China‘s building fire safety regulatory landscape is undergoing a profound transformation. GB 8624-2025 “Classification for burning behavior of building materials and products” was officially released on December 31, 2025, by the State Administration for Market Regulation and the National Standardization Administration. With a mandatory implementation date of January 1, 2027, it will replace GB 8624-2012. Aligned with the “Full-Chain Remediation Action Plan for Hidden Safety Hazards of Building Insulation Materials,” this revision adopts a core approach of “Scope Expansion, Category Refinement, Dimension Elevation, Application Strengthening, and Traceability Promotion”. For manufacturers and importers of insulation materials, roofing membranes, photovoltaic modules, and decorative composites, understanding the new combustibility categories and requirements under GB 8624-2025 is essential. This guide provides a complete breakdown of the revision‘s most consequential changes, the new four-dimensional evaluation system, and a practical compliance roadmap.
1. Revised Framework: From Material-Centered to “Scenario Safety”
The 2025 revision shifts the underlying logic from a purely “material‑centered” approach to a “scenario safety” approach. The purpose is to align material combustibility ratings with the actual fire risks of specific application environments. The guiding principles are: expanding the scope to include photovoltaic modules, roofing coverings, and decorative materials; refining the classification of building insulation into five sub‑categories; elevating the evaluation dimension beyond simple “burns or does not burn”; strengthening application requirements to match testing conditions with real‑world scenarios; and promoting traceability through mandatory QR codes or electronic labels on insulation products.
2. Scope Expansion: New Product Categories and the “Three‑Dimension, Nine‑Category” System
The revised standard significantly expands its scope from the traditional “building materials and building products” to include “building materials and products, decorative materials and products, and non‑metallic materials and products for equipment and devices”. This expansion is a direct response to emerging fire risks in high‑rise buildings, large complexes, and new energy facilities, and fills critical regulatory gaps. The new system introduces a “Three‑Dimension, Nine‑Category” classification: Dimension 1 covers building materials and products (including thermal insulation, roofing, and pipes); Dimension 2 covers decorative materials and products (including wallpapers, foams for furniture, and fabrics); and Dimension 3 covers non‑metallic materials and components for equipment. This refined system enables tailored safety requirements for each distinct product type.
Key newly added categories include:
- Photovoltaic (PV) modules: For the first time, PV modules used in building‑integrated photovoltaics (BIPV) are included in the combustibility classification system, with dedicated test methods under GB/T 46980-2025.
- Roof covering materials and products: A completely new independent category covering waterproofing membranes, metal roofing sheets, and other roofing components, each with dedicated test protocols.
- Building insulation materials and products: Elevated to an independent major category and refined into five sub‑categories: wall insulation products, roof insulation products, floor insulation products, double‑faced sandwich composite insulation products, and pipe insulation products.
3. The Four‑Dimensional Combustibility Evaluation System
The most transformative change in GB 8624-2025 is the introduction of a four‑dimensional evaluation system that moves beyond the simple question of “does it burn” to a comprehensive assessment of real fire risk. All materials assigned to combustibility classes A2, B, C, or D (i.e., any class other than the highest A1 level) must now be qualified across four distinct dimensions.
The four dimensions are:
- Combustibility (Euroclass equivalent A2, B, C, D): The base combustibility rating determined through standardized tests such as SBI (single burning item), gross calorific value, and flame spread.
- Smoke production (s1, s2, s3): Rated from s1 (low smoke) to s3 (high smoke), determined by the smoke production rate (SMOGRA) and total smoke production (TSP) in the SBI test.
- Flaming droplets/particles (d0, d1, d2): Rated from d0 (no flaming droplets) to d2 (severe flaming droplets falling within 1200 seconds), as observed during the SBI test.
- Smoke toxicity (t0, t1, t2): Rated from t0 (non‑toxic) to t2 (highly toxic). Even if combustibility criteria are met, a product rated t2 (high toxicity) will be directly disqualified from use.
The new rating format is illustrated by “B1(B-s1, d0, t1)” which indicates that the material is a flame‑retardant material (B1 equivalent to Euroclass B) producing low smoke (s1), no flaming droplets (d0), and having low toxicity (t1). For the highest safety class, A2 grade must meet the rigorous combined criteria of s1, d0, and t0 simultaneously – a requirement that mandates both physical fire resistance and suppression of toxic emissions.
4. Grade Nomenclature and Classification Structure
Although public guidance sometimes simplifies the system to a four‑tier framework – A1 (non‑combustible), A2 (near non‑combustible with very low heat release), B (flame‑retardant), and C (combustible) – the official detailed structure in the standard document actually comprises seven base levels (A1, A2, B, C, D, E, F) when fully defined. The familiar “B1, B2, B3” nomenclature remains standard in industry practice, corresponding to the core material categories where A1 and A2 are grouped as “Class A non‑combustible material,” B1 as “flame‑retardant material,” B2 as “combustible material,” and B3 as “highly combustible material.”
It is essential to note that the standards for achieving each grade have been substantially upgraded. The previous distinction between B1 and B2, which relied heavily on a single small‑flame test, is now insufficient. Passing B1 today requires a successful Single Burning Item (SBI) test with a peak heat release rate ≤ 150 kW and flame spread ≤ 150 mm, as well as meeting all associated smoke, drip, and toxicity sub‑ratings. Lower‑performance grades, such as B2, must now undergo an updated version of the GB/T 8626 ignition test, which now demands that a specimen not ignite after 30 seconds of flame exposure for the product to remain in the “self‑extinguishing” or “limited flame spread” classification. Many wallpapers and furnishings may be downgraded.
5. New Requirements for Roofing Materials and PV Modules
The inclusion of roofing materials and PV modules marks a major step forward in building fire safety. Previously, roofing materials (e.g., bituminous or polyvinyl chloride membranes) were only assessed under a generic “waterproofing membrane” category, not as a distinct building element. Under GB 8624-2025, roofing covering materials and products are now a distinct and independent product category with their own specific classification criteria. These criteria require a modified external fire exposure test as defined in GB/T 30735 “External fire exposure to roofs and roof coverings”, which measures fire spread on a roof assembly at a standardized gradient.
The test protocol uses a simulated wind‑driven flame and a radiant panel heat source applied at the eave line, and the classification result (A, B, or C) is determined by the distance the flame front travels. For most BIPV applications, the PV modules themselves are now subject to a dedicated flame spread test per GB/T 46980-2025, which simulates the propagation of fire across the surface of the array. Manufacturers must ensure that the complete roof assembly (substrate, insulation, waterproofing membrane, and PV covering) meets the required classification, not just the individual PV module.
6. Detailed Sub‑Categorization of Insulation Materials and the Thermal Conductivity Requirement
The standard elevates building insulation materials and products to an independent major category and refines them into five sub‑categories: wall insulation products, roof insulation products, floor insulation products, double‑faced sandwich composite insulation products, and pipe insulation products. Each sub‑category has its own set of test protocols (e.g., SBI for wall insulation, a specialized pipe test for cylindrical forms, and a compression test for floor insulation).
Thermal conductivity must be simultaneously determined during combustibility testing of insulation materials using GB/T 10294 (Guarded Hot Plate) or GB/T 10295 (Heat Flow Meter). This ensures that “fire safety” is not achieved at the expense of thermal performance. This is a crucial safeguard against the use of dense, fire‑retardant but thermally inefficient fillers. The product‘s label must now carry its thermal conductivity value alongside the fire rating, enabling architects to verify that the material meets both safety and energy efficiency standards in a single document.
7. Updated Test Methods: Replacing Obsolete Protocols with Realistic Scenarios
The “GB 8624 series” of test methods (e.g., GB/T 5464-2026 for non‑combustibility, GB/T 8625-2026 for difficult flammability, GB/T 8626-2026 for flammability) has been fully upgraded. The previous “flame spread index” has been replaced with more precise metrics, such as the FIGRA (Fire Growth Rate) derived from the SBI test. This index measures the rate at which a fire develops and is a critical differentiator between materials that are “ignitable” versus those that are “progressive fire spreaders.” Key changes include:
- Revised B2 test method: GB/T 8626-2026 now requires that the specimen not ignite after 30 seconds of flame exposure for the product to be classified as B2, tightening the threshold. Old test results from the 2012 standard are invalid.
- Welding spark test for insulation: Based on GB/T 40327, this test is specifically designed to evaluate an insulation material‘s ability to resist ignition from welding sparks – a common on‑site construction hazard.
- SBI (Single Burning Item) test: This test has become more central to the classification system, as it directly measures real‑time heat release, smoke production, and dripping behavior under a realistic corner fire scenario, rather than simplified lab scale tests.
These new method standards (GB/T 5464-2026, GB/T 8626-2026, GB/T 20284-2026, and others) are already available, and official training indicates that any test report issued using the old methods (pre‑2026) will be considered invalid for the new classification after the 2027 deadline.
8. Mandatory QR Code or Electronic Label Traceability for Insulation Materials
In a move to enhance supply chain transparency, the 2025 revision mandates that all building insulation materials and products must carry a QR code or electronic label permanently affixed to the product or its packaging. Scanning the code with a mobile device must provide immediate access to the following key data points:
- Manufacturer‘s name and authorized production facility
- Product name, specification, and primary application
- Declared combustibility grade (including all four dimensions)
- Test standard and reference number for the verification report
- Name of the issuing inspection agency
The data must be hosted on a publicly accessible server and must remain accessible for at least the product‘s intended service life. This traceability measure bridges a known gap where non‑compliant materials entered the supply chain with counterfeit documentation. Inspectors on construction sites can now instantly verify a product’s compliance by scanning the QR code, rendering generic paper certificates virtually obsolete.
9. Industry Impacts and Compliance Roadmap for Manufacturers and Importers
With mandatory enforcement set for January 1, 2027, manufacturers and importers should consider the following steps:
- Product portfolio gap analysis: Immediately review your product line to identify which items fall under the expanded scope, especially any roofing membranes, PV modules, decorative foams, or insulation for new energy facilities.
- Update test reports to 2025 criteria: All new product certification must be based on the 2025 edition. Engage a CNAS‑accredited lab to perform SBI testing (for A2 – D products) and to measure the new toxicity, smoke, and dripping parameters (s, d, t). Reports based on the 2012 standard will be invalid post‑transition.
- Re‑engineer formulations for toxicity compliance: For foam plastics (e.g., polyurethane, polystyrene) and halogenated materials, invest in reformulation to achieve t0 or t1 smoke toxicity ratings. Halogen‑free fire retardants will be essential.
- Implement QR labeling system: Work with your IT team or a service provider to generate unique, persistent QR codes for each product batch or SKU. Ensure that the attached data portal remains active and accessible to the public.
- Engage supply chain partners: For imported products, work closely with your overseas supplier to ensure their test reports reference GB 8624-2025 and that their labeling meets the QR code requirement prior to shipment.
Products not compliant by January 1, 2027, will be subject to customs holds, recall, or market removal.
Summary: GB 8624-2025 introduces a new paradigm in building fire safety through a “scenario safety” approach, a three‑dimension, nine‑category product classification, and a four‑dimensional evaluation system covering combustibility, smoke, dripping, and toxicity. The standard expands its scope to include roofing materials and PV modules, refines insulation into five distinct sub‑categories, mandates an updated set of test methods, and introduces a mandatory QR code traceability mechanism for insulation products. Manufacturers and importers must transition from the 2012 standard to the 2025 edition before the January 1, 2027 enforcement date.