What EN 13501-1 A2-s1,d0 Actually Means for an ACP Facade
Two quotations for the same facade panel can both read “A2” and still be describing two different products. One supplier is quoting a panel whose core has been tested to the European reaction-to-fire standard and can hand over the classification report. The other is using “A2” the way “fireproof” gets used in a brochure. The gap between those two is the full code, and a document.
This guide breaks the string “A2-s1,d0” down into what each part is saying, which numbers a panel has to hit to earn it, why A2 is a different test regime from FR rather than simply a better version of it, and what to check on the certificate before you commit to a container.
How the EN 13501-1 scale is built
EN 13501-1 is the European standard for classifying the reaction to fire of construction products. It is a scale, not a pass or fail. A1 sits at the top, A2 just below it, then B, C, D, E and F, which is the unrated end. A product does not “have” fire performance in the abstract; it occupies a position on that ladder.
The scale is built from three different test methods, and this is where most of the confusion starts. Non-combustibility and calorific potential are measured in a furnace and a bomb calorimeter. Fire growth and smoke are measured in a room-corner test. A classification only exists if the relevant tests were run on the relevant construction, so a report for one core does not transfer to another.
| Test | What it measures |
|---|---|
| EN ISO 1182 | Non-combustibility: temperature rise and mass loss in a furnace |
| EN ISO 1716 | Gross calorific potential (PCS): how much energy the material can release per kilogram |
| EN 13823 (SBI) | Single Burning Item: fire growth rate, heat release, smoke and falling droplets |
Breaking down “A2-s1,d0”
The letter is the headline class. The two suffixes that follow it are additional classifications, and on a facade they are not decoration. A2 alone tells you the panel burns very little. The suffixes tell you what it does while it is doing so.
| Part | What it means |
|---|---|
| A2 | Limited combustibility. The panel may contribute a very small amount of fuel to a fire, but almost nothing compared with a standard panel. |
| s1 | The lowest smoke production band. s2 and s3 allow progressively more smoke. |
| d0 | No flaming droplets or particles. d1 and d2 allow them, with d2 the worst case. |
A1 products are effectively non-combustible in themselves, so the top class does not need a smoke or droplet suffix. Once you drop to A2 and below, the suffixes start carrying part of the story.
What a panel must actually pass to be called A2
A2 is not awarded for looking non-combustible. It is awarded against specific numbers, and the same test set produces the s and d suffixes alongside it.
| Property | A2 limit | Test |
|---|---|---|
| Gross calorific potential (PCS) | ≤ 3.0 MJ/kg | EN ISO 1716 |
| Furnace temperature rise | ≤ 50 °C | EN ISO 1182 |
| Fire growth rate (FIGRA) | ≤ 120 W/s | EN 13823 (SBI) |
| Total heat release over 10 minutes (THR600s) | ≤ 7.5 MJ | EN 13823 (SBI) |
| Smoke growth rate, for s1 (SMOGRA) | ≤ 30 m²/s² | EN 13823 (SBI) |
| Total smoke produced, for s1 (TSP600s) | ≤ 50 m² | EN 13823 (SBI) |
The practical consequence: an A2 core is a mineral-filled core. The mineral content is what keeps the calorific potential down, and it is also what makes the panel heavier and more expensive than a PE or FR core of the same thickness. You are not buying a coating or a surface treatment. You are buying what is inside the panel.
Why A2 and B are not the same family
This is the single most useful thing to understand when you compare quotations, because it explains why one supplier’s “fire-rated” panel is so much cheaper than another’s A2.
A2 and B share the same thresholds on the fire growth test. Both must reach FIGRA ≤ 120 W/s and THR600s ≤ 7.5 MJ. On the room-corner evidence alone they look like neighbours. What separates them is a test that has nothing to do with fire growth:
| Property | A2 | B |
|---|---|---|
| Gross calorific potential (PCS) | ≤ 3.0 MJ/kg | No cap |
| FIGRA | ≤ 120 W/s | ≤ 120 W/s |
| THR600s | ≤ 7.5 MJ | ≤ 7.5 MJ |
So a B-class panel can behave acceptably in the corner test and still be full of combustible material. A2 puts a hard ceiling on how much energy the panel contains, and that ceiling is what a mineral core buys you. If a specification calls for A2, a B-class panel is not a cheaper route to the same place. It is a different product answering a different question.
What “B1” is, and why it is not on this scale
Exporters and buyers often use “B1” and “A2” in the same sentence, as though B1 were the rung below A2. It is not. B1 does not appear in EN 13501-1 at all. It comes from older national and Chinese schemes, where building materials were grouped into classes numbered roughly from non-combustible downwards.
In practice, when a supplier in this industry says “FR core” or “B1”, they usually mean a flame-retardant core with a mineral filler that resists ignition but can still burn, and which would sit somewhere in the B or C region of the European scale if it were tested to it. That may be perfectly adequate for the project. It is simply not A2, and the two labels should not be treated as interchangeable in a specification or a purchase order.
How to verify an A2-s1,d0 claim before you order
A classification is only as good as the document behind it. Six things are worth checking, and all of them are quick.
- Is it a classification report, not a marketing line? You want a document issued by a notified test body, not a sentence in a catalogue.
- Does it name the exact construction? Core type, panel thickness and the specific build that will be shipped. A report for a 4 mm panel does not automatically cover a 6 mm one.
- Does it name your coating and finish? A2 classification covers the panel as tested. A different coating system is a different specimen.
- Is the standard cited the one your market uses? EN 13501-1 for the EU, GB 8624 for China, ASTM E84 and NFPA 285 for the United States. Do not accept a certificate for a standard your building code does not reference.
- Which body issued it, and when? The issuing laboratory should be identifiable, and the report should still be current.
- Does the suffix match the specification? If the drawing says A2-s1,d0, a report showing A2 without the smoke and droplet classification is not the same document.
Ask for these before the deposit, not after the panels arrive at the port. A supplier who has the tests will send them; the request itself tells you something about the ones who do not.
Frequently asked questions
Is A2-s1,d0 the highest class available?
A1 is higher. A1 products are effectively non-combustible and carry no smoke or droplet suffix. For an aluminium composite panel with an organic coating, A2-s1,d0 is the realistic top of the range, and it is the grade most often written into high-rise and public building specifications.
Is A2 the same as B1?
No, and the two are not on the same scale. B1 is not a class in EN 13501-1. A B1 or FR core resists ignition and may be entirely suitable for a project, but it is a different product from an A2 mineral core and should not be substituted where the specification calls for A2.
Why does the s1 part matter if the panel is already A2?
Because in a real fire most casualties are caused by smoke, not flame. Two panels can both be A2 while one produces far more smoke than the other. On a tall building or an escape route, s1 is doing serious work.
Do you supply the test documentation?
Yes. Tell us the destination market and the fire clause your specification uses, and we will send the documentation that applies to it, so you can check the claim against the certificate rather than take our word for it.
About Jinxiang
Zhejiang Jinxiang Panel Industry Co., Ltd. manufactures aluminium composite panel and colour-coated aluminium coil in Jinhua, Zhejiang, with an annual capacity of 6 million square metres of composite panel and 8,000 tonnes of coated coil. The coil, the coating and the composite panel stay under one roof, and our dedicated A2 fire-rated line can produce panels up to 2,000 mm wide, which means fewer joints across an elevation. We export to more than 70 countries. MOQ is one standard container for stock colours, with a 500 sqm minimum per colour for custom colours, and lead time is 10–15 days after deposit.
Send us your specification, the destination market and the fire clause you are working to, and we will quote the core and the certificate that satisfy it. See the A2 fireproof aluminium composite panel range, read how PE, FR and A2 cores compare or the A2 sourcing guide, compare against the full aluminium composite panel range, or contact us for a quote, a sample kit or a factory tour.