Surface spread of flame test

The number of small scale test methods, used for classification purposes, should be limited and based on ISO tests, presumably the Cone Calorimeter /10/ (see Fig. 8) and possibly the ISO Surface Spread of Flame test /11/. 

Surface spread of flame test. The 13 materials listed in Table I were tested in the IMO and ISO surface spread of flame tests. 

Table I. Results from the Surface Spread of Flame Test and the Cone Calorimeter... 

Figure 1. Surface spread of flame test for particle board.

A description is given of the initiatives carried out within the European Community for the harmonization of fire testing. The technical and economic reasons are explained for such initiatives, which are taken in order to remove barriers to trade from the European internal market. Of the various fire aspects, only fire reaction testing is taken into consideration here, because it appears as a major technical obstacle to the free circulation of construction materials. All possible approaches are considered for the attainment of such a harmonization and one, the so called interim solution, is fully described. The proposed interim solution, is based on the adoption of three fundamental test methods, i.e. the British "Surface Spread of Flame", the French "Epiradiateur" and the German "Brandschacht", and on the use of a rather complicated "transposition document", which should allow to derive most of the national classifications from the three test package. 

BS 476 Part 7 1987 Fire tests on building materials and structures Method for classification of the surface spread of flame of products. 

Boron compounds can be added in combination with other chemicals such as nitrogen and phosphorus. A solution containing sodium tripolyphosphate, boric acid, and ammonia provides a ready-to-use treatment on cellulose products such as plywood, fiberboard, and cardboard (87). The resulting products passed the British Standard 476, Section 6 (Fire Propagation test) Class 0 and Class I requirements of the British Standard Section 7 (Surface Spread of Flame). 

ISO DIS 9239 [83] determines the surface spread of flame of textile floor coverings using a radiant heat test and is similar to the test defined in ASTM E648 [84]. 

Surface spread of flame on building materials is tested according to ISO DP 5658-1977. A specimen board measuring 800 mm x 155 mm with a maximum thickness of 40 mm is ignited by the simultaneous application of a radiating surface and an 80 mm long propane flame. The vertically positioned radiating surface. 

Few unsaturated polyester resin-based laminates can achieve better than the F2 level with most only able to reach F3. However, in recent years, developments in resin technology have resulted in Ml (the best surface spread of flame requirement in the French test, which is equivalent to BS476 Part Class 1), and FO classifications with some filled resins (Seott Bader Crystic 343A). The major limitation is a maximum fibre eontent, by weight, of just 20%, which limits applications to semi- or non-struetural components only. Henee, sueh materials can be used for many decorative internal eomponents and cladding panels supporting their own weight. 

Spread of flame/LIFT (IMO FTP Code, Part 5 and ISO 5658-2) [International Maritime Organisation, Fire Test Procedures, test for surface flammability, 1998 and Lateral surface spread of flame on building products with specimen in vertical configuration, 1995]... 

British Standards Institution, London BS 476 Fire tests on building materials and structures Parts 1 2 withdrawn Part 3 1975 External fire exposure roof test Part 4 1970 Non-combustibility test for materials Part 5 1968 Ignitability test for materials Part 6 1968 Fire propagation tests for materials Part 7 1971 Surface spread of flame... 

France NF P92-501 - radiation test for rigid materials. A 400 mmx400 mm specimen is mounted at an angle of 45° and parallel to an electrically heated radiation source. Two propane gas burners are positioned close to the upper and lower faces of the specimen, to ignite flammable gases evolved from it. The test is carried out for a total of 20 minutes and flame spread is recorded. Surface spread of flame is also measured in test method NF P92-504. 

BS 476 Part 7 1987 details the method for classification of the surface spread of flame of products (and its predecessor BS 476 Part 7 1971). The test is a classification system based on the rate and extent of flame spread and classifies products 1,2, 3 or 4 with Class 1 being the highest classification. 

In Test 3, the rates of vertical and horizontal spread of flame are measured. Pretesting is performed to find which surface of the material spreads flame the faster. This is the side to be ignited. Two timers are actuated by trip threads located horizontally at 300 mm and 600 mm above the level of application of the butane flame. A third one is connected by either of the vertical trip threads located at 75 mm on both sides of the centre line. The igniting flame is applied for 10 s. The following are observed and recorded ... 

BS 476 1968 Part 7 - surface spread offlame. Specified in Building Regulations in UK, Netherlands, Denmark and France. A 900 mm long specimen is mounted in front of a radiant panel in such a way as to be subjected to a specific hat intensity gradient. Six specimens of each material are tested and, if five show no more than 165 mm spread of flame and the sixth no more than 190 mm, the material is classified as Class 1. There is also a small-scale test, with specimens 300 mm long. Similar large-scale tests are described in NEN 3883 and DS 1058 3. NF P 92-506 can be compared with the small-scale test. 

These deal with materials, linings and surface finishes in buildings, particrrlarly fire-isolated exits. Three indices are used - flarrrrrrability, spread-of-flame and smoke-developed which are measured by standard tests. In additiorr, protection of sides and edges from exposrrre to air may be a reqrrirement. 

The surface burning characteristics (flame spread index and smoke developed index) for wood and wood products as measured by American Society for Testing and Materials (44) can be reduced with fire retardant treatments, either chemical impregnation or coatings (48). Fire retardant treatments also reduce the heat release rate of a burning piece of wood (49,50). The heat release rates (51) of the burning materials are an important factor in fire growth. 

As mentioned earlier, the fire hazard of interior finish materials is primarily due to the potential for rapid wind-aided flame spread over the surface. It is therefore not a surprise that reaction-to-fire requirements for interior finish materials in U.S. building codes are primarily based on performance in a wind-aided flame spread test. The apparatus of this test is often referred to as the Steiner tunnel. The Steiner tunnel test is described in ASTM E 84. Although the test does not measure any material properties that can be used in a model-based hazard assessment, a discussion of the test is included here due to its practical importance for the passive fire protection of buildings in the United States. 

A typical criticism of this test method, for example, is that ordinary newsprint, and even tissue paper, will meet its requirements. That is a valid criticism. However, there seems to be general agreement that, in spite of its lack of sophistication, this test method has been successful in eliminating the fabrics with the poorest fire performance from the general population of fabrics in use for apparel in the United States. Thus, fabric types such as the fibrous torch sweaters with raised surface fibers that ignite readily and spread flame quickly are no longer legally sold in the United States due to the test requirements. The test has also been able to screen out the use of very sheer... 

Measurement of flame spread under external heat flux is necessary where the thermal radiation is likely to impinge on the textile materials, for example, the flooring material of the building or transport vehicles whose upper surfaces are heated by flames or hot gases, or both. The French test method, NF P 92-503 Bruleur Electrique or M test involves radiant panel for testing flame spread of flexible textile materials. This test method (flame spread under external heat flux) is the basis of that used by the FAA (Federal Aviation Administration) for assessing flammability of textile composites used in thermal/acoustic insulation materials (FAR 25.856 (a)) used in aircraft and has also been included by the EU for fire test approval of floorings such as prEN ISO 9239 and BS ISO 4589-1. 

ASTM D 3675 Surface Flammability of Flexible Cellular Materials Using a Radiant Heat Energy Source This method may be used on cellular elastomeric materials such as flexible polyurethane foam and neoprene foam. It employs a radiant panel heat source consisting of a 300 by 460-nun (12 by 18 in.) panel in front of which an inclined 150 by 460-m (6 by 18 in.) specimen of the material is placed. The orientation of the specimen is such that ignition is forced near its upper edge, and the flame front progresses downward. Factors derived from the rate of progress of the flame front and heat liberated by the material under test are combined to provide a flame spread index. The method was developed to test cellular elastomeric materials which could not be tested by ASTM E 162. 

ASTM E 286 Eight-Foot Tunnel Test. This test, a smaller version of the Steiner Tuimel Test (ASTM E 84), covers the measurement of surface flame spread of materials capable of being mounted and supported within a 13.75 in. (349-mm) x 8 ft. (2.44-m) test frame. The test also includes techniques for measuring the oke density and heat... 

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