This standard defines the classification of construction products (excluding floor coverings) based on their reaction to fire.

Materials are classified into 3 categories:

• Non-combustible or low combustible: classification A1, A2, and B
• Combustible: classification C, D, and E
• Very easily combustible: classification F

These 7 classes are defined based on the thermal potential of the product.

Products resulting from the bonding of one or more non-combustible materials (such as concrete, mineral wool, ceramics, etc.) are considered to belong to class A1 without prior testing (provided that the adhesive content does not exceed 0.1%).

The Single Burning Item (SBI) test is carried out for classes A2, B, C, D, and E (NF EN 13823) to determine additional criteria (indices s and d).

For this, a specimen (consisting of two vertical wings forming a right angle) is exposed to the flame of a 30kW burner for 20 minutes. The material’s performance is then assessed according to the following criteria:

• Smoke opacity defined by the s index (for “smoke”) and divided into 3 categories: s1 (low quantity and speed), s2 (medium quantity and speed), and s3 (high quantity and speed).
• The formation of droplets or flaming debris characterized by the d index (for “droplets”) as follows:

• • Index d0 = no flaming debris or droplets during the first 600 seconds of product exposure.

• • Index d1 = no debris and droplets whose combustion does not last more than 10 seconds during the first 600 seconds of product testing.

• • Index d2 = for materials that are not d0 or d1