Reaction to Fire – Euroclasses

For 10 years, the only valid reaction to fire rating for construction materials, apart from the aforementioned exception of textile elements, has been theEuroclases.

Euroclasses are defined in the European classification UNE-EN 13501-1 and are expressed by a code containing a main classification, ranging from “A” to “F”, a smoke sub-index, ranging from “s1” to “s3”, and a droplet sub-index, from “d0” to “d2”.

Non-combustible. No contribution to fire.
Non-combustible. No contribution to fire.
Combustible. Very limited contribution to fire.
Combustible. Limited contribution to fire.
Combustible. Average contribution to fire.
Combustible. High contribution to fire.
Unclassified. No behaviour determined.
Additional smoke opacity indicators
Low smoke production.
Average smoke production.
High smoke production.
Additional droplet/particle falling indicators
No droplets/particles are produced.
Falling of non-burning droplets/particles.
Drop of burning droplets/particles.
B ROOF (t1)
Combustible. Very limited contribution to fire.
F ROOF (t1)
Unclassified. No behaviour determined.

To determine the Euroclass, two laboratory tests are performed to determine the fire performance of the panel:

  • The small flame test
    This test, also known as the “flammability test”, follows Standard ISO 11925-2 and consists of applying a flame to the insulating core of the panel. The height of the flame produced by burning the insulation foam must not exceed 15 cm. The behaviour of the panel foam is determined in this test.
  • “SBI” Test
    This test follows EN 13823 and simulates the behaviour of the panel during the initial phase of a fire. It involves the application of a 30 kW fire source at the corner where two insulation panels meet. This test lasts 20 minutes and determines the reaction to fire of the entire panel.

Fire Resistance

The reaction to fire must be set apart from the concept of fire resistance.

Resistance measures how long a material can remain stable during a fire. The greater the resistance, the more time there will be for rescue work.

The fire resistance test on sandwich panels is performed by increasing the temperature inside the facility. Results are measured in minutes and expressed using three symbols.

  R – For the roof resistance capacity

  E – For the structural integrity of the panel

  I – Thermal insulation capacity

The symbols are used as follows:

Supporting elements (roofs and floors)

  • REI (time): the minimum time during which all criteria are met
  • RE (time): Minimum time during which the load-bearing capacity and structural integrity criteria are met
  • R (time): Minimum time during which the supporting capacity criterion is met

Non-supporting elements (walls and ceilings)

  • EI (time): Minimum time during which integrity and insulation criteria are met
  • E (time): Minimum time during which the integrity criterion is met

FM Factory Mutual


FM Global is an American brand that provides testing and certification services for commercial and industrial products worldwide through FM Approvals. Globally recognised and respected, FM Approvals® certification ensures customers receive a product or service that has been objectively tested and meets the highest national and international standards.

FM Standards - Sandwich Panels
Class 1 Panel Roofs
Class 1 Insulated Wall and Ceiling Panels - Fire
Class 1 Exterior Wall Systems
Class 1 Interior Wall and Ceiling Systems - Smoke Sensitive Occupancies
FM Standards - Roofs and Walls
FM 4880 - No height limit. No Sprinklers

FM 4880 is an approval standard for “Class 1 fire rating of insulated walls or wall and roof/ceiling panels, interior finish materials or coating and exterior wall systems” that evaluates the fire performance of construction panels or interior finishing materials in terms of combustibility and self-propagation.

FM 4881 – Exterior Use. Zone at risk of hurricanes. Zone H

This standard establishes approval requirements for exterior wall systems that are subject to hazards and weather conditions (e.g. wind, hail, and wind-driven debris).
All exterior wall systems must be approved by FM with a Class 1 fire rating. Therefore,
Class 4880 FM approval is a prerequisite for all exterior wall systems.

FM 4882 – Minimum smoke generation in agrifood and pharmaceutical industry

FM 4882 is an approval standard for clean room interior wall materials. It is applied to interior walls for clean rooms in pharmaceutical and food processing plants and is intended to minimise potential safety hazards and risks in the event of an unexpected fire (to prevent the spread of fire and minimise potential smoke damage).

FM 4471 – Roof behaviour in the event of a hurricane

Roofs are the first line of defence of buildings against the wind and can be built using different options. One of the most commonly used is the construction of roofs using insulation panels. Standard FM 4771 certifies that the elements have been strictly evaluated and tested against fire, wind, and atmospheric phenomena, such as hail.

Avis Technique CSTB

The “Avis Techniquedocument is issued by the CSTB (Centre Scientifique et Technique du Bâtiment), a science and technology centre dealing in construction quality and safety activities and specialising in the evaluation of innovative building element technologies.

The Avis Technique is an official document on the suitability of a product or procedure that offer confidence with regard to its performance. It certifies all the mechanical and insulation properties of the product: thermal transmittance, self-supportability, properties of the finishes, etc., along with the installation instructions and all the elements that must be used.

CE marking


Self-supporting insulation sandwich panels with double metal side. Factory-made products.

PAP insulation panels are compliant with the CE marking, certifying compliance with the following tasks:

1. Factory Production Control (FPC)

FPC involves the control of the production process, controlling the raw materials, the product in progress, and the finished product by performing the tests set out in the standard.

2. Initial Type Testing (ITT)

Initial type testing is performed by accredited laboratories on different parameters, as set by the standard, of a test piece of a sandwich panel or a complete panel. This means that the panels will be produced with the same characteristics as the samples already tested by the laboratory.

The mandatory characteristics must be tested. The following Initial Type Tests have been performed on MULTIPANEL:

  • Core density
  • Thermal transmission
  • Tensile strength
  • Shear resistance
  • Reduced long-term shear resistance
  • Shear stress module
  • Yield coefficient
  • Compression strength (core)
  • Bending strength on a span (pressure) – Bending strength on a span (suction)
  • Bending strength on an intermediate support (pressure) – Bending strength on an intermediate support (suction)
  • Wrinkling stress (outer side) / On span – Wrinkling stress (outer side) / On central support
  • Wrinkling stress (inner side) / On span – Wrinkling stress (inner side) / On central support
  • Reaction to fire
  • Reaction to external fire
  • Fire resistance
  • Watertightness
  • Airtightness
  • Steam permeability
  • Durability
  • Sound absorption
  • Airborne sound insulation
3. Declaration of Performance

PAP issues a declaration of performance. This is a declaration showing a list of the products with their identification, intended use, assessment system, harmonised standard, notified bodies (laboratories), and declared performance of the products according to the results of tests in external laboratories.

This declaration entitles PAP to attach CE Marking labels to the products.

4. Marking and labelling

All panels manufactured at PAP are labelled with the CE Marking to show that each panel is compliant with the characteristics of the tests performed.

The CE Marking consists of a label bearing the CE marking symbol. This label is attached to the product in a visible, legible and indelible manner using a label attached to the packaging.

The marking indicates that the product is compliant with the implementing directives, and it must be attached at the end of the production control phase.