reaction to fire testing bttg

Reaction to Fire

Part 1: Classification using data from reaction to fire tests


BS EN 13501-1 provides the reaction to fire classification procedure for all construction products, including products incorporated within building elements.  Products are considered in relation to their end use application.  BS EN 13501-1 separates these types of products into three categories, which are:-

  • Construction products, excluding floorings and linear pipe thermal insulation products;
  • Floorings;
  • Linear pipe thermal insulation products.


To classify in accordance with BS EN 13501-1, dependant on the product, a combination of the following tests are required.

BS EN ISO 1182 - Non-Combustibility Test

BS EN ISO 1716 - Heat of Combustion Test (Calorific value)

BS EN 13823 Single - Burning Item Test (SBI)

BS EN ISO 9239-1 - Radiant Panel Test (Floorings only)

BS EN ISO 11925-2 - Single-flame Source Test


The classification is split into three parts, the main classification, the smoke classification and the flaming droplet classification.

  • The main part of the classification is its letter – A1, A2, B, C, D, E and F.  A1 (Non-combustible) is the highest level of performance, with F the lowest performance level (No performance determined).  Flooring materials and linear pipes thermal insulation products are classified according to the same classes A1, A2, B, C, D, E and F followed by the abbreviation ‘fl’ flooring and ‘L’ linear pipe thermal insulation products.  Products classified in A1 and A2 classes are non-combustible materials and from B to F are combustible materials in ascending order.
  • There is a smoke classification of s1, s2 or s3.  s1 is the highest level of performance and s3 is the lowest performance level.  There are no smoke requirements for Class E products.
  • There is a classification of flaming droplets of d0, d1 or d2.  d0 is the highest level of performance and d2 is the lowest performance level.  There is no flaming droplet requirement for floorings.

BS EN 13501-1 is the fire classification specified in each of the product standards that enable products to be CE Marked, as required by The Construction Products Regulation (EU) No 305/2011.

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