Combustible building materials are divided according to their smoke-generating ability. Determination of flammability groups of substances and materials

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 of July 22, 2008 No. 123-FZ “ Technical regulations about the requirements fire safety» (hereinafter referred to as the Technical Regulations) establishes requirements for construction materials.

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

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.

By flammability Construction Materials are divided into flammable (G) and non-flammable (NG).

Construction materials are non-combustible when following values flammability parameters determined experimentally: temperature increase - no more than 50ºС, 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 temperature flue gases no more than 135 ºС, degree of damage along the length of the test sample no more than 65%, degree of damage by weight of the test sample no more than 20%, duration of independent combustion 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. In terms of flammability, combustible building materials (including flooring carpets) depending on the value of the critical surface density heat flow 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, on the basis of hazard classes, the scope of application of decorative finishing, facing materials and floor coverings on escape routes and in halls in buildings of various functional purposes, number of floors and capacity is determined, 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 a 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

“Fire safety of buildings and structures” on the fire-technical classification of building materials, as well as the provisions of other regulatory documents on fire safety to which this document refers.

For non-combustible building materials, other fire hazard indicators are not determined or standardized.

flammability- the ability of substances and materials to ignite.

ignition - the beginning of flaming combustion under the influence of an ignition source, in this standard test is characterized by stable flaming combustion.

ignition time- time from the start of the test to the occurrence of stable flame combustion.

stable flame combustion- combustion that continues until the sample is next exposed to flame from the ignition source.

Radiant heat flux acting on a unit surface area of ​​a sample.

The minimum value of the surface heat flux density at which stable flame combustion occurs.

flame spread- propagation of flame combustion over the surface of the sample as a result of the impact provided for by this standard;

surface heat flux density (SHFD)- radiant heat flux acting on a unit surface of the sample;

critical surface heat flux density (CSHDD)- the amount of heat flow at which the flame stops spreading.

In clause 5.7 of SNiP 21-01-97* it is established that combustible building materials are divided into three groups according to their smoke-generating ability:

D1 (with low smoke-generating ability);

D2 (with moderate smoke-generating ability);

D3 (with high smoke-generating ability).

Groups of building materials according to smoke-forming ability are established in accordance with GOST 12.1.044-89 "SSBT. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination." This document contains the following provisions regarding the smoke emission coefficient.

Smoke coefficient- an indicator characterizing the optical density of smoke generated during flaming combustion or thermal-oxidative destruction (smoldering) of a certain amount of solid substance (material) under special test conditions.

The smoke production coefficient value should be used to classify materials according to their smoke generation ability. There are three groups of materials:

with low smoke-generating ability - smoke generation coefficient up to 50 m2kg-1 inclusive;

with moderate smoke-forming ability - smoke-formation coefficient St. 50 to 500 m2kg-1 inclusive;

with high smoke-forming ability - smoke-formation coefficient St. 500 m2kg-1.

The smoke emission coefficient value must be included in the standards or technical specifications on solids and materials.

In accordance with clause 5.8 of SNiP 21-01-97*, combustible building materials are divided into four groups based on the toxicity of combustion products:

T1 (low hazard);

T2 (moderately dangerous);

T3 (highly dangerous);

T4 (extremely dangerous).

Groups of building materials based on the toxicity of combustion products are established in accordance with GOST 12.1.044-89 "SSBT. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination." The named document regarding the toxicity indicator of combustion products polymer materials provides the following.

The toxicity indicator of combustion products is the ratio of the amount of material per unit volume of a closed space in which gaseous products formed during the combustion of the material cause the death of 50% of experimental animals.

The value of the toxicity indicator of combustion products should be used for comparative assessment of polymer materials, and also be included in the technical specifications and standards for finishing and thermal insulation materials. The classification of materials according to the toxicity index of combustion products is given in the table.

The essence of the method for determining the toxicity index is to burn the material under study in a combustion chamber at a given heat flux density and identify the dependence of the lethal effect of gaseous combustion products on the mass of the material per unit volume of the exposure chamber.

The table, which is established in GOST 12.1.044-89, is reproduced in table 2 of the appendix to the commented Law (see commentary to the specified table).

11. In accordance with Part 11 of the commented article, fire hazard classes of building materials are distinguished depending on the fire hazard groups of building materials. These classes - KM0, KM1, KM2, KM3, KM4 and KM5 - are given in Table 3 of the appendix to the commented Law. It should be noted that the selection of these classes is an innovation, since previously in regulatory documents in terms of fire safety (primarily, in SNiP 21-01-97* “Fire safety of buildings and structures”), only fire hazard groups of building materials were identified.

12. In part 12

New class of LINOLEUM KM2 V2, D2, T2, RP1

According to changes in the Federal Law (hereinafter referred to as Federal Law No. 117) the application vinyl linoleum KM2 in hospitals, schools and pre-school, general education institutions have been significantly expanded.

New fire hazard requirements for floor coverings

HOMOGENEOUS LINOLEUM KM2

HETEROGENEOUS LINOLEUM KM2

A flammability group indicator is no longer required for linoleum floor coverings (G1, G2, G3, G4)

Notes: 1. The "+" sign indicates that the indicator must be applied.

2. The "-" sign indicates that the indicator is not applicable.

You can also use PVC coverings, commercial linoleum, in most premises that are considered evacuation routes.

Everything you need to know, articles on how to choose flooring

From the point of view of ensuring fire safety, thermal insulation materials are characterized by flammability properties.

There are non-flammable (NG group) and combustible materials, which in turn are divided into: G1 - low-flammable, G2 - moderately flammable, G3 - normally flammable, G4 - highly flammable.

Building materials are non-combustible (natural stone, cement concrete, glass, hardware) at the following values ​​of flammability parameters, determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50%, duration of stable flame combustion - no more than 0 seconds.

Combustible building materials are divided into the following groups:
1) 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%, the degree of damage along the mass of the test sample is not more than 20%, the duration of independent combustion is 10 seconds. Low-flammable materials include: asphalt concrete, gypsum and concrete materials containing organic filler more than 8% of the mass, mineral wool slabs on a bitumen binder with its content from 7 to 15%, etc.

2) 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%, the degree of damage along the mass of the test sample is not more than 50%, the duration of independent combustion is no more than 30 seconds;

3) normal-flammable (NG), having a flue gas temperature of no more than 450 degrees Celsius, the degree of damage along the length of the test sample is 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 no more than 300 seconds;

4) 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%, 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.

For materials belonging to flammability groups G1-GZ, the formation of burning melt drops 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.

All organic materials, such as wood, belong to the group of flammable materials, and their fire hazard increases with the addition of various polymers. For example, paints and varnishes not only increase flammability, but also contribute to faster spread of flame over the surface, increase smoke formation and toxicity. To reduce the fire hazard of organic building materials, as is the case with polymeric substances, they are treated with fire retardants. Applied to the surface, under the influence high temperatures Flame retardants may foam or release non-flammable gas.

One of the central places is occupied by the assessment of fire danger and the competent selection of building materials based on current standards and standards and taking into account the functional purpose and individual characteristics building.

According to experts, the flammability group of a material is not the main criterion for choosing insulation, since the fire hazard class is important for the design. And it is determined on the basis of full-scale tests. Very often, even flammable materials make it possible to achieve the required fire hazard ratings of a structure.

To determine the likelihood of a flame occurring, the flammability of substances and various materials is of primary importance. This characteristic determines the fire hazard category of structures, premises, and industries; allows you to choose the right means to eliminate outbreaks.

The flammability group of all material components of an object determines the success of fire fighting and minimizes the likelihood of casualties.

Features of various substances

It is known that substances can be in different states of aggregation, which are important to consider when determining the flammability group. GOST provides for classification based on quantitative indicators.

If a substance can burn, the flammability group G1 is more optimal for fire safety than G3 or G4.

Has flammability great importance for finishing, heat-insulating, building materials. On its basis, the fire hazard class is determined. So, plasterboard sheets have flammability group G1, stone wool - NG (does not burn), and insulating polystyrene foam belongs to flammability group G4, and the use of plaster helps reduce its fire hazard.

Gaseous substances

When determining the flammability class of gases and liquids, standards introduce such a concept as a concentration limit. By definition, this is the maximum concentration of a gas in a mixture with an oxidizer (air, for example), at which a flame can spread from the point of ignition to any distance.

If such a limit value does not exist and the gas cannot spontaneously ignite, then it is called non-flammable.

Liquid

Liquids are called flammable if there is a temperature at which they can ignite. If the liquid stops burning in the absence external source heating, it is called low-flammability. Non-flammable liquids do not ignite at all in the air atmosphere under normal conditions.

Some liquids (acetone, ether) may flash at 28 ℃ and below. They are considered especially dangerous. Liquids that ignite at 61…66 ℃ and above are classified as flammable (kerosene, white spirit). Tests are carried out in open and closed crucibles.

Solid

In the construction industry, the most relevant is the determination of the flammability group hard materials. It is preferable to use substances of the flammability group G1 or NG, as they are the most resistant to ignition.

Classification

The intensity of the combustion process and the conditions under which it occurs determine the likelihood of a fire intensifying and an explosion occurring. The outcome of the incident depends on the totality of the properties of the feedstock.

General division

According to the national fire and explosion hazard standard, substances and various materials made from them are divided into the following groups:

• absolutely non-flammable;
• difficult to burn;
• flammable.

They cannot burn in air, which does not exclude interaction with oxidizing agents, with each other, and with water. Consequently, some members of the group pose a fire hazard under certain conditions.

Compounds that are difficult to combust include those that burn when ignited in air. As soon as the source of fire is eliminated, the burning stops.

Under certain conditions, flammable substances ignite on their own or in the presence of a fire source and continue to burn intensely.

The classification of flammability of construction raw materials and products is discussed in a separate updated standard. National construction standards take into account the categories of all types of products used in work.

According to this classification, non-combustible building materials (NG) are divided into two groups depending on the test mode and the values ​​of the indicators obtained.

Group 1 includes products in which the temperature inside the oven increases by no more than 50 ℃. The reduction in sample mass does not exceed 50%. The flame does not burn at all, and the heat released does not exceed 2.0 MJ/kg.

Group 2 NG includes materials with the same indicators of temperature increase inside the furnace and weight loss. The difference is that the flame burns for up to 20 seconds, the heat of combustion should not be more than 3.0 MJ/kg.

Flammability classes

Combustible materials are examined according to similar criteria and are divided into 4 groups or classes, which are designated by the letter G and the number next to it. For classification, the values ​​of the following indicators are taken into account:

• temperature of gases released with smoke;
• degree of size reduction;
• amount of weight reduction;
• flame retention time without a combustion source.

G1 refers to a group of materials with a smoke temperature not exceeding 135 ℃. The loss of length is 65%, weight loss is 20%. The flame itself does not burn. Such construction products are called self-extinguishing.

G2 includes a group of materials with a smoke temperature not exceeding 235 ℃. The loss of length is 85%, weight loss is 50%. Self-combustion lasts no more than 30 seconds.

G3 includes materials whose smoke temperature does not exceed 450 ℃. The loss of length is more than 85%, weight loss - up to half. The flame itself burns for no more than 300 seconds.

The G4 flammability group includes materials with a smoke temperature exceeding 450 °C. Loss of length exceeds 85%, weight loss – more than 50%. Self-combustion lasts more than 300 seconds.

It is acceptable to use the following prefixes in the name of each flammability group in order of increasing digital index:

• weak;
• moderately;
• Fine;
• highly flammable materials.

The given flammability indicators, along with some other characteristics, must be taken into account when developing project documentation, budgeting.

The ability to generate smoke, the toxicity of combustion products, the speed of possible fire spread, and the likelihood of rapid ignition are also of great importance.

Class confirmation

Samples of materials are tested in laboratories and in open areas according to standard methods separately for non-combustible and combustible building materials.

If the product consists of several layers, the standard requires testing for the flammability of each layer.

Determinations of flammability are carried out on special equipment. If it turns out that one of the components is highly flammable, then this status will be assigned to the product as a whole.

The installation for carrying out experimental determinations should be located in a room with room temperature, normal humidity, and without drafts. Bright sunlight or artificial light in the laboratory should not interfere with readings from the displays.

Before starting to study the sample, the device is checked, calibrated, and warmed up. Then the sample is fixed in the holder of the internal cavity of the furnace and the recorders are immediately turned on.

The main thing is that no more than 5 seconds have passed since the sample was placed. The determination is continued until a temperature balance is achieved, at which the changes do not exceed 2 °C over 10 minutes.

At the end of the procedure, the sample along with the holder is removed from the oven, cooled in a desiccator, weighed and measured, assigning them to the flammability group NG, G1, and so on.

Flammability test method

All building materials, including finishing, facing, paint and varnish coatings, regardless of homogeneity or multi-layering, are tested for flammability using a single method.

Pre-prepare 12 units of identical samples with a thickness equal to the actual values ​​during operation. If the structure is layered, samples are taken from each surface.

The samples are then kept at room temperature and normal ambient humidity for at least 72 hours, weighing periodically. Aging should be stopped when constant weight is reached.

The installation has standard design, consists of a combustion chamber, an air supply system and the removal of released gases.

The samples are placed in the chamber one by one, measurements are taken, weight loss, temperature and amount of gaseous products released, and burning time without a flame source are recorded.

By analyzing all the obtained indicators, they determine the level of flammability of the material and its belonging to a certain group.

Application in construction

When constructing buildings, several different types building materials: structural, insulating, roofing, finishing with different purposes and loads. All products must have certificates available and be presented to potential buyers.

You should familiarize yourself with the parameters characterizing safety in advance and know exactly what each abbreviation and numbers can mean. The law requires the use of only materials of flammability group G1 or NG for the frames of building ceilings.