Fire

Fire resistance and reaction: 

In fire safety, a distinction has to be made between:

• Fire resistance (time during which the material will limit propagation of the fire)
• Behavior in a fire (the combustible material that can contribute to the start and growth of the fire)

Fire rating (3 classifications):

"Fire resistance" is the time during which a structural component (floor, wall, metal structure, etc.) will retain its mechanical properties.

• R rating (formerly SF, fire stable): time during which the structure will remain mechanically stable (ie, retain its mechanical strength). During a given period of time, the construction component will retain its load-bearing and self-supporting properties.
• RE rating (formerly FR, flame retardant): in addition to the R rating, the tested component has to be flameproof and inflammable gas proof. During a given period of time, the component will avoid the propagation of combustible gases and smoke to the unaffected side.
• REI rating (formerly FR fire stop): in addition to the RE rating, the REI rating limits to 140°C (average) and 180°C (maximum) the rise in the temperature of the surface not exposed to the fire (thermal insulation). During a given period of time, the component prevents the propagation of heat to the unaffected side.

Table:

Reaction to fire:

The "reaction to fire" classification concerns the behaviour of the material as a fuel.
Its combustibility corresponds to the amount of heat emitted by complete combustion of the material (referred to as its calorific value).

Its flammability correspondence to the quantity of more or less flammable gases emitted by the material when subjected to heat.

The "Euro classes" (classification recognised in all EU member states), replaces the type M ratings (French system) according to the decree of 21 November 2002.

This classification (Euroclass) now takes into account and has added two more criteria to the M classification: the smoke released (S for smoke) and any burning droplets (D for drop or droplets).

S = PRODUCTION AND OPACITY OF SMOKE (QUANTITY AND SPEED/RATE):

• s1: low quantity/speed
• s2: average quantity/speed
• s3: high quantity/speed

D = PRODUCTION OF BURNING DROPLETS AND DEBRIS

• d0: no debris (droplets or particles) occurs before 600 seconds
• d1: no debris whose ignition persists for more than 10 seconds occurs before 600 seconds
• d2: neither d0 nor d1 (does not meet the classification criteria).

EUROCLASSES correspondence table – category M: