Fire hazard classes. Fire safety requirements for building materials How many fire hazard indicators have been established for building materials

I. Classification building materials By fire danger

Building materials are characterized only by fire hazard.
The fire hazard of building materials is determined by the following fire-technical characteristics: flammability, flammability, flame spread over the surface, smoke-generating ability and toxicity.
Building materials are divided into non-combustible (NG) and combustible (G). Combustible building materials are divided into four groups:

P (low flammability);
G2 (moderately flammable);
GZ (normally flammable);
G4 (highly flammable).

81 (flammable);
82 (moderately flammable);
83 (highly flammable).

RP1 (non-proliferating);
RP2 (low-propagating);
RPD (moderately spreading);
RP4 (highly spreading).

D1 (with low smoke-generating ability);
D2 (with moderate smoke-generating ability);
DZ (with high smoke-generating ability).

T1 (low hazard);
T2 (moderately dangerous);
TK (highly hazardous);
T4 (extremely dangerous).

II. Classification of building materials by degree of fire resistance

BUILDING CONSTRUCTION

Building structures are characterized by fire resistance and fire hazard.
An indicator of fire resistance is the fire resistance limit. The fire hazard of a structure is characterized by its class.
Fire resistance limit building structures is established by the time (in minutes) of the onset of one or sequentially several, normalized for a given design, signs of limit states:

• loss of bearing capacity (R);
• loss of integrity (E);
• loss of thermal insulation ability (I).

KO (non-fire hazardous);
K1 (low fire hazard);
K2 (moderate fire hazard);
Short circuit (fire hazardous).

BUILDINGS, FIRE COMPARTMENTS, PREMISES

Buildings, as well as parts of buildings separated by fire walls - fire compartments (hereinafter referred to as buildings) - are divided according to degrees of fire resistance, structural and functional fire hazard classes.
The degree of fire resistance of a building is determined by the fire resistance of its building structures
The class of structural fire hazard of a building is determined by the degree of participation of building structures in the development of a fire and the formation of its hazardous factors.
The functional fire hazard class of a building and its parts is determined by their purpose and the characteristics of those located in them. technological processes.
Buildings and fire compartments are divided according to degrees of fire resistance according to the table.
The load-bearing elements of a building include structures that ensure its overall stability and geometric immutability in case of fire - load-bearing walls, frames, columns, beams, crossbars, trusses, arches, braces, stiffening diaphragms, etc.
Fire resistance limits for filling openings (doors, gates, windows and hatches) are not standardized, except for specially specified cases and filling openings in fire barriers.
In cases where the minimum fire resistance limit of the structure is specified as R15 (R 15, REI15), it is allowed to use unprotected steel structures regardless of their actual fire resistance limit, except in cases where the fire resistance limit of the load-bearing elements of the building according to the test results is less than R 8

In accordance with SNiP 21-01-97 “Fire safety of buildings and structures”, the fire hazard of building materials is characterized by the following indicators:

flammability;

flammability;

spread of flame over the surface;

smoke generating ability;

toxicity of combustion products.

Based on flammability, building materials are divided into non-combustible (NG) and combustible (G). Combustible building materials are divided into four groups:

G1 – low-flammable;

G2 – moderately flammable;

G3 – normally flammable;

G4 – highly flammable.

Based on flammability, combustible building materials are divided into three groups:

81 – hardly flammable;

82 – moderately flammable;

83 – highly flammable.

Based on the spread of flame over the surface, combustible building materials are divided into four groups:

RP1 – flame retardant;

RP2 – low flame propagation;

RP3 – moderately spreading flame;

RP4 – highly propagating flame.

The group of building materials for flame propagation is established only for the surface layers of roofing and floors (including carpeting).

According to their smoke-generating ability, combustible building materials are divided into three groups:

D1 – with low smoke-generating ability;

D2 – with moderate smoke-generating ability;

D3 – with high smoke-generating ability;

Based on the toxicity of combustion products, combustible building materials are divided into four groups:

T1 – low-hazard;

T2 – moderately hazardous;

T3 – highly dangerous;

T4 is extremely dangerous.

Fire and explosion hazard conditions when using substances and materials

To ensure fire and explosion safety of the processes of production, processing, storage and transportation of substances and materials, it is necessary to use data on fire and explosion hazard indicators of substances and materials with the safety factors given in Table. 3

Reproducibility of the method for determining the fire danger indicator at a confidence level of 95%;

Safe temperature, °C;

Permissible flash point, °C;

Flash point in a closed crucible, °C;

The most important quality of the material used in construction is its flammability. Flammability is the property of a material to resist the effects of flame. Therefore, five flammability groups are legally defined. Four groups of flammable materials and one non-flammable. IN Federal law No. 123 they are defined by abbreviations: G1, G2, G3, G4 and NG. Where NG stands for non-flammable.

The main indicator when determining the flammability group of a particular material is the burning time. The longer the material can withstand, the lower the flammability group. Burn time is not the only indicator. Also, during fire tests, the interaction of the material with the flame will be assessed, whether it will support combustion and to what extent.

The flammability group is inextricably linked with other parameters of the fire resistance of the material, such as flammability, release of toxic substances and others. Taken together, the fire resistance indicators make it possible to judge the flammability class. That is, the flammability group is one of the indicators for assigning a flammability class; it precedes it. Let's take a closer look at the elements of assessing the fire resistance of a material.

All substances in nature are divided into. Let's list them:

• Non-flammable. These are substances that by themselves cannot burn in air. But even they can, when interacting with other media, be sources of formation of flammable products. For example, interacting with oxygen in the air, with each other or with water.
• Difficult to burn. Building materials that are difficult to combust can only ignite when exposed to an ignition source. Their further combustion cannot occur on their own when the ignition source ceases; they go out.
• Combustible. Combustible (combustible) building materials are defined as capable of ignition without an external ignition source. Moreover, they quickly ignite if such a source is available. Materials of this class continue to burn even after the ignition source disappears.

It is preferable to use non-combustible materials in construction, but not all are widely used construction technologies may be based on the use of products that may have such a remarkable property. More precisely, there are practically no such technologies.

The fire safety characteristics of building materials also include:

• flammability;
• flammability;
• the ability to release toxins when heated and burning;
• intensity of smoke formation at high temperatures.

Flammability groups

The tendency of building materials to burn is indicated by the symbols G1, G2, G3 and G4. This series begins with the flammability group of slightly flammable substances, designated by the symbol G1. The series ends with a group of highly flammable G4. Between them there is a group of materials G2 and G3, which are moderately flammable and normally flammable. These materials, including the weakly flammable G1 group, are mainly used in construction technologies.

The flammability group G1 shows that this substance or material can emit flue gases heated no higher than 135 degrees Celsius and is not capable of burning independently, without external ignition action (non-flammable substances).

For completely non-combustible building materials characteristics fire safety are not studied and standards for them are not established.

Of course, the G4 group of materials also finds its application, but due to its high tendency to burn, it requires additional fire safety measures. As an example of such additional measures, there can be a floor-by-floor fire-proof cut-off made of steel inside the ventilation façade structure, if a windproof membrane with flammability group G4, that is, flammable, was used. In this case, the cutoff is designed to stop the flame inside the ventilation gap within one floor.

Application in construction

The use of materials in the construction of buildings depends on the degree of fire resistance of these buildings.

The main classification of building structures according to fire safety classes is as follows:

To determine which flammability materials are acceptable in the construction of a particular facility, you need to know the fire hazard class of this facility and the flammability groups of the building materials used. The fire hazard class of an object is established depending on the fire hazard of the technological processes that will occur in this building.

For example, for the construction of buildings for kindergartens, schools, hospitals or nursing homes, only materials of the flammability group NG are allowed.

In fire-hazardous buildings with fire resistance of the third level, low-fire K1 and moderate-fire K2, it is not allowed to make external cladding of walls and foundations from flammable and low-combustible materials.

For non-load-bearing walls and translucent partitions, materials can be used without additional fire hazard testing:

• structures made of non-combustible materials - K0;
• structures made from materials of group G4 - K3.

Any building structures should not spread latent combustion. There should be no voids in the wall partitions or the places where they are connected, which are separated from one another by continuous fillings made of flammable materials.

Confirmation of class and degree of flammability

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The fire hazard of building materials is characterized by the following properties:

1. Flammability;
2. Flammability;
3. The ability to spread flame over a surface;
4. Smoke generating ability;
5. Toxicity of combustion products.

By flammability building materials are divided into combustible (G) and non-combustible (NG).

Construction materials are classified as non-combustible with the following values ​​of flammability parameters determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50 percent, duration of stable flame combustion - no more than 10 seconds.

Construction materials that do not satisfy at least one of the parameter values ​​specified in Part 4 of this article are classified as flammable. Combustible building materials are divided into the following groups:

• Low-flammable (G1), having a flue gas temperature of no more than 135 degrees Celsius, the degree of damage along the length of the test sample is not more than 65 percent, the degree of damage along the mass of the test sample is not more than 20 percent, the duration of independent combustion is 0 seconds;
• Moderately flammable (G2), having a flue gas temperature of no more than 235 degrees Celsius, the degree of damage along the length of the test sample is not more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is not more than 30 seconds;
• Normally flammable (NG), having a flue gas temperature of no more than 450 degrees Celsius, a degree of damage along the length of the test sample of more than 85 percent, a degree of damage along the mass of the test sample of no more than 50 percent, and a duration of independent combustion of no more than 300 seconds;
• Highly flammable (G4), having a flue gas temperature of more than 450 degrees Celsius, a degree of damage along the length of the test sample of more than 85 percent, a degree of damage along the mass of the test sample of more than 50 percent, and a duration of independent combustion of more than 300 seconds.

For materials belonging to flammability groups G1-GZ, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.

By flammability flammable building materials (including floor carpets) depending on the critical value surface density heat flow are divided into the following groups:

• Refractory (B1), having a critical surface heat flux density of more than 35 kilowatts per square meter;
• Moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;
• Highly flammable (HF), having a critical surface heat flux density of less than 20 kilowatts per square meter.

By flame propagation speed on the surface, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:

• Non-propagating (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;
• Low propagation (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
• Moderately spreading (RPZ), having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
• Highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter.

By smoke-generating abilities of combustible building materials, depending on the value of the smoke generation coefficient, are divided into the following groups:

• With low smoke-forming ability (D1), having a smoke-formation coefficient of less than 50 square meters per kilogram;
• With moderate smoke-generating ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
• With high smoke-generating capacity (SCP), having a smoke generation coefficient of more than 500 square meters per kilogram.

By toxicity combustion products, combustible building materials are divided into the following groups in accordance with Table 2 of the Appendix to this Federal Law:

• Low hazard (T1);
• Moderately dangerous (T2);
• Highly hazardous (HH);
• Extremely dangerous (T4).

Depending on the fire hazard groups, building materials are divided into the following Fire hazard classes:

In order to protect the life, health, property of citizens and legal entities, state and municipal property, legislation Russian Federation there are requirements for various types products.

Such requirements are contained in technical regulations.

Federal Law No. 123-FZ of July 22, 2008 “Technical Regulations on Fire Safety Requirements” (hereinafter referred to as the Technical Regulations) establishes requirements for building materials.

Article 13 of the Technical Regulations establishes the classification of building materials according to fire hazard.

This classification is based on the properties of materials to form fire hazards.

The fire hazard of building materials is characterized by the following properties:

1) flammability;

2) flammability;

3) the ability to spread flame over the surface;

4) smoke generating ability;

5) toxicity of combustion products.

Based on flammability, building materials are divided into combustible (G) and non-combustible (NG).

Construction materials are classified as non-combustible with the following values ​​of flammability parameters determined experimentally: temperature increase - no more than 50ºC, sample weight loss - no more than 50%, duration of stable flame combustion - no more than 10 seconds. Construction materials that do not satisfy at least one of the specified parameter values ​​are classified as flammable.

Combustible building materials are divided into the following groups:

Low-flammable (G1), having a flue gas temperature of no more than 135 ºС, the degree of damage along the length of the test sample is not more than 65%, the degree of damage along the mass of the test sample is not more than 20%, the duration of independent combustion is 0 seconds;

Moderately flammable (G2), having a flue gas temperature of no more than 235 ºС, the degree of damage along the length of the test sample is not more than 85%, the degree of damage along the mass of the test sample is not more than 50%, the duration of independent combustion is not more than 30 seconds;

Normally flammable (G3), having a flue gas temperature of no more than 450 C, a degree of damage along the length of the test sample of more than 85%, a degree of damage along the mass of the test sample of no more than 50%, and a duration of independent combustion of no more than 300 seconds;

Highly flammable (G4), having a flue gas temperature of more than 450 ºС, a degree of damage along the length of the test sample of more than 85%, a degree of damage along the mass of the test sample of more than 50%, and a duration of independent combustion of more than 300 seconds.

At the same time, for materials belonging to flammability groups G1 - G3, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.

7. Based on flammability, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:

Refractory (B1), having a critical surface heat flux density of more than 35 kW/m2;

Moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kW/m2;

Highly flammable (B3), having a critical surface heat flux density of less than 20 kW/m2.

8. Based on the speed of flame spread over the surface, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:

Non-propagating (RP1), having a critical surface heat flux density of more than 11 kW/m 2 ;

Low-propagating (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kW/m2;

Moderately spreading (RP3), having a critical surface heat flux density of at least 5, but not more than 8 kW/m2;

Highly propagating (RP4), having a critical surface heat flux density of less than 5 kW/m2.

9. According to their smoke-generating ability, combustible building materials, depending on the value of the smoke generation coefficient, are divided into the following groups:

With low smoke-forming ability (D1), having a smoke-formation coefficient of less than 50 m 2 /kg;

With moderate smoke-forming ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 m 2 /kg;

With high smoke-forming ability (D3), having a smoke generation coefficient of more than 500 m 2 /kg.

10. Based on the toxicity of combustion products, combustible building materials are divided into the following groups:

Low hazard (T1);

Moderately dangerous (T2);

Highly hazardous (T3);

Extremely dangerous (T4).

The purpose of determining the fire hazard groups of materials is to assess the possibility of their use in specific buildings and structures.

Based on the fire hazard groups of materials, fire hazard classes are determined in accordance with Part 11 of Article 3 and Appendix 3 of the Technical Regulations.

Fire hazard classes of building materials

And in turn, based on the hazard classes, the scope of application of decorative and finishing materials is determined. facing materials and floor coverings on escape routes and in halls in buildings of various functional purposes, number of floors and capacity, in accordance with Part 6 of Article 134 and Appendices 28, 29 of the Technical Regulations.

Scope of application of decorative finishing, facing

materials and floor coverings on escape routes

Scope of application of decorative, finishing, facing materials and floor coverings in halls, with the exception of floor coverings for sports arenas, sports facilities and floors for dance halls

To determine the fire hazard groups of building materials, tests are carried out according to the methods contained in the national standards included in the List approved by Order of the Government of the Russian Federation dated March 10, 2009 No. 304-r:

Fire resistance tests are carried out in accordance with GOST 30244-94. Construction materials. Combustibility test methods (MethodI);

Tests to determine flammability groups are carried out in accordance with GOST 30244-94. Construction materials. Combustibility test methods (MethodII);

Tests to determine flammability groups are carried out in accordance with GOST 30402-96 Construction materials. Flammability test method;

Tests to determine groups of flame propagation over a surface are carried out in accordance with GOST R 51032-97 Construction materials. Flame propagation test method;

Tests to determine smoke-forming ability groups are carried out in accordance with GOST 12.1.044-89 (ISO 4589-84) Interstate standard. System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination (clause 4.18);

Tests to determine the toxicity groups of combustion products are carried out in accordance with GOST 12.1.044-89 (ISO 4589-84) Interstate standard. System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination (clause 4.20).

The State Budgetary Institution “Center for Expertise, Research and Testing in Construction” operates a Fire Test Laboratory and a Fire Control Department. At the same time, the Fire Control Department is entrusted with the functions of an inspection body for sampling and evaluating test results. The fire testing laboratory performs the functions of testing product samples, and the test results are sent via sample encryption to the Fire Control Department for assessment and assignment of specific fire hazard groups.

The fire testing laboratory of the State Budgetary Institution “Center for Expertise, Research and Testing in Construction” conducts daily tests of building materials.

Over 9 months of 2017, 285 tests were carried out, based on the results of which protocols were drawn up containing indicators of materials used directly at new construction sites in Moscow.

The main types of products subjected to testing are: facing slabs of facade systems (121 tests), paints (28 tests), insulation (74 tests), linoleum (15 tests), other types of products (59 tests) [varnish, floor coverings, vapor barrier, wallpaper].

It should be noted that a significant number of tests reveal the non-compliance of the materials used with the requirements placed on them.

Thus, 73% of tested fiber cement boards for facade finishing are not non-flammable (NG). At the same time, 100% of fiber cement boards tested for flammability correspond to flammability group G1.

Also, many linoleum samples do not pass tests according to the declared flammability groups (B). 83% of linoleum samples correspond to flammability group B3, while products with higher ratings (B1 or B2) should be used.

The paints used on construction sites also often do not correspond to the declared indicators. 100% of the tested paints do not meet the non-flammability rating (NG). In terms of flammability (G), 85% of the tested paint samples correspond to flammability group G1 and 15% to group G2. In terms of flammability (B), 22% of the tested paint samples do not correspond to the declared indicators. 78% of them correspond to group B1, the rest to groups B2 and B3.

100% of the tested samples of mineral wool insulation correspond to the non-combustibility index (NG).

Based on the laboratory protocols, the inspection body of the State Budgetary Institution “TsEIIS” issues conclusions containing fire hazard groups of materials, as well as conclusions about the compliance or non-compliance of the materials used with the requirements of design and regulatory documentation.

Tests to determine the fire hazard indicators of building materials used directly on construction sites are necessary input control, aimed at preventing fires and reducing damage from fires at new construction sites.

Literature:

1. Federal Law of December 27, 2002 No. 184-FZ “On Technical Regulation”.

2. Federal Law of July 22, 2008 No. 123-FZ “Technical Regulations on Fire Safety Requirements.”

3. GOST 30244-94. Construction materials. Combustibility test methods.

4. GOST 30402-96 Construction materials. Flammability test method.

5. GOST R 51032-97 Construction materials. Flame propagation test method.

6. GOST 12.1.044-89 (ISO 4589-84) Interstate standard. System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination.

The text of the article was:

Leading engineer of the State Budgetary Institution “TsEIIS” S.V. Rusyaev

Checked:

Head of LOI State Budgetary Institution “TsEIIS” N.V. Afanasiev