Soft furnishing fires: They're still a problem

Home fires in which soft furnishings were first ignited or contributed to fire spread cause a disproportionate share of US home fire deaths. Although the death toll from these fires is much lower than in the 1980s, the rate of death per 1000 reported fires has doubled. Data from the National Fire Incident Reporting System and the National Fire Protection Association's annual Fire Experience Survey were used to create national estimates of these fires and casualties. Including both fires in which upholstered furniture was the item first ignited and contributed most to fire spread, in 2013‐2017, upholstered furniture was involved in an estimated average of 7120 (2%) home fires per year, resulting in an average of 570 (22%) deaths per year. Mattresses or bedding were involved in estimated average of 10 530 (3%) home fires per year, resulting in an average of 370 (14%) deaths annually. In most of these fires and deaths, the item was first ignited. Smoking materials were the leading cause of these fires (20%‐26%) and associated deaths (52%‐54%). Various types of operating equipment and small open flames also play a role. Understanding the causes of these fires is essential to develop new strategies to prevent them.     

Toxic gas tests in perspective

A study of the 1979 UK fire statistics and the Annual Report of the Office of Population Censuses and Surveys shows that only 1 death per 1000 is attributable to toxic gases from combustion. However, of the ‘deaths by violence’ it rises to 30 (3%). As 37% of all fires in occupied buildings were confined to the first item ignited and 53% to the area of origin it is postulated that such fires (and the consequent deaths) largely concerned substances which will burn on their own. From experience these are largely materials with limiting oxygen indices below 22 or 22–28 for restricted burning only. Those with limiting oxygen indices >28 cannot on their own sustain combustion. These considerations suggest the mode in which toxic gas tests should be conducted, i.e., horizontally or vertically and vertically only for the first two groups, respectively, and in the presence of a fire sustainer for the limiting oxygen index >28 group. Wood in the form of a wooden crib is suggested as suitable. To this end some experiments are described with PVC placed on top of a No. 5 crib (PSA). These latter show that, making the best assumption possible from the existing data, the wood contributes about 63% to the toxicity and the PVC 37%. On the large scale, other work has shown that wooden cribs alone will give lethal concentrations of carbon monoxide for significant periods. Thus difficult-to-burn substances need to evolve gases of exceptional toxicity for their contribution to be worth considering.     

The generation of CO in bench-scale fire tests and the prediction for real-scale fires

Carbon monoxide (CO) is the single most important factor associated with deaths in fires; thus, predictions of CO developed in fires is an essential aspect of fire quantification. It is considered crucial to have correct CO prediction methods for post-flashover fire stages, since, in the United States at least, the majority of fire deaths are associated with fires which have gone to flashover. In this paper it is shown that the yiels of CO observed in real-scale fires are generally not related to either the chemical nature of the material being burned nor to the yield observed for the same material in bench-scale testing. Instead, the generation of CO in real-scale fires is determined largely according to the oxygen available for combustion, with thermal conditions of the fire plume also playing a significant role. This behavior is in sharp contrast to many other material fire properties, including yields of gases such as CO₂ and HCI, which can be predicated for real-scale fires from bench-scale results. Finally, results from various studies completed thus far indicate how effective prediction of real-scale CO yields may be accomplished. While bench-scale measurements are not necessary to predict real-scale CO, bench-scale toxic potency measurements can be in error if the CO component in them does not reflect on the real-scale CO yield. Thus, a method is developed whereby the bench-scale toxic potency measurements can be computationally corected to better approximate the toxic potencies measured in real-scale, post-flashover room fires. These techniques will, undobtedly, be further refined as additional experimental results become available.     

Estimating the impact of the mattress fire safety Standard 16 CFR Part 1633 on bed fire outcomes

Beds are a prevalent combustible in fatal fires in the United States effective 1 July 2007, the US Consumer Product Safety Commission promulgated a standard to severely reduce the heat release rate and the early heat output from mattresses and foundations when ignited by a flaming ignition source. This study estimates the Standard's success over its first decade using fire incidence, US population, and mattress sales data. The technique mitigates the influence of some exogenous factors that might have changed during this decade. The Standard is accomplishing its purpose, preventing approximately 65 fatalities (out of an estimated 95 fatalities in 2002‐2005) from bed fires annually during 2015‐2016, although not all pre‐Standard mattresses had yet been replaced. Compared to residential upholstered furniture fires, which were not affected by the Standard, the numbers of bed fires decreased by 12%, injuries by 34%, and deaths by 82% between 2005‐2006 and 2015‐2016. Per bed fire, injuries decreased by 25% and fatalities decreased by 67%, indicating that the severity of bed fires is being reduced.     

Statistics of fires in dwellings involving textiles in the United Kingdom

There is widespread concern at present about the fire risk form the use of modern materials in upholstery and other domestic articles. One of the main characteristics of fires in dwellings which start with the ignition of textiles or furniture is that they have a high casualty rate compared with other kinds of domestic fires. Most of the casualties form such fires occur in fires which start in upholstery or bedding, often accidentally ignited by smokers' materials. Asphyxiations by smoke is the commonest cause of death in ‘textile’ and ‘upholstery’ fires. This paper presents relevant statistical information on fires in dwellings attended by local authority fire brigades which result from the ignition of upholstery, bedding, other textiles or furniture and the casualties which these fires cause.     

Bench-Scale Tests on Simultaneous Ignition of Two Different Plastics Through “Bridge-Mixing”

“Bridge-mixing” was proposed earlier to explain why different combustibles might be ignited simultaneously during flashover. Different fuel vapors gasified from those combustibles were ignited by thermal radiation first. Thermal feedback from flames above the combustibles would then ignite the solid. This point is further studied in this article by bench-scale tests with a cone calorimeter. Sample cubes of two materials with different ignition temperatures were tested at a high thermal radiative heat flux of 70 kWm^?2. Materials selected are polymethylmethacrylate (PMMA) and polyvinyl chloride (PVC). The two sample cubes were placed on the cone tray at different separation distances. In this way, different mixing of gasified fuel vapors released from the plastics can be achieved. Those two combustibles were found be ignited simultaneously at shorter separation distances. This might explain why combustible items of different ignition temperatures appear to be ignited at roughly the same time during flashover for some scenarios. On the basis of this study, the mixing of gasified fuel vapors from different combustibles by the fire-induced airflow is a key factor in igniting each item. Geometry of the rooms, combustibles, and ventilation provisions are important factors affecting simultaneous ignition.     

Highway vehicle fire data based on the experiences of US fire departments

In 2003–2007, US fire departments responded to an average of 267 600 highway vehicle fires per year. These fires caused an average of 441 civilian deaths, 1326 civilian injuries, and $1.0bn (in US dollars) in direct property damage annually. Highway vehicles include cars, trucks, and other vehicles designed for highway use; highway vehicle fires can occur anywhere, not just on a highway. While these fires and associated losses have been falling in recent years, highway vehicles fires accounted for 17% of reported US fires, 12% of US fire deaths, 8% of US civilian fire injuries, and 9% of the direct property damage from reported fires. Data from the US Fire Administration's National Fire Incident Reporting System and the National Fire Protection Association's fire department survey were used to provide details about the circumstances of highway vehicle fires. Mechanical or electrical failures caused roughly three‐quarters of the highway vehicle fires but only 11% of the deaths. Collisions and overturns were factors contributing to the ignition in only 3% of the fires, but fires resulting from these incidents caused 58% of these vehicle fire deaths. The rate of bus fires per billion miles driven was 3.5 times that for highway vehicle fires overall. Copyright © 2012 John Wiley & Sons, Ltd.     

Furniture and furnishings in the home—some fire statistics

A statistical study of fires in the United Kingdom involving the ignition of furniture and furnishings is presented. This paper examines the data for one year (1970). The analysis shows that in fires starting in furniture and furnishings the chance of a fatality is over twice that in other domestic fires. The majority of furniture fires involve upholstery or bedding and over 90% were started by smokers' materials, electric appliances, space heating or as the result of the activities of children or suspected arsonists. Eighty-five percent of the fatalities were found in the room of origin of the fire. Eighty per cent were overcome by smoke or toxic gases. Sixty percent of the fatalities were either under 5 or over 65 years of age. Monetary values are assigned for damage, casualties and deaths in fire. These costs can be used to assess the value of fire precautions. With the values taken, the total losses in furniture fires in the home amounted to £19 million in 1970. Life loss accounted for the major part of this sum. The expected annual loss per dwelling as a result of the ignition of furniture is thus only about £1, and is only £3 for all dwelling fires. This low figure suggests an approach of either selective spending on those most at risk (the elderly and handicapped) or by government activity through publicity and education.     

Solving the soft furnishings fire problem (without incurring collateral damage)

Fires in which soft furnishings (upholstered furniture and beds) were either the first item ignited or were identified as the major item in the fire's growth are the deadliest of residential fires. This Special Issue of Fire and Materials on Furniture Flammability grew from a small session on this subject in Interflam 2019. The issue contains 14 papers that describe the fire problems of soft furnishings, research to better understand their burning behavior, and recent success in and promising approaches to reducing the losses from these fires. This introduction concludes with the author's challenges to the fire safety community for reducing the number and consequences of soft furnishings fires.     

Update on smoke toxicity of vinyl compounds

All organic materials burn and give off toxic products. These always include water, carbon dioxide, and the single gas causing the greatest hazard in fires—carbon monoxide (CO). The intrinsic toxicity of the smoke of all combustible materials, including PVC, is very similar in terms of lethality, with very few exceptions. Toxicity of vinyl compounds is due to two major gases: CO and hydrogen chloride (HCI). Since natural combustible materials are not chlorinated, speculation has arisen about the toxicity of HCl and of PVC smoke. Recent studies have shown that it takes similar doses of HCl and CO to kill rats. Furthermore, rats and baboons will tolerate the same levels of HCl. However, mice are much more sensitive than either rats or baboons towards HCl. Baboons are a very good model for humans; therefore, mice will be killed by exposure to much lower HCl levels than those required to kill humans. HCl concentrations in real fires are quite low: HCl decays rapidly by reacting with wall materials such as gypsum, cement, or ceiling tile. It does not, however, react rapidly with plastic or glass walls, which is where toxicity tests are carried out. Therefore PVC smoke is less hazardous in reality than it appears to be from toxicity test results. Since most products have similar intrinsic toxicities, as regards lethality, the real toxicity in a fire is a consequence of the rate of generation of gases. PVC is a difficult polymer to ignite and burns very slowly, so that it will give off less toxic products per unit time than many other common materials and cause lower fire hazard.     

RSET/ASET,a flawed concept for fire safety assessment

For the evaluation of occupant safety in the case of building fires, the Required Safe Egress Time/Available Safe Egress Time (RSET/ASET) concept has become widespread and is now commonly used in the fire safety engineering profession. It has also become commonly used by smoke detector (smoke alarm) manufacturers in assessing whether a particular detector technology is adequate. It is shown in this paper that the concept is intrinsically flawed and its use promotes the diminishment of fire safety available to building occupants. The concept innately ignores the wide variations in capabilities and physical condition of persons involved in fire. It is based on implicitly assuming that, after a brief period where they assess the situation and mobilize themselves, occupants will proceed to the best exit in a robotic manner. This assumption completely fails to recognize that there are very few fires, especially in residential occupancies, where occupants perished or were seriously injured who had endeavored to exit in this robotic manner. Instead, in the vast majority of fire death and serious injury cases, the occupants did not move in such a manner and their evacuation took longer than anticipated on the basis of robotic movement. There is a wide variety of reasons for this, and these are well known in the profession. The concept also ignores that there can be a wide variation in fire scenarios. The same building and the same fire protection features can be evaluated, but both RSET and ASET can change drastically, depending on the scenario used. The consequence of using the RSET/ASET concept for fire safety engineering or product design purposes is that fire deaths and injuries are permitted to occur, which are preventable. Copyright © 2010 John Wiley & Sons, Ltd.     

The fire performance of electrical insulating materials used in fluorescent lighting fixtures

Analysis of a major fire incident at a home furnishings warehouse led to the conclusion that extended exposure of electrical insulating materials composing a lampholder in a fluorescent lamp were the initial items ignited. It was thought that these items, composed of thermoset polymers, were ignition‐resistant materials. However, analysis showed that thermally induced degradation caused the material to degrade into an easily ignited, char‐like residue. The parent polymer, highly cross‐linked urea formaldehyde, had been initially cast into the lampholder configuration to prevent high voltage conditions and arcing. Thermal and elemental analyses as well as the investigation conducted at the fire site, helped to determine that the original polymer had pyrolysed into a residue differing in both chemical composition — reduced hydrogen and oxygen content — and physical characteristics when compared with the parent material. The changes in the chemical and physical properties of the original polymer explain the observed thermal inertia of the residue and its tendency to smolder (as opposed to the ‘parent polymer’). They are characterized by (1) an increased accessibility to oxygen, (2) reduced thermal conductivity and (3) increased proportion of carbon. Copyright © 2002 John Wiley & Sons, Ltd.     

Hybrid composite materials

Hybridization of carbon fibre with basalt fibre significantly increases production of carbon-fibre-reinforced plastics, which allows expanding the areas of application of these effective materials not only for special purposes, but also for the most important types of products in machine building, auto and rail transport, in the river and marine fleet, etc. The increased demand for hybrid carbon-fibre-filled plastics requires nitron manufacturers to increase, and not decrease output and to use it not only in industry but also for manufacturing domestic wool-like items, which will reduce imports. Hybridization of carbon fibres with 30–40% basalt fibres will stimulate the development of the basalt fibre, yarn, and fabric sector, which will reduce their cost and expand the areas of application particularly for roads and transportation so that basalt will be as valuable a resource for our country as oil and gas. Translated from Khimicheskie Volokna, No. 6, pp. 5–7, November-December, 2008.     

化工企业消防安全信息化管理简析

化工企业,无论是生产还是存储,都需要接触化学原料和化学产品,而化学原料和产品都有一定危险性。化工企业属于国民经济中的重要组成,对于推动国民经济发展有重要促进作用,但是化工企业存在的危险性也比较大,企业中一些易燃、可燃以及易爆物品在满足条件的情况下,很有可能引发火灾,进而对化工企业发展产生不良影响。因此化工企业应该注重消防安全管理的实施,并且将信息化技术充分运用其中,实现信息化管理,提升管理效率和质量。     

Bench Scale Tests on Controlling Plastic Fires with Water Mists

Bench scale tests are proposed to study the performance of a water mist fire suppression system on plastic fires. The effects of water mist on burning solid polymethylmethacrylate (PMMA) and polyvinylchloride (PVC) are compared with a cone calorimeter. A scaled nozzle developed earlier for discharging water mist in a cone calorimeter was used. Operating pressures of 0.2–0.7 MPa, corresponding to water flow rates of 68 mL/min and 134 mL/min, were used. It was observed that PMMA samples could be ignited easily and liberated significant amounts of heat at high release rates. PVC was more difficult to ignite, but gave out large quantities of smoke. Discharging water to both did not increase the heat release rate significantly. However, both smoke quantity and carbon monoxide concentration increased. This was more obvious for PMMA fires. Hazard assessment parameters for thermal aspects and smoke were measured and presented as a ‘hazard diagram' to understand the action of water mist and the potential for re‐ignition. It is suggested that bench scale tests can also give useful results for designing water mist systems. The discharging time of water mist is a key factor in controlling PMMA fires. If the discharging time is not long enough, re‐ignition might occur once the discharging of water stops.     

A comparative study of test methods for assessment of fire safety performance of bus interior materials

This work concerns the assessment of fire performance of interior materials in buses. The widely used test method ISO 3795/FMVSS 302 has received much criticism mainly based on the fact that the test is a small‐scale method not suited for bus fires induced by for example fire in the engine compartment or fire in a tyre. Furthermore, test specimens are oriented horizontally, whereas much fire spread in a real bus fire occurs on vertically oriented products. Seventeen products were investigated: 11 textiles, four solids and two insulations. Three test methods were compared: ISO 3795, ISO 6941 and ISO 5658‐2. Given the existing criteria for interior materials, it was found that ISO 6941 and ISO 5658‐2 place harder requirements on the materials. When the three methods were compared, it was found that ISO 3795/FMVSS 302 and ISO 6941 are insufficient for simulating bus fires typically occurring today. Such fires are often initiated by a fire in the engine compartment or in a tyre and can hardly be simulated by small‐scale methods as ISO 3795/FMVSS 302 or ISO 6941 even if the ISO 6941 method to some extent gives results similar to the established large‐scale ISO 5658‐2 method. Copyright © 2011 John Wiley & Sons, Ltd.     

Toxicity of the pyrolysis and combustion products of poly(vinyl chlorides): A literature assessment

Poly(vinyl chlorides) (PVC) constitute a major class of synthetic plastics, Many surveys of the voluminous literature have been performed. This report reviews the literature published in English from 1969 through 1984 and endeavors to be more interpretive than comprehensive. PVC compounds, in general, are among the more fire resistant common organic polymers, natural or synthetic. The major products of thermal decomposition include hydrogen chloride, benzene and unsaturated hydrocarbons. In the presence of oxygen, carbon monoxide, carbon dioxide and water are included among the common combustion products. The main toxic products from PVC fires are hydrogen chloride (a sensory and pulmonary irritant) and carbon monoxide (an asphyxiant). The LC₅₀ value calculated for a series of natural and synthetic materials thermally decomposed according to the NBS toxicity test method ranged from 0.045 to 57 mg l^?1 in the flaming mode and from 0.045 to > 40 mg l^?1 in the non-flaming mode. The LC₅₀ results for a PVC resin decomposed under the same conditions were 17 mg l^?1 in the flaming mode and 20 mg l^?1 in the non-flaming mode. These results indicate that PVC decomposition products are not extremely toxic when compared with those from other common building materials. When the combustion toxicity (based on their HCI content) of PVC materials in compared with pure HCI experiments, it appears that much of the post-exposure toxicity can be explained by the HCI that is generated.     

Performance evaluation of bromofluoropropene in extinguishing liquid fuel spray fires

Liquid fuel spray fires emit high radiation heat fluxes, posing great threat to humans. The study of suitable agents and techniques for extinguishing this particular type of fire is of great importance. In this study, degradable 2‐bromo‐3,3,3‐trifluoropropene (BTP), a new clean fire extinguishing agent, was tested for its effectiveness in extinguishing three types of liquid fuel spray fires, namely diesel, gasoline, and ethanol. Bench‐scale experiments were conducted in a 6 × 5 × 3 m compartment with natural ventilation. The liquid fuels sprayed at varying pressures were ignited by a small open flame and then extinguished by a portable BTP extinguisher. Results showed that BTP of less than 60.0 g could extinguish all liquid fuel spray fires of 0.20 to 1.0 MPa in less than 2.0 s. The results also showed that when compared with fire sparked by gasoline and diesel, it is significantly easier to put out ethanol spray fires because of its high flame temperature and low flame power. Based on well‐established fire suppression theories and experimental results, the detailed mechanism of how BTP functions as an extinguishing agent in the suppression of liquid fuel spray fires will be discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

聚双环戊二烯制品的除臭技术

简要介绍了国内外聚双环戊二烯制品除臭技术的研究进展。除臭技术主要包括加入各种添加剂、改进催化体系、改进聚合工艺、制品表面处理等方法。传统的聚双环戊二烯制品只用于户外材料,经除臭后可扩大使用范围,用于室内装饰、家具、建材等领域。     

黄金尾矿制备水泥和混凝土的研究进展

黄金生产具有高价值、高成本、高污染、高排放的特点,黄金产业的绿色化对可持续发展具有重要意义。由于黄金矿石的含矿量低,生产过程中会产生大量尾矿,这些尾矿大量占用土地,造成巨大的环境负担,因此,黄金尾矿的资源化利用具有重要意义。黄金尾矿中富含硅元素,尾矿颗粒细小且具有潜在的火山灰活性,利用黄金尾矿生产水泥混凝土是实现尾矿建材化利用的理想途径。本文从黄金尾矿的物理-化学特性、颗粒特征和宏观颗粒群性质等方面出发,分析了黄金尾矿用于制备水泥熟料、砂浆及混凝土制品的可能性,总结了国内外利用黄金尾矿生产水泥、砂浆混凝土的研究进展,旨在为黄金尾矿的建材资源化高效利用和相关研究提供借鉴和参考。