Fire hazard of substances, various materials - a set of properties that characterize their ability to quickly ignite and further spread the combustion process, which may result in a fire or even explosion.
Classification of buildings based on functional fire hazard
Within the framework of this aspect, it is necessary to interpret some important concepts. Buildings (their parts, fire compartments, structures) - premises (groups of rooms) that are functionally interconnected by such a criterion as a functional fire hazard.
Depending on the methods of their operation and on the degree of threat of being inside them in a situation of fire (taking into account their age, probability of being in a state of sleep, physical condition, etc.), it is customary to distinguish the following classes:
- F1 - the class of functional fire hazard of a building intended for temporary residence, residence of people (pre-school institutions, hotels, single and multi-apartment dormitories, specialized houses for the disabled and elderly, hospitals, etc.).
- F2 - a class that includes the premises of spectacular, various kinds of cultural and educational institutions (cinemas, circuses, libraries, theaters, dance and concert halls, sports facilities with stands, museums, etc.).
- F3 - the class of functional fire hazard of the building of enterprises whose activities are related to public services (trade institutions, public catering organizations, clinics, banks, train stations, post offices, etc.).
- F4 - a class that includes buildings of educational, research institutions, editorial and publishing, information and design organizations, fire stations, buildings of government agencies.
- F5 - the class of functional fire hazard of premises, such as bookstores, storage (production) premises (this also includes similar buildings from the above classes, as well as laboratories).
Why is this classification needed and where is it indicated?
The class of premises for fire hazard is indicated in the special design documentation for the relevant facility. This classification is used to establish requirements for a constructive and space-planning decision regarding buildings, as well as the regulation of these requirements (in relation to the evacuation of people in a fire).
Categories of explosion and fire hazard of buildings and premises
The concept of “categorization”, from the point of view of the aspect under consideration, is interpreted as the correlation of structures (buildings) for fire, explosion hazard to certain categories. It is mandatory, and the following objects are subject to it:
- All industrial buildings (structures, structures), workshops, laboratory and industrial premises (functional fire hazard class F5.1).
- Any outdoor installations in the form of a complex of technical equipment and devices that are located outside buildings (structures).
- Warehouse buildings (structures, structures), as well as parking lots (excluding repairs and maintenance), book storage facilities , storage facilities and archives (functional fire hazard class F5.2).
Categorization is carried out exclusively for warehouse, industrial premises. The determination of premises for fire hazard proceeds at the design stage on the basis of fire safety standards or departmental documents developed on their basis.
Based on the fire and explosion hazard, all rooms are divided into five categories: A, B, V1-B4, G, D.
The categories of explosive and fire hazard of premises are determined specifically for the most adversely affecting fuel (relative to fire and explosion in devices, rooms), its quantity, the nuances of the technological process, and fire hazard properties.
Categorization of warehouse, industrial premises by fire, explosion hazard
Categories of premises | The main characteristics of the materials and substances present in the room |
1. A (explosive) | Flammable liquids, flammable gases (flash point above 28 ° C), which in an amount sufficient to form explosive liquid-gas mixtures, and which, when ignited, develop an explosion overpressure of ˃ 5 kPa Substances, materials that can explode, burn in the process of interaction with oxygen, water or with each other (if the value of the calculated overpressure of the explosion is ˃ 5 kPa) |
2. B (explosive) | Flammable fibers or dust, flammable liquids (flash point above 28 ° C) in an amount that forms explosive dust or vapor-air mixtures, during the ignition of which an excess explosion pressure of ˃ 5 kPa appears |
3. V (fire hazardous) | Liquids (combustible, slow-burning), substances (solid combustible, slow-burning), including fibers and dust, as well as materials and substances that can only burn in the process of interaction with oxygen, water or with each other (if the room in which they are located, do not fall under the above categories) |
4. G | Non-combustible materials, all kinds of substances (in a hot, hot or molten state) that during the process of processing emit heat, flame, sparks, flammable liquids and gases, solids intended for disposal as fuel. |
5. D | Non-combustible materials, various kinds of substances in the cold state. |
Building Category Guidelines
The determination of the fire hazard category of premises is carried out on the basis of the following indications of a non-mandatory nature:
1. The object belongs to the first category (A), provided that the total area of its building exceeds the total area of all rooms inside it (200 m 2 ) by 5%. It is allowed not to classify the building as category A (explosive) if its total area does not exceed the established value (25%) calculated from the total area of all rooms located in it (no more than 1000 m 2 ), provided they are equipped with special automatic fire extinguishing installations.
2. A building falls under category B, which, firstly, cannot be classified as category A. And secondly, it has a value of the total area of its premises (A, B) that exceeds 5%, calculated from the total area of the entire complex of premises located inside it (or 200 m 2 ). It is permissible not to classify the building on the condition that the total area of its premises (A, B) does not exceed a value of 25% calculated from the total area of all rooms located inside it (no more than 1000 m 2 ) if they are equipped with installations special automatic fire extinguishing.
3. The conditions for classifying a building as Category B are:
- it does not fall into any of the above categories;
- the value of the total area of the premises (A-B) exceeds 5% (or 10% in the absence of rooms of other categories) of the total area of the premises located inside the building.
It is permissible not to classify a building if the total area of its premises (A-B) does not exceed 25% of the total area of all rooms located inside it (no more than 3500 m 2 ), provided they are equipped with special automatic fire extinguishing installations.
4. The conditions for classifying a building as category G are:
- it does not fall into any of the above categories;
- the value of the total area of premises (AG) exceeds 5% (or 10% in the absence of rooms of other categories) of the total area of premises located inside the building.
It is permissible not to classify a building as a category if the total area of its premises (A-G) does not exceed 25% of the total area of all rooms located inside it (no more than 5000 m 2 ), provided that the equipment is equipped with special automatic fire extinguishing facilities of category A IN.
5. The building is classified as category D provided that it does not fall into any of the above categories.
Determining the fire hazard category of buildings serves as a guideline in determining the probability of individual fires (level of fire resistance of buildings) and solid (building density).
How to calculate the category in question?
In order to calculate the category of fire hazard, you will first need to collect data on the corresponding room (its plan is mandatory). Next, make measurements of the walls and the height of the ceilings of the areas most dangerous during the fire (this is done directly by fire safety specialists). Then determine the temperature regime of the evaluated object, as well as the material from which the floor covering is made. It is important to establish the presence of special fire extinguishing systems and ventilation outlets.
Calculation of the fire hazard category - calculations that allow you to establish the hazard class of the explosion (fire) based on the analysis of stored, used and processed substances, as well as the process and equipment. It is regulated by Russian legislation in the field of fire safety.
Calculation of the fire hazard category of the premises is carried out in order to formulate the relevant requirements with regard to the area under consideration, which are aimed at reducing the likelihood of a fire, as well as adequate provision of professional fire protection for people (valuable property) in the event of its onset.
Classification of structures based on constructive fire hazard
The existing class of structural fire hazard of a structure (building) is established by the degree of participation of the corresponding building structures in the process of fire development and the formation of fire hazard factors.
There are 4 classes in the framework of this aspect: C0, C1, C2, C3. It is important to note that the class of constructive fire hazard of a building is directly dependent on the fire hazard classes of the main load-bearing, building envelope (building): crossbars, walls, ceilings, stairwell walls, columns, fire barriers, trusses, partitions, coatings, platforms and marches stairs. The fire hazard in relation to filling the openings enclosing the building structure is not standardized (except for openings of fire barriers).
Class C0 is the best in terms of fire safety. Here, all structures are made exclusively of non-combustible materials (they do not burn, do not produce a thermal effect, are not damaged, and do not form toxic smoke emissions).
Class C1 - the use in buildings of structures made using slow-burning materials.
Class C3 - most structures (in addition to walls, fire barriers, structural staircases and partitions), which are not subject to fire requirements.
Fire hazard classification of structures
Building structures in this aspect are divided into classes:
- K0 - fire hazard class of structures, which includes non-fire hazardous structures;
- K1 - class of low fire hazard structures;
- K2 - class of moderate fire hazardous structures:
- K3 - class of fire hazardous structures.
The numerical values of the criteria by which the assignment of building structures to the corresponding class proceeds are determined on the basis of the methods established by regulatory documents regarding fire safety.
The definition of the fire hazard class of structures is prescribed in Appendix 6 of the Federal Law (No. 123 dated 07.22.08).
Requirements for the location of premises of a different class of functional fire hazard within the same building
They have the following form:
1. Premises with a functional fire hazard class F2 – F4 are allowed to be placed within the same fire compartment (including technical rooms and storage rooms).
2. A prerequisite is the presence of fire hydrants in an amount of at least three pieces.
3. It is permissible to design evacuation staircases (general purpose) for rooms inside one object (the functional fire hazard of the rooms is different), provided they are equipped with non-smoke-filled fire doors of the second type with filling door openings. In this case, there must be an appropriate calculation of the validity of these buildings, taking into account the dynamics of hazardous factors preceding the fire; the required conditions for the evacuation of people must be provided.
4. Cinema complexes, the total capacity of the cinema halls of which is more than 300 seats, must be allocated to separate fire compartments and provided with separate evacuation exits or stairwells (at least two).
5. Buildings should be equipped with the following elements:
- professional automatic fire extinguishing installations, as well as special address type fire alarms;
- systems of special smoke protection;
- collective and individual rescue equipment;
- fire warning system, starting from the fourth type;
- external and internal fire water supply;
- power supply of special fire protection systems, starting from the first category of reliability.
6. The differentiation of premises of a different class of functional fire hazard within the same building is carried out by means of fire barriers of the second and first types. Also, the distinction between the respective fire compartments is made using fire walls and ceilings of the first type.
7. In the process of designing multi-functional buildings, calculations are necessarily made that will allow us to justify the correctness of previously adopted space-planning decisions.
Ensuring proper fire safety
All structures (buildings) are objects with a certain degree of fire hazard, most of which have various kinds of combustible substances. Their number may be sufficient to cause substantial damage. Also there is most often an oxidizing agent in the form of oxygen and an ignition source (conditions for a fire).
The main fire safety problem of a building is to bring its fire hazard into proper condition, in which the probability of a fire is excluded, and in the situation with a fire, protection of people (valuable property) is professionally ensured.
Proper fire safety is achieved through the following:
- fire prevention systems ;
- organizational and technical complex of measures;
- special fire protection systems.
In this regard, the general condition regarding ensuring proper fire safety of a structure is as follows: it will be achieved provided that the actual amount of measures aimed at ensuring proper fire safety matches the amount of measures regulated and approved by the relevant rules and norms.
What does the incorrect classification of a building lead to?
It is generally accepted that a competent and correct definition of the class of functional fire hazard is a guarantee of security. A set of rules regarding fire safety are mandatory measures that must be clearly observed. However, these rules are established through certain characteristics, one of which is the assignment of the functional fire hazard class of a structure (building).
In order to prevent a fire, it is important to correctly classify the corresponding building (building, structure, fire compartment). It is the final decision that will be taken into account in the process of drawing up the above rules for various organizations.
If it is not installed correctly, then the current rules will be grossly violated, and as a result, the likelihood of a fire will increase significantly. This identification in relation to the functional purpose is carried out according to three main characteristics, the most important of which is classification based on the functional fire hazard of structures (buildings).
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