventilation conditions and the status of doors in such buildings on fire evolution and smoke plume characteristics through experiments. The temperature variation in the fire room and corridor is measured under different ventilation power, ventilation time, and door opening width conditions. This shows that the width of the door has the greatest impact on fire development. A smaller gap in the door opening restricts air circulation between the interior and exterior of the room, resulting in a rapid decrease in the oxygen concentration within the fire room and a decrease in the combustion reaction rate of wood fires. The ventilation power exerts the most significant influence on the temperature variation in the corridor. These findings provide empirical data and a basis for fire science studies in high-altitude hermetic pressurized buildings and can guide existing fire protection design and management for improved safety.

Development of Risk Indicator Incorporating Regional Characteristics for Fire-Following Earthquake Risk Assessment

Secondary damages caused by earthquakes, such as fires, tsunamis, and landslides, significantly damage buildings (or structures) and adversely affect humans. Historical cases have highlighted the severe dangers posed by fire-following earthquakes (FFEs). The risk of FFE is determined by regional characteristics, such as the density of buildings and the types of fire-resistant structures. However, researchers have previously evaluated this risk by comparing relative fire burn rates without considering regional characteristics. Hence, a methodology used previously is adopted in this study to calculate regional-level fire burn rates in Pohang City. Subsequently, the relationship between regional characteristics and fire burn rates is examined. Based on the analysis results, a new risk indicator is proposed for evaluating the FFE risk while considering regional characteristics, and the results obtained for Pohang City are compared with those published in the literature (FFE risk ranking in L, Northern, Pohang = 3 or 2 vs. 2).

Predicting Forest Fire Area Growth Rate Using an Ensemble Algorithm

Due to its unique geographical and climatic conditions, the Liangshan Prefecture region is highly prone to large fires. There is an urgent need to study the growth rate of fire-burned areas to fill the research gap in this region. To address this issue, this study uses the Grey Wolf Optimizer (GWO) algorithm to optimize the hyperparameters in the eXtreme Gradient Boosting (XGBoost) model, constructing a GWO-XGBoost model. Finally, the optimized ensemble model (GWO-XGBoost) is used to create a fire growth rate warning map for the Liangshan Prefecture in Sichuan Province, China, filling the research gap in forest fire studies in this area. This study comprehensively selects factors such as monthly climate, monthly vegetation, terrain, and socio–economic aspects and incorporates monthly reanalysis data from forest fire assessment systems in Canada, the United States, and Australia as features to construct the forest fire dataset. After collinearity tests to filter redundant features and Pearson correlation analysis to explore features related to the burned area growth rate, the Synthetic Minority Oversampling Technique (SMOTE) is used to oversample the positive class samples. The GWO algorithm is used to optimize the hyperparameters in the XGBoost model, constructing the GWO-XGBoost model, which is then compared with XGBoost, Random Forest (RF), and Logistic Regression (LR) models. Model evaluation results showed that the GWO-XGBoost model, with an AUC value of 0.8927, is the best-performing model. Using the SHapley Additive exPlanations (SHAP) value analysis method to quantify the contribution of each influencing factor indicates that the Ignition Component (IC) value from the United States National Fire Danger Rating System contributes the most, followed by the average monthly temperature and the population density. The growth rate warning map results indicate that the southern part of the study area is the key fire prevention area.

Size scale effect on mass burning flux and flame behavior of solid fuels

The study investigates the horizontal fuel size effect on free-burning fires for PMMA plates and wood cribs. The fuel size effect on mass burning flux and flame behavior is mainly discussed and compared with typical pool fires. For the PMMA plate and liquid pool, when the fuel size is small (< 10 cm), either the 3D sidewall burning of PMMA or the container wall heated by flame can promote the burning flux at the horizontal projection area. As the fuel size increases, these side wall burning or heating effects decrease, causing the drop in burning flux with fuel scale for both the PMMA plate and liquid pool. For small-scale wood cribs, fire cannot self-sustain due to the large airflow cooling. With the increase in wood crib size, the burning rate first remains constant and then gradually increases, driven by the enhanced internal radiation. As the fuel size increases above 20–30 cm, the flame radiation dominates the burning flux for all fuel types. Fire dynamics simulator (FDS) was adopted to simulate the horizontal size effect by setting a varied fire source (horizontal projection) area. First, the flame geometry and heat release rate (HRR) of simulations were validated against experimental results. Subsequently, the validated fire model generates cases covering a broad range of fire scales. Finally, a new correlation of flame height with the fire heat release rate and fuel size is proposed, and its prediction capability is validated in the numerical fire modeling. This study quantifies the size effect on the burning rate for common solid fuels and provides valuable information for the numerical modeling of multi-scale fires.

Assessing thermal hazards and toxicity of raw biomass particles from prevalent agricultural crops in China

Fire and explosion hazards pose significant safety concerns in the processing and storage of biomass particles, warranting the safe utilization of these particles. This study employed scanning electron microscopy, thermogravimetric analysis, and cone calorimetry to investigate the thermal hazards and toxicity of raw biomass particles from four prevalent agricultural crops in China: rice, sorghum, corn, and reed. Among the samples, corn exhibited the highest heat output of 8006.82 J/g throughout the thermal decomposition process. The quantitative evaluation of critical heat flux, heat release rate intensity, fire growth rate index (FIGRA), post-ignition fire acceleration (PIFA) and flashover potential (X) revealed a substantial fire risk inherent to all the examined straw samples. Notably, corn displayed the lowest FIGRA value of 8.30 kW/m2 s, while rice demonstrated the minimum PIFA value of 16.11 kW/m2 s. Moreover, the X values for all four biomass particle types exceeded 10 under varying external heat flux levels, indicating their high propensity for fire hazards. Analysis of CO and CO2 emissions during combustion showed all four biomass samples exhibited high concentrations throughout, from the initial stages to the end. The present study offers crucial insights for formulating comprehensive fire safety guidelines tailored to the storage and processing of biomass particles.

Study on the window spill fire plume trajectory of over-ventilated intermediate-scale compartment fires

The fire plume behavior of over-ventilated compartment fire is believed to be related with the façade fire. When the fire plume is reattached to the façade wall, the combustible materials over building wall are potential to be ignited soon. To investigate the window spill fire plume trajectory of over-ventilated intermediate-scale compartment fires, a modeling of fire plume trajectory is set up by using the energy conservation equation and spread theory. The temperature history of over-ventilated compartment fire is conducted by using a 1.35 m (L) × 1.35 m (H) × 1.35 m (W) compartment with window opening aspect varied from 1.12 to 4.44 and HRR differed from 200 kW to 1000 kW. The temperature of fire plume is recorded by the thermocouple mesh and the IR camera. It shows that the modelling theory could be used to predict the shape of fire plume. It agrees well with experimental result. The heat release rate of compartment fire is found to impact little influence on the shape of fire plume regarding a fixed opening dimension. It could provide a reasonable method for fire plume trajectory prediction of the intermediate-scale enclosure fire under an over-ventilated condition.

Risk Assessment of Hydrogen Cyanide for Available Safe Egress Time in Fire Simulation

The majority of fatalities in building fires are attributed to asphyxiation caused by toxic gases. Hydrogen cyanide (HCN) is one of the toxic gases that can be released during a fire, posing a lethal risk to humans even at low concentrations. However, analysis of the risk posed by HCN in fire risk assessments using fire simulations is relatively rare. This study conducted fire simulations to examine the potential risks of HCN to occupants during a fire. The simulations considered various fire conditions in residential buildings by varying fuel types, fire growth rates, and HCN yields. The relative risk score (RRS) was derived based on the time to reach the threshold values of parameters considered critical for life safety. The results of the fire simulations indicated that the RRS for HCN was approximately 20–40 points higher than that of O2, CO, and CO2, reaching a maximum of 92 points. However, the risk posed by HCN was found to be limited in comparison to the risks associated with temperature and visibility. Nevertheless, considering that the primary cause of fatalities in fires is asphyxiation due to toxic gases, HCN must be regarded as a critical factor in fire risk assessments. Additionally, since HCN yield values can increase up to nine times depending on temperature and ventilation conditions, the risk posed by HCN could be significantly higher.