Fires involving electric vehicles have attracted considerable attention in the media. In particular, the toxic gases released upon combustion of electric vehicles and lithium-ion batteries has been a major concern. In this study, the results of six large-scale vehicle fire tests are presented including three electric vehicles, two internal combustion engine vehicles, and one electric vehicle with the battery pack removed. Additionally, separate battery component tests were performed. In two of the vehicle fire tests a sprinkler system was used to assess the effect of water application on the combustion gases. Furthermore, calculations of the heat release rate, peak heat release rate and total heat release were performed, as well as chemical analysis of gas and soot. Peak heat release rate and total heat release were affected by the fire scenario and vehicle model, but not significantly by the type of powertrain. Regarding the combustion gases, hydrogen fluoride represented the largest difference between electric vehicles and internal combustion engine vehicles. Additionally, battery specific metals such as manganese, nickel, cobalt and lithium were found in higher concentrations in the electric vehicle tests than in the internal combustion vehicle tests, in which larger quantities of lead were found.

The construction sector is of great importance to the Swedish economy, but its impact on the climate is significant and the sector accounts for about 40% of Sweden's total energy consumption. The sector also generates a significant share of the total material flows and waste quantities in the society. Thus, due to the large impact of the construction sector, there are great opportunities to contribute positively by reducing the climate impact through change and modernization. There are many activities focused on reducing construction waste in various ways and the issue of material and product reuse has received increasing attention in recent years. However, very little work has focused on products associated with fire safety requirements. This paper provides an overview of research on the reuse of materials and products with a focus on products with fire safety requirements. In addition, it provides a review of the Swedish building legislation and its impact on the possibility of reusing materials and products with fire safety requirements. Finally, possible paths are explored for introducing more large-scale reuse of such materials and products. © 2023 The Authors

Materials used for interior parts in buses are today fire classified according to UNECE Regulation 118, evaluating the horizontal and vertical burning rates and the melting behaviour. However, in recent accidents, the smoke has been identified as the critical parameter for deaths. An evaluation has been made of six materials used as interior parts in busses and is presented in this paper. Fire testing was conducted according to UNECE R 118 and smoke production including smoke gas toxicity was further evaluated with the smoke chamber test, EN ISO 5659-2 and EN 17084. All six tested materials fulfilled the requirements of UNECE R 118; however, most materials showed fire properties which are not desirable, such as dark smoke and melting of large burning pieces. The tests with the smoke chamber showed that all materials gave a very high smoke production, in fact a smoke density value of the highest possible for the equipment to measure. This occurred only after a few minutes of test time. Thus, it can be concluded that this high smoke production will, in case of fire in a bus, reduce the visibility, and limit the ability of the passengers to safely evacuate. In addition, several toxic gases were detected in the smoke, both irritants and suffocating gases. © 2022 The Authors.

The demands on bus interior products have increased with increasing sustainability, circularity and a reduction of harmful substances, today’s materials must be improved with regards of additives, such as flame retardants. A comprehensive study was made to evaluate the possibility to use phosphorous flame retardants (FRs) instead of the commonly used halogenated FRs compounded with ABS. The study showed that the fire performance could be improved with phosphorous FRs regarding heat release and smoke production. However, it was noted that the smoke production still was high, and that the smoke density was highest possible, i.e., no visibility through the smoke layer. Further testing of today’s bus interior materials showed that the high smoke density was achieved already after a few minutes of test time. Thus, it can be concluded that, in case of a fire, the visibility in the bus will be reduced and limit the ability of the passengers to safely evacuate. In addition, several toxic gases were detected in the smoke, both irritants and suffocating gases. The bus fire regulation R118 for interior materials basically deals with burning rate and melting through a fine mesh. Critical fire parameters such as smoke production and smoke toxicity is not dealt with. The R118 regulation need to be improved with these critical parameters in order to have fire safe materials inside the bus.

The phosphorous-based flame retardant additives poly(m-phenylene methylphosphonate) (PMP) and resorcinol bis(diphenyl phosphate) (RDP) are reacted with bisphenol F and aniline–based benzoxazine (BF-a). DSC, rheological analysis, FT-IR, and soxhlet extraction reveal the covalent incorporation of both FR additives—initiating phenols in PMP structure as well as free phenols generated via transesterification reaction in the case of RDP. In contrast to PMP, RDP elongates the processing window but decreases the thermo–mechanical properties. Both additives increase the resistance in reactions against small flames with solely a phosphorous loading of 0.3 wt%, resulting in a V-0 rating and an improvement in the OI value by up to 2% for RDP and 4% for PMP. Both FRs reduce the heat release rate but increase the smoke production and the smoke toxicity in the case of RDP. 

Sales of electric vehicles doubled in 2021 compared to the previous year and nearly 10% of the global new-car sales were electric in 2021. In the recent IEA Global EV Outlook 2022, Norway, Iceland, and Sweden were reported to have the highest electric car shares of the new car market: 86%, 72% and 43%, respectively. Electrification of transport has multiple benefits but has also raised some concerns. For example, the use of rare metals and their sourcing are concerns from an environmental perspective, the capacity of the electricity network and the limited number of charging stations has been raised as an implementation barrier, and the new fire and explosion risks of batteries have caused concerns amongst users, property owners and rescue services alike society.Fires starting in the traction batteries (lithium-ion battery) are rare but if the battery catches fire, it can be difficult to extinguish since the battery packs are generally well protected and difficult to reach. To cool the battery cells, firefighters must prolong the application duration of suppression agent. This generally results in use of large amounts of water/fire extinguishing agent, which could carry pollutants into the environment.In this work, extinguishing water from three vehicle fires as well as from one battery pack fire has been investigated. Large-scale fire tests were performed with both conventional and electric vehicles. Tests were performed indoors at RISE, Borås, which also allowed analysis of combustion gases for both inorganic and organic pollutants in the gas and liquid phase.It was found that nickel, cobalt, lithium, manganese and hydrogen fluoride appeared in higher concentrations in the effluents from the battery electric vehicle and lithium-ion battery compared to from the internal combustion engine vehicle. However, lead was found in higher concentrations in the effluents from the internal combustion engine vehicle, both in the combustion gases as well as in the extinguishing water. Ecotoxicity analysis showed that extinguishing water from all vehicle and battery fires analysed in this work were toxic against the tested aquatic species.

Microencapsulated phase-change-materials (PCMs) incorporated in cementitious grout can be used as a source of energy in an underground thermal energy storage system. Differential scanning calorimetry (DSC) is a widely used technique to measure the latent heat or specific heat of PCM-embedded cementitious materials. However, using milligram sample sizes (as required by DSC) of a cementitious material fails to represent the actual scale of cementitious components. This is the reason why, in the present paper, non-isothermal heat conduction microcalorimetry (MC) was evaluated as a tool for determining the thermal properties of PCM-embedded grout as well as pure PCM (three PCMs were used). An MC experimental protocol (using both single and 5–6 temperature cycles) was developed and used to measure latent heat and melting and crystallization temperatures, which were in good agreement with those reported for pure PCMs by the producers. In addition, the specific heats of the PCM-containing grout also agreed with measurements using the hot disk technique. Overall, the results show that the MC technique can be used as a potential standard method in determining thermal processes in complex systems, such as in PCM-embedded cementitious systems, where a large sample size is needed to represent the material.

ISO 5660-1 specifies the cone calorimeter method for characterizing the ignition and surface burning behavior of materials. The specimen is irradiated through a square opening in the frame of the specimen holder. The frame is intended to protect the edges of the specimen from irradiation but covers the edges with only a few mm. In tests with products such as composite laminates and sandwich wall panels, the production of pyrolysis gases from the edges and, in many cases, burning have been observed. Early contribution from the edges in the test is not representative for surface burning. A modified specimen holder was developed with a larger specimen size to allow better protection of the edges. The opening for exposure to irradiance of the retainer frame is circular and of the same area as that of the original frame. The distance between the exposed surface and the specimen edges is larger in order to prevent early exposure of edges. Tests using the standard specimen holder resulted in pyrolysis and burning from edges that took place outside of the specimen holder. Comparative tests using the modified specimen holder showed that it prevented the exposure and pyrolysis from edges for an extended time. However, the influence on ignition time and peak heat release due to the increased size of the modified specimen holder has not been characterized fully, and test results should not be used for direct comparison with those of the standard holder.

As material age, the durability, strength, and other mechanical properties are impacted. The lifespan of a material generally decreases when exposed to weathering conditions such as wind, temperature, humidity, and light. It is important to have knowledge of how materials age and how the material properties are affected. Regarding materials´ fire behaviour and the effect of ageing on these properties, the knowledge is limited. The research questions of the current work are: Are the fire properties of composite materials affected by ageing? And if so, how is it affected? The study is on material at Technology Readiness Level 9 (TRL). In this study, three composite fibre laminates developed for marine applications were exposed to accelerated ageing. Two different ageing conditions were selected, thermal ageing with an increased temperature of 90°C and moisture ageing in a moderately increased temperature of 40°C and a relative humidity of 90%. Samples were collected after one, two and four weeks of ageing. The reaction-to-fire properties after ageing was evaluated using the ISO 5660–1 cone calorimeter and the EN ISO 5659–2 smoke chamber with FTIR gas analysis. The test results showed that the fire behaviour was affected. Two of the composite laminates, both phenolic/basalt composites, showed a deteriorated fire behaviour from the thermal ageing and the third composite laminate, a PFA/glass fibre composite, showed an improved fire behaviour both for thermal and moisture ageing. The smoke toxicity was affected by the accelerated ageing, especially for the PFA/glass fibre composite that showed a higher production of CO and HCN, both for the thermal aged and the moisture aged samples. © 2021, The Author(s).