Standard No.:	GB 8624-2025
English Name:	Classification for burning behavior of building materials and products
Chinese Name:	建筑材料及制品燃烧性能分级
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR, SAC
Issued on:	2025-12-31
Implemented on:	2027-1-1
Status:	to be valid
Superseding:	GB 8624-2012 Classification for burning behavior of building materials and products
Target Language:	English
File Format:	PDF
Word Count:	15500 words
Translation Price(USD):	465.0
Delivery:	via email in 1~3 business day

ICS 13.220.50 CCS C 80 National Standard of the People’s Republic of China GB 8624-2025 Replaces GB 8624-2012 Classification for burning behavior of building materials and products 建筑材料及制品燃烧性能分级 (English translation) Issue date: 2025-12-31 Implementation date: 2027-01-01 Issued by the State Administration for Market Regulation of the People's Republic of China the Standardization Administration of the People's Republic of China Contents Foreword III Introduction IV 1 Scope 1 2 Normative references 1 3 Terms, definitions, symbols and abbreviations 2 3.1 Terms and definitions 2 3.2 Symbols and abbreviations 4 4 Classification and grading 5 4.1 Classification 5 4.2 Burning behavior grade 5 5 Criteria for determining burning behavior grades 6 5.1 Building materials and products 6 5.2 Materials and products for decoration 17 5.3 Non-metallic materials and products for equipment components 19 6 Application of classification results 20 7 Classification description, labeling, and reporting 20 7.1 Classification description 20 7.2 Classification labeling 21 7.3 Classification reporting 21 Classification for burning behavior of building materials and products 1 Scope This document specifies the classification and grading of the burning behavior of building materials and products, the criteria for determining burning behavior grades, the application of classification results, as well as the classification description, labeling and reporting. This document applies to the classification and determination for burning behavior of building materials and products, decorative materials and products, and non-metallic materials and products used in equipment components. The classification for burning behavior of other materials and products may be referenced accordingly. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB/T 2406.2 Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test GB/T 2408 Plastics - Determination of burning characteristics - Horizontal and vertical test GB/T 5169.16 Fire hazard testing for electric and electronic products - Part 16: Test flames - 50 W horizontal and vertical flame test methods GB/T 5454 Textiles - Burning behaviour - Oxygen index method GB/T 5455 Textiles - Burning behaviour - Determination of damaged length, afterglow time and afterflame time of vertically oriented specimens GB/T 5464 Non-combustibility test method for building materials GB/T 8333 Plastic - Test method for flammability of rigid cellular plastic - Vertical burning method GB/T 8626 Test method of flammability for building materials GB/T 8627 Test method for density of smoke from the burning or decomposition of building materials GB/T 10294 Thermal insulation - Determination of steady-state thermal resistance and related properties - Guarded hot plate apparatus GB/T 10295 Thermal insulation - Determination of steady-state thermal resistance and related properties - Heat flow meter apparatus GB/T 11785 Reaction to fire tests for floorings - Determination of the burning behaviour using a radiant heat source GB 14402 Reaction to fire tests for building materials and products - Determination of the heat of combustion GB/T 16172 Test method for heat release rate of building materials GB/T 17596 Textiles - Commercial laundering procedure for textile fabrics prior to flammability testing GB 17927 Safety technical specification of flame resistance for furniture GB/T 20284 Single burning item test for building materials and products GB/T 20285 Toxic classification of fire effluents hazard for materials GB/T 27904 Testing method for fire characteristics of furniture and subassemblies exposed to flaming ignition source GB/T 30735 Test methods for external exposure of roofs and roof coverings to fire GB/T 34441 Upholstered furniture - Assessment of burning behavior of mattress GB/T 40237 Test method for ignitability of foamed plastic - Welding spark method GB/T 40238 Reaction to fire tests for building materials and products - General rules for selection of substrates,conditioning and mounting of specimen GB/T 46980 Test method for fire resistance of photovoltaic modules 3 Terms, definitions, symbols and abbreviations 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 material single substance or mixture of uniformly dispersed substances Example: Metals, stone, wood, concrete, polystyrene resin, polyurethane resin, glass wool, rock wool, etc. 3.1.2 product materials, components or assemblies that require the provision of relevant information Example: Artificial boards and products, extruded polystyrene foam, polyurethane composite insulation boards, rock wool boards, nylon carpets, decorative finishing products (such as decorative fabrics, mattresses, and rigid furniture), etc. 3.1.3 burning behaviour reaction of materials and products to fire under specified conditions 3.1.4 flat material and product materials and products with a cross-section approximately rectangular in shape, where the width is much greater than the thickness Note 1: The surface of flat material and product is generally flat, but some products may exhibit regular protrusions or indentations on the surface. Note 2: Flat material and product are typically applied in areas such as building walls, partitions and ceilings. 3.1.5 flooring material and product materials or products laid on the floor Example: Carpets, plastic flooring, wood flooring, floor mats, floor coatings, etc. 3.1.6 roof covering material and product covering materials and products applied to the base surface of building roofs 3.1.7 thermal insulation material and product for building thermal insulation materials and products used for insulating walls, roofs, floors, pipes and other parts of buildings 3.1.8 wall thermal insulation product thermal insulation products used for interior and exterior walls of buildings 3.1.9 roof thermal insulation product thermal insulation products used for building roofs 3.1.10 floor thermal insulation product thermal insulation products laid on interior floors of building 3.1.11 sandwich composite thermal insulation product composite insulation product made by bonding non-combustible panels on both sides of insulation material, used for building walls and roofs (excluding edge sealing materials) Example: Metal-faced thermal insulation sandwich panels and calcium silicate faced composite insulation boards for building use. 3.1.12 pipe thermal insulation product functional product either prefabricated or applied on-site to the outer surface of pipelines to inhibit heat conduction and reduce heat transfer of the medium Note 1: Including tubular insulation products and flat pipe thermal insulation products. Note 2: Thermal insulation products with an outer diameter not greater than 300 mm are considered as tubular thermal insulation products, while those with an outer diameter greater than 300 mm are considered as flat pipe thermal insulation product. 3.1.13 photovoltaic module complete photovoltaic cell assembly with encapsulation and internal connections, capable of independently providing direct current output Note: A photovoltaic module typically consists of a laminated assembly, a junction box, and a frame (if any). 3.1.14 homogeneous product product made from a single material or having even density and component 3.1.15 non-homogeneous product product failing to meet the definition of a homogeneous product, consisting of multiple substantial and/or non-substantial components 3.1.16 substantial component material with a single-layer surface density ≥1.0 kg/m² or thickness ≥1.0 mm, which constitute the main part of a non-homogeneous product Note: If two or more adjacent secondary layers of non-substantial components (i.e., no substantial components between them) combine as a whole meet the requirements for a layer of substantial component, then the combination shall be considered as a substantial component. 3.1.17 non-substantial component material with a single-layer surface density <1.0 kg/m² and thickness <1.0 mm, which do not constitute the main part of a non-homogeneous product Note 1: If two or more adjacent secondary layers of non-substantial components (i.e., no substantial components between them) combine as a whole fail to meet the requirements for a layer of non-substantial component, then the combination shall not be considered as a non-substantial component, but a substantial component. Note 2: If two or more adjacent secondary layers of non-substantial components (i.e., no substantial components between them) combine as a whole meet the requirements for a layer of non-substantial component, then the combination shall be considered as a non-substantial component. 3.1.18 internal non-substantial component non-substantial component that is covered with at least one substantial component on both sides 3.1.19 external non-substantial component non-substantial component that is not covered with non-substantial component on one side 3.1.20 substrate material located at the back of the product, in direct contact with the product or with an appropriate air gap Example: Concrete walls, wood, metal panels, etc. 3.1.21 standard substrate product that represents the actual substrate in practical application 3.1.22 gross heat of combustion; PCS heat released when a unit mass of material is completely burned and all water produced from the combustion condenses into liquid state 3.1.23 net heat of combustion; PCI heat released when a unit mass of material is completely burned and all water produced from the combustion condenses into gaseous state 3.1.24 flaming droplets/particle substance or particle that separate from the specimen during a combustion test and continue to burn for at least the minimum duration specified by the test method 3.1.25 critical heat flux; CHF heat flux at flameout or heat flux at 30 min of testing (corresponding to the heat flux at the furthest flame spread distance within 30 min), whichever is smaller 3.1.26 fire growth rate index; FIGRA maximum value of the ratio of the heat release rate of the specimen to the exposure time Example 1: FIGRA0.2 MJ indicates the maximum value of the ratio of the heat release rate of the specimen to the exposure time after the heat released by the specimen's combustion reaches 0.2 MJ. Example 2: FIGRA0.4 MJ indicates the maximum value of the ratio of the heat release rate of the specimen to the exposure time after the heat released by the specimen's combustion reaches 0.4 MJ. 3.1.27 smoke growth rate index; SMOGRA maximum value of the ratio of the smoke growth rate of the specimen to the exposure time 3.1.28 smoke toxicity degree of injury/harm caused by toxic and harmful substances in smoke 3.2 Symbols and abbreviations For the purposes of this document, the following symbols and abbreviated terms apply. CHF: critical heat flux ,kW/m2 d: flaming droplets/particle rating FIGRA: fire growth rate index, W/s Fs: flame tip height, mm LFS: lateral flame spread OI: oxygen index, % PCI: net calorific value, MJ/kg PCS: gross heat of combustion, MJ/kg or MJ/m2 SDR: smoke density rating SMOGRA: smoke growth rate index, m2/s2 s: smoke growth characteristic rating t: smoke toxicity rating tf: continuous burning time, s THR600s: total heat released within 600 s after the specimen is exposed to fire, MJ TSP600s: total smoke produced within 600 s after the specimen is exposed to fire, m2 ΔT: temperature rise, ℃

Contents Foreword III Introduction IV 1 Scope 2 Normative references 3 Terms, definitions, symbols and abbreviations 3.1 Terms and definitions 3.2 Symbols and abbreviations 4 Classification and grading 4.1 Classification 4.2 Burning behavior grade 5 Criteria for determining burning behavior grades 5.1 Building materials and products 5.2 Materials and products for decoration 5.3 Non-metallic materials and products for equipment components 6 Application of classification results 7 Classification description, labeling, and reporting 7.1 Classification description 7.2 Classification labeling 7.3 Classification reporting