What Is Reaction to Fire?
Reaction to fire examines how much a material contributes to the ignition and growth phase of a fire. Classification is made not with a single test but a set of tests: the single burning item (SBI) test, the small-flame ignitability test, and calorific value and non-combustibility tests if required. The result is given as letters under the Euroclass system; smoke production (s) and flaming droplets (d) are additional indicators.
Purpose of Reaction to Fire
The purpose is to classify a material's contribution to fire spread. While fire resistance measures how long a compartment holds out, reaction to fire measures how much the material feeds the fire; these are two different questions.
Which Products Is Reaction to Fire Applied To?
- Insulation materials
- Facade cladding and composite panels
- Floor coverings and carpets
- Suspended ceiling and wall panels
- Pipe and cable insulation
In Which Sectors Is Reaction to Fire Used?
Standards Related to Reaction to Fire
- EN 13501-1 (reaction to fire — classification)
- EN 13823 (single burning item test — SBI)
- EN ISO 11925-2 (ignitability by direct small flame)
- EN ISO 1716 (gross calorific value) and EN ISO 1182 (non-combustibility)
Reaction to Fire Conditions
- Experiment set
- SBI, flammability and, if necessary, calorific value/non-flammability according to the targeted class
- Application condition
- The material is tested with its actual end use (substrate, adhesive, thickness)
- Quantities measured
- Heat release rate, fire growth rate, smoke production, flame spread, flaming drip
- Conditioning
- Samples are conditioned at standard temperature and humidity
Equipment for Reaction to Fire
- SBI test room and corner rig
- Heat release rate measurement system (calorimeter)
- Smoke measurement setup
- Small-flame ignitability chamber
- Bomb calorimeter and non-combustibility furnace
Sample Requirements for Reaction to Fire
- The sample must be taken so as to represent the batch and in accordance with the sampling rules of the relevant standard.
- The sampling date, location and the person who took the sample must be recorded.
- Samples requiring curing or conditioning must be stored under the defined conditions.
- The number of samples must meet the minimum required by the standard.
- The sample must not be damaged during transport.
Duration of Reaction to Fire
Each test is brief, but classification requires multiple tests. The study can extend over several weeks including sample preparation and conditioning.
Reaction to Fire Procedure
- 1The material's end-use condition (substrate, thickness, joint) is defined.
- 2The tests to be applied are determined per the targeted class.
- 3Samples are prepared to the dimensions in the standard and conditioned.
- 4The SBI test is run; heat and smoke are measured.
- 5The small-flame ignitability test is applied.
- 6Calorific value and non-combustibility tests are performed if required.
- 7Results are classified per EN 13501-1.
Reaction to Fire Acceptance Criteria
The acceptance class does not come from the test method but from the product standard and the project: concrete class, reinforcement class, aggregate category, or fire performance class is defined in the specification. The report gives the measured value; the conformity decision is made against the relevant product standard.
Evaluation of Results
The class is determined by comparing test results against the criteria in EN 13501-1, and the main class is given together with the smoke (s) and droplet (d) indicators. Which class is required comes from the fire regulation according to the building's use and height.
Reaction to Fire Report
- Sample description, sampling location and date
- Sampling method and witness sample information, if any
- Standard and test conditions applied
- Sample dimensions, curing conditions and age information
- Measured values and calculated results
- Failure mode or damage description (where applicable)
- A statement that the result applies only to the specimen submitted for testing
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 authorisationsRelated Regulations
- EU 305/2011 Construction Products Regulation (CPR)
- Construction Products Regulation (Turkey)
- TS 500 / Requirements for Design and Construction of Reinforced Concrete Structures
- Turkish Building Earthquake Code
Construction Materials 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.
Construction materials testing shows whether a product performs the function it takes on within the structure. A wide field is gathered in this family, from the compressive strength of concrete to the thermal transmittance of glass, from sieve analysis of aggregate to the watertightness of windows.
What sets this family apart from the others is that the result turns directly into a REGULATORY DECLARATION. For products covered by construction products legislation a declaration of performance (DoP) is mandatory, and every essential characteristic in the declaration rests on a test result. Reaction-to-fire class, thermal conductivity, compressive strength, water permeability and release of dangerous substances are declared in this way. The declaration is a legal text carrying the manufacturer's signature; the test record behind it is the first document requested in an inspection.
The second distinguishing feature is that the product is assessed over its SERVICE LIFE. An electronic device runs for five years; a building component stays in place for fifty and is exposed throughout that time to freeze-thaw cycles, UV, moisture, chemical attack and load. Durability tests (freeze-thaw, carbonation, alkali-silica reaction, ageing) therefore carry as much weight in this field as classical strength tests.
Tests are separated by material type and each group has its own set of standards: cement and concrete, aggregate, masonry units, wood-based panels, thermal insulation, glass and glazing units, ceramic tiles, floor coverings, screeds, joint fillers and coating systems. Where the product will be installed determines which set applies — the same panel is assessed against different standards on a wall and on a floor.
Factory production control (FPC) is a continuous component of the field. CE marking on a construction product is not obtained with a single test and then left; the manufacturer must set up a system showing that it monitors production consistency, takes samples regularly and intervenes when there is a deviation. Depending on the product group, this system may have to be audited by a notified body.
Site testing is a separate body of work. In the laboratory the product is approved; on site it is checked that the product really is of the declared class and that it has been applied correctly. Fresh concrete slump, cylinder sampling, aggregate sieve analysis and in-situ watertightness tests fall within this scope.
Method groups in this field
Concrete and cement
Slump, air content and unit weight in fresh concrete; compressive and flexural strength, water permeability and freeze-thaw resistance in hardened concrete. For cement, compressive strength, setting time and composition analysis.
Aggregate
Sieve analysis, particle shape, Los Angeles abrasion resistance, freeze-thaw, alkali reactivity and density/water absorption.
Thermal and energy performance
Thermal conductivity and thermal resistance, calculation of thermal transmittance (U value) in glazing units, solar energy transmittance.
Facade and joinery
Air permeability, watertightness and wind load resistance in windows and doors; fire performance in facade systems.
Fire performance
Reaction-to-fire classification and fire resistance tests; these are two separate concepts and are addressed by separate standards.
Masonry, tile and flooring
Compressive strength, water absorption, abrasion resistance, slip resistance, stain and chemical resistance.
Emissions and dangerous substances
Formaldehyde release from wood-based panels, VOC emissions from construction products, leaching behaviour of aggregates and waste.
Commonly confused in this field
- REACTION to fire and RESISTANCE to fire are different concepts: one describes the material's contribution to a fire, the other how long a component holds the fire back.
- A declaration of performance is not a certificate; it is the manufacturer's declaration. Notified body involvement varies with the product group and the assessment system.
- A test result is valid for the mounting arrangement in which the product was tested. A different substrate, a different thickness or a different joint detail may require reassessment.
- A site sample and a laboratory sample are not the same thing. A concrete cylinder taken on site also reflects application and curing conditions; it does not replace product approval.
- ASTM and EN construction standards measure similar quantities with different specimens and scales; the results cannot be converted one-to-one.
Which decisions these results support
- Declaration of performance (DoP) and CE marking
- Establishing and maintaining the factory production control system
- On-site conformity control of concrete, aggregate and workmanship
- Meeting fire and energy performance requirements
- Verifying the technical items in the project and tender specification
Related Tests
Frequently Asked Questions About Reaction to Fire
Are reaction to fire and fire resistance the same thing?
No. Reaction to fire measures whether the material feeds the fire, while fire resistance measures how long a building element withstands fire. There are two different test sets and two different classification systems.
Can the same material receive a different class?
Yes. The class depends on the material's end-use condition: the result changes when the substrate, thickness, air gap, or joint detail changes. The application condition is therefore stated separately in the classification report.