Introduction. At the moment, the provisions of regulatory documents governing fire risk calculations need up­dating and clarification in narrowly focused problem issues.
Methods. The existing regulatory framework is presented for the most part by the departmental order of Emercom of Russia. With the development of fire-fighting and fire-fighting technologies, as well as computational methods capable of simulating this or that emergency situation, the possibility of substantiating various fire development scenarios has expanded. Experiments on calculations for objects of various functional purposes, issued by leading scientific organizations of our country, as well as specialists involved in fire risk calculations, have shown the re­levance and the need for changes and clarifications in the regulatory framework governing these ­types of work. At the same time, it should be noted that the above-mentioned departmental norms and recommendations, ­despite their practical significance, do not reflect the issue of using fire doors for practical purposes and cannot serve the tasks that modernity sets for itself.
Results and discussion. Due to the existing problems of design and state examination, commissioning of construction supervision bodies and supervision of objects already operated by state fire supervision authorities Emercom of Russia, is almost universally preceded by the development of fire risk calculations in order to confirm fire protection objects. The peculiarity of such calculations is, first of all, the need to present those to a specific capital construction object, while in some cases even the presence of all the fire protection systems of a building does not en­sure people’s safety due to various reasons. The main one of which is the rapid blocking of evacuation routes by fire and resulting in death of people.
Conclusions. The use of fire doors in the calculations of fire risk, which are used more than once at various protec­tion facilities and confirmed their effectiveness at the implemented facilities, seems appropriate to reflect in the relevant regulatory documents, which will greatly improve the actual safety of people.

Introduction. Polymer materials are widely used, however the actual object is to provide polymers combustion ­model to predict their behavior under fire, and reducing flammability. The work is devoted to the experimental ­study and numerical simulation of flame propagation over the surface of horizontally and vertically placed slabs of polymer in still air.
Methods. The object of the investigation was cast polymethylmethacrylate (PMMA). The experiment was focused on measurement of the spatial distributions of the temperature and species concentrations of the PMMA pyrolysis and combustion products in the gas-phase over the surface of PMMA. Temperature was measured by micro­thermocouple with diameter of 50 microns. Probe mass-spectrometry was used for the measurement of the spa­tial distribution of species concentrations in the flame.
Results and discussion. The main species (mehylmethacrylate (MMA), O2, CO2, H2O, N2, C2H4 (ethylene), C3H6 (propylene)) were identified and their concentration profiles were measured on the different distance from the flame front. The chemical structure of the flame was established to be in good agreement with the thermal one. The size of the “dark zone” of the flame, in which the temperature near the surface of the polymer is minimal, correlated well with the size of the oxygen-free zone. The mass burning rate, the velocity of flame propagation, the width of the pyrolysis zone and the temperature distribution in the condensed phase were also measured. Based on the experimental results, densities of conductive and radiation heat fluxes from the flame to the fuel surface were deter­mined. Calcula­tion of the radiation heat flux density was carried out under the assumption of an optically thin ­model. Modeling of the horizontal flame propagation over the PMMA surface was carried out using a two-dimen­sional conjugated laminar combustion model that takes into account one-step reactions — the decomposition reaction of PMMA in the condensed phase and the oxidation of decomposition products in the gas phase. Modeling of the vertical flame propagation over the PMMA surface was carried out using economical model of FDS.
Conclusion. The model was shown to describe satisfactorily the experimental data such as the mass burning rate, flame propagation velocity, as well as the temperature distribution and concentration of species near the flame front.

Introduction. Fires at high-rack storages with a discrete fire load develop dramatically fast, while fire detection and suppression systems might activate too late, which leads to significant property damage. The objective of this work is to demonstrate applicability of the thermal pyrolysis model in predictions of fire development in high-rack storage facilities.
Methods. The simulations are performed using FDS 6.6. In the thermal pyrolysis model, the solid material is ex­posed to inert heating until its surface temperature reaches the ignition temperature; combustible material then ignites and burns at a prescribed burning rate. The advantage of this approach is its simplicity and a limited number of input parameters, which include ignition temperature, mass loss rate per unit area, burn-out time and heat of gasification. The model parameters selection procedure is based on literature and experimental data. In this work, FDS simulations are performed for 3- and 5-tier high racks with 2 rows of cardboard boxes (243 = 24 and 245 = 40 boxes in total). Fire suppression systems are not activated.
Results and discussions. Simulations results show that high-rack storage fire dynamics can be replicated using thermal pyrolysis model provided that model parameters are properly selected. Fire growth mechanisms include upward and horizontal flame spread over the combustible surfaces. Net heat flux and surface temperature distributions, in-rack gas velocity and temperature are also reported. When number of tiers is increased to 5 the heat ­release rate grows faster compared to the 3-tier case.
Conclusions. Thermal pyrolysis model enables reasonable replication of high-rack storage fire dynamics, which is proven by comparison with the full-scale experimental data. The model could be used to simulate fire dynamics in rack storages of different configurations at different ceiling heights, with the purpose of predicting fire detection and the performance of fire suppression systems.

Introduction. The data given in the article show that the problem of fire safety in motor vehicles is highly relevant. The purpose of the article is to develop a scientifically based method of research for the copper conductor exposed to overcurrent to find the reason of its damage when making a fire investigation.
Materials and methods. The research was conducted using the JSM-6390LV scanning electron microscope for energy dispersive spectroscopy. The surfaces of the copper conductor rupture were analyzed without any preliminary sample preparation.
Results and discussion. The analysis of the experimental evidence demonstrates that the temperature of the copper conductor exposed to current overload varies significantly along its length. It was found through the field studies and experimental results that the rupture of the copper conductor under the action of overcurrent happens in the sections that have prestress due to the plastic deformation. The experiment proved that the formation of ball fusing of the copper conductor exposed to current overload may take place at a substantially lower temperature than that of the copper smelting. The analysis of the theoretical data shows that during the current overload not only thermal and electromagnetic processes but also plastic distortion occur at the copper conductor. It also demonstrates that the strand connection of copper wires results in a fire hazard not in every instance.
Conclusion. A method for differentiating fire damages at the copper conductor (current overload, short circuit) was suggested. The current overload has such features as blistering or ball fusing in the bending points and the lack of any signs of mass transfer. It was found that the features of the damaged surfaces of the copper conductor exposed to overcurrent are stable and not subject to changes in the natural storage conditions. The data given in the article can be used by specialists when making an expert examination of copper conductors from the fire locations, identifying a mechanism for their damage and, finally, a cause of fire.

The article provides information about the fire deaths and fire injuries in the world at the beginning of the XXI century. An estimate of the total number of fire deaths and fire injuries on Earth was made. According to the data of Center of Fire Statistics (CFS) of International Association of Fire and Rescue services (CTIF) total number of fire deaths in the world can be estimated at 100–120 thous. inh. per year and total number of fire injuries at 300–350 thous. inh. per year. CFS CTIF received data from fire services of the countries. The values of the fire death risk (by 54 countries) and fire injury risk (by 43 countries) are presented. It is shown that the fire injury risk is 3–4 times higher than the fire death risk. The data on mortality in the world from fire, heat and hot substances according to the World Health Organization (WHO) is given — an average of 189 thousand people per year (for the period of 2000–2016). A comparison of statistics on the death of people from fire, heat and hot substances according to WHO data and fire deaths according to the CPS CTIF in 35 countries in 2012 and in 17 countries of the world in 2016 was made. The total data set for the countries represented varies by 35–45 %. For the first time, sufficiently reliable estimates of fire deaths and fire injuries in the world were obtained.

The efficiency of robotic fire monitors depends on the fire extinguishing method chosen for these programmable devices to the large extent. This efficiency depends on the correct target, it means on the correct positioning. This issue contains final materials based on fire tests conducted according to the program and methods of VNIIPO in 2014–2018 years. Options for RFM positioning with respect to fire area are described. Curves of coverage by ­static high-angled or frontal streams are given. It is shown that curves depend on the angle of stream attack to the protected surface. The features of fire extinguishing with static streams at angles of attack of 90° and less than 90° are given. The parameters at which fire is to be extinguished by static stream are given for stream contact spot with surface and covered area.

Introduction. The purpose of the study is to formulate and analyze problems that should be solved before implementing the ideas of fire fighting in high-rise buildings by using unmanned aircraft systems (UAS). To achieve this purpose, the following concepts were considered and assessed: the possibilities of water and water-based fireextinguishing solutions delivery to the fire source from a ground pumping station using a hose line; delivering compression foam along a vertically positioned hose line; and, the possibilities of UAS for fire extinguishing; supply of fire extinguishing powders and aerosols placed on the UAS to the center of fire. Methods. The adopted in Russia hydraulic calculation methods, the results of the experimental studies on the compression foam, the existing theoretical and practical advances in the field of fire-extinguishing by jet delivering fire-extinguishing substances. Conclusions. The results achieved show that one of the ways to increase fire extinguishing capability in high-rise buildings can be provided by applying UAS for continuous horizontal supply of water based solution or compression foam to the center of fire, as well as supply of fire extinguishing powders and aerosols using powder fire barrels and pyrotechnic cartridges. However, to implement each of these methods, certain problems need to be solved. They are: the fire extinguishing height limitations a large capacity of UAS needed; a hydraulic calculation methodology for compression foam supply systems; safe use of UAS under the conditions of compression foam separation; the possibilities for developing supply equipment, which can be utilized by the UAS.

Regulatory requirements on the classification of hazardous areas are considered. Comparative analysis of classes according to existing standards is conducted. New classification of hazardous areas is presented and explana­tions to the places of their occurrence are presented. Features in determining the geometric dimensions of zones are marked. Comparison of categories of fire-explosion of premises with classes of hazard zones is made.