Know-How · 04

Reaction to fire vs fire resistance

Two different concepts, both fundamental to fire safety.

Concept 1

Reaction to fire

Describes the behaviour of a material when exposed to a heat source in the ignition phase of a fire.

It measures whether, and how much, the material:

Ignites
Contributes to fire spread
Produces smoke
Generates flaming droplets

Classification (Euroclasses)

A1 · A2 · B · C · D · E · F

(+ subclasses s1–s3 for smoke, d0–d2 for flaming droplets)

Concept 2

Fire resistance

Describes the ability of a building element to maintain its functions during a fully developed fire.

It measures for how long the element:

R — maintains its load-bearing capacity
E — blocks the passage of flames and hot gases (integrity)
I — prevents heat transmission (insulation)
W — limits radiated heat

Classification

R / RE / REI / EI / EW · 30 → 240 min

E.g. EI 120 = 120 minutes of integrity + insulation

Why the difference matters

A material with a poor reaction-to-fire class can still be used within a system of high fire resistance, provided it is protected. Conversely, a non-combustible (A1) material does not in itself guarantee fire resistance: an A1 board fixed to a poor frame fails quickly.

Global Building FIREGUARD boards are Euroclass A1 (reaction to fire) and are built into systems certified EI up to 240 minutes (fire resistance). The two performances add up: the system is safe in the ignition phase and resistant in the fully developed phase.

Which one does my project need?

It depends on the type of occupancy and the performance level required by the Italian Fire Prevention Code (D.M. 3/08/2015):

Escape routes (corridors, stairs, smoke-proof lobbies): require class A1/A2 reaction-to-fire materials for linings.
Fire compartmentation (partition walls, floor slabs): requires EI/REI certified elements with an appropriate duration (typically EI 60–120).
Load-bearing structures (columns, beams): require class R (e.g. R 60, R 120), achieved with intumescent protection or board encasement.

Technical support

When in doubt, ask us.

The Global Building technical department can help you identify the class the regulations require and the correct certified solution for your occupancy.

Request technical advice →Open the solutions catalogue