Influence of modern plastic furniture on the fire development in fires in homes: large‐scale fire tests in living rooms

About 80% of all fire fatalities in Germany occur because of fires in homes. It has been known for some time that modern materials (synonym for materials consisting mostly of synthetic polymers) tend to burn differently from older materials (synonym for materials consisting mostly of fibrous cellulosic substances) and it has been acknowledged that the amount of combustible plastics in homes has increased significantly over the last decades. To investigate the influence of modern furniture and ventilation conditions of fires in homes, a series of four large‐scale tests in two living rooms (LRs) with adjacent rooms (ARs) was performed by BAM and the Frankfurt fire service. Two LRs, one with older furniture and one with modern furniture, were tested twice each. Each test started with the ignition of a paper cushion on an upholstered chair. The influence of modern materials on the fire development was investigated, as well as the influence of the ventilation on the fire development. In all settings, an upholstered chair was the first burning item. Results of the test series show that fires in rooms with modern furniture develop faster than fires in rooms with older furniture. This is true for temperature development in the rooms as well as for smoke production.


| INTRODUCTION
Fires in homes cause about 80% of all fire fatalities in Germany. 1 U.K. statistics, which are much more detailed than German statistics, show that living and bedroom fires are more often responsible for fatalities than kitchen fires. In the United Kingdom, kitchen fires occur much more often. 2 According to the U.S. fire statistics, in the years from 2010 to 2014 alone, there were 5630 home fires that can be traced back to the ignition of upholstered furniture. These fires caused 440 deaths and more than 260 million U.S. dollar in property damage. From this fire statistics, it can also be deduced that an average of 1 in 13 reported upholstered furniture fires resulted in the death of people. 3 It has been known for some time that modern materials tend to burn differently from older materials, and it has been acknowledged that the amount of combustible plastics in homes has increased significantly over the last decades. [4][5][6][7][8] In this paper, the terms "old" in comparison to "modern" furniture were used. In the early 1940s, furnishings consisted mainly of cellulosecontaining materials such as wool and cotton. However, the increasing use of materials based on wood and polymers is leading to a change in the material composition of furnishings in homes. The furnishings used for the investigation of this paper were briefly defined as "old," because they tend to contain cellulose-containing materials, and "modern" tend to consist of different synthetic polymers. The aim of this investigation was to describe the influence of these changed material composition of furnishings on the course of room fires as well as on the associated energy and mass release. In addition, the influence of ventilation conditions was examined. Therefore, a test series of four experiments in living rooms (LRs) with adjacent rooms (ARs) has been performed with the Frankfurt fire service and BAM, the German Federal Institute for Material Research and Testing. The four tests aimed on investigating on one hand the influence of older and modern furniture and ventilation conditions on the fire and smoke development of fires in homes, and on the other hand to assess the differences in conditions for inhabitants, who are in the room of fire origin or in the AR. 9 In all four large-scale experiments, a similar furnishing of the LR has been used, which is seen to be typical for German LRs approximately 30-40 years ago and today. The modern furniture had been purchased new in a very popular Scandinavian furniture store, the old furniture had been purchased secondhand. The old furniture is used in contrast to the modern furniture.
In two experiments the old furniture was used, and in two experiments modern furniture was used. The experiments had different ventilation conditions, which were realised by open and closed windows, see next section for details. With temperature measurements in the room of fire origin and the AR and gas measurements in the AR and video footage inside the rooms, the fire and smoke development could be assessed. In all four experiments, an upholstered chair was chosen as the F I G U R E 1 Test site, building with two living rooms and two adjacent rooms and one measurement room in the middle (left), living room with adjacent room-schematic (right) [Colour figure can be viewed at wileyonlinelibrary.com] F I G U R E 2 Photos of the two living rooms, with older furniture (left) and with modern furniture (right) 9 Figure 1). One of the rooms was furnished like a common German LR and designated as room of fire origin. The unfurnished AR was included in the experimental setup to assess the temperature and smoke development in the AR additionally to the room of fire origin,

| Instrumentation
An overview of the measurements and locations is given in Figure 4. For many applications in gas phase measurement, a resolution of 1 cm −1 or less is selected (high resolution). However, high resolution requires longer measurement and computing times. The signal-tonoise ratio gets worse with higher resolution. According to studies by Larjava et al., 10 a low-resolution FTIR spectrometer offers some useful advantages, especially for applications outside the laboratory, as the signal-to-noise ratio is better, and the measurement speed is faster.
In the ISO 19702 standard, 4 cm −1 or better is recommended, but in these experiments CO, CO 2 and HCN were evaluated that are more than 8 wavenumbers apart, so they can also be evaluated quantita-

| Test execution
In all four experiments, see Table 1, an upholstered chair was ignited by a burning paper cushion. The paper cushion was a 100-g cushion The "older" furnishings used in the fire experiments came from the 1960s to 1970s. Their material composition is described below, in Figure 6, as "old furnishings." They were purchased second-hand and were used. The furnishings used in the fire experiments with "modern furniture" came from the present. They were purchased new from a popular Scandinavian furniture store. Their material composition is described below in Figure 6 as "modern." To minimise further material influences, wallpapers and floor coverings were removed from all rooms. The AR was not furnished because only the smoke spread and dispersion was examined for this room.

| RESULTS OF THE EXPERIMENTS
In experiments 1_1, 1_2 and 2_1, solely the upholstered chair burned.
Only in experiment 2_2, the fire developed further. In Figure 7  Photographs taken after the fire tests are shown in Figure 12.
The damage in the room with modern furniture is obviously much higher than in the room with older furniture.