Euroclass System

You can take confidence from the fact that ROCKWOOL stone wool insulation is classified as A1 - the highest ranking available.

The European Reaction to Fire classification system (Euroclasses) is the EU common standard for assessing the qualities of building materials in the event of fire. This information is relevant for the United Kingdom and the Republic of Ireland.

ROCKWOOL insulation is non-combustible and can withstand temperatures of over 1000°C without melting.


Key points:

  • Compares ignitability, flame spread, heat release, smoke production and propensity for producing flaming droplets/particles etc.
  • Accepted by all European Union States (but not mandatory in the UK)
  • Seven classification levels, from A1 to F
  • Products achieving A1 classification are defined as non-combustible in UK Regulations


1. Understanding if an insulation product is combustible

By law, all building insulation products subject to a harmonised EN standard must be CE marked - which means manufacturers must declare a fire performance classification known as a Euroclass rating for each of their products.

The Euroclass system determines a product’s fire performance by measuring a comprehensive set of characteristics, including ignitability, flame spread, heat release, smoke production and propensity for producing flaming droplets/particles. The classifications run from A1 to F and are defined with examples in the table below. In summary:


A1 is non-combustible

A2 is of ‘limited combustibility’ (limited contribution to fire growth)

B and below are combustible


Euroclass Definition Example Materials
A1 Non-combustible Stone wool, Glass wool, Concrete, Bricks
A2 Limited Combustibility Some A1 Materials with Organic Facings
B Combustible Some Phenolic Foams
C Combustible Phenolic, some PIR
D Combustible PIR
E Combustible Flame Retarded EPS/XPS, PUR
F Combustible PUR


2. ‘Class 0’ is NOT an indication of a product’s combustibility

Some combustible insulation products focus on a ‘Class 0’ rating when discussing fire performance. However, it is important to note that this limited classification refers only to spread of flame, and therefore has limited relevance to a product’s combustibility.


3. Where can Euroclass ratings be found?

The Euroclass rating of a product can often be missing from its data sheet, particularly for combustible products with poor ratings. However, manufactures are legally bound to report this information in the product’s ‘Declaration of Performance’ (or ‘DoP’).

The DoP is a legal document in which the manufacturer identifies the product and its intended use, indicating compliance in relation to the relevant Harmonised Product Standard and performance in relation to specified “essential characteristics”.

These documents should be freely available from the manufacturer’s website, but you may find that you have to specifically ask for a copy.


All ROCKWOOL DoP’s can be found here