Flammability group materials are determined according to GOST 30244-94 "Building materials. Combustibility test methods", which corresponds to the International Standard ISO 1182-80 "Fire tests - Building materials - Non-combastibility test". Materials, depending on the values ​​of flammability parameters determined according to this GOST, are divided into non-flammable (NG) and flammable (G).

Materials include to non-flammable at the following values ​​of flammability parameters:

1. temperature increase in the furnace is no more than 50°C;
2. sample weight loss no more than 50%;
3. Duration of stable flame combustion is no more than 10 seconds.

Materials that do not satisfy at least one of the specified parameter values ​​are classified as flammable.

Depending on the values ​​of flammability parameters, combustible materials are divided into four flammability groups in accordance with Table 1.

Table 1. Flammability groups of materials.

Material flammability group determined according to GOST 30402-96 "Building materials. Flammability test method", which corresponds to the international standard ISO 5657-86.

In this test, the surface of the sample is exposed to radiant heat flux and flame from an ignition source. In this case, the surface heat flux density (SHFD) is measured, that is, the amount of radiant heat flux affecting a unit surface area of ​​the sample. Ultimately, the Critical Surface Heat Flux Density (CSHDD) is determined - the minimum value of the surface heat flux density (HSHDD) at which stable flaming combustion of the sample occurs after exposure to a flame.

Depending on the KPPTP values, materials are divided into three flammability groups indicated in Table 2.

Table 2. Flammability groups of materials.

To classify materials according to smoke generation abilities use the value of the smoke generation coefficient, which is determined according to GOST 12.1.044.

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

Depending on the relative smoke density, materials are divided into three groups:
D1- with low smoke-generating ability - smoke generation coefficient up to 50 m²/kg inclusive;
D2- with moderate smoke-generating ability - smoke generation coefficient from 50 to 500 m²/kg inclusive;
D3- with high smoke-forming ability - smoke generation coefficient over 500 m²/kg.

Toxicity Group combustion products building materials determined according to GOST 12.1.044. The combustion products of the material sample are sent to a special chamber where experimental animals (mice) are located. Depending on the condition of the experimental animals after exposure to combustion products (including death), the materials are divided into four groups:
T1- little dangerous;
T2- moderately dangerous;
T3- highly dangerous;
T4- extremely dangerous.

It is determined by the following fire-technical characteristics: flammability, flame spread over the surface, flammability, smoke-generating ability, toxicity of combustion products. These indicators establish the nomenclature of indicators fire danger fire retardant compounds to determine their scope of application in the construction and decoration of buildings and premises.

Flammability

Building materials are divided into non-combustible (NG) and combustible (G). Materials treated with fire retardants can have one of 4 groups: G1 - low-flammable, G2 - moderately flammable, G3 - normally flammable, G4 - highly flammable.
Flammability and flammability groups are established according to GOST 30244-94.

To carry out the flammability test, 4 samples are taken - boards treated with a fire retardant compound. A box is built from these samples. It is placed in a chamber containing 4 gas burners. The burners are ignited in such a way that the flame acts on the lower surface of the samples. At the end of combustion, measure: the temperature of the exhaust flue gases, length of the damaged section of the sample, mass, residual combustion time. Having analyzed these indicators, wood treated with a fire retardant composition is classified into one of four groups.

Flame Spread

Combustible building materials are divided into 4 groups based on the spread of flame over the surface: RP1 - non-propagating, RP2 - weakly spreading, RP3 - moderately spreading, RP4 - highly spreading.

GOST R 51032-97 regulates testing methods for building materials (including those treated with fire retardants) for flame propagation. To carry out testing, the sample is exposed to the heat of a radiation panel located at a slight angle and heated to a certain temperature. Depending on the heat flux density, the value of which is determined by the length of flame propagation along the sample, the material treated with a fire retardant composition is assigned one of four groups.

Flammability

Combustible building materials are divided into groups according to their flammability: B1 – hardly flammable, B2 – moderately flammable, B3 – highly flammable.

GOST 30402 defines methods for testing building materials for flammability. The group is determined depending on the heat flux of the radiation panel at which ignition occurs.

Smoke generating ability

According to this indicator, materials are divided into 3 groups: D1 - with low smoke-generating ability, D2 - with moderate smoke-generating ability, D3 - with high smoke-generating ability.
Smoke generating ability groups are established according to GOST 12.1.044. For testing, the sample is placed in a special chamber and burned. During combustion, the optical density of the smoke is measured. Depending on this indicator, wood with a fire retardant applied to it is classified into one of three groups.

Toxicity

Based on the toxicity of combustion products, there are 4 groups of materials: T1 - low-hazardous, T2 - moderately hazardous, T3 - highly hazardous, T4 - extremely hazardous. Toxicity groups are established according to GOST 12.1.044.

Ch. 3 tbsp. 13 Federal Law dated July 22, 2008 No. 123-FZ

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

1. flammability;
2. flammability;
3. ability to spread flame over a 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 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:

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 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;

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 percent, the degree of damage along the mass of the test sample is not more than 50 percent, 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 percent, the degree of damage along the mass of the test sample is not more than 50 percent, 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 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.

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:

1) hardly flammable (B1), having a critical surface heat flux density of more than 35 kilowatts per square meter;

2) moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;

3) flammable (HF), having a critical surface heat flux density of less than 20 kilowatts per square meter.

According to the speed of flame propagation 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:

1) non-propagating (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;
2) weakly propagating (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
3) moderately spreading (RPZ), having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
4) highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter.

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

1) with low smoke generation capacity (D1), having a smoke generation coefficient of less than 50 square meters per kilogram;
2) with moderate smoke-generating ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
3) with high smoke-forming capacity (S), having a smoke generation coefficient of more than 500 square meters per kilogram.

Based on the toxicity of combustion products, combustible building materials are divided into the following groups in accordance with Table 2 of the appendix to this Federal Law:
1) low-hazard (T1);
2) moderately dangerous (T2);
3) highly dangerous (HH);
4) extremely dangerous (T4).

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

Fire hazard properties of building materials	Fire hazard class of building materials depending on groups
	KM0	KM1	KM2	KM3	KM4	KM5
Flammability	NG	G1	G1	G2	G2	G4
Flammability	—	B1	B1	B2	B2	B3
Smoke generating ability	—	D1	D3+	D3	D3	D3
Toxicity of combustion products	—	T1	T2	T2	T3	T4
Flame propagation over flooring surfaces	—	RP1	RP1	RP1	RP2	RP4

Fire hazard properties of building materials Fire hazard class of building materials depending on groups
materials KM0 KM1 KM2 KM3 KM4 KM5
Flammability NG G1 G1 G2 G2 G4
Flammability - B1 B1 B2 B2 B3
Smoke generating ability - D1 D3+ D3 D3 D3
Toxicity of combustion products - T1 T2 T2 T3 T4
Flame spread over the surface for flooring - RP1 RP1 RP1 RP2 RP4

When receiving substances and materials, application, storage, transportation, processing and disposal.

To establish requirements fire safety to the design of buildings, structures and systems fire protection classification of building materials according to fire hazard is used.

Indicators of fire and explosion hazard and fire hazard of substances and materials

List of indicators necessary to assess the fire and explosion hazard and fire hazard of substances and materials depending on their state of aggregation, is given in Table 1 of the Appendix to Federal Law FZ-123 (“Technical Regulations on Fire Safety”).

Methods for determining indicators of fire and explosion hazard and fire hazard of substances and materials are established regulatory documents on fire safety.

Indicators of fire and explosion hazard and fire hazard of substances and materials are used to establish requirements for the use of substances and materials and calculate fire risk.

List of indicators necessary to assess the fire hazard of substances and materials depending on their state of aggregation

Fire danger indicator	Substances and materials in various states of aggregation			Dust
	gaseous	liquid	hard
Safe experimental maximum clearance, millimeter	+	+	-	+
Release of toxic combustion products per unit mass of fuel, kilogram per kilogram	-	+	+	-
Flammability group	-	-	+	-
Flammability group	+	+	+	+
Flame propagation group	-	-	+	-
Smoke generation coefficient, square meter per kilogram	-	+	+	-
Flame emissivity	+	+	+	+
Fire and explosion hazard index, Pascal per meter per second	-	-	-	+
Flame Spread Index	-	-	+	-
Oxygen index, volume percent	-	-	+	-
Concentration limits of flame propagation (ignition) in gases and vapors, volume percentages, dusts, kilogram per cubic meter	+	+	-	+
Concentration limit of diffusion combustion of gas mixtures in air, volume percentage	+	+	-	-
Critical surface heat flux density, Watt per square meter	-	+	+	-
Linear speed of flame propagation, meter per second	-	-	+	-
The maximum speed of flame propagation along the surface of a flammable liquid, meter per second	-	+	-	-
Maximum explosion pressure, Pascal	+	+	-	+
Minimum phlegmatizing concentration of gaseous phlegmatizing agent, volume percentage	+	+	-	+
Minimum ignition energy, Joule	+	+	-	+
Minimum explosive oxygen content, volume percentage	+	+	-	+
Lower working heat of combustion, kilojoule per kilogram	+	+	+	-
Normal flame propagation speed meter per second	+	+	-	-
Indicator of toxicity of combustion products, gram per cubic meter	+	+	+	+
Oxygen consumption per unit mass of fuel, kilogram per kilogram	-	+	+	-
The maximum speed of breakdown of the diffusion torch, meter per second	+	+	-	-
Explosion pressure rise rate, megaPascal per second	+	+	-	+
Ability to burn when interacting with water, air oxygen and other substances	+	+	+	+
Ignition ability under adiabatic compression	+	+	-	-
Capacity for spontaneous combustion	-	-	+	+
Exothermic decomposition ability	+	+	+	+
Ignition temperature, degrees Celsius	-	+	+	+
Flash point, degrees Celsius	-	+	-	-
Self-ignition temperature, degrees Celsius	+	+	+	+
Smoldering temperature, degrees Celsius	-	-	+	+
Temperature limits of flame propagation (ignition), degrees Celsius	-	+	-	-
Specific mass burnout rate, kilogram per second per square meter	-	+	+	-
Specific heat of combustion, Joule per kilogram	+	+	+	+

Classification of substances and materials ( excluding construction, textile and leather materials) according to fire danger

The classification of substances and materials by fire hazard is based on their properties and ability to form dangerous fire or explosion factors.

Based on flammability, substances and materials are divided into the following groups:
1) non-flammable- substances and materials that cannot burn in air. Non-flammable substances can be fire-explosive (for example, oxidizers or substances that release flammable products when interacting with water, air oxygen, or with each other);
2) flame retardant- substances and materials capable of burning in air when exposed to an ignition source, but unable to burn independently after its removal;
3) flammable- substances and materials capable of spontaneous combustion, as well as ignite under the influence of an ignition source and burn independently after its removal.

Test methods for the flammability of substances and materials are established by fire safety regulations.

Classification of construction, textile and leather materials by fire hazard

The classification of building, textile and leather materials by fire hazard is based on their properties and ability to form fire hazards.

The fire hazard of building, textile and leather materials is characterized by the following properties:
1) flammability;
2) flammability;
3) ability to spread flame over a surface;
4) smoke generating ability;
5) toxicity of combustion products.

Speed ​​of flame spread over the surface

According to the speed of flame propagation 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:

1) non-proliferative (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;

2) low propagation (RP2) having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;

3) moderate spreading (RP3) having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;

4) highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter..

Smoke generating ability

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

1) with low smoke-generating ability (D1) having a smoke generation coefficient of less than 50 square meters per kilogram;

2) with moderate smoke-generating ability (D2) having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;

3) with high smoke-generating ability (D3), having a smoke generation coefficient of more than 500 square meters per kilogram..

Toxicity

Based on the toxicity of combustion products, combustible building materials are divided into the following groups in accordance with table 2 appendices to Federal Law No. 123-FZ:

1) low-hazard (T1);
2) moderately hazardous (T2);
3) highly hazardous (T3);
4) extremely dangerous (T4).

Classification of combustible building materials according to the toxicity index of combustion products

Hazard class	Indicator of toxicity of combustion products depending on exposure time
	5 minutes	15 minutes	30 minutes	60 minutes
Low hazard	more than 210	more than 150	more than 120	more than 90
Moderately dangerous	more than 70, but not more than 210	more than 50, but not more than 150	more than 40, but not more than 120	more than 30, but not more than 90
Highly dangerous	more than 25, but not more than 70	more than 17, but not more than 50	more than 13, but not more than 40	more than 10, but not more than 30
Extremely dangerous	no more than 25	no more than 17	no more than 13	no more than 10

Classification of certain types of substances and materials

For floor carpets, the flammability group is not determined.

Textile and leather materials are divided into flammable and low-flammable based on flammability. A fabric (non-woven fabric) is classified as a flammable material if the following conditions are met during testing:

1) the flame combustion time of any of the samples tested when ignited from the surface is more than 5 seconds;

2) any of the samples tested when ignited from the surface burns out to one of its edges;

3) cotton wool catches fire under any of the tested samples;

4) the surface flash of any of the samples extends more than 100 millimeters from the point of ignition from the surface or edge;

5) average length The charring area of ​​any of the samples tested when exposed to flame from the surface or edge is more than 150 millimeters.

To classify construction, textile and leather materials, the value of the flame propagation index (I) should be used - a conditional dimensionless indicator characterizing the ability of materials or substances to ignite, spread flame over the surface and generate heat. Based on flame propagation, materials are divided into the following groups:

1) not spreading flame over the surface, having a flame propagation index of 0;

2) slowly spreading flame over the surface, having a flame spread index of no more than 20;

3) quickly spreading flame over the surface, having a flame spread index of more than 20.

Test methods for determining fire hazard classification indicators for construction, textile and leather materials are established by fire safety regulations

Flammability group- This classification characteristic the ability of substances and materials to.

When determining the fire and explosion hazard of substances and materials (), we distinguish :

• gases– these are substances whose saturated vapor pressure at a temperature of 25 °C and a pressure of 101.3 kPa exceeds 101.3 kPa;
• liquids– these are substances whose saturated vapor pressure at a temperature of 25 °C and a pressure of 101.3 kPa is less than 101.3 kPa. Liquids also include solid melting substances whose melting or dropping point is less than 50 °C.
• solids and materials– these are individual substances and their mixed compositions with a melting or dropping point greater than 50 ° C, as well as substances that do not have a melting point (for example, wood, fabrics, etc.).
• dust– These are dispersed solids and materials with a particle size of less than 850 microns.

One of the indicators of fire and explosion hazard of substances and materials is flammability group.

Substances and materials

According to GOST 12.1.044-89, in terms of flammability, substances and materials are divided into the following groups ( excluding construction, textile and leather materials):

1. Non-flammable.
2. Low-flammability.
3. Flammable.

Non-flammable – these are substances and materials that are unable to burn in air. Non-flammable substances can be fire-explosive (for example, oxidizers or substances that release flammable products when interacting with water, atmospheric oxygen, or with each other).

Low-flammability – these are substances and materials that can burn in air when exposed to an ignition source, but are unable to burn independently after it is removed.

Flammable – these are substances and materials that can spontaneously ignite, as well as ignite when exposed to an ignition source and burn independently after its removal.

The essence of the experimental method for determining flammability is to create temperature conditions, promoting combustion, and assessing the behavior of the substances and materials under study under these conditions.

Solid (including dust)

The material is classified as non-flammable if the following conditions are met:

• the arithmetic mean change in temperature in the oven, on the surface and inside the sample does not exceed 50 °C;
• the arithmetic mean value of mass loss for five samples does not exceed 50% of their mean value of the initial mass after conditioning;
• the arithmetic mean value of the duration of stable combustion of five samples does not exceed 10 s. The test results of five samples in which the duration of stable combustion is less than 10 s are taken equal to zero.

Based on the value of the maximum temperature increase (Δt max) and mass loss (Δm), materials are classified:

• flame retardant: Δt max< 60 °С и Δm < 60%;
• flammable: Δt max ≥ 60 °C or Δm ≥ 60%.

Combustible materials are divided depending on the time (τ) to reach (t max) into:

• hardly flammable: τ > 4 min;
• average flammability: 0.5 ≤ τ ≤ 4 min;
• highly flammable: τ< 0,5 мин.

Gases

If there are concentration limits for flame propagation, the gas is classified as flammable ; in the absence of concentration limits for flame propagation and the presence of a self-ignition temperature, the gas is classified as flame retardant ; in the absence of concentration limits for flame propagation and auto-ignition temperature, the gas is classified as non-flammable .

Liquids

If there is an ignition temperature, the liquid is classified as flammable ; in the absence of an ignition temperature and the presence of a self-ignition temperature, the liquid is classified as flame retardant . In the absence of flash points, ignition, self-ignition, temperature and concentration limits for flame propagation, the liquid is classified as non-flammable . Flammable liquids with a flash point of not more than 61 ° C in a closed crucible or 66 ° C in an open crucible, phlegmatized mixtures that do not have a flash in a closed crucible are classified as flammable . Particularly dangerous These are flammable liquids with a flash point of no more than 28 °C.

Classification of building materials

Determination of the flammability group of a building material

The fire hazard of building, textile and leather materials is characterized by the following properties:

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

Building materials, depending on the values ​​of flammability parameters, are divided into groups into non-combustible and combustible (for floor carpets the flammability group is not determined).

NG (non-flammable)

Based on test results using methods I and IV (), non-combustible building materials are divided into 2 groups.

Construction materials are classified as non-combustible group I

• temperature increase in the oven no more than 30 °C;
• duration of stable flame combustion – 0 s;
• calorific value not more than 2.0 MJ/kg.

Construction materials are classified as non-combustible group II with the following arithmetic average values ​​of flammability parameters according to methods I and IV (GOST R 57270-2016):

• temperature increase in the oven no more than 50 °C;
• weight loss of samples no more than 50%;
• the duration of stable flame combustion is no more than 20 s;
• calorific value not more than 3.0 MJ/kg.

Allowed to be classified as non-flammable of group I without testing the following building materials without painting their outer surface or with painting the outer surface with compositions without the use of polymer and (or) organic components:

• concretes, mortars, plasters, adhesives and putties, clay, ceramic, porcelain stoneware and silicate products (bricks, stones, blocks, slabs, panels, etc.), fiber cement products (sheets, panels, slabs, pipes, etc.) with the exception of in all cases of materials manufactured using polymer and (or) organic binder fillers and fiber;
• inorganic glass products;
• products made from alloys of steel, copper and aluminum.

Building materials that do not satisfy at least one of the above specified values ​​of parameters of I and II groups of non-combustibility belong to the group of combustibles and are subject to testing according to methods II and III (GOST R 57270-2016). For non-combustible building materials, other fire hazard indicators are not determined or standardized.

Combustible building materials, depending on the values ​​of flammability parameters determined by method II, are divided into four flammability groups (G1, G2, G3, G4) in accordance with the table. Materials should be classified into a certain flammability group provided that all arithmetic mean values ​​of the parameters specified in the table for this group correspond.

G1 (low flammable)

Low flammable – these are materials with a flue gas temperature of no more than 135 °C, 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%, and the duration of spontaneous combustion is 0 seconds.

G2 (moderately flammable)

Moderately flammable – these are materials with a flue gas temperature of no more than 235 °C, the degree of damage along the length of the test sample is no more than 85%, the degree of damage along the mass of the test sample is no more than 50%, and the duration of independent combustion is no more than 30 seconds.

G3 (normally flammable)

Normally flammable – these are materials with 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.

G4 (highly flammable)

Highly flammable – these are materials with a flue gas temperature of 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 more than 50%, and a duration of independent combustion of more than 300 seconds.

Table

Material flammability group	Flammability parameters
	Flue gas temperature T, °C	Degree of damage along length S L, %	Degree of damage by weight S m, %	Duration of independent combustion t c.g, s
G1	Up to 135 inclusive	Up to 65 inclusive	Up to 20	0
G2	Up to 235 inclusive	Up to 85 inclusive	Up to 50	Up to 30 inclusive
G3	Up to 450 inclusive	Over 85	Up to 50	Up to 300 inclusive
G4	Over 450	Over 85	Over 50	Over 300
Note. For materials belonging to flammability groups G1-G3, the formation of burning melt drops and (or) burning fragments during testing is not allowed. For materials belonging to flammability groups G1-G2, the formation of a melt and (or) melt drops during testing is not allowed.

Video, what is a flammability group

Sources: ; Baratov A.N. Combustion – Fire – Explosion – Safety. -M.: 2003; GOST 12.1.044-89 (ISO 4589-84) System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination; GOST R 57270-2016 Construction materials. Combustibility test methods.