Reaction to Fire Testing FAQs


Single burning item testing
Small flame ignitability testing at Chiltern International Fire
Single burning item testing at Chiltern International Fire
Chiltern International Fire's SBI test rig
Untitled document

1. What is reaction to fire testing?
2. Why is reaction to fire testing important?
3. When is reaction to fire testing required?
4. How are European classification and National classification for reaction to fire testing related?
5. What standards are used in European reaction to fire testing?
6. How are tests used to give a classification?
7. Why are different tests used depending on the level of classification aimed for?
8. What do SBI and SFI mean?
9. What is an SFI or Small Flame Ignitability test?
10. What size specimen is testing in a SFI test?
11. What is a SBI or Single Burning Item test?
12. What size specimen is tested in a SBI test?
13. What variations in a product can influence its reaction to fire performance?
14. What information is required to produce a full quotation for reaction to fire testing?
15. What are the advantages of an indicative test?
16. Do any materials get a classification without testing?
17. What is a classification document?
18. How do I know if a classification document covers a certain product? 

1. What is reaction to fire testing?

Two key aspects to fire testing are Fire Resistance and Reaction to Fire and there is often confusion between the two. Fire resistance is the measurement of the ability of a material or system to resist, and ideally prevent, the passage of fire from one distinct area to another. Reaction to fire is the measurement of how a material or system will contribute to the fire development and spread, particularly in the very early stages of a fire when evacuation is crucial.

SBI, SFI, Flammability, ignitability, surface spread of flame and classification are all terms people might use to describe reaction to fire testing.

FAQ list

2. Why is reaction to fire testing important?

The contribution of a product to a developing fire, in terms of ease of ignition, energy produced and flame spread will have an impact on how easy it is for people to escape from the area of the fire.

FAQ list

3. When is reaction to fire testing required?

Reaction to fire testing can be required in order to comply with the Building Regulations. In England and Wales this is covered by Approved Document B; in Scotland by Technical Handbooks Domestic and Non-Domestic; in Northern Ireland by Technical Booklet E; and in the Republic of Ireland by Technical Guidance Document B.

Reaction to fire testing is required for certain products destined for railway applications and produced in accordance with the standard DD CEN TS 45545.

Even when reaction to fire testing is not required under the building regulations, a relevant insurer or authority for a building may request an enhanced reaction to fire performance for which testing is required.

Some manufacturers carry out reaction to fire testing to find out more about their product, or to demonstrate the superiority of their product in the market place.

FAQ list

4. How are European classification and National classification for reaction to fire testing related?

The national class cannot be assumed to equate to the new European class. While European classification is recognised in the UK, the converse is not true - national class is not accepted in Europe and hence European test evidence must be obtained if a product is to be used in mainland Europe.

The European tests and National tests are physically different, although they are all used to demonstrate reaction to fire performance.

Location European class National class

Small rooms of area not more than:
a) 4m2 in residential accommodation
b) 30m2 in non-residential accommodation

D-s3, d2 3
Other rooms (including garages) C-s3, d2 1
Circulation spaces within dwellings
Other circulation spaces, including the common areas of blocks of flats  B-s3, d2 0

Table 1: Example of requirements taken from Table 10 Classification of linings in Approved Document B for England Volume 2 – Buildings other than dwellinghouses.

 

Euro-class EN 13501-1 England, Wales, Northern Ireland Scotland
A1 Non-combustible Non-combustible
A2 (or better) Limited combustibility
B-s3, d2 (or better) 0 Low risk (0)
C-s3, d2 (or better) 1 Medium risk (1)
D-s3, d2 (or better) 3 High risk (2 & 3)
E-s3, d2 (or better) 4 Very high risk
F-s3, d2 (or better) Unclassifiable

Table 2: Transposition table of reaction to fire classification showing European and British standards

FAQ list

5. What standards are used in European reaction to fire testing? 

The four standards listed below are used for reaction to fire classification of a wall or ceiling lining product. Sometimes other standards are used for different products such as floorings.  This table shows how different classifications utilise testing to different standards.

Classification Relevant test standard

A1

BS EN ISO 1716
BS EN ISO 1182

A2 BS EN ISO 1716
BS EN ISO 1182
BS EN 13823
B, C, D BS EN ISO 11925-2
BS EN 13823
E BS EN ISO 11925-2

FAQ list

6. How are tests used to give a classification?

To achieve a classification, a product must be tested to the required standards, and the required performance achieved. The resulting reports are then used to create a classification document.

FAQ list

7. Why are different tests used depending on the level of classification aimed for? 

Reaction to fire testing can be conducted on products with very different performance. Products that do not easily combust will not produce observable test results in a test designed to challenge a product that ignites and burns easily. For this reason there is a range of European tests used to cover the different classification, just as there is a range of tests used for the British test standards.

FAQ list

8. What do SBI and SFI mean?

The main reaction to fire tests are commonly referred to by the title of the test in word, or a shortened version of this. The main tests used to establish European reaction to fire classifications are listed below, with the commonly used names for these tests written in italics:

BS EN ISO 1182: 2002 Reaction to fire tests for building products - Non-conbustibility test
BS EN ISO 1716: 2002 Reaction to fire tests for building products - Determination of the heat combustion (Bomb calorimeter)
BS EN 13823: 2002 Reaction to fire tests for building products - Building products excluding floorings exposed to the thermal attack by a single burning item (SBI)
BS EN ISO 11925-2: 2002 Reaction to fire tests - Ignitability of building products subjected to direct impingment of flame - Part 2: Single-flame source test (SFI)

FAQ list

9. What is an SFI or Small Flame Ignitability test?

The SFI test uses a single small flame source to assess the ignitability of the product. The product is mounted in the test apparatus in a vertical orientation and the flame is applied. Observations are made on whether the product has ignited, the flame propagation up the product, and any flaming particles that may fall from the product.

FAQ list

10. What size specimen is tested in a SFI test?

The specimen must be 250 (+0, -1) mm x 90 (+0, -1) mm. A minimum of 8 specimens are required, with more specimens required if the product is to be tested on its edge as well as its surface.

FAQ list

11. What is an SBI or Single Burning Item test?
The SBI test replicates a small fire in the corner of a room, with the room corner being constructed from the product to be tested. A flame from a burner with a known output is applied to the product. The products of any resulting combustion are measured, and these allow calculation of the energy that the product has contributed to the fire. Classification will be assessed on the rate of energy production, the total energy produced over a certain period of time, lateral spread of flame and the observation of any flaming particles that may fall from the product.

FAQ list

12. What size specimen is tested in a SBI test?

Each specimen is constructed from a “short wing” and a “long wing”. The long wing is 1500mm high by 1000mm wide. The short wing is 1500mm high by 495mm wide. All tolerances are ± 5mm.

A minimum of 3 specimens are required. Further specimens may be required if a product produces a result on the border line between two classification and the higher classification is sought. Further specimens may also be required for testing of variations in the product.

FAQ list

13. What variations in a product can influence its reaction to fire performance?

The following product variations and end use applications can all affect the performance of a product, and can be assessed using the SBI test:

Product variable:

  • Thickness
  • Colour
  • Density

End use application:

  • Mounting and fixing
  • Substrates used
  • Air gap
  • Exposed edges
  • Joints


FAQ list

14. What information is required to produce a full quotation for reaction to fire testing?

A detailed discussion with the client is required before producing a full quotation for reaction to fire testing. There are possible variations in the approach to testing, and a full knowledge of the product is required in order to give advice on the best course of action for the client.

Questions may be asked about the product, its variations and its end use.

Questions about the product variable:

  • Material
  • Thickness
  • Colour
  • Density

Questions about the products end use application:

  • Mounting and fixing
  • Substrates used
  • Air gap
  • Exposed edges
  • Joints


FAQs list

15. What are the advantages of an indicative test?

Full testing to achieve a classification involves testing to one or more standards, conditioning of the specimen prior to testing and testing of multiple specimens. An indicative test involves a single test only, and can give an indication of the performance of a product at a lower cost and in a shorter timescale than full testing. This is useful where a product is still at the development stage.

FAQ list

16. Do any materials get a classification without testing?

Yes, some materials for which there is a lot of historic data, such as wood and metal can be classified without testing. The Building Regulations provide details for “typical performance ratings of some generic materials and products”.

FAQ list

17. What is a classification document?

A classification document is produced using the products test reports. It is the classification, and not the test reports that demonstrate the classification of the product. It is the classification document that a manufacturer will show to customers and enforcers to demonstrate compliance with the regulations.

FAQ list

18. How do I know if a classification document covers a certain product?

A classification document must contain the product name and product description including:

  • thickness
  • colour
  • mounting and fixing
  • air gap
  • substrate
  • edge testing
  • joint testing


Some product description information may be contained in the test reports, and not the classification document. If this is the case you must ask to see all the relevant documentation to be sure that the classification document relates to the product you wish to purchase.

FAQ list

Contact Details


Terry Wentworth

01494 569841