UNE 23727 Reaction of Building Materials to Fire Test - Classification of Building Materials

The standard “UNE 23727 Reactions of building materials to fire tests - Classification of building materials” developed by the Spanish Organization for Standardization (UNE) describes classes M0, M1, M2, M3 and M4 for materials according to their flammability and combustibility. This classification indicates the tendency of the material to assist the development of fire. Namely,

• M0: Not flammable, not combustible
• M1: Flammable, not flammable
• M2: Flammable, moderately flammable
• M3: Flammable, moderately flammable
• M4: Flammable, highly flammable

The UNE 23727 standard has been abolished and replaced by the UNE-EN 13501 standard. This new standard is divided into 6 sections according to the materials or structural elements to be tested:

• UNE-EN 13501-1 Classification based on data from fire reaction tests
• UNE-EN 13501-2 Classification based on data obtained from fire resistance tests, excluding ventilation installations
• UNE-EN 13501-3 Classification based on data obtained from fire resistance tests of products and elements used in building service installations
• UNE-EN 13501-4 Classification based on data from fire resistance tests of smoke control system components
• UNE-EN 13501-5 Classification based on data obtained from tests on roofing materials under the influence of external fire
• UNE-EN 13501-6 Classification based on data obtained from fire resistance tests of electrical cables

The difference between resistance and response is that resistance measures how long an element can resist fire (e.g. fire doors), while response measures how materials contribute to fire.

The results that can be obtained in tests conducted in accordance with the “EN 13501-1 Classification based on data obtained from fire reaction tests” standard are as follows:

• A1: Non-flammable. No maximum contribution to fire. This level includes products that cannot contribute to fire at any stage of the fire.
• A2: Non-flammable. No minimum contribution to fire. This level includes products that have very limited calorific value and do not contribute significantly to the fire load or contribute to the development of fire in a fully developed fire.
• B: Flammable. Flammable products that make a very limited contribution to the fire.
• C: Flammable. Flammable products that make a limited contribution to the fire.
• D: Flammable: Flammable products that contribute moderately to fire.
• E: Flammable. Flammable products that contribute highly to fire.
• F: Not classified. This level includes products that fail to meet any of the previous requirements or whose performance has not been evaluated.

These classifications are further supplemented with the corresponding subscripts as follows:

• According to smoke opacity:
  • S1: Low smoke emission rate and amount
  • S2: Medium smoke emission rate and amount
  • S3: High smoke emission rate and amount
• According to droplet or flaming particle fall:
  • d0: No droplets
  • d1: No droplets, (at least 10 seconds)
  • d2: Unclassified

M23727 building materials, which are classified as flammable and non-combustible according to the UNE 0 standard, are classified as A13501, A1, S1 and d2 according to the UNE-EN 1-0 standard.

M23727 building materials, which are classified as flammable but non-combustible according to the UNE 1 standard, are classified as B, S13501 and d1 according to the UNE-EN 3-0 standard.

M23727 building materials, which are classified as moderately flammable according to the UNE 2 standard, are classified as C, S13501 and d1 according to the UNE-EN 3-0 standard.

M23727 building materials, which are classified as moderately flammable according to the UNE 3 standard, are classified as D, S13501 and d1 according to the UNE-EN 3-0 standard.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the standard “UNE 23727 Reactions of building materials to fire tests - Classification of building materials” with its trained and expert staff and advanced technological equipment.