Euroclass reaction to fire is the European system (BS EN 13501-1) that rates how much a material contributes to a fire, from Class A1 (contributes least) down through A2, B, C, D and E to F (worst-performing or untested). Two sub-classes are added: a smoke rating from s1 to s3 (s1 = least smoke) and a flaming-droplets rating from d0 to d2 (d0 = none). So B-s1,d0 describes a high reaction-to-fire class that also produces the least smoke and no flaming droplets.
What the Euroclass letters and sub-classes mean
Euroclass is the classification given by BS EN 13501-1. It rates a material's reaction to fire — how much a wall or ceiling lining adds to a fire in its early, growing stages. There are seven main classes: A1, A2, B, C, D, E and F, running from A1 (the top class, contributing least) down to F (the worst-performing, or a material that has not been tested).
Two extra letters travel with the main class. The smoke sub-class rates how much smoke a material gives off — s1, s2 or s3, with s1 the least. The flaming-droplets sub-class rates whether it sheds burning droplets or particles — d0, d1 or d2, with d0 meaning none. That is why a full classification is written as a string, such as B-s1,d0.
What does B-s1,d0 mean?
Read it in three parts. The B is the main reaction-to-fire class — near the top of the A1-to-F scale, so a material that contributes little to fire growth. The s1 says it produces the least smoke, and the d0 says it produces no flaming droplets. Put together, B-s1,d0 is a strong all-round reaction-to-fire result across the three things the standard measures: contribution to fire, smoke and droplets.
It is worth being precise about what this class does and does not tell you. It says how the surface would behave in a growing fire; it says nothing about how long a wall or door would hold a fire back. Those are two different properties, covered next.
Reaction to fire is not fire resistance
These two are easy to confuse and are not the same thing. Reaction to fire — the Euroclass system — measures how a surface or lining contributes to a fire's growth. Fire resistance measures how long a building element, such as a wall, floor or fire door, holds back a fully developed fire, expressed in minutes. They use different tests and different standards, and one cannot be read off the other.
An acoustic wall or ceiling lining is normally assessed for reaction to fire, because it is a surface that could help a fire spread. Fire resistance, by contrast, is a property of separating elements like compartment walls and fire doors. A Euroclass rating on a panel therefore answers the lining question, not the how-many-minutes question.
Where timber sits — and how it reaches Class B
Untreated timber typically achieves around Class D. Reaching a higher class such as Class B generally requires a fire-retardant treatment or a specific construction — and that improved result only counts when it is evidenced by a test report to BS EN 13501-1 for that exact build-up. This is one of the practical differences between materials covered in wood vs foam vs fabric panels.
For that reason, our own fire-rated acoustic range — including the fire-rated acoustic panel — is always stated against its test report, never a generic claim. A Euroclass figure with no report behind it, or one copied from a different construction or thickness, is not evidence of anything.
When is a reaction-to-fire class required?
The required class is not chosen by the panel — it is set by the building itself. The building's fire strategy and the relevant Building Regulations fire-safety guidance (in England, Approved Document B) determine the reaction-to-fire performance a lining must meet, based on the building's use, its height and the specific location within it.
Some spaces, such as protected escape routes and circulation areas, are typically held to a higher standard than an ordinary room. The reliable route is to establish the class the fire strategy calls for at each location, then specify a finish whose tested Euroclass meets it — rather than assuming a material's class or working backwards from a product.
Frequently asked questions
Is B-s1,d0 a good fire rating?
It is a high reaction-to-fire classification. B sits near the top of the A1-to-F scale, s1 is the least smoke, and d0 means no flaming droplets. Whether it is the right rating depends on what the building's fire strategy requires for that location — the tested class must match the requirement, evidenced by a test report.
Is Euroclass the same as a fire-resistance rating?
No. Euroclass (BS EN 13501-1) rates reaction to fire — how a surface contributes to a fire's growth. A fire-resistance rating measures how many minutes an element such as a wall or fire door holds a fire back. They are separate tests and are not interchangeable.
Does a Class A absorption panel also have a Class A fire rating?
Not necessarily — they are unrelated systems that happen to share letters. Sound absorption Class A to E (BS EN ISO 11654) describes how much sound a panel soaks up; Euroclass A1 to F describes reaction to fire. A panel can be Class A for absorption and a different Euroclass for fire, so always read the two separately.
Can any wood acoustic panel be made fire-rated?
Many can, through a fire-retardant treatment or a specific construction, but the resulting Euroclass must be proven by a test report to BS EN 13501-1 for that exact build-up. Because untreated timber typically sits around Class D, a higher class is never assumed — it is tested and documented.