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2026: A Paradigm Shift in Flame Retardant Testing
For decades, flame-retardant testing asked a single question: "Can it burn?" A sample was ignited for a dozen seconds, the flame was removed, and if the material self-extinguished, the report was stamped "qualified." Now imagine that same material in a real bedroom fire: within the first minute or two it can release several hundred kilowatts of heat, pushing room temperature past the flashover threshold. Would that "qualification" still keep occupants safe?
This is exactly what the new national standards, being implemented intensively in 2026, are designed to correct. Flame-retardant testing should no longer be limited to "can it burn" — it must also answer how dangerous it is when it burns.
SL-FL76 Vertical Flame Test Machine
The new national standards being released intensively in 2026 provide a brand-new answer.
I. 2026: The Year of “Paradigm Shift" in Flame-Retardant Testing
For decades, traditional flame-retardant testing focused on one question: “Can it burn?" — whether the material self-extinguishes after ignition, how long the charred length is, how high the smoke temperature is. This logic is essentially a qualitative judgment: qualified / unqualified, a binary choice.
The multiple national standards released and implemented in 2026 have pushed the industry into a profound transformation from “qualitative" to “quantitative." The core change can be summed up in one sentence:
No longer just answering “will it ignite," but precisely calculating how fast it burns, how much heat it releases, how much smoke it produces, and whether the smoke is toxic.
The following four standards form the backbone of this upgrade:
Standard No.
Name
Key Time Node
Core Change
GB/T 20284-2026
Single Burning Item (SBI) Test
Fully implemented 2026-10-01
Introduces quantitative indicators FIGRA, THR and SMOGRA
GB/T 16172-2026
Heat Release Rate & Smoke Production Rate
Released 2026-01-28; implemented 2026-08-01
Cone calorimeter method; newly adds smoke-production-rate measurement
GB/T 8625-2026
Difficult-to-Ignite Performance
Implemented in 2026
Introduces heat-release parameters beyond damaged length and smoke temperature
GB 8624-2025
Classification of Burning Behavior
Released 2025; effective 2026
Four-dimensional system: combustion + smoke + droplets + toxicity
1) GB/T 20284-2026 — Single Burning Item Test (SBI)
The key advance over the old version is that it no longer simply looks at “whether it burned through." Instead, it outputs a set of numbers that can be directly compared to assess danger: the Fire Growth Rate Index (FIGRA), Total Heat Released (THR), and Smoke Growth Rate Index (SMOGRA).
SL-FL13 Single Burning Item Test Machine (SBI)
2) GB/T 16172-2026 — Cone Calorimeter Method
Based on the oxygen-consumption principle: the method measures how much oxygen the material consumes, then back-calculates the heat released (burning 1 kg of oxygen releases approximately 13.1 MJ of heat). It can continuously and dynamically measure the Heat Release Rate (HRR) and the Smoke Production Rate (SPR).
The old version focused only on heat-release rate; the new version adds smoke-characteristics testing, filling the long-standing gap in “smoke hazard."
SL-FL01 Building Materials Cone Calorimeter
3) GB/T 8625-2026 — Difficult-to-Ignite Test
This standard also introduces heat-release parameters, changing the traditional difficult-to-ignite test’s narrow focus on “charred length and smoke temperature," and giving “difficult-to-ignite" a more multidimensional definition.
SL-FL03 Heat Release Rate Test Machine
4) GB 8624-2025 — Classification of Combustion Performance
This is the “master framework" of the entire evaluation system. It expands a material’s grade from the single dimension of “will it ignite" to four dimensions:
Combustion characteristics (A, B1, B2, B3, etc.)
Smoke-production characteristics (s1 / s2 / s3 — the less smoke, the higher the grade)
Combustion droplets (d0 / d1 / d2 — presence of ignitable molten droplets)
Smoke toxicity (t0 / t1 / t2 — the lower the toxicity, the higher the grade)
For a material to achieve a high grade, simply “not igniting" is no longer enough — it must also be low-smoke, non-dripping, and low-toxicity.
SL-FL75 Building Material Smoke Density Fire Tester
SL-FL87 Building Materials Burning Calorific Value Tester
Key Life-Saving Technical Terms
HRR (Heat Release Rate): The heat released per unit time, in kilowatts (kW). It is the most critical danger indicator — the higher the HRR, the faster the fire grows and the shorter the escape window.
FIGRA (Fire Growth Rate Index): The "acceleration" of the fire, expressed in kW/s. The lower the FIGRA, the more time people have to escape.
THR (Total Heat Released): The integral of HRR over time, in megajoules (MJ). The more heat, the more likely a structure is to collapse.
SMOGRA (Smoke Growth Rate Index): Measures how fast smoke is produced. Dense smoke blocks visibility and escape routes.
Flashover: The critical point at which a localized fire becomes a full-room fire, with temperatures surging to 500-600 °C.
Why "How Dangerous" Matters More Than "Can It Burn"
Back to the opening question. In a real fire, Heat Release Rate (HRR) determines almost everything: it directly dictates fire-spread speed, escape-window length, and firefighting/rescue difficulty.
Consider this comparison:
Material A: self-extinguishes after the flame is removed (traditionally “flame retardant"), with a peak HRR of only 50 kW/m².
Material B: also self-extinguishes after flame removal (also “flame retardant"), but with a peak HRR as high as 300 kW/m².
Both materials “passed the vertical burning test." But in a real fire, Material B would push the room past flashover within minutes, while Material A might give occupants precious extra escape time.
“Can it burn" only tells you whether the fire is easy to ignite; “how dangerous when it burns" tells you how lethal the fire truly is.
Even more critical are smoke and toxicity. Firefighting statistics repeatedly show that the vast majority of fire casualties are not caused by burns, but by asphyxiation from inhaling toxic smoke — carbon monoxide, hydrogen cyanide, and high-temperature dense smoke. This is precisely why the new national standards separately score “smoke-production characteristics" and “smoke toxicity": the fire may not kill, but the smoke does.
This is the core logic of the 2026 national standards: upgrading from “pass / fail" to “how dangerous."
Old Paradigm vs. New Paradigm
Dimension
Old Paradigm (“Can It Burn?")
New Paradigm (“How Dangerous When It Burns?")
Judgment
Qualified / Unqualified
Quantitative scoring
Core Indicators
Self-extinguishing, charred length, smoke temperature
HRR, FIGRA, THR, SMOGRA, toxicity, droplets
Focus
Ease of ignition
Fire growth, heat release, smoke hazard
Real-World Meaning
Whether the fire is easy to start
Whether people can survive once the fire starts
Three Hurdles Enterprises Face
Across-the-board shift in testing standards: Old-version reports such as GB/T 20284-2006 will gradually become invalid, requiring retesting and recertification.
Testing equipment must be upgraded: New methods demand new equipment, including cone calorimeters, SBI apparatus, non-combustibility test furnaces, and flooring radiant heat-flux fire test machines.
Compliance thresholds are significantly higher: GB 46520-2025 requires smoke-production grade no lower than s2, droplet grade no lower than d1, and smoke-toxicity grade no lower than t1 — these are red lines, not recommendations.
A Global Perspective
Chinese standards are not an island. Understanding mainstream international systems is especially important for export-oriented and benchmark-oriented enterprises.
ISO (International Organization for Standardization)
The globally accepted baseline, often directly adopted or adapted by individual countries.
ISO 1182 — Non-combustibility test
ISO 1716 — Determination of combustion heat
ISO 11925-2 — Combustibility under direct flame
ISO 5660-1 — Cone calorimeter method (heat release, smoke)
ISO 9705 — Full-scale room fire test
ISO 834-1 — Fire resistance (standard fire exposure)
ISO 5659-2 — Smoke density test
ISO 9239-1 — Flame spread on flooring materials
EN (European)
The unified EU market-access system, with the strictest classification framework (A1–F).
EN 13501-1 — Fire classification of construction products (A1–F)
EN 13823 (SBI) — Single Burning Item test
EN 16733 — Continuous smoldering test
ASTM / NFPA (United States)
The mainstream North American approach, oriented toward “real fire scenarios."
ASTM E84 (NFPA 255) — Steiner tunnel method (flame spread + smoke density)
ASTM E119 — Fire resistance
ASTM E136 — 750 °C vertical tube furnace combustibility
ASTM E162 — Surface flammability under radiant heat
NFPA 285 — Fire propagation in exterior wall assemblies
BS (British Standards)
Widely used across the Commonwealth, with a long history.
BS 476 series: non-combustibility (476-4), fire propagation (476-6), surface flame spread (476-7), roof fire tests (476-3)
DIN (Germany)
An important European reference, known for its rigor.
DIN 4102-1 — Fire classification of building materials (combustion, smoke, toxicity)
For building-materials and fire-protection enterprises, the new standards are both a compliance pressure and an opportunity to upgrade product capability — quantify the “danger" clearly one step earlier, and you put safety in your hands one step earlier.
SKYLINE Instruments has been deeply engaged in the combustion-testing field for nearly 20 years. Its equipment solutions have served combustion projects in multiple countries, and it can provide testing equipment and technical support covering the above mainstream standards (ISO / EN / ASTM / NFPA / BS / DIN, and the Chinese GB system), helping you meet the compliance requirements of different markets with confidence.
Turning Compliance Pressure into Product Capability
For building-materials and fire-protection enterprises, the 2026 standards are both a compliance pressure and an opportunity. SKYLINE Instruments has been deeply engaged in the combustion-testing field for nearly 20 years. Its equipment solutions have served combustion projects in multiple countries, providing testing equipment and technical support covering the mainstream ISO, EN, ASTM, NFPA, BS, DIN and Chinese GB systems — helping manufacturers meet the compliance requirements of different markets with confidence.