
Save your favorites
Select and save the products and documents you need for your projects
The fire safety of construction sites and buildings depends heavily on the types of materials used. Almost all building materials and furnishings contribute to the so-called fire load. The intensity, the nature of the heat flow, the duration and the temperature reached by a fire are a consequence of the fire load and the heat release rate, which considers the aggregate properties of materials used in the construction of the building. The materials are conventionally divided into combustible substances and non-combustible materials. This classification will be discussed in more detail in what follows.
Standard EN 13501-1 ‘Fire classification of construction products and building elements (Part 1: Classification using data from reaction to fire tests)’ aims at defining a harmonised approach to classifying the fire reactions of construction products (including products incorporated within building elements) under the Euroclass system. Products are considered in relation to their end-use application and are divided into three separate categories:
Electrical cables are classified in terms of different test and classification standards.
EN 13501-1 also specifies test methods classified in relation to the envisioned reaction to fire, while each method further describes the principles of testing, specimen preparation and minimum number of tests. The following test methods are used for evaluation of the reaction of materials to fire:
Building materials are classified as non-combustible and combustible. The classification takes into account the contribution to the development of a fire before the flashover and the contribution to the fire load of a room in a fully developed fire.
‘Non-combustible’ building materials are those which, under the prescribed test conditions, cannot burn or contribute to the development of a fire. These are, according to the EN 13501-1 qualification, class A1 and A2 materials.
Note that a material A2, even if not literally ‘not combustible ’, is classified in the same ‘macro-class ’ as A1 because the contribution to the fire development and to the heat release is extremely limited.
‘Combustible’ building materials are those which ignite under the prescribed test conditions. In consideration of their contribution to the development of a fire, combustible materials are divided into flammable (B and C), normally flammable (D and E) and highly flammable (F).
Floorings are classified according to the same classes as construction products but are tested horizontally. The classification letters are followed by the ‘fl ’ abbreviation (e.g., A1fl).
The following table sums up the different product categories, test methods and combustibility classes:
Classification according to EN 13501-1 | ||||||
Definition | Test method | Construction products | Floorings | |||
Non-combustible materials | Non-combustibility test and heat of combustion test | A1 | A1fl | |||
Non-combustibility test or heat of combustion test and SBI |
A2 – s1 d0 A2 – s2 d0 A2 – s3 d0 |
A2 – s1 d1 A2 – s2 d1 A2 – s3 d1 |
A2 – s1 d2 A2 – s2 d2 A2 – s3 d2 |
A2fl – s1 | A2fl – s2 | |
Combustible materials – very limited contribution to fire | Ignitability test and SBI test |
B – s1 d0 B – s2 d0 B – s3 d0 |
B – s1 d1 B – s2 d1 B – s3 d1 |
B – s1 d2 B – s2 d2 B – s3 d2 |
Bfl – s1 | Bfl – s2 |
Combustible materials – limited contribution to fire |
C – s1 d0 C – s2 d0 C – s3 d0 |
C – s1 d1 C – s2 d1 C – s3 d1 |
C – s1 d2 C – s2 d2 C – s3 d2 |
Cfl – s1 | Cfl – s2 | |
Combustible materials – medium contribution to fire |
D – s1 d0 D – s2 d0 D – s3 d0 |
D – s1 d1 D – s2 d1 D – s3 d1 |
D – s1 d2 D – s2 d2 D – s3 d2 |
Dfl – s1 | Dfl – s2 | |
Combustible materials – high contribution to fire | Ignitability test | E | E - d2 | Efl | ||
Combustible materials –easily flammable | F | Ffl |
In addition to the basic letter designations for combustibility (A1, A2, B, C, D, E and F), building materials need additional classifications regarding the emission of smoke and the production of flaming droplets and/or particles. These classifications are the following:
Additional classification | Level | ||
Smoke emission level during combustion | s | 1 | Absent or weak speed/quantity of emission |
2 | Average intensity of speed/quantity of emission | ||
3 | High intensity speed/quantity of emission | ||
Flaming droplets and/or particles production during combustion | d | 0 | No dripping |
1 | Slow dripping | ||
2 | High dripping |
Subclass d2 is provided only for classification E.
For most buildings, pre-construction by definition involves obtaining various permits, the same goes for restorations, extensions, technical re-equipment of buildings, repairs and other activities. Sometimes a certain type of building requires additional fire examination and this issue is regulated by law. This includes the assessment of building materials for ignitability, combustibility, etc. That is, a change in the functional purpose of the structure is also a sufficient reason for the study of building materials, and, if necessary, the designation of another class of fire.
Contact our technical support team with your questions on passive fire protection solutions, our products and systems or installation advice...
Find the product datasheets, system brochures, Declarations of Performance, installation manuals and other documents you need to get the job done.