GOST 31565-2012 is an interstate standard that establishes the classification of cable products according to fire hazard indicators and the requirements for them. In Kazakhstan, the standard has been in force since 1 January 2014, is applied directly as an interstate standard, with an amendment put into effect on 29 September 2025. The document is mandatory for cables intended for installation in buildings and structures subject to fire safety requirements.
The main practical value of the standard is the system of versions, which allows the designer and procurement specialist to unambiguously select a cable according to the conditions of the facility. The indices in the marking (ng, LS, HF, FR, LTx) are not marketing — each of them corresponds to a specific indicator tested during certification.
What GOST 31565-2012 Regulates
The standard covers two interrelated tasks. The first is the classification of cable products according to fire hazard indicators. The second is the establishment of requirements for these indicators depending on the type of version and area of application. The document does not describe the cable design, conductor material or electrical characteristics — that is the subject of other standards, in particular GOST 31996-2012. GOST 31565-2012 answers only the question: how does the cable behave during a fire and under what conditions is it permissible to use it.
The scope is directly stated in the text: cable products subject to fire safety requirements, intended for installation in buildings and structures. These are power, control, management, signaling, communication and other cables, if they are laid inside facilities and must comply with fire safety norms.
Which Cable Products It Covers
The scope of the standard includes cables with insulation made of polyvinyl chloride compound, cross-linked polyethylene, rubber, as well as halogen-free polymers. Typical types for which classification according to GOST 31565-2012 is mandatory: VVGng, VVGng-LS, VVGng-FRLS, AVVGng, KVBbShvng, PPGng-HF, PPGng-FRHF and similar.
The standard applies to cables with copper and aluminium conductors, with a number of conductors from one to several tens. The specific fire hazard class is assigned to the cable based on test results and is indicated in the technical specifications for the type. For cables intended for operation in tropical climates, the index “T” is added to the type.
Key Requirements of the Standard
The standard classifies cables according to five main fire hazard indicators. Each indicator has a letter designation and numerical categories.
| Indicator | Letter designation | What it means in practice |
| Flame propagation limit for single installation | PRGO | The cable does not propagate combustion when laid singly. Categories O1 and O2. |
| Flame propagation limit for grouped installation | PRGP | The cable does not propagate combustion in a bundle. Categories P1a, P1b, P2, P3, P4. |
| Fire resistance limit | PO | Time of maintaining operability in a flame: from 30 to 180 minutes (8 categories). |
| Corrosion activity indicator of smoke and gas emission products | PKA | Content of halogen acids and conductivity of the aqueous solution. Categories 1 and 2. |
| Equivalent toxicity indicator of combustion products | PTPM | Toxicity of combustion products of polymeric materials. Categories 1 and 2. |
Source: Table 1 of GOST 31565-2012. The values of the evaluation criteria for each indicator are given in the standard and are used during testing.
Based on these indicators, the standard establishes types of cable versions. Each type of version is designated by a letter index in the cable marking.
| Version | Decoding | Key requirement |
| without designation | Does not propagate combustion in single installation | PRGO — O1 or O2 |
| ng (A F/R, A, B, C, D) | Does not propagate combustion in grouped installation | PRGP — P1a, P1b, P2, P3 or P4 |
| ng (*)-LS | With reduced smoke and gas emission | PRGP + PKA category 1 |
| ng (*)-HF | Does not emit corrosion-active gaseous products | PRGP + PKA category 1 (halogen-free) |
| ng (*)-FRLS | Fire-resistant, with reduced smoke and gas emission | PRGP + PO + PKA category 1 |
| ng (*)-FRHF | Fire-resistant, does not emit corrosion-active gases | PRGP + PO + PKA category 1 (halogen-free) |
| ng (*)-LSLTx | With reduced smoke and gas emission and low toxicity | PRGP + PKA + PTPM |
| ng (*)-FRLSLTx | Fire-resistant, with low toxicity and reduced smoke emission | PRGP + PO + PKA + PTPM |
| ng (*)-FRHFLTx | Fire-resistant, halogen-free, with low toxicity | PRGP + PO + PKA (halogen-free) + PTPM |
Source: Section 6 of GOST 31565-2012; decoding of indices according to the text of the standard. The symbol (*) is replaced by a category: A F/R, A, B, C or D. The index “FR” (Fire Resistance) — fire-resistant version. “LS” (Low Smoke) — low smoke and gas emission. “HF” (Halogen Free) — absence of halogens. “LTx” (Low Toxic) — low toxicity.
Separately, the standard normalises fire resistance. The value of the PO indicator for cables with the FR index must be not less than the value specified in the standards or technical specifications for specific types. The minimum value according to the standard is 30 minutes (category 8), the maximum is 180 minutes (category 1).
What the Standard Does NOT Regulate
GOST 31565-2012 does not establish requirements for the electrical characteristics of the cable: rated voltage, conductor cross-section, insulation resistance. These parameters are regulated by GOST 31996-2012, GOST 22483 and the technical specifications for specific types.
The standard does not determine the cable design: conductor material, insulation type, presence of armour or screen. The fire hazard classification applies to the finished cable product regardless of its design. A cable with copper or aluminium conductors, with PVC or halogen-free insulation — is classified according to the same indicators.
The standard does not establish permissible currents, voltage drop or installation conditions. It answers only the fire safety question. The selection of cross-section by heating, the thermal stability check during a short circuit and the calculation of voltage drop are the subject of the PUE RK and other normative documents.
The standard does not replace the conformity assessment with the requirements of technical regulations. For cables for voltages from 50 to 1000 V, certification according to TR CU 004/2011 is mandatory, and for cables for voltages up to 500 V — declaration according to TR EAEU 037/2016 (restriction of hazardous substances).
Related Standards and Norms
GOST 31565-2012 operates within a system of interrelated documents. Without understanding these connections, the classification remains a formal set of indices.
| Normative document | How it relates to GOST 31565-2012 |
| TR CU 004/2011 “On the safety of low-voltage equipment” | Mandatory technical regulation of the EAEU. Cables for voltages from 50 to 1000 V are subject to certification. GOST 31565-2012 is included in the list of standards for the regulation. |
| TR EAEU 037/2016 “On the restriction of the use of hazardous substances” | For cables for voltages up to 500 V — declaration. Restricts the content of lead, mercury, cadmium. |
| GOST 31996-2012 | Establishes requirements for the design of power cables with plastic insulation. GOST 31565-2012 supplements it with a fire hazard classification. |
| IEC 60332-3-22 | International test method for flame propagation along vertically arranged bundles of cables. In Kazakhstan, the identical standard ST RK IEC 60332-3-22-2010 is in force. |
| ST RK IEC 60332-3-22-2010 | National standard of Kazakhstan, identical to IEC 60332-3-22. Used for testing cables for non-propagation of combustion in grouped installation. |
| GOST 15150 | Climatic designs. Cables according to GOST 31565-2012 are produced in designs UHL, KhL, T with placement categories 1–5. |
It is important not to mix requirements from different systems. The classification according to GOST 31565-2012 does not cancel the need to check electrical parameters according to GOST 31996-2012 and calculate permissible currents according to the PUE RK. These are different levels of requirements for the same cable.
Practical Application
For the Designer
When selecting a cable for a facility, the designer determines the required type of version according to the purpose of the room and fire safety requirements. For cable structures (trestles, galleries, tunnels), cables with the index ng(A) or ng(B) are used — they do not propagate combustion in grouped installation. For preschool and educational institutions, the 2025 amendment clarified the scope: cables with reduced smoke and gas emission are used in these buildings.
For fire protection systems (fire alarm, emergency lighting, smoke extraction), cables with the FR index — fire-resistant — are used. In control and monitoring circuits of building fire protection systems, cables of the FRHF version are used. The minimum time of maintaining operability is selected according to the project, but not less than 30 minutes according to the standard.
For the Procurement Specialist and Buyer
In the procurement documentation, it is sufficient to specify the cable type with a full set of indices: for example, VVGng(A)-FRLS 3×2.5. Each index corresponds to a specific indicator tested during certification. If the supplier offers a cable “ng-LS” without specifying the category, it is worth clarifying which specific PRGP category is assigned to the cable and whether it is confirmed by a test report.
For the Installer
Cables with the index ng-LS and ng-HF have limitations on the minimum bending radius and installation temperature. For cables with the index “KhL”, installation without pre-heating is allowed at a temperature not lower than minus 30 °C, for other versions — not lower than minus 15 °C. Non-observance of these conditions leads to damage to the insulation and a reduction in fire safety properties.
For the Certification and Testing Specialist
GOST 31565-2012 defines the list of indicators that are checked during certification. For cables with the ng index, tests for flame propagation along a bundle are carried out according to ST RK IEC 60332-3-22-2010. For cables with the FR index — fire resistance tests according to the methods specified in the standard. The results are documented in a report that confirms the fire hazard class.
For the practical selection of a cable for a specific task, not only fire safety indices are important, but also design features. The differences between VVG and VVGng concern primarily behaviour during combustion and smoke emission. The choice between copper and aluminium conductors affects the permissible current and voltage drop. Single-core or multi-core design determines the ease of installation and the flexibility of the line. The general design of a power cable and its characteristics are analysed in a separate material: power cable: design, types, characteristics and areas of application.
FAQ
What is the difference between ng-LS and ng-HF?
Both versions do not propagate combustion in grouped installation. The difference is in the combustion products. ng-LS emits a reduced amount of smoke, but halogens (chlorine in PVC) remain in the polymer composition. ng-HF does not contain halogens, therefore during combustion it does not emit corrosion-active gases (hydrogen chloride and others). For rooms with electronic equipment and server rooms, ng-HF is preferable.
What does the number after the FR index mean?
The number indicates the category of the fire resistance limit: from 1 to 8. Category 1 corresponds to 180 minutes of maintaining operability, category 8 — 30 minutes. The specific required value is determined by the project. For fire protection systems, usually not less than 60–90 minutes is taken.
Can a ng-LS cable be used instead of ng(A)-FRLS?
No. ng-LS is not fire-resistant — it does not maintain operability in a flame. ng(A)-FRLS combines non-propagation of combustion in grouped installation, reduced smoke emission and fire resistance. For circuits that must operate during a fire, replacement is not allowed.
Is GOST 31565-2012 in force in Kazakhstan?
Yes. The standard is applied in the Republic of Kazakhstan as an interstate standard. The amendment to GOST 31565-2012 was put into effect on 29.09.2025, which is confirmed by official publications of Rosstandart. Cables of types VVGng, VVGng-LS, PPGng-HF and others are certified in Kazakhstan taking into account the requirements of this standard.
What fire hazard class does the cable VVGng(A)-LS have?
The fire hazard class for a specific cable type is indicated in the technical specifications and the test report. The typical class for a cable with the index ng(A)-LS is P16.8.2.5.4 according to the classification of GOST 31565-2012. The exact value depends on the cable design and is confirmed by tests of a specific batch.
Normative Sources Used
- GOST 31565-2012 “Cable products. Fire safety requirements” — in force, introduced 01.01.2014, amendment put into effect on 29.09.2025 — https://meganorm.ru/mega_doc/norm/gost_gosudarstvennyj-standart/3/gost_31565-2012_mezhgosudarstvennyy_standart_kabelnye.html
- Amendment to GOST 31565-2012 (put into effect on 29.09.2025) — in force — https://meganorm.ru/mega_doc/norm_update_01122025/popravka_popravki/0/popravka_k_gost_31565-2012_kabelnye_izdeliya_trebovaniya.html
- Amendment to GOST 31565-2012 on the official website of Rosstandart — in force — https://protect.gost.ru/document1.aspx?control=31&baseC=6&page=9&month=9&year=2025&search=&id=268406
- GOST 31996-2012 “Power cables with plastic insulation for rated voltages of 0.66; 1 and 3 kV” — in force — https://star-pro.ru/gost/31996-2012
- ST RK IEC 60332-3-22-2010 “Tests on electric and optical fibre cables under fire conditions. Part 3-22. Test for vertical flame spread of vertically-mounted bunched wires or cables. Category A” — in force, approved 20.05.2010 — https://meganorm.ru/Data2/1/4293741/4293741183.pdf
- TR CU 004/2011 “On the safety of low-voltage equipment” — in force — https://docs.eaeunion.org/docs/ru-ru/0145005
- TR EAEU 037/2016 “On the restriction of the use of hazardous substances in electrical and radio-electronic products” — in force — https://docs.eaeunion.org/docs/ru-ru/01413570
- Decision of the Board of the Eurasian Economic Commission — list of standards for TR CU 004/2011, including GOST 31565-2012 — in force — https://adilet.zan.kz/rus/docs/H15B0000107
