Defines the reaction-to-fire classification procedure for construction products via the Euroclasses (A1, A2, B, C, D, E, F), supplemented by additional classes for smoke production (s1-s3) and flaming droplets (d0-d2). It is the reference for CE marking on reaction to fire.
Applies to construction products and building elements that must declare their reaction to fire (e.g. for CE marking). It provides the common European classification language referenced by national fire-safety rules.
The standard organises products on a descending scale of Euroclasses, from non-combustible to highly flammable, and adds two sub-classifications describing smoke production and flaming droplets. We describe its logic here — without reproducing tables or values.
Understanding how this standard is built means understanding a language that recurs throughout fire safety: the Euroclasses. They are the standardised way, valid across the European Union, of stating how much a material contributes to a fire.
The main class (the letter) tells only part of the story. For materials from A2 to D, the standard also requires declaring two behaviours that can be decisive in a real fire: how much smoke they produce and whether they release flaming droplets. These are the sub-classes s (smoke) and d (droplets).
| Symbol | What it describes | Logic |
|---|---|---|
| s1 → s3 | Smoke production | from low (s1) to high (s3) |
| d0 → d2 | Flaming droplets | from none (d0) to significant (d2) |
Reaction to fire (this standard) measures how much a material contributes to the fire; fire resistance — classified by UNI EN 13501-2 — measures how long an element withstands it. The two standards are complementary: together they provide the full vocabulary with which fire-safety rules set requirements.
Reaction to fire (this standard) measures how much a material contributes to a fire — a property of the product. Resistance to fire instead measures how long an element keeps performing (load-bearing, compartmentation) during a fire, and is classified by other standards (R, E, I criteria).
No. The required class depends on the application and is set by the fire-safety rules (e.g. the Fire Prevention Code) for that specific use, not by this standard. This standard only provides the classification language; it does not impose which class to use.
Because the main class alone is not enough: smoke and flaming droplets matter in a real fire. The additional sub-classes (s for smoke, d for droplets) complete the classification for the relevant classes.
No: it is one of the measures. Fire-safety rules (e.g. the Fire Prevention Code) combine it with fire resistance, evacuation, detection and other measures. The reaction class concerns the product, not the whole building.