Fire classification of construction products and building elements - Part 1: Reaction to fire
Summary
TAV. 00Defines 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.
Scope of application
TAV. 01Applies 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.
How this standard works
TAV. CThe 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.
One letter is not enough: the two sub-classes
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 and resistance: two standards, one system
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.
Key points
TAV. K- Euroclasses from A1 (non-combustible) to F (not classified/not determined)
- Additional classes: smoke production s1-s3, flaming droplets d0-d2
- Harmonised basis for CE marking (reaction to fire) of products
- Pairs with UNI EN 13501-2 (fire resistance): reaction + resistance
Materials concerned
TAV. MFrequently asked questions
TAV. QWhat is the difference between reaction to fire and resistance to fire?
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).
Is an A1 material always required?
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.
Why are some letters followed by codes like s1, d0?
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.
Is reaction to fire alone enough to ensure fire safety?
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.
Glossary
TAV. G- Euroclasse
- The European reaction-to-fire class of a product, from A1 (non-combustible) to F (not classified).
- Reazione al fuoco
- The behaviour of a material that, by decomposing, contributes to the fire it is exposed to.
- Marcatura CE
- The marking by which a construction product declares its performance against a harmonised standard, including reaction to fire.
- Produzione di fumo (s)
- Sub-class (s1-s3) expressing how much smoke a product develops during combustion, from low (s1) to high (s3).
- Gocciolamento ardente (d)
- Sub-class (d0-d2) expressing the release of flaming droplets or particles, from none (d0) to significant (d2).