CBUF - Combustion Behaviour of Upholstered Furniture

A major cause of fire fatalities is associated with burning of upholstered furniture and beds. However, little was known about the fire properties of these products. For that reason the European Commission initiated a large research programme on the combustion behaviour of upholstered furniture, CBUF.

CBUF - a research programme concerning fire safety of upholstered furniture

To promote harmonisation at a high and consistent safety level, the Commission of the European Community formulated a requirement for a testing and assessment system capable of addressing a specific hazard, i.e. "the atmosphere in the room in which the upholstered furniture or related article are on fire should, despite the production of heat and smoke......, remain for a reasonable period of time after ignition such that it does not endanger the lives or physical well being of exposed persons. This will be achieved by controlling the rates of heat release, smoke and toxic gas production." 

By the time there were no system for testing and analysis available that could address the problem. Therefore CBUF, Combustion Behaviour of Upholstered Furniture, was created. The research programme and the findings is shortly presented here.

CBUF contact

CBUF is one of the largest projects launched in the fire area and large amounts of information is available. A book , the CBUF final report, test protocols, reports on specific topics and a video is available. Still work is published with more or less direct connection to CBUF.

For more information contact Björn Sundström,
phone + 46 10 5165086
E-mail bjorn.sundstrom@ri.se

The CBUF-research programme was funded by the European Commission and national resources in member states. The work was performed in two years by a consortium of 11 partners from 8 countries.

Relationships were developed between (1) the conditions occurring in a full scale room scenario (ISO 9705 and larger rooms) due to the burning of a piece of furniture, and (2) the results of bench scale tests on composites consisting of various layers of fabric, interliner and padding used in the construction of the furniture. These relationships were based on room fire models and furniture fire models insofar as possible. Rate of heat release, smoke and toxic gas production were the main fire parameters considered. 

The furniture calorimeter (NT FIRE 032) and the cone calorimeter (ISO 5660) are the tests used. Relationships were developed between test data from the cone calorimeter on composites and the large scale burning behaviour on full sized furniture, as measured in the furniture calorimeter. Also a model where data on component materials, i.e. fabric, interliner and padding, can be combined to predict the composite fire data as measured in the cone calorimeter was developed.

Functional requirements were examined by conducting room fire tests on furniture. Measured room fire conditions were interpreted by doing fire hazard analysis and identifying tenability limits and associated times. These data were then compared with predictions based on (1) furniture calorimeter data and existing room fire models and (2) cone calorimeter furniture fire models and correlations.

CBUF results in short

The CBUF programme included extensive work of development of test procedures, testing in large and small scale and mathematical fire modelling. The starting point for the modelling work is the hazard in the room of fire origin.

The hazard analysis showed that the smoke layer height is a good measure of tenability. The position of the smoke layer in the room can be derived from the heat release rate. Therefore it may not be necessary to determine smoke and toxic gases to measure tenability. Examples are given of effects of choosing different strategies of safety. They show that there are some furniture items which are "inherently safe". Others may or may not qualify depending on selected safety level. The hazard analysis is largely independent of the test procedures, for example the specific ignition procedures used in the tests are not influencing the results.

The HRR can be predicted from the cone calorimeter data. Three models are developed in CBUF. Correlations as well as physics based models are developed. Therefore it is not necessary to carry out large scale tests to determine fire performance. Small scale testing in the Cone Calorimeter will do.

The determination on performance can be based on either testing small samples of the composite or testing of the individual components. A certification system could be based on testing the combined fabric/filling combination in the Cone Calorimeter, introduce a style factor for the actual furniture item, predict the performance and compare with requirements. Alternatively, filling and fabric are tested separately and performance is expressed based on these components only. This alternative lifts the testing burden from the furniture industry. Selection of testing procedure should be based on versatility in practise and required precision of hazard prediction.

Test programme

The CBUF testing programme comprised about 1000 tests in the Cone Calorimeter and 200 large scale tests in the furniture calorimeter and different room configurations. Thus, based on an extensive data base generated from reliable test methods the mathematical modelling was performed. A set of test procedures of high accuracy was developed in CBUF. These are test protocols for the Cone Calorimeter, the Furniture Calorimeter as well as FTIR and Ion Chromatography for toxic gases.

The test conditions chosen were found to accurately model the large scale heating conditions. The test protocol was also examined in a three stage Round Robin. Reproducibility and repeatability were very good and found to be entirely acceptable. A total of 250 tests were performed during this phase.

The protocol for large scale testing of upholstered furniture in the furniture calorimeter, NT FIRE 032, was validated and modified. The modifications were based on an earlier Round Robin under a separate Commission contract. Different ignition sources and ventilation conditions were studied. The test protocol proved to work very well and to be especially robust for changes in ignition configuration. A total of about 50 large scale tests were performed.

A test method for measuring toxic gases was developed. The FTIR analysis proved to be very useful. Based on the NT FIRE 047 it was demonstrated that this technique could be used for on line measurements on a routine basis. In addition, ion chromatography was extensively investigated and proved to be an equally powerful measuring technique.

The CBUF partners

CBUF was a co-operative work between 11 organisations from 8 countries:

DBI Dansk Brandteknisk Institut Denmark
FIRA Furniture Industry Research Association United Kingdom
FMC FMC Corporation (UK) Ltd. United Kingdom
FMPA Forschungs- und Materialprüfungsanstalt Baden-Württemberg Germany
FRS Fire Research Station United Kingdom
ICL Interscience Communications Ltd. United Kingdom
LNE Laboratoire National d'Essais France
LSF Laboratorio di Studi e Ricerche sul Fuoco srl Italy

Sveriges Provnings- och Forskningsinstitut

UG Universiteit Gent Belgium
VTT Valtion teknillinen tutkimuskeskus Finland

The CBUF book

CBUF, Fire Safety of Upholstered Furniture - the final report of the CBUF research programme. Edited by Björn Sundström. Report EUR 16477 EN. 395 pages, bound, colour illustrations. Price SEK 750. Contact Kaisa Kaukoranta, phone + 46 10 516 5080,  kaisa.kaukoranta@ri.se

The CBUF video

The CBUF video gives an introduction to the fire phenomena associated with upholstered furniture fires. A fully furnished room is tested and the burning history is compared with the possibilities for the fire brigade to rescue people. The video is 5 min 50 sec long.
Price 350 SEK. Contact Kaisa Kaukoranta, phone + 46 10 516 50 80, kaisa.kaukoranta@sp.se

The CBUF reports

During and after the project reports and papers on specific objects was published, for example the data management system and specific data reports. A list is given below. For orders, contact Kaisa Kaukoranta, phone + 46 10 516 50 80, fax + 46 33 41 77 59,  kaisa.kaukoranta@ri.se

There are also reports and papers published by the other project participants. For more information, please contact those institutions directly.

SUNDSTROM, Bjorn. "Fire Safety Design of Upholstered Furniture- Application of the CBUF project", SP Fire Technology, Sweden, Interflam 96, Conference proceedings pp 3 - 13, ISBN 0 9516320 9 4, Interscience Communications Ltd.

SUNDSTROM, Bjorn. "Fire Safety Design of Upholstered Furniture- Application of the CBUF project", SP Fire Technology, Sweden, Interflam 96, Conference proceedings pp 3 - 13, ISBN 0 9516320 9 4, Interscience Communications Ltd.

BABRAUSKAS, Vytenis and WETTERLUND, Ingrid. "Fire Testing of furniture in the Cone Calorimeter - The CBUF Test Protocol", 1994. 21 s. SP-rapport, 1994, nr 32. ISBN 91-7848-491-X.

SUNDSTROM, Bjorn. "Quantative Large-Scale Tests of Furnishings in Europe", paper in "Fire and Flammability of Furnishings and Contents of Buildings", ASTM, STP 1233.

SUNDSTROM, Bjorn. "CBUF-Combustion Behaviour of Upholstered Furniture". paper in European Community Measurements & Testing, March 1995, Vol 3, No 1.

SUNDSTROM, Bjorn. "Combustion Behaviour of Upholstered Furniture Tested in Europe : Overview of Activities and a Project Description", paper in "Fire and Polymers II, Materials and Tests for Hazard Prevention", edited by Gordon L Nelson, ACS Symposium Series 599, 1995.

VAN HEES, Patrick, GRAYSON, Stephen and SUNDSTROM, Bjorn. "The major objectives and findings of CBUF", 4th International Conference and Exhibition "Fire and Materials ‘95", November, 15-16, 1995, USA.

SODERBOM, Johan. "Combustion Behaviour of Upholstered Furniture (CBUF) Work Package Report on Data Management", 1996, 22 s. SP-rapport 1995, nr 50. ISBN 91-7848-577-0.

SODERBOM, Johan. "Combustion Behaviour of Upholstered Furniture (CBUF) Work Package Report on Room Fire Zone Modelling", 1996, 26 s. SP-rapport 1995, nr 53. ISBN 91-7848-581-9.

BABRAUSKAS, Vytenius and WETTERLUND, Ingrid. "The CBUF Cone Calorimeter Test Protocol, Results from International Round Robin Testing", 1996, 34 s. SP-rapport 1996, nr 12. ISBN 91-7848-616-5.

SODERBOM, Johan, VAN HEES, Patrick and MEIRSSCHAERT, Pascal. "Influence of Ignition Sources on Heat Release Rate in the Furniture Calorimeter", paper in "Fire and Materials", vol 20, No 2, March-April 1996.

SUNDSTROM, Bjorn. "Furniture Reaction to Fire : Test Methods and Models", SP-rapport 1993:10.

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Contact Persons

Björn Sundström

Phone: +46 10 516 50 86

RISE Research Institutes of Sweden, Phone 010-516 50 00, E-mail info@ri.se

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