Reaction to Fire – EN 13501-1

What Is Reaction to Fire — EN 13501-1?

Reaction to fire test is the test group in which the building material is evaluated in terms of flammability, heat release, flame spread, smoke production and burning drop formation and assigned to Euroclass (A1, A2, B, C, D, E, F) and smoke (s) and drop (d) subclasses according to EN 13501-1.

Purpose of Reaction to Fire — EN 13501-1

The aim is to classify the contribution of the building material to the initial phase of the fire and to show its compliance with the building fire safety requirements.

Which Products Is Reaction to Fire — EN 13501-1 Applied To?

Wall and ceiling coverings
Insulation materials
Floor coverings
Facade systems and panels

In Which Sectors Is Reaction to Fire — EN 13501-1 Used?

ConstructionConstructionDemiryoluElectricalConsumer Products

Standards Related to Reaction to Fire — EN 13501-1

EN 13501-1Reaction to fire class in building materials test

Reaction to Fire — EN 13501-1 Conditions

Experiment set: Varies depending on the targeted class: EN ISO 1182 and 1716 for A1/A2; EN 13823 and EN ISO 11925-2 for B–D
SBI (EN 13823): Single burning object experiment; FIGRA, THR600s, SMOGRA and TSP600s are measured
Small flame: Surface and edge ignition in EN ISO 11925-2; flame spread is measured
Application condition: The sample must be representative of the actual end-use assembly (backspace, carrier)

Equipment for Reaction to Fire — EN 13501-1

SBI (single burning object) test rig
Fireproofing furnace (EN ISO 1182)
Bomba kalorimetre (EN ISO 1716)
Small flame test cabinet

Sample Requirements for Reaction to Fire — EN 13501-1

The sample must be prepared with actual end-use assembly
Thickness, density and layer pattern must represent the actual product
Conditioning should be done in the environment defined in the standard
The number of samples is defined in the standard for each experiment.

Duration of Reaction to Fire — EN 13501-1

Typically 4–8 weeks depending on target class.

Reaction to Fire — EN 13501-1 Procedure

1The target Euroclass and end use condition are determined.
2The required set of experiments is selected.
3Samples are prepared and conditioned with actual assembly.
4Experiments are performed and measurements are recorded.
5FIGRA, THR, SMOGRA and TSP are evaluated.
6Classification is given according to EN 13501-1.

Reaction to Fire — EN 13501-1 Acceptance Criteria

Acceptance criteria are the limit values defined for each class in EN 13501-1; smoke (s1–s3) and drop (d0–d2) subclasses are assigned separately.

Evaluation of Results

Classification depends on the end-use assembly of the sample; If the backspace, carrier and detection method change, the class becomes invalid. The report must clearly state which installation condition it applies to. Euroclass does not replace ship (IMO FTP) or railway (EN 45545) classifications.

Reaction to Fire — EN 13501-1 Report

Applied standards
Product description, thickness and layer layout
End use installation condition
Measured quantities (FIGRA, THR, SMOGRA, TSP)
Euroclass and subclasses

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Construction Products Directive (EU) 305/2011
National building fire safety regulations

Fire Testing — What Does This Testing Field Cover?

The section below describes the field that the Reaction to Fire test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Fire testing measures two different concepts, and confusing them is the most common mistake in the field. REACTION to fire describes how much a material contributes to the start and growth of a fire. RESISTANCE to fire is the ability of a building element to hold a fire back for a defined period. One is a material property, the other a property of an element.

On the reaction side, ignitability, flame spread, heat release, smoke production, flaming droplets and toxic gas release are measured. The result is translated into an EN 13501-1 class in Europe, ASTM E84 indices in North America and a UL 94 class for appliance plastics. These three systems cannot be converted into one another; their scales and set-ups differ.

On the resistance side, furnace tests are carried out. The element is exposed to a defined temperature-time curve and it is measured how long it maintains three functions: load bearing (R), integrity (E) and insulation (I). For a fire door, the designation EI 60 says the element maintains its integrity and insulating function for sixty minutes.

SCALE is decisive in this family and directly affects cost. Small flame tests are suitable for screening materials and are fast and inexpensive. But real fire behaviour changes with scale: a material that self-extinguishes on a small specimen may sustain a flame over a large surface. Large-scale set-ups such as the room corner test and full-scale facade tests are therefore indispensable in critical applications.

Facade systems have become the most sensitive subject in the field in recent years. The rapid spread of facade fires in tall buildings has led national regulations to require large-scale facade testing. What is assessed here is not a single material but the SYSTEM: insulation, cladding, air cavity, fixings and fire barriers are tested together.

Smoke and toxicity form a separate body of work, because most deaths in a fire are caused by smoke rather than flame. In rail systems and on ships, smoke density and gas toxicity measurements are mandatory items; in an enclosed space the time available for evacuation depends on these values.

Cables have a sub-body of their own. A cable bundle inside a building can form a serious path for fire to spread between floors; flame spread, smoke production, halogen content and circuit integrity are therefore assessed for cables under separate standards, and in Europe the EN 13501-6 classification is used.

Method groups in this field

Non-combustibility and calorific value
The EN ISO 1182 non-combustibility furnace and EN ISO 1716 gross calorific value; the determinants of classes A1 and A2.
Single burning item (SBI)
EN 13823; heat release, flame spread and smoke production are measured together in a medium-scale corner set-up.
Small flame
Ignitability with a single flame source to EN ISO 11925-2; UL 94 horizontal and vertical burning; needle flame and glow wire.
Cone calorimeter
ISO 5660 / ASTM E1354; heat release rate, total heat release and smoke production are measured. The most informative test in material development.
Fire resistance
Furnace tests with the standard temperature-time curve; separate set-ups for doors, walls, floors, glazing and service penetrations.
Large scale
Room corner test (ISO 9705, NFPA 286), facade fire tests and vertical flame spread tests on cable bundles.
Smoke and toxicity
Optical smoke density, smoke gas analysis and toxicity indices; mandatory in rail systems and marine.

Commonly confused in this field

Reaction to fire and resistance to fire are different concepts; the specification must be explicit about which is required.
UL 94, ASTM E84 and EN 13501-1 results cannot be converted into one another.
A small-scale result is not evidence of large-scale behaviour; large-scale testing is required in critical applications.
A class is valid together with the end-use installation of the product; a different substrate or air cavity changes the result.
For facade systems a result for a single material is not sufficient; the system must be tested as a whole.
The fire class of a product does not show the fire resistance of an assembly made from it.

Which decisions these results support

The fire class in the declaration of performance for construction products
Regulatory compliance in the selection of cables, flooring and interior linings
Approval of interior materials for rail vehicles, ships and aircraft
Approval of the facade system design
Meeting insurance and project specification requirements

Related Tests

Frequently Asked Questions About Reaction to Fire — EN 13501-1

What is the difference between class A2 and class B?

A2 materials have limited heat of combustion and include fireproofing tests; Class B is flammable but shows very limited heat release and flame spread in the SBI test. The experimental sets are also different.