EN 13501-1 vs ASTM E84: What a Fire Classification Actually Means
Two different fire tests, two different markets. What EN 13501-1 and ASTM E84 measure, why a class from one never implies the other, and the questions to ask a supplier.
CYC Acoustic Team
CYC Acoustic Panel Specialists
A fire class from one standard never implies a class under another. If a supplier quotes EN 13501-1 and your specification asks for ASTM E84, you do not have the evidence you need — you have a different test.
The two standards
EN 13501-1 is the European system for reaction-to-fire classification. Products are tested and then grouped into classes from A1 (essentially non-combustible) down to F, with additional suffixes for smoke production (s1–s3) and flaming droplets (d0–d2). A typical interior panel classification looks like B-s1, d0.
ASTM E84 is the North American surface burning test. It measures flame spread and smoke development and reports two indices — a Flame Spread Index and a Smoke Developed Index — which map to classes such as Class A, B or C.
The tests differ in specimen orientation, ignition source, duration and what is measured. There is no simple conversion. A product that is B-s1, d0 under EN 13501-1 has not thereby been tested to ASTM E84, and vice versa.
Reaction to fire is not fire resistance
This is the second common confusion. Reaction-to-fire describes how a material itself behaves when exposed to fire — how readily it ignites, how much it contributes. Fire resistance describes how long a construction (a wall, a door, a floor) holds back a fire, expressed in minutes.
A panel can have an excellent reaction-to-fire classification and contribute nothing to the fire resistance of the wall it sits on. Those are different properties of different things, tested to different standards.
What to ask a supplier
Ask for these, in writing, before you specify:
- The test report number, and the name of the testing laboratory
- The exact standard the product was tested to
- The classification or indices as reported, verbatim
- The thickness and construction tested — a classification applies to the sample tested, not to every variant
- Whether fire resistance of the assembly is claimed, and if so under which standard
If a supplier gives a class but cannot produce the report, you do not have a classification. You have a claim.
Where we stand, plainly
This is a live issue for us too. CYC Acoustic does not currently hold an ASTM E84 classification, and our reaction-to-fire classification is pending supplier test documentation. We publish no fire class until we hold the report, and we would rather tell you that than quote a number we cannot support.
If your project needs a fire classification now, tell us the standard your specification calls for and we will tell you straight away whether we can meet it.
The wider lesson
Fire claims are the easiest thing in this industry to copy from one product page to another, and the most expensive to get wrong. Treat any fire class you see online as unverified until you have seen the report — including ours.