Architects and Designers > Fire Ratings Explained

Fire Ratings Explained


Tristone UK Limited is committed to ensuring all users of our products are informed on the quality standards that our products adhere to.

We know that being informed on the characteristics and features of a product is pivotal when specifying for projects; domestic and commercial. That is why we make our certification and classifications publically available on our website and on all our platforms.

To give you a clearer picture of the standards of our products, we have created this page to briefly explain the UK and EU standards for Fire Ratings.


UK Standards


British Standards

The building regulations stipulates the rules and the degree of fire resistance of the elements of structure. The British Standard 476 (BS476) dictates the appropriate fire tests for these elements of structure/materials and grades the level of fire resistance. The tests that are relevant to the Solid Surface industry are the BS476 part 6, and BS476 part 7.

  • BS 476 part 6: Fire Propagation Test.

  • BS 476 part 7: Surface Spread of Flame Test.

    • The test produces a fire rating of Class 1, 2, 3 or 4 depending upon how far a flame travels over a surface.

What is a Class 1 Building Material?

Class 1 is the best rating i.e. the lowest flame spread. This classification is given after BS476 part 7.

What is the Class 0 Fire Rating?

The Class 0 fire rating is actually a classification as outlined in the UK building regulations for fire safety within and around buildings. This classification is outlined in Parts 1 and 2 of the Fire Safety: Approved Document B which is available on the HM Government Portal.

How does a product achieve the Class 0 Fire Rating?

To achieve a Class 0 Fire Rating, products must meet specific British Standards and pass a series of tests designed to test flame spread and propagation.

  • The product must first meet the fire propagation requirements as outlined in BS 476-6:1989+A1:2009

  • A product must be also be classified as a Class 1 building material for BS 476 - 7:1997

European Standards


Testing is standardised through the use of EN 13501-1: Fire classification of construction products and building elements. The most widely recognised standards are the German (DIN 4102) and French (NF P 92 503-507 (M1)). The European classifications based on the EN13501-1 standard break down into codes. Products that have been given a fire rating on the European Classification will look like the following: A2, s1,d1. This classification shows the properties of a product based on 3 criteria.

There are 7 reaction to fire classifications levels available:
The reaction to fire classification determins how much (if any) a material contributes to the spread of flame:

  • A1, A2 = Non Combustible Materials.

  • B, C, D = Ranges from very limited to medium contribution to fire.

  • E, F = High contribution to fire.

The ‘s’ part relates to total smoke propagation, during the first ten minutes of exposure.
These determine a ‘smoke’ index:

  • S1 = a little or no smoke

  • S2 = quite a lot of smoke

  • S3 = substantial smoke

The ‘d’ part relates to ‘flaming droplets and particles’ during the first 10 minutes of exposure.
The index is:

  • D0 = none

  • D1 = some

  • D2 = quite a lot




Smoke Propagation

Flaming Droplets

Non-Combustible Materials






and all variations

Combustible materials: Very limited contribution to fire




and all variations

Combustible materials: Limited contribution to fire




and all variations

Combustible materials: Medium contribution to fire




and all variations

Combustible materials: High contribution to fire



Combustible materials: Easily flammable



External Links:

BS 476-6:1989+A1:2009. Fire tests on building materials and structures. Method of test for fire propagation for products

BS 476-7:1997. Fire tests on building materials and structures. Method of test to determine the classification of the surface spread of flame of products

Fire Safety Approved Document B. Building regulation in England covering fire safety matters within and around buildings.

Ministry of Housing, Communities and Local Government. Final Impact Assessment: Ban on combustible materials in external wall systems.