5.1 This test method provides a means to measure a variety of fire-test-response characteristics resulting from burning a specimen of upholstered furniture. The upholstered furniture specimen is allowed to burn freely under well-ventilated conditions after ignition using a propane gas burner. The most important fire-test-response characteristic measured is the rate of heat release, which quantifies the intensity of the fire generated.

5.2 The rate of heat release is measured by the principle of oxygen consumption. The assumptions and limitations of oxygen depletion calorimetry are discussed in Annex A4, and in particular in A4.1.2.

5.3 Other fire-test-response characteristics are measured, namely smoke obscuration and combustion gas release, as they are also important in making decisions on fire safety.

5.4 The most important gaseous components of smoke are the carbon oxides, present in all fires. They are indicators of the toxicity of the atmosphere and of the completeness of combustion. Measurement of concentrations of carbon oxides are useful for two purposes: as part of fire hazard assessment calculations and to improve the accuracy of heat release measurements. Other toxic combustion gases, which are specific to certain materials, are less crucial for determining combustion completeness and are optional measures, but fire hazard assessment often requires their measurement.

5.5 The type of ignition chosen (a flaming source) is common in both accidental and intentional fires in public occupancies. This test method is thus applicable to upholstered furniture in public occupancies. Such facilities include, but are not limited to, jails, prisons, nursing care homes, health care facilities, public auditoriums, hotels, and motels.

5.6 It has been shown that if the gas burner is used at a flow rate of 13 L/min for 80 s (equivalent to 19.3 kW), as is the case in California Technical Bulletin (CA TB) 133, it approximates the ignition propensity of five crumpled sheets of newspaper located on the seating cushion.

5.7 This test method specifies both a particular flow rate of propane gas and a period of gas flow. If the ignition conditions are changed, the results would then deviate from the model selected for this test.

5.8 This test method is not applicable to ignition of upholstered furniture by cigarettes.

5.9 One of the following three test configurations is to be used in this test method:

5.10 Measurements in the three test configurations listed in 5.9 have been shown to give similar results for heat release in the duct, for heat release rates lower than 600 kW (see X1.4) (1).9

5.11 Measurements of temperatures, gas concentrations, and smoke obscuration in the room, which are optional in this test method, are dependent on room size.

5.12 This test method has been designed to give details for the means to build and operate equipment capable of running tests as required by CA TB 133. This test method is, however, more general than that technical bulletin.