Introduction. The text of draft amendments to Technical Regulation “General requirements to fire safety” was published on January 16, 2020. Draft amendments were developed with in the framework of the“regulatory guillotine”approach. The mission of the proposed amendments was to eliminate excessive and duplicative fire safety requirements, inter alia, requirements applicable to fire safety and fire extinguishing devices that had been established by Technical Regulation of the Eurasian Economic Union (EAEU)“Оn Requirements for fire safety and extinguishing devices” (TR EEU 043/2017).
The purpose of this article is to substantiate the in expediency of, or, on the contrary, the need to make the proposed amendments to Federal Law No. 123-FZ of July 22, 2008 “Technical Regulation of Fire Safety Requirements”.
The body (analytical part) of the work. The proposed amendments to the regulatory legal act titled “Technical Regulations on Fire Safety Requirements” were drafted within the framework of the “regulatory guillotine” approach. In the course of the comparative analysis of effective fire safety requirements and proposed amendments the co-authors came up with recommendations for their improvement. The co-authors of the article present arguments to substantiate the inexpediency of some particular amendments, but at the same time, they support the need to make other amendments to Federal Law No 123-FZ. The co-authors comment on the proposed draft document that has twenty-eight amendments.
Conclusions. Fire safety regulations must represent a single consolidated document, rather than several “fragments” available in the Technical Regulations of the Eurasian Union, Technical Regulations of All-Russian Significance and Technical Regulations of Safety of Buildings and Structures.

Introduction. It is accepted that the depth of heating of the dust/gas/air mixture by the radiation of combustion products S_R is equal to the length L_R of the free path of radiation in the mixture. Numerical simulation of combustion of a gas-air mixture that has inert particles, taking into account the re-radiation of heat by heated particles of the fresh mixture, led to ratio S_R >> L_R. In this work, the analytical assessment of ratio χ_S = S_R/L_R is performed.
One-dimensional problem model. The co-authors determined stationary temperature distribution over the flow of initially cold monodisperse particles suspended in vacuum. Particle velocity V is directed toward a heat-radiating, absolutely black surface that is permeable by particles. Simplifying assumptions are used: radiation consists of two oppositely-directed flows of electromagnetic energy; interaction between particles and radiation is described in the approximation of geometric optics; the temperature inside the particle is the same.
Problem solving. It is shown that χS is determined by V=Vc_p / (ε_T ^0,5, σT_b)³ , where c_p, ε_T, σ, T_b are, respectively, heat capacity per unit volume of the suspended matter, integral emissivity of the particle material, the Stefan-Boltzmann constant, and the surface temperature. For ≤ 2.8, re-emission can be neglected: χ_S ≈ 1. At ≤ 1.2, temperature distribution regulates re-emission: χ_S ≈ 5 ^–1/(2 – ε_T) >> 1.
Solution discussion. The analytical solution satisfactorily describes the available numerical solutions and experimental data for the case of combustion of a dust/gas/air mixture after specifying the parameters of a simplified model: the radiating surface should be understood as the flame front, T_b is the combustion temperature, and c_p is the overall heat capacity of the mixture. The estimate ≤ 1.2 indicates the final high temperature of the gas suspension, the possibility of its autoignition far from the flame, and the need to change initial assumptions when simulating re-emission.
Conclusions. Analytical evaluations make it possible to employ ratios S_R >> L_R and S_R ≈ L_R for the suspension over a thermal radiation source in vacuum. Conditions for the application of the results of simplified simulation of re-emission to the combustion of a dust/gas/air mixture are formulated.

Introduction. At present, the house-building industry, that produces timber structures, is in the process of sufficiently intensive development; however, high flammability of wood is the factor that restrains widespread use of timber in construction. The purpose of this work is to optimize the conditions of application of fire-retardant timber in the construction industry. The co-authors believe that the following problems are to be solved to attain this objective:
● a comparative analysis of the fireproofing efficiency of several fire-proofing agents applied to different species of wood;
● determination of the character of influence produced by fire proofing agents on fire retardant properties of wood.
Methods of research. The fire proofing efficiency of sample compositions designated for wood was measured in compliance with the benchmark testing method specified in GOST R 53292 (p. 6.2). Experiments were launched pursuant to the methodology and with the help of measurement instruments specified in GOST 30244–94 (Method 2) to study the extent of the pine-tree timber flammability suppression. Critical values of thermal loads that may trigger inflammation and flame propagation in timber structures, that can be described using values of the critical surface density of the heat flow, were determined pursuant to GOST 30402–96 and GOST R 51032–97. The toxicity of combustion products and the smoke generation ability of fire-retardant pine-tree samples was assessed using standard methods and measurement instruments pursuant to GOST 12.1.044–89 (paragraphs 4.18 and 4.20).
Research results and discussion. Biological flame retardants, integrated biological flame retardants that also ensure moisture protection, intumescent coatings, lacquers and varnishes that are ready for use and labelled as having group I and II fire-retardant efficiency pursuant to GOST R 53292, were studied in the course of this research project. The co-authors have identified that the mass loss by all fire-retardant compositions is below 9 %, if applied to samples of larch and oak-tree timber, same as if it were applied to standard samples of pine-tree timber.
The findings of the experiment conducted to assess the flammability, ignitibility, flame propagation, smoke generation ability and toxicity of combustion products have proven the maximal efficiency of the composition designated for full-cell pressure impregnation of timber that ensures the properties of the material labelled as G1, V1, RP1, T2, D2.
Conclusions. Hence, the research results have enabled the co-authors to assess the discrepancy between average mass loss values demonstrated by the samples of different species of timber (alder, linden, pine-tree, larch, and oak-tree).
The comprehensive study of flammability properties of timber, treated by compositions that vary in their chemical composition and mode of action of the fire proofing agent, enabled the co-authors to identify the impact produced by versatile fire-proofing agents on different flammability properties of pine-tree timber with regard taken of the fire-safe use of construction materials and constructions of buildings and structures.

Introduction. Corporate resources translate into a strong in-house capacity that ensures sustainable production processes. We present a novel integrated area of activity, whose purpose is to solve problems by identifying the factors of influence, coming from employees of versatile departments (structural units) and focused on industryspecific (sectoral) functions that are part of the comprehensive safety system of an enterprise.
Methods of research. The author employed the established methods of comprehensive safety assurance to analyze a number of approaches. He also explored the features of their application. The author also substantiated the choice of the Lagrange multiplier method, used to formulate the problem of rational allocation of the resource designated for the sustainable performance of functions that assure the comprehensive safety of an enterprise.
Problem statement. The author addresses the problem of rational allocation of the resource (the labor potential), considered as a factor of influence produced on the sustainable performance of industry-specific (sectoral) functions that comprise the system of comprehensive safety of an enterprise.
An exemplary solution. The author offers an example that represents a description of the process of consecutive identification of critical points that are relevant to the impact (a coefficient) produced by the personnel on the sustainable performance of industry-specific (sectoral) functions that contribute to the comprehensive safety of an enterprise.
Conclusions. Solutions for specific tasks, forming part of a methodologically described problem, will make it possible to develop a methodology for the synthesis of the comprehensive safety which is adaptable to different conditions of operation of an enterprise (day-to-day operations, as well as threats and emergencies of natural and man-induced origin), and each is of great economic importance for Russia.

Introduction. Spun reinforced concrete columns are widely used in the present-day international construction practice. Known formulas, used to calculate temperatures of cross sections of reinforced concrete structures, needed to assess their fire resistance limit, are successfully applied to homogeneous structures that have solid sections. However, they are inapplicable to spun reinforced concrete columns due to their structural features. The purpose of this work is to develop a method for solving a thermal problem of spun reinforced concrete columns and adapt existing calculation formulas.
Materials and methods. This work addresses the heating of spun reinforced concrete structures in case of fire. Ansys Workbench was employed to perform the computer simulation needed to study the influence of the characteristics of spun reinforced concrete columns on their heating.
Results and discussion. In the course of the theoretical studies, the effect, produced by column cavities, the heterogeneity of spun concrete and thin walls of these structures on the heating of their cross sections was assessed with regard for the results of full-scale fire tests of spun reinforced concrete columns. Correction coefficients were obtained in order to take account of these factors. A regression equation was derived as a result of the simulation performed in the context of a full-scale factorial experiment involving coefficient k_hol, which takes into account the rising temperature of hollow reinforced concrete structures in comparison with solid ones. K_het heating acceleration coefficient is applicable to spun reinforced concrete structures due to the heterogeneity of concrete in the cross section. This coefficient represents a function of the wall thickness. Coefficient k_th, which allows for the heating acceleration in the course of crack opening in thin-walled structures, varies in the range of 1.00…1.40. The concrete cracking temperature is 550 °C.
Conclusion. A new method allows to solve the thermal problem of fire resistance of spun reinforced concrete columns. The engineering formula used to calculate the temperature in a cross-section was adapted. The results of computer-aided simulation and calculation of temperature values, performed using the adapted formula, show acceptable convergence with the experimental data.

Introduction. Fire risk calculation is performed to substantiate the compliance of space planning solutions of buildings and structures with fire safety requirements. The calculation of time needed for hazardous factors of fire to block evacuation routes is performed with account for unlimited fire propagation. The only system, whose operation is taken into account if the fire risk value is exceeded, is the smoke ventilation system. The operation of other fire safety systems is disregarded due to the unavailability of reliable engineering methods of analysis of their influence on fire escalation. The problem of development of modified mathematical models, used to analyze the fire escalation pattern, with account to be taken of the process of fire extinguishing and its influence on fire propagation, is relevant. The purpose of this research is to develop common principles that allow to take account of the pattern of fire suppression in solid materials and combustible liquids by fire extinguishing substances having various origins and degrees of dispersion, if the fire extinguishing substances are added to integrated and zone models of development of hazardous factors of fire escalation.
Calculation methodology. The calculations are based on the equation compiled in furtherance of principles of conservation of mass and energy in the flame zone above the surface of the combustible material.
Research results. The co-authors suggest general principles for the introduction of a flame suppression pattern into integrated and zone models used to analyze the evolution of hazardous factors of indoor fires. The coauthors present the main provisions and parameters needed to modify integrated and zone models in case of different methods of fire extinguishing. The co-authors have analyzed hazardous factors of fire with account for the flame suppression pattern.
Conclusions. The co-authors applied the research findings to develop the modified integrated and zone models that allow to analyze the dynamics of hazardous factors of fire with account for the extinguishing of solid materials and combustible fluids by fire extinguishing substances having various origins and degrees of dispersion.

Introduction. The relevance of this work resides in the need to perform an unbiased comparative assessment of fire extinguishers. The focus must be placed on the efficiency of a fire-fighting agent, as it has a major impact on the process of fire extinguishing. The purpose of this work is to confirm the applicability of a dimensionless efficiency indicator of portable fire extinguishers, assess the measurement accuracy (correctness and precision) and their statistical values.
Materials and methods. The co-authors used the methodology specified in GOST R 51057–2001 applicable to the fire extinguishing of class A model fire seats. The model fire seat had samples of materials attached to its upper edge at the angles whose values were obtained using a specialized test bed. A specialized test bed was used to perform the testing and identify the sample’s inclination angles that prevented the fire extinguishing agent, applied to their surface, from streaming down or crumbling. The accuracy (correctness and precision) was assessed pursuant to the methodologies specified in GOST R ISO 5725-1–2002, GOST R ISO 5725-6–2002. The statistical significance of measurements was assessed using Student’s t-test.
Results and discussion. The co-authors offer the results of the experiments aimed at the identification of an inclination angle of the fire seat surface that prevents the fire extinguishing agent from streaming down or crumbling. The results of comparative fire testing of fire extinguishers that contain quick setting foam and powder are provided. The formula of a dimensionless efficiency indicator, applicable to portable fire extinguishers, is provided, and its applicability is proven.
Conclusions. The measurement accuracy assessment, performed pursuant to the methodologies, specified in the regulations, has shown the effectiveness of mean arithmetic values of all indicators applied to calculate P_eo efficiency indicator. The assessment of the statistical significance of experimentally obtained values of all indicators, performed with the help of Student’s t-test, has demonstrated that the discrepancy of their mean arithmetic values is reliable and it doesn’t have a random nature. The superiority of the quick setting foam extinguisher over the powder one was proven in an experiment. The value of its P_eo efficiency indicator exceeds the one of a powder extinguisher 50-fold due to the comprehensive impact made by the extinguishing agent and the construction of a fire extinguisher.

The purpose of this work has nothing to do with the measurement of this contradiction or its pace; rather, it is aimed at the observation of facts and identification of the smoothest way (means, logistics) to resolve this problematic situation. This approach stems from the fact that the recent international centennial practice has shown that the “relief” of years-long social tensions (that hamper any further development) by means of revolutionary public changes does not lead to protection of safeguarded public values (primarily, human health and lives, as well as human welfare); everything happens the other way round.
The Centre for Education and Research into the Management of Supervisory Activities of the Academy of State Fire Service of Emercom of Russia has accumulated successful experience in application of the risk-oriented model of regulation of relations in the technosphere (the case of fire safety assurance aimed at the resolution of problematic situations in the process of design, operation, and organization of supervisory activities, fire investigations performed within the framework of court-appointed examinations, in the process of revising the legal and regulatory framework). This experience enables actors to make conclusions of public significance. The main conclusion deals with conversion of the present-day legal and regulatory framework focused on public relations in the field of the technosphere into the framework full of striking and proactive chaos. Specialists, trained to apply the standard model of state supervision, are unable to comprehend and adequately apply the effective legislation.
The co-authors have formulated the assumption that the introduction of a risk-oriented model into the system of state supervision requires a drastic change in the professional mindset (professional culture) of executives responsible for governing the relations dealing with the technosphere, or (fire) safety assurance (employees of licensing and authorization departments)).

International and Russian regulatory documents, setting the rules of application of arc-fault detection devices (AFDD) to electrical installations serving residential and public buildings, are considered. An overview of scientific research into the effectiveness of AFDDs is presented. Cases of arcovers are provided, followed by the analysis of their fire hazard. Cases of possible false alarms of AFDDs and methods of reducing the number of such shutdowns are demonstrated. The research data on AFDD operation are generalized and respective conclusions are drawn.