ALBERT

Notes: Heat Release Rates of organic materials are studied in many countries, but there is no mathematical formula to represent their shape. We considered a mathematical expression of the Heat Release Rate Curve by a simple equation. And we also derived the index of degree of combustibility, named ‘Burning Index (BI)’. The Heat Release Rate Curve is expressed by the derivative of a probability function of maximum value and has three parameters; an amplitude coefficient, a time width coefficient and an ignition index. BI is in proportion to an amplitude and a time width and in inverse proportion to an ignition index. BI values of cable plastic compounds with flame-retardant material had good relations with the quantity of non-organic ingredients. © 1998 John Wiley & Sons, Ltd.

Notes: The paper describes results of investigations of conveyor belt flammability in full scale, using the large-scale gallery method and using cone calorimeter. On the basis of oxygen consumption calorimetry, the amounts of heat release during burning of conveyor belts were calculated. A correlation was found between results of conveyor belt flammability obtained using both methods. Criteria for conveyor belt flammability assessment were established for the cone calorimeter method, which define a level that would be equivalent to that for the large-scale gallery test. © 1998 John Wiley & Sons, Ltd.

Notes: The gasification behavior for a wide range of polydimethylsiloxane fluids in a nitrogen atmosphere was investigated. Part 1 of this study addressed the measurement of the energy (global heat of gasification) required for the gasification of a wide range of dimenthylsiloxanes. Several significant corrections were required to reconcile measured gasification energy(s) with calculated heat(s) of gasification based on fundamental thermochemical data. The identification of the dominant mode(s) of gasification via the characterization of pyrolysis products provided a firm basis and rationale for understanding and directing efforts at quantifying these correction factors. In Part 2, the gasification products were identified and quantified at various stages of the gasification process corresponding to ignition, fire growth, and steady-state burning. Pyrolysis of methylated siloxanes occurs via two modes: (1) the volatilization of short chain and intermediate chain length species native to the polymer, and (2) the volatilization of short chain and intermediate chain length species resulting from thermal degradation via siloxane rearrangement. The former process is the dominant gasification mechanism for short chain oligomers and low viscosity fluids (η〈10 cS) and the latter process is dominant in all higher molecular weight polymers (η〉100 cS). Both gasification mechanisms are evident in all polymers (η〉20 cS); the dominant mechanism is dependent upon polymer size and distribution thereof, the gasification stage, and the presence of trace catalysts in the polymer. Because of their structural similarity, the combustion of all gasification products emanating from PDMS regardless of the stage of the pyrolysis process or the dominant mode of gasification will result in virtually identical combustion products, i.e. SiO2, CO2, and H2O. Copyright © 1998 John Wiley & Sons, Ltd. This paper was written under the auspices of the US Government and is therefore not subject to copyright in the US.

Notes: High-temperature pyrolysis of various classes of polymers have been discussed. For the non-carbonizing polymers it was shown that polymer structure can affect the pyrolysis characteristics. Data on the high-temperature pyrolysis of some polypropylene samples with different crystallinity have been presented. Modification of the standard method allowing one to obtain kinetic data from the single experiment was discussed. A kinetic model for the degradation of char-forming polymers in conditions of high-temperature pyrolysis has been suggested. It has been supposed that pyrolysis of carbonizing polymers proceeds in some (two in present work) parallel stages with different activation energies, temperatures and pyrolysis rates. Questions of the applicability of the suggested model to describe the various types of charring systems have been discussed. High-temperature pyrolysis for a number of epoxy resin-based polymeric compositions have been investigated. Kinetic parameters of the pyrolysis have been computed. © 1998 John Wiley & Sons Ltd.

Notes: The oxygen index (OI) of poly(butylene terephthalate) (PBT) tends to decrease when it is combined with milled-glass fibres either with or without the sizing treatment. This shows that the previously found apparent increase of flammability of PBT glass fibre composites (GFPBT) as compared to PBT is not due to the introduction of the flammable sizing together with the glass fibres in the polymer which was one suggested explanation in the literature, but rather to the wick and anti-dripping effects of glass fibres. The effectiveness of a typical brominated organic compound-antimony trioxide fire retardant system (FR), as measured by OI, is found to be larger in GFPBT as compared to PBT. A linear increase of the temperature index (TI) of PBT and of GFPBT is observed with increasing concentration of the FR. The fire retardant increases the time to ignite while it decreases the maximum rate of heat release and increases the smoke optical density and CO evolution on burning in the cone calorimeter. The dependence of fire risk and hazard assessement on the combustion model of the combustion test method is discussed for OI and cone calorimeter in the case of PBT, GFPBT and FR corresponding materials. © 1998 John Wiley & Sons, Ltd.

Notes: The study presented addresses the fire behaviour of polypropylene compounded with six classes of flame retardants. The application of cone calorimetry for the assessment of the thermal characteristics of the tested materials and their comparison with thermogravimetry are the central point of this research. This study only presents data for 25 kW/m2 of incident heat flux exposure and includes five tests for polypropylene with no additives and five tests for polypropylene with flame retardants based on triglycidylisocyanurate and lignin. The data collected include the rate of heat release, mass loss rate, char yield, time to ignition and time of total combustion. Results represent meaningful comparison between the behaviour of the materials under simulated fire conditions, using the cone calorimeter, and in the slow dynamic environment utilized in thermogravimetric analysis. © 1998 John Wiley & Sons Ltd.

Notes: Fire-retardant wood treatment with fire-retardant chemicals consisting of basic nitrogen compounds and phosphoric acid have been thoroughly examined. The fire retardance and endurance of wood were influenced by the treatment method. Here two treatment methods were compared, heat-pressed treatment method improved these qualities more than heat-dried treatment method. Furthermore, to gain lasting fire retardance, it was considered necessary to react basic nitrogen compounds and phosphoric acid with formaldehyde as in the dicyandiamide-formaldehyde-phosphoric acid or melamine-dicyandiamide-formaldehyde-phosphoric acid system. In the treated wood, the concentration of chemicals gradually decreased as it approached the center. The functional fire retardance could be graded in accordance with the chemical content. © 1998 John Wiley & Sons, Ltd.

Notes: This study demonstrates the shielding effects of a silica-ash layer on the combustion of silicones and their possible applications on the fire retardancy of organic materials. The deposited silica-ash layer, formed on the surface of silicone materials during combustion, has shielding effects on the combustion of silicones. It insulates the burning surface from the radiant heat of flame, as well as from the radiant heat produced from the burning of adjacent materials. It also restricts the diffusion of fuels into the combustion zone and the access of oxygen to the unburned fuels. The shielding effects provide some of the fundamentals for the development of silicone-based fire retardants. © 1998 John Wiley & Sons, Ltd.

Notes: The thermal decomposition of six different samples of wood and leaves in nitrogen has been studied by using dynamic thermogravimetry. In the experiments two main weight loss processes took place and the total weight loss at 500°C was over 95% in all six cases. By means of the Doyle method, the two processes were found to fit most closely the plot for the second-order equation in the form dα/dt=k(1-α)2, and each of the weight loss processes was found to be controlled, respectively, by two dominant reactions as the temperature increases. It was inferred that competing reactions occur during the overall temperature interval for all the six samples. By comparing the activation energies using this model with those by the method of Moll et al., and by comparing the experimental and theoretical thermogravimetric curves, the ‘second-order’ model was tested to be able to predict the weight loss processes of the samples with very good accuracy. It can be concluded that the ‘second-order’ kinetic model acts much better than the conventionally adopted first-order model. © 1998 John Wiley & Sons, Ltd.

Notes: Ion exchangers prepared from beech sawdust by introduction of weak and strong basic ion-exchanging groups were analysed with thermogravimetry, differential scanning calorimetry and limited oxygen index methods to evaluate their thermal stability and flame-retarding properties. By cross-linking with epichlorohydrin in the presence of NH4OH, ion exchangers in free form or in H3BO3 or H3PO4 form were obtained with increased thermal stability in comparison to the starting material. By cross-linking and quaternization of sawdust in one step with 1,3-bis(3-chloro-2-hydroxypropyl)imidazolium hydrogen sulfate, a material with better thermal stability and flame-retarding properties was obtained than by the previous procedure. This resulted in greater residues at higher temperatures as measured by dynamic thermogravimetry. The values of rate constants and activation energies of gasification calculated from isothermal thermogravimetric measurements decreased with improved thermal resistance similar to heat effects observed with differential scanning calorimetry. Limited oxygen index values up to 35.6% were obtained. © 1998 John Wiley & Sons, Ltd.

Notes: In the paper entitled ‘Comparison of the Propensity of Cigarettes to Ignite Upholstered Furniture Fabrics and Cotton Ducks (500-Fabric Study)’ (Fire Mater. 21, 123-141 (1997)) Marcelo M. Hirschler addresses the validity of a test method, proposed by NIST, for smoldering cigarette ignition propensity of upholstery fabrics. The thrust of the study is to establish similarities ‘between the ignition propensity of cigarettes assessed by (1) a set of 500-upholstery fabrics (chosen at random among typical upholstery fabrics) and (2) a test method proposed by NIST (NIST 851) and based on “cotton duck” fabrics’. The conclusion of Hirschler's study is that ‘the overall results obtained from the 500-upholstery fabric study correlate well with those of the “cotton duck” study.’ In addition, the author states that ‘the “cotton duck” can be considered, as a whole, to behave similarly to the majority (estimated at perhaps 80%) of the upholstery fabrics available at the time of the study, and the test is valid’. In an attempt to validate these statements, the ignition patterns generated by the five test cigarettes on each of the 500-upholstery fabrics were compared with the NIST “cotton duck” pattern. Only 6.6% were found to generate a pattern similar to the NIST pattern and 94% of this group were heavyweight (greater than 14 oz/sq yd.) fabrics. Assessment of the test results fails to substantiate Hirschler's statements. © 1998 John Wiley & Sons, Ltd.

Notes: This work reports one-dimensional predictions of methane/air fuel combustion in inert porous media using four combustion models: full mechanism (FM, 49 species and 227 elemental reactions), skeletal mechanism (SM, 26 species and 77 elemental reactions), 4-step reduced mechanism (4RM, 9 species) and 1-step global mechanism (1GM). The effects of these models on temperature, species, burning speeds and pollutant emissions are examined. The calculations are compared with available experimental data. It is concluded that the already known limitation of the 1-step global mechanism can be partially eliminated by the present 4-step reduced mechanism. This 4RM model compares very satisfactorily with the full mechanism in the simulation of combustion in porous media. This conclusion is encouraging for the simulation of practical porous media burners because the 4RM model improves the stability of the calculation process and can be used with reduced computational resources and cost. © 1998 John Wiley & Sons, Ltd.

Notes: A thorough review was recently conducted to verify the correctness of equations being used to calculate heat release rate in standard test methods. The review incorporated 17 different standard test methods from American Society of Testing and Materials (ASTM), National Fire Protection Association (NFPA), Uniform Building Code (UBC), California Technical Bulletin (CA TB), International Standards Organization (ISO), and British Standards (BS). The standard test methods reviewed were ASTM D5424, ASTM D5537, ASTM E1354, ASTM E1537, ASTM E1590, ASTM E1623, ASTM E1822, NFPA 264, NFPA 265, NFPA 266, NFPA 267, CA TB 129, CA TB 133, UBC 8-2, UBC 26-8, ISO 5660, BS 476. Through this review, incorrect equations were found in 12 of the 17 standards with a total of 22 incorrect equations overall. The following paper provides the correct heat release rate equations and a summary of the review. © 1998 John Wiley & Sons, Ltd.

Notes: Silicones comprise a wide variety of materials such as fluids, elastomers, resins, and foams. This paper reports the ignitability of some typical silicones under various external radiant heat fluxes. The ignitability of silicones was studied using a cone calorimeter under radiant heat flux levels of 0.5-60 kW m-2. The time to ignition of the silicones was found to be proportional to a power of the incident heat flux that varies from -1.33 to -2.84. For silicone fluids, viscosity (or molecular size) is the key variable in controlling the ignitability. For silicone elastomers, the fillers play an important role in controlling the ignitability, especially at incident heat fluxes lower than 35 kW m-2. The ignitability of silicone resins depends on the chemical structure of the resins: the pure trifunctional resin has the lowest ignitability. The ignitability of the silicone foams having the same density depends on the foam thickness, especially at incident heat fluxes lower than 30 kW m-2. © 1998 John Wiley & Sons, Ltd.

Notes: Fire retardant fast-growing wood product was developed by coating with fire retardant and densifying the surface of wood. Trimethylol melamineformaldehyde resin mixed with phosphoric acid was coated on the wood surface, preheated and followed by hot pressing. Effects of the amount of coating, preheating temperature, and densifying ratio on the fire retardancy of sugi (Cryptomeria japonica D. Don) wood, and pressing temperature and pressing time on that of albizia (Paraserianthes falcataria Becker) wood were discussed. Bending strength, creep performance under fire and fire retardancy were evaluated. The results showed that the treatments improved the fire retardancy of woods without reduction in the bending strength. © 1998 John Wiley & Sons, Ltd.

Notes: Smoke evolution [in NBS chamber by the ASTM E-622-(1983) method] and ignitability (by the oxygen-index method) was investigated for glass-reinforced polyester (GRP) laminates obtained with unsaturated polyester (UP) resins containing chlorine and bromine in the chain. In these studies, the effect on the properties of such additives as Sb2O3, Al (OH)3, MoO3, Mg(OH)2 and melamine diphosphate in an amount up to 30 mass-% was determined. The most efficient ignition and smoke-evolution retarder of the investigated compounds was Mg(OH)2, whereas an essential reduction in smoke evolution was observed also with MoO3. GRP laminates with these additives meet the fire-safety recommendations concerning smoke evolution from materials used in transportation means and in the building industry. © 1998 John Wiley & Sons, Ltd.

Notes: Transient gasification rates and fluid temperatures were measured for polydimethylsiloxane fluids ranging in viscosity from 0.65 cS to 60 000 cS in a nitrogen atmosphere at external radiant fluxes from 20 kW/m2 to 70 kW/m2. A detailed energy balance for each fluid sample was conducted to determine its global heat of vaporization. Two major energy loss corrections were identified and quantified. The absorption of incident radiation by the volatile products from short chain oligomers was measured and found to substantially reduce the incident flux to the sample surface; the energy loss due to re-radiation was determined to be a substantial factor in reducing the net heat flux to the sample for long chain length fluids. Other energy losses, e.g. heat loss to the substrate, were observed but were less significant. The average gasification rate for each fluid increased linearly with increasing external radiant flux. The global heat of gasification increases with an increase in the chain length (molecular weight) for the siloxane oligomers. These agreed well with calculated values. The global heat of gasification for 50 cS fluid is about 1200 kJ/kg and its value remains nearly constant for all higher molecular weight dimethylsiloxanes. Pyrolysis rates for siloxane fluids are very sensitive to trace catalysts. Measurements of the global heat of gasification for ultra-clean polymers resulted in significantly higher values (3000 kJ/kg). The gasification of siloxanes occurs via two modes or combinations thereof: (1) volatilization of molecular species native to the polymer, and (2) volatilization of thermal degradation products. The former process dominates for low molecular weight siloxanes (η〈10 cS) and the latter process dominates for high molecular weight siloxanes (η〉1000 cS). For the intermediate molecular weight siloxanes, both volatilization and degradation processes occur. © 1998 John Wiley & Sons, Ltd.

Notes: Although the fire resistance of wood depends on its dimensions, it needs a lot of time and energy to fire retard thick wood. On the other hand, it is easier and takes less time and energy to treat thin materials. The fire resistance of wood was improved by compressed treatment, even untreated wood, and moreover compressed wood loaded with chemicals was improved more. Fire resistance of a laminated board was the same as a solid compressed board, and also fire resistance of a laminated board which was arranged with compressed thin wood on two sides of untreated wood showed similar fire endurance. A laminated lathe veneer board showed better fire resistance than solid untreated wood and a laminated board with treated veneers arranged concentratively showed better fire resistance than it did when arranged dispersively.So it was judged that it was important to retard fire ignition and to form a carbonized layer effectively in a fire by physical and chemical treatment, especially on the surface of a material. © 1998 John Wiley & Sons Ltd.

Notes: A theory for approximately steady thermal degradation of solids is developed from a superset of nonlinear integral-differential equations. The theory extends previous work, using a degradation model that is more consistent than previously published models and fully accounts for surface radiation losses. The thermal decomposition of the solid is assumed to follow a single-step first-order Arrhenius reaction. A quasi-steady regime is identified and approximate solutions are compared with experimental results for PMMA and numerical results obtained by integrating the full model. The numerical solutions are found to compare well with experimental results and the approximate solutions compare well with the numerics. Furthermore, it is found that the quasi-steady mass loss rate gives a good estimate of the average mass loss rate even during thermally thin degradation. To simplify interpretation and to aid the analysis, the degradation kinetics are re-cast in terms of a critical temperature and a critical temperature range. Application of the theory to practical situations and other modelling approaches is also discussed. © 1998 John Wiley & Sons, Ltd.

Notes: This work compares the fire degradation of ethylene-vinyl acetate 8% copolymer (EVA8) with two flame-retarded formulations, using the cone calorimeter. The first one, EVA8/ammonium polyphosphate (APP) leads to the protection of the material, in the conditions of a fire, by means of blowing up and weak carbonization. The addition of polyamide-6 (PA-6) in EVA8/APP improves the protection by forming an intumescent carbonaceous shield. The fire hazard of the virgin polymer and of the FR systems are quantified, in terms of rate of heat release, weight loss, effective heat of combustion, volume of smoke production and CO and CO2 production. It assesses the effectiveness of the fire retardant additives APP and APP/PA-6 in EVA8-based materials under simulated real fire test conditions.The respective temperatures of the degradation front are deduced from the weight loss data recorded in the course of the cone calorimeter experiments and the results of the invariant kinetic parameters method applied to the different specimens. The addition of APP/PA-6 in EVA8 leads to a superficial phenomenon; the degradation zone is thus located on the upper volume of the specimen during all the exposure to the heat flux. © 1998 John Wiley & Sons, Ltd.

Notes: A set of small-scale experiments was carried out to study the effects of material structural properties on the re-ignition characteristics of solid fuels. The influence of other key parameters, such as the incident heat flux and pre-burn, was also carefully investigated. The experiments were conducted on specimens of wood and PMMA using a cone calorimeter. As expected, the effect of water on the re-ignition time was found to be significant. It was also found that the re-ignition characteristics of charring materials, such as wood, are quite different from non-charring materials, mainly due to the structural differences. Based on the experimental observations two different mathematical models were developed to analyse the data for both wood and PMMA samples. Calculations of the re-ignition time made using these models agree generally well with the measurements and confirm that the material structure plays a vital role in its re-ignition behaviour. © 1998 John Wiley & Sons, Ltd.

Notes: The behaviour of wood with the heat-compressed treatment method was evaluated. Fire retardance and endurance of wood treated with basic nitrogen compounds and phosphoric acid were much improved by the compressed method using a hot press. In this way, the concentration of chemical contents and the density of wood were raised at the surface of the treated wood and it increased the specific gravity of the treated wood as a whole. It was recognized that the increase of specific gravity improved fire retardance and endurance, and fire endurance of wood was indicated by the equation of addition of chemicals and specific gravity. It is more effective to increase the specific gravity of wood at the surface to improve fire endurance. Wood treated with chemicals showed a high limiting oxygen index in proportion to the increase in the addition of chemicals regardless of the treatment method, and high fire endurance was not always accompanied by a high limiting oxygen index. © 1998 John Wiley & Sons, Ltd.

Notes: This paper describes how a standard polyester cloth was irradiated in the presence of a cross-linking reagent to produce a fabric whose thermoplastic melt-drip behaviour had been modified to that of a charring thermoset material. British Crown Copyright 1998/MoD.

Notes: We report here on the results of our continuing effort to study the flame-retardant mechanism of silica gel and potassium carbonate. These additives reduce the flammability of a wide variety of common polymers such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), and cellulose. In an effort to determine how these additives reduce polymer flammability, we have used electron paramagnetic resonance spectroscopy and solid-state 13C and 29Si nuclear magnetic resonance spectroscopy to characterize the combustion chars or residues. These data indicate that, in the case of poly(vinyl alcohol), the additives do not change the type of char formed, but they do change the rate of char formation relative to the rate of fuel generation. We also found that, using only CP/MAS 13C NMR, there can be significant intensity distortions which complicate interpretation, if the char is hydrogen depleted and contains paramagnetic centres. © 1998 John Wiley & Sons, Ltd.

Notes: The dynamics of microgravity concurrent flame spread over thin cellulosic sheets are theoretically investigated. The mathematical model is based on the laminar, reactive Navier-Stokes equations coupled to solid-phase enthalpy and mass conservation equations. Simulations have been made for forced flow velocities in the range 0.25-15 cm/s, by decreasing the oxygen mass fraction of the concurrent flow below the ambient value and by increasing the solid charring rate (fire-retarded cellulose). For air, non-retarded cellulose and flow velocites larger than 5 cm/s, the dynamics of concurrent flame spread are qualitatively similar to those of normal gravity. As the concurrent flow is decreased below 5 cm/s, after short transients, a transition from fast flame spread to slow solid burning and then to flame quenching is predicted. Flame quenching is also observed, for relatively high flow velocities, in vitiated air or for fire-retarded cellulose. Finally, blow-off at the highest velocity considered (15 cm/s) is predicted only for sufficiently low oxygen concentrations. © 1998 John Wiley & Sons, Ltd.

Notes: WALL2D, a two-dimensional computer model for predicting heat transfer through uninsulated wood-stud walls protected by gypsum board, has been under development at Forintek for several years. This paper describes major revisions which improve the description of heat transfer through the entire assembly, but, most notably, across the cavity. WALL2D's predictions for time-dependent temperature profiles in wood-stud walls are in very good agreement with the results of both small- and full-scale fire resistance tests. Although further refinement of WALL2D will continue, the model, in its current form, is suitable for application to fire safety engineering design. © 1998 John Wiley & Sons, Ltd.

Notes: The fire retardance of wood treated with basic nitrogen compounds and phosphoric acid is improved. It was investigated which chemicals were suitable for the fire retardant treatment of wood and how chemicals influenced fire retardance and endurance from the perspective of chemical reaction and also it was investigated how chemicals and treatment methods influenced fire retardance and endurance from a thermal perspective. Although the fire endurance was improved by a heat-pressed treatment method, the chemical reaction was carried out by heat irrespective of the pressing or drying method. The wood structure would become complex as the cross-linked structure occurred by chemicals and pressure. Its structure would be maintained at combustion. Fire endurance of wood is shown to be related to a cross-linked structure created by a chemical and/or physical reaction rather than thermal factors related to the carbonized product. © 1998 John Wiley & Sons, Ltd.

Notes: The measurements of effective heat of combustion obtained from the Cone Calorimeter test for several wood composites (different types of plywood and particle board) at horizontal configuration are presented. Comparison of the average effective heat of combustion at different irradiation shows no correlation to gross heat of combustion measured in the oxygen bomb calorimeter. It was also found, that for the materials studied, there is no statistically significant correlation of heat of combustion to lignin content, but on the other hand, there is an evidence of correlation to the burning weight loss of the samples, but further investigation is necessary. Additionally, the effective heat of combustion is shown as a function of time for different external radiant heat-flux level for the chosen materials. Similar profiles have been found for remaining samples. Two different types of such curves can be distinguished. © 1998 John Wiley & Sons, Ltd.

Notes: An analysis has been made to compare the repeatability and reproducibility of three tests for cigarette ignition of upholstered furniture composites: ASTM E1352, ASTM E1353 and NIST 851 mock-up. The first two of these tests are traditional methods designed to assess the potential of upholstered furniture components to being ignited by cigarettes while the last one, NIST 851 mock-up, is a new method designed to assess the propensity of cigarettes to ignite upholstered furniture composites. The traditional methods, ASTM E1352 and ASTM E1353 use a single cigarette for each determination and can be run in two ways: to obtain a numerical output of char length on the substrate (following the standard) or to obtain a pass/fail result for the substrate (practical use); the precision was analysed in both fashions. The new method, NIST 851 mock-up, uses 144 cigarettes for each determination (48 each on three substrate composites), and assesses the fraction of substrates that have been ignited (char length exceeding 10 mm), i.e. by a combination of pass/fail data. The analysis for actual char length was made according to ASTM E691 guidelines, while the analysis of the pass/fail was made according to a modification applicable to binary data. The precision of the test methods was as follows (in descending order):NIST 851〉ASTM E1353 P/F〉ASTM E1352 P/F〉ASTM E1353〉ASTM E1352© 1998 John Wiley & Sons, Ltd.

Notes: The charring of wood studs has been studied in the cone calorimeter at constant heat flux 50 kW/m2 and compared to data from full-scale furnace wall tests. The wood studs were unprotected or protected by gypsum plasterboards on the exposed side. Similar charring depths were found and the data analysed mainly in terms of fire exposure. A simple small-scale technique was developed to measure the heat transfer through protective boards and the charring depth of wood studs. These properties are essential for the load bearing capacity of wood frame structures. © 1998 John Wiley & Sons, Ltd.

Notes: Silica gel combined with potassium carbonate is an effective fire retardant for a wide variety of common polymers (at mass fraction of only 10% total additive) such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), cellulose, and to a lesser extent polystyrene and styrene-acrylonitrile. The peak heat release rate is reduced by up to 68% without significantly increasing the smoke or carbon monoxide levels during the combustion. © 1997 by John Wiley & Sons, Ltd.

Notes: Flame-retarded epoxy composites and phenolic composites containing fiberglass, aramid (Kevlar® 49), and graphite fiber-reinforcements were tested using the NASA upward flame propagation test, the controlled-atmosphere cone calorimeter test, and the liquid oxygen (LOX) mechanical impact test. The upward flame propagation test showed that phenolic/graphite had the highest flame resistance and epoxy/graphite had the lowest flame resistance. The controlled-atmosphere cone calorimeter was used to investigate the effect of oxygen concentration and fiber reinforcement on the burning behavior of composites. The LOX mechanical impact test showed that epoxy/fiberglass had the lowest ignition resistance and phenolic/aramid had the highest ignition resistance in LOX. The composites containing epoxy resin and/or aramid fiber reinforcement reacted very violently in LOX upon mechanical impact. © 1997 by John Wiley & Sons, Ltd.

Notes: Higher surface temperatures were required for ignition in the Intermediate Scale Calorimeter than in the Cone Calorimeter. Air velocity measurements were made in front of calcium silicate and particleboard specimens in the Intermediate Scale Calorimeter and temperature measurements were carried out on their exposed surfaces. The higher ignition temperature in the Intermediate Scale Calorimeter was the result of the high induced upward air velocity due to the large specimen size (1.0 m by 1.0 m). This caused the flame to blow off. A higher surface temperature was needed to produce a downward flame spread rate sufficient to overcome the upward air velocity. To counteract this effect, a horizontal projection plate extending 100 mm out from the bottom edge of the specimen was installed. This created an eddy, causing a downward air velocity near the surface at the bottom of the specimen. The igniter was a hot wire across the width of the specimen at a height of 100 mm. The flame quickly spread down from the igniter to the bottom edge and attached there. Under these conditions the temperature required for ignition of particleboard in the Intermediate Scale Calorimeter was less than it was in the Cone Calorimeter. © 1997 John Wiley & Sons, Ltd.

Notes: The use of the cone calorimeter to predict the performance of upholstered furniture in open-flame ignition tests such as Cal 133 is reviewed. Fabric-fire blocker-foam composite tests are correlated to full-scale chair burn results for a wide range of upholstery fabrics. The ACT/DFA study as well as CBUF models are discussed. © 1997 John Wiley & Sons, Ltd.

Notes: Zinc hydroxystannate (ZHS), at levels of 2-5 phr, and the hydrated fillers, magnesium hydroxide (MH) and alumina trihydrate (ATH), at levels of 20-50 phr, are effective flame retardants and smoke suppressants for flexible PVC. Novel ZHS-coated hydrated fillers are found to exhibit markedly improved fire-retardant properties, particularly with regard to increasing LOI values, reducing heat release rates and suppressing smoke generation, when compared with conventional uncoated forms. The ZHS coating appears to change the filler particle morphology and there is evidence that the coating is largely retained on the filler surface after melt processing into the PVC. The improved dispersion of the active tin compound in the polymer matrix leads to enhanced fire retardancy and this, in turn, allows significant reductions to be made in overall filler loading, with no loss in flame-retardant or smoke-suppressant performance. © 1997 John Wiley & Sons, Ltd.

Notes: Fire testing of furniture has been a focus of much attention in the 1990s, particularly in terms of the heat it releases in real-scale fires. One aspect that has received insufficient attention is the case of stacked chairs, often found in places of assembly. Early data have shown that the fire hazard resulting from burning a stack of chairs is often much higher than would have been expected simply from the combined hazard of the individual chairs. A test has been designed, ASTM E1822, in which the flames from a propane gas burner (at 12 l min-1) are applied to a vertical stack of 5 chairs for 80 s, and the important fire properties measured. This test was developed with the collaboration of two laboratories; the variables studied were: number of chairs in the stack and duration of exposure. In order to evaluate the repeatability of the method, one laboratory tested six different types of chairs, in triplicate, in a furniture calorimeter. The chairs were donated by different manufacturers for this purpose. A statistical analysis was conducted on seven properties (peak rate of heat release, total heat released, peak rate of smoke released, total smoke released, mass loss, time to peak rate of heat released and initial mass). The overall relative standard deviations for the properties studied ranged between 1% and 20%, which is adequate for a fire test. Thus, the repeatability study was successful. It is of interest that very poor correlation was found between mass loss and heat release, so that the highest fractional mass loss corresponded to the chairs with the lowest heat release rate. Additionally, there is also relatively poor correlation between heat and smoke release rates. The peak heat release rate of the stacks of chairs ranged from almost 300 kW to 〉1 MW, and the chairs lost between 4% and 40% of their initial mass; only one set of chairs did not release enough heat in any test for a room containing it to go to flashover. Thus, the results suggest that the potential exists for severe fires to develop when such chairs burn. © 1997 John Wiley & Sons, Ltd.

Notes: The theoretical bases for calculation of heat release rate during burning of conveyor belts in the fire-testing gallery has been presented. Taking as an example the results of measurements of oxygen, carbon dioxide and monoxide content in the products of combustion of conveyor belts during the testing of their flammability in the full-scale fire gallery, the possibility has been demonstrated for using the calculations of heat release rate in an assessment of conveyor belt flammability. The total quantity of heat released during the belt fire in the experimental gallery can provide the basis to develop a new method of testing as well as the criteria for assessment of fire resistance of the conveyor belts using oxygen consumption calorimetry. © 1997 John Wiley & Sons, Ltd.

Notes: The effect of melting behaviour on upward flame spread of thermoplastic materials when subjected to small ignition sources and considered to suffer no external flux was studied using large-scale tests. For moderate fire conditions the cone calorimeter was utilized, with the sample set in a vertical orientation to study the melting behaviour of the specimens. Under these conditions the results indicate that the melting behaviour significantly affects upward flame spread behaviour. A pool of the melt which formed at the base of the vertically oriented sample tested creates a pool fire which then controls the fire growth and flame spread. In contrast, it was found that some thermoplastic materials which have higher glass transition temperatures or undergo a special pyrolysis process such as depolymerization, intumescing or charring do not experience significant melting behaviour when exposed to the same thermal insult. As a result, they behave very differently in terms of upward flame spread. The study also indicates that the melting behaviour of thermoplastic materials is an important characteristic in fires which should be taken into account in the development of modelling, in particular for upward flame spread models. © 1997 by John Wiley & Sons, Ltd.

Notes: An investigation of cone calorimeter test procedures was performed using two types of mattress composites with various specimen preparations and equipment configurations. The objective was to discover suitable procedures for testing mattress composites. Concurrent with this work a much larger and more sophisticated project known as CBUF was underway in Europe. One of CBUF's secondary objectives was to provide an appropriate test protocol for testing upholstered furniture composites, including mattresses. Most of the CBUF protocol was available at the time of this study and a modified form of the specimen preparation technique was used in this investigation. Preliminary tests found unacceptable test performance with some configurations. Subsequent testing examined variations of the established test protocols and other test procedures. The data sample was small, but observations of the data indicate trends that might be attributable to the use of the different procedures. Significantly it was determined that the edge frame used to hold specimens in place during the test does affect the test results. A modified CBUF protocol proved to be the best procedure, but it requires extensive experience with the CBUF specimen preparation method in order to be able to produce satisfactory specimens. © 1997 by John Wiley & Sons, Ltd.

Notes: Fire hazard assessments must be primarily driven by life safety variables. Concern is often highly focused on toxicity issues, since fire deaths, in the majority of cases, are found (in whole or in part) to be due to toxic gas inhalation. Procedures have recently been published by ISO, wherein the toxicity assessment of fire products is focused primarily on bench-scale testing for toxic potency (the ‘per-gram toxicity’). Yet hazards of products with regards to fire toxicity may be determined much more by their differences in burning rates than by any differences in toxic potency. Burning rates are not assessed in the pertinent standards (ISO 13344 and ISO TR 9122). For most product categories, techniques for predicting full-scale burning rates from bench-scale data are not yet in hand. Thus, today the best means of comparing actual, full-scale toxic fire hazards is the full-scale fire test, equipped with additional gas measuring instrumentation. Such an approach is not among the recommended methods of the international standards, yet it is the only one with innate validity. In the present work, a series of sandwich panel products were tested in a full-scale room configuration. Bench-scale comparison was made to the ISO 5660 Cone Calorimeter and the DIN 53436 tube furnace. The toxic gases were quantified in all cases by chemical analysis. The product which showed the best performance in the full-scale tests (rock wool insulated sandwich panel) did not achieve a good fire toxicity performance due to minimization of toxic potency. Instead, the successful performance was attributed wholly to reduction of burning rate. Bench-scale measurements of toxic potency were shown to lack relevance to reality in such cases where even the full-scale toxic potency is not a determining factor. © 1997 John Wiley & Sons, Ltd.

Notes: Melamine and its salts added to polyamide 6 (PA-6, nylon 6) improve its fire retardancy as measured by oxygen index and UL94 tests. The mechanism of the fire-retardant action of the additives was studied using thermogravimetry, kinetics of thermal decomposition and characterization of solid residues and evolved high-boiling products. It was found that melamine, melamine oxalate, melamine phthalate and melamine cyanurate facilitate thermal decomposition of PA-6 with increasing evolution of oligomeric chain fragments instead of caprolactam, which is the principal product evolved from the nonfire-retarded PA-6. These additives promote non-combustible flow dripping and help extinguishment of the flame. The observed increase in solid residue from the thermal decomposition of the formulations or the endothermic cooling due to melamine evaporation might give an additional but less important contribution to fire retardancy. In the case of dimelamine phosphate and melamine pyrophosphate, PA-6 reacts with liberated phosphoric acids producing phosphoric esters which give char upon further thermal decomposition. The fire-retardant effect of these two salts is mostly attributed to polymer mass retention and intumescent layer protection mechanisms. © 1997 John Wiley & Sons, Ltd.

Notes: The National Building Code of Canada provides architects, engineers and builders with a simple, practical calculation method for assigning fire-resistance ratings to wood-frame and steel-frame wall, floor and roof-ceiling assemblies. It was originally devised in the early 1960s and is commonly known as the Component Additive Method (CAM). A collaborative industry-government research program was carried out recently at the National Research Council Canada to develop new fire-resistance ratings for gypsum-board protected walls. Forintek Canada Corp. and the Canadian Wood Council participated in that program on behalf of Canada's wood industry. As part of the research program, a number of full-size fire-endurance tests were carried out on wood-frame and steel-frame walls. The results of those fire tests have allowed us to revisit those sections of the Component Additive Method which are applicable to light-frame walls lined with gypsum board. © 1997 John Wiley & Sons, Ltd.

Notes: Tests were conducted on two fabrics intended for use in protective clothing: an aramid (used extensively in firefighter gear) and a modified viscose cellulosic fabric. Both were exposed to very high heat (temperatures above 400°C) and their performance as thermal insulators was assessed by the temperature transmitted through the fabric, both in their dry state and after being exposed to a water spray. Both fabrics performed satisfactorily, but the modified viscose fabric improved its thermal insulation properties when damp, while the aramid fabric remained unaffected (or perhaps negatively affected) by the water spray. Overall, the modified viscose fabric seemed a better thermal insulator than the aramid. © 1997 John Wiley & Sons, Ltd.

Notes: The present study investigates the validity of a test method for smoldering cigarette ignition propensity of upholstery fabrics based on using ‘cotton duck’ fabrics, and proposed by NIST. A comparison was made between the ignition propensity of cigarettes as assessed by (1) a set of 500 upholstery fabrics (chosen at random among typical upholstery fabrics) and (2) a test method proposed by NIST (NIST 851), and based on ‘cotton duck’ fabrics. The set of 500 fabrics can be assumed to be a representative cross-section of the upholstery fabrics available in the early 1990s, while the ‘cotton duck’ fabrics are not typical upholstery fabrics, and it was unclear whether they would behave similarity or differently from upholstery fabrics. Of the 500 fabrics tested, only 145 fabrics were ignitable by cigarettes, all of them predominantly (or completely) cellulosic. This study found that the overall results obtained from the 500-upholstery fabric study correlate well with those of the ‘cotton duck’ study. Therefore, the ‘cotton ducks’ can be considered, as a whole, to behave similarly to the majority (estimated at perhaps 80%) of the upholstery fabrics available at the time of the study, and the test is valid. In this study it was also found that the ‘cotton duck’ test method correlated well with an earlier cigarette ignition test method, shown to be a good predictor of full-scale upholstered furniture cigarette ignition results, when using a set of five cigarettes. Finally, a fabric density threshold was found, above which the percentage of ignitions of cellulosic fabrics, the percentage of cellulosic fabrics that are ignitable and the flame spread rate of fabrics in a flaming ignition test are all unaffected. © 1997 John Wiley & Sons, Ltd.

Notes: The modelling of the spread of fire and its extinguishment still represents a significant challenge. As part of a combined experimental and computational study of fires we have developed a general Computational Fluid Dynamics (CFD) model of fire spread and extinguishment. The primary objective was to produce a flexible computational tool which can be used by engineers and scientists for design or research purposes. The present paper deals with the description and validation of a solid pyrolysis model which has been applied, as a sub-model, in this general computer fire code. The pyrolysis model has been formulated using the heat-balance integral method. The model can be applied to slabs of char forming solids, such as wood, as well as non-charring thermoplastic materials, such as PMMA. Results are compared with analytical solutions, numerical simulations and experimental data. In all cases the integral model performs well. © 1997 by John Wiley & Sons, Ltd.

Notes: No Abstract

Notes: The fire response of a potassium aluminosilicate (Geopolymer) matrix carbon fiber composite was measured and the results compared to organic matrix composites being used for transportation, military, and infrastructure applications. At irradiance levels of 50 kWm-2 typical of the heat flux in a well-developed fire, glass- or carbon-reinforced polyester, vinylester, epoxy, bismaleimde, cyanate ester, polyimide, phenolic, and engineering thermoplastic laminates ignited readily and released appreciable heat and smoke, while carbon-fiber reinforced Geopolymer composites did not ignite, burn, or release any smoke even after extended heat flux exposure. The Geopolymer matrix carbon fiber composite retains 67% of its original flexural strength after a simulated large fire exposure. © 1997 US Government

Notes: A mathematical and computational model simulating the coupled heat and mass transfer and related processes in porous media exposed to elevated temperatures has been developed. Taking into account the conservation of mass, momentum and energy, and including the effects of evaporation and dehydration processes on the transport phenomena, a set of three coupled nonlinear differential equations is obtained. Siliceous aggregate concrete slabs subjected to the ASTM E119 standard fire exposure are modeled and validated against test data. Output depicts the coupled relationships between the material's temperature, moisture content, and pore pressure histories and distributions. © 1997 John Wiley & Sons, Ltd.

Notes: Dust explosion hazard exists in plants and facilities handling combustible dusts. The minimum ignition temperature of dust clouds is an important parameter requiring special attention to designing the explosion preventive measures. This paper presents a model developed for determining the minimum ignition temperature for an organic dust cloud, polyethylene, simulating the conditions in the Godbert-Greenwald furnace. The model correlates the particle size, as well as the dust concentration with the minimum ignition temperature. It is based on the two-stage oxidation mechanism involving devolatilization/decomposition of the solid particle and homogeneous oxidation of volatile combustible products. In the case of polyethylene, the main combustible gas responsible for ignition and flame propagation has been confirmed to be butylene. The results of the computations were compared with the experimental values and those predicted by Mitsui and Tanaka. The predicted values by the model developed are in close agreement with the experimental data which confirm the proposed ignition mechanism. The model can be used for the prediction of minimum ignition temperature of organic dusts having an autoignition mechanism similar to polyethylene dust. © 1997 John Wiley & Sons, Ltd.

Notes: Application of zone model for studying atrium smoke-filling process was evaluated. The fire zone model FIRST was selected as the fire simulator. Studies were focused on the plume model, the geometry of the atria and the heat release rate of fires. Six plume models reported in the literature were reviewed. Their expressions on the velocity, temperature and mass flow were compared. Three halls of same volume but different shapes were taken as the samples. A small volume of 2000 m3 was used because a zone model should work in halls of this size. Numerical simulations of the fire environment in the atrium buildings with those six plume models were carried out using the zone model FIRST. A total number of 108 simulations were performed with nine sets of fires. © 1997 John Wiley & Sons, Ltd.

Notes: In accordance with the Montreal Protocol, production of all Halon fire suppressants ceased on 1 January 1994. FAR/JAR regulations require Halon 1211 or equivalent hand extinguishers to be installed on transport category aircraft. Although there is a Halon ’bank‘, a replacement agent will have to be found. The Aviation Authorities require that ’no loss of safety‘ should occur if a replacement agent is used. One proven benefit provided by Halon 1211 is the ability to extinguish hidden fires by a total flooding effect. Therefore, it is necessary to quantify the hidden fire-extinguishing ability exhibited by Halon 1211. Following an invitation for competitive tenders to develop a standard hidden fire test protocol, the Civil Aviation Authority (CAA) awarded a contract to Kidde International Research. After some range-finding work, a suitable test fixture was devised. This test fixture comprised arrays of four fires in two of five locations to establish in which regions an extinguishing concentration had been attained. A matrix of 10 tests ensured that each fire location was adequately represented. Tests have been carried out with hand extinguishers from four manufacturers. Results varied from 45% extinguishment to 60%, depending on the quantity of Halon contained in the extinguisher, and the discharge rate (a faster discharge rate creates more turbulence, aiding mixing and dispersion). In addition, tests were carried out using under- and over-filled extinguishers to examine the sensitivity of the test method. With the exception of one hand extinguisher, all results could be correlated to the mass and mass flow rate of agent used. This device extinguished a significantly higher percentage of fires than would be expected, based on its mass/mass flow rate characteristics. Limited testing was carried out with six Halon replacements: FM-200, FE-25, CEA-4.10, CEA-6.14, FE-36 and Triodide, using apparatus designed to give a constant discharge time (10±1 s). The results obtained appeared to be similar to Halon 1211 (50±5% extinguishment), provided the quantity of agent is scaled according to its n-heptane cupburner concentration. The two exceptions are agents with markedly different volatilities to Halon 1211 (b.p.-4°C): FE-25, b.p. -49° C, (65% extinguishment) and CEA-6.14, b.p.+58°C (35% extinguishment). Implications for the size and weight of a hand extinguisher, based on the results of these tests, are for the physically acting agents, a weight penalty of 1.4 to 2.6, and a volume penalty of 1.9 to 2.9. If Triodide is considered, there is a weight penalty of 1.06, and no volume penalty. However, it should be borne in mind that any hand extinguisher, before it is evaluated against hidden files, will have had to have passed the traditional ratings (currently UL 5B:C, BS 3A:34B) to be approved for aviation use. © 1997 John Wiley & Sons Ltd.

Notes: Results are presented of a project to evaluate the combustibility and surface flammability of building interior finish materials commonly used in Taiwan. The project was conducted at the Fire Laboratory of the Architecture and Building Research Institute in Taipei. Eighteen different wall-covering materials were tested according to Chinese National Standard (CNS) 6532, which is equivalent to Japanese Industry Standard (JIS) 1321, and according to ASTM E 1354-92 (Cone calorimeter). A comparison of test results is presented, and a qualitative relationship is developed between the performance in the two methods. The classification system for degrees of combustibility developed in Canada by Richardson and Brooks was hereby used to group materials based in performance in the ASTM test method. © 1997 John Wiley & Sons, Ltd.

Notes: A series of 37 cigarettes were analysed to develop a model, based on cigarette physical properties, to predict the ignition propensity of the cigarettes towards cellulosic fabrics. The properties used were: cigarette circumference (in mm), tobacco packing density (in g cm-2), paper permeability (in CORESTA units) and the presence or absence of citrate additives in the paper (used independent of concentration, although typical additions range from 0.5 to 0.8 wt%). Two empirical models were developed, one for low and medium paper permeabilities, and one for very high paper permeabilities (above 50 CORESTA units). The latter exceed the paper permeability of most commercial cigarettes, and have medium to high ignition propensities. Thus, they are probably only of interest from the point of view of a mathematical curiosity. The former model, however, addresses cigarettes in the range where commercial cigarettes are potentially viable. The resulting ignition propensities exhibited cover the entire feasible range, from 0% to 100%. Both models predicted the ignition propensities of the tested cigarettes quite well, within an error range which did not exceed 30% for any cigarette. Physical rationales are presented for the effects of the variables used. However, the rationale for the discontinuity in ignition propensity found for the cigarettes with extremely high paper permeability is less clear. One explanation is that there is probably excess oxygen present so that a fuel/oxygen mixture is obtained with a ratio which is less than the lower flammability limits and is too lean to support combustion. However, further analysis of this issue is warranted. The empirical model for low and medium paper permeability cigarettes is potentially useful for developing cigarettes with lower ignition propensity, since it is a practical way of combining the individual properties that most heavily affect cigarette ignition propensity. © 1997 by John Wiley & Sons, Ltd.

Notes: In the EC-sponsored CBUF (Combustion Behaviour of Upholstered Furniture) study three different models were developed for using Cone Calorimeter results to predict full-scale furniture burning. Model I is a correlation-based approach and has the most comprehensive coverage of styles and furniture types. Model II is based on area-convolution. It has been developed, so far, for several of the common upholstered furniture styles. Model III is based on an extension of a thermal flame spread model and is here developed only for mattresses. Models II and III offer the prediction of the burning item's time history, while Model I computes the peak HRR, the time to peak, and several other primary characteristics. The predictability of all three models is good. At present, the models presented do not consider furniture with plastic frames, and only a limited predictability is offered for office-type furnitures items which contain a hard-plastic shell. The models offer a very significant improvement over the existing state of the art. © 1997 John Wiley & Sons, Ltd.

Notes: The study presented here was designed to provide information on the nature of fibres subjected to the action of raised temperature and on the possibility of determination of the incinerated material. X-ray powder diffraction was used as the most reliable method of identifying the composition of crystalline substances. The subject of study was natural and synthetic fibres, the most frequently used in Poland in recent years; for the simulation of phenomena caused by the action of raised temperature the fibres were incinerated in a muffle furnace. The samples of analyzed incinerated fibres were of different chemical species, and those differences were more evident for natural fibres, where from five to seven chemical species or minerals were detected. In specific forensic cases related to incinerated fibres FTIR, SEM/EDX, polarized light microscope and X-ray powder diffraction techniques should be used simultaneously to give full results. © 1997 John Wiley & Sons, Ltd.

Notes: The contrast attenuation coefficient characterizes smoke production properties of a material. These properties are closely connected with a contrast of luminance of a scene observed in a smoky medium, the range of visibility, and mass concentration in an environment volume. The range of visibility determines a person's chances of moving about in a fire zone. This paper presents considerations on conditions of visibility in smoky compartments, a method of the contrast attenuation measurement and test results for some materials. © 1997 John Wiley & Sons, Ltd.

Notes: This paper extends earlier work which explored the possibility of undertaking a life cycle analysis of flame-retardant cotton and polyester textiles and consequently enabled semi-quantitative estimations of their relative environmental impacts to be made. This model is extended to undertake full environmental audits of a range of flame-retardant textiles and requires full consideration of each stage from fibre/raw material production to eventual disposal. The need for comprehensive data at all stages, however, demonstrates that comparisons between competing products are neither simple nor, at present, possible. Thus an environmental rank value is given to each stage in the manufacturing process and product life of each flame retardant fibre and derived textile. Summation of rank values enables an overall environmental index to be defined which may be used to compare the environmental impact of each generic type of currently available flame retardant, single fibre-containing textile. The results show that each of the eleven generic fibres analysed yield environmental index values within a range 32-51% where 100% denotes the worst environmental position possible. This relatively low range of values suggests that current production and processes which attempt to maximize economic viability also tend to reduce environmental impact. © 1997 John Wiley & Sons Ltd.

Notes: A correlation has been developed between closed-cup flash points and normal boiling points for silicone compounds. In addition, a more general correlation has been developed between these two properties for the general organic compounds, including silicone compounds. The closed-cup flash points can be predicted using empirical equations. The standard errors of estimate are 11.06 and 11.66°C for silicone compounds and general organic compounds (including silicone compounds), respectively. © 1997 John Wiley & Sons, Ltd.

Notes: The incorporation of two brominated compounds/antimony trioxide blends into a PP-PE copolymer were studied. Both brominated trimethylphenyl indane (FR 1808) and poly(pentabromobenzyl acrylate) (FR 1025) confer good flame retardancy at 40% loading. A comparison was made with the incorporation of magnesium hydroxide at higher loadings (up to 64%) in the same copolymer. The mineral filler improves both fire resistance and stiffness of the copolymer, nevertheless the high loading causes a dramatic decrease in impact resistance. Moreover, the necessary surface treatment of the filler significantly lowers the maximal tensile strength. In order to maximize both fire resistance and mechanical properties, we combined each brominated flame-retardant system (20% in weight) with magnesium hydroxide or talc (20% in weight). Talc is used as reference. These composites show interesting fire-retardant properties in comparison with the copolymers containing only 40% of the brominated flame-retardant systems. In addition, the mechanical properties are on the whole improved. © 1997 John Wiley & Sons, Ltd.

Notes: A controlled-atmosphere cone calorimeter was used to investigate the burning of a silicone fluid and two silicone elastomers. The silicone materials were tested at 50 kW/m2 incident heat flux in environments containing 15-30% oxygen. The test results were compared with a high molecular weight hydrocarbon fluid and an ethylene propylene rubber in terms of time to ignition, peak heat release rate and total heat released, carbon monoxide yield and carbon monoxide production rate, and smoke production and smoke production rate. The data from this study show that when materials burn in oxygen-enriched, normal, and vitiated atmospheres, silicone-based materials have a comparatively low peak heat release rate, total heat released, average CO production rate, and average smoke production rate as compared with organic-based materials. The smoke production and smoke production rate of silicone elastomers can be significantly reduced by adding appropriate smoke suppressants and additives. © 1997 John Wiley & Sons, Ltd.

Notes: The fire standard for aircraft interior panels has been compared to the corresponding marine standard with respect to smoke emission and heat release rate. This has been performed by testing an aircraft panel approved by the Federal Aviation Administration according to one of the International Maritime Organization standards for High-Speed Craft, according to the full-scale room fire test, ISO 9705. The test showed that even if the panel met the strict requirements of the Federal Aviation Administration it did not fulfil the apparently even stricter requirements of the International Maritime Organization. The panel failed on several accounts, including smoke production, heat release and structural integrity. © 1997 John Wiley & Sons, Ltd.

Notes: No Abstract

Notes: No Abstract

Notes: Small amounts of polytetrafluoroethylene (PTFE) are shown to modify the combustion behaviour of Acrylonitrile-Butadiene-Styrene terpolymers (ABS) fire retarded with a bromine/antimony synergistic system. PTFE makes ignition more difficult and decreases the rate of flame propagation in the early stage of combustion. The action of PTFE is shown to occur in the condensed phase by accumulation of fluorine in the residue of combustion and by reaction of PTFE with Sb2O3 to give volatile moieties. A catalytic action of fluorinated species formed in the presence of PTFE is suggested to take place on reactions of the bromine/antimony system increasing its effectiveness. © 1997 John Wiley & Sons Ltd.

Notes: The pulmonary effects of acute (30 min) and chronic (7, 14, or 21 days; 30 min day-1) exposure to smoke from white polycarbonate structural foam, or a Ni-urethane coated version of this plastic, were analyzed by exposing groups of 4 mice in a dome chamber apparatus. The lungs of test fatalities were consistently inflamed and hemorrhagic, and characterized histologically by areas of atelectasis and hyperinflation. The Ni-coated material was more toxic than the uncoated material, and produced greater intrapulmonic hemorrhage. A histological method was developed for assessing the proliferation of type II pneumocytes as an index of damage to the alveolar epithelium. Examination of lungs from animals sacrificed at 2, 4, 8, 14, 21, or 28 days following acute exposure revealed that only the 8-day animals in the Ni-exposure group had significantly more type II pneumocytes than controls (P〈0.01). Similar examination of lungs from chronically exposed animals sacrificed at 1 day following the last exposure revealed no significant differences between experimental animals and controls. The Ni content of coated samples and the ash following thermal decomposition was determined by atomic absorption spectrophotometry. The original samples were 2.5% Ni. Nickel lost during pyrolysis could account for the increased toxicity of the coated material through production of toxic Ni compounds. These results indicate that pulmonary irritants produced by these plastics affect the vascular elements of the lungs more than the alveolar epithelium, and that the pulmonary damage produced in mice under these conditions does not persist in survivors beyond 1 day post-exposure. The acute combustion toxicity of Ni-coated plastics may reflect the formation of toxic Ni compounds. © 1997 John Wiley & Sons, Ltd.

Notes: This paper reports an analysis of data from a study conducted by the cigarette industry to determine whether the fabrics used in a measurement method for cigarette ignition propensity reasonably represent the ignition behaviour of actual upholstery fabrics. A ‘consistency score’ is defined to evaluate objectively the relative agreement of ignition test results on various test fabrics compared with the cotton duck fabrics used in the measurement method. Particular attention is paid to those cases where the cigarettes show statistically significant differences by the chi-squared test. This analysis finds that the aggregated set of 79 industry fabrics ranks the four test cigarettes in the same order as do the three cotton duck fabrics in the measurement method. Thus, to the extent that the industry set is representative of those fabrics used in upholstery, it would be proper to use the three test fabrics as surrogates for the purpose of determining the relative ignition propensity of a cigarette. The analysis does identify six to ten fabrics that would be expected to show persistent reversals compared to the aggregate ordering; however, three-fourths of the fabrics rank the cigarettes consistently with the cotton duck fabrics. © 1997 John Wiley & Sons, Ltd.

Notes: No Abstract

Notes: An estimate of the annual generation of polychlorodibenzodioxins and furans (PCDD/F) in the United States as a result of PVC burning in house fires is made using building data and fire loss statistics and soot and ash samples obtained from laboratory experiments and building fires involving PVC. Using conservative estimates for construction, fire involvement and formation, dioxin generation from PVC in house fires is estimated to be in the range of 0.074 to 8.6g TEQ yr-1 as soot, 0.4 to 14g TEQ yr-1 as ash, and thus 0.47 to 23g TEQ yr-1 total. The maximum likelihood estimate is approximately 0.3g TEQ yr-1 as soot and 1g TEQyr-1 as ash. Any of these estimates constitutes a minuscule fraction of the 9300g annual air emissions or the 20000-50000g (TEQ) annual deposition from the air estimated by EPA.

Notes: This paper gives an overview of the Combustion Behaviour of Upholstered Furniture (CBUF) project. The work described is the collective effort of 11 CBUF partners, laboratories, universities, industries, in eight countries. It became possible to do this research thanks to the European Commission's interest in the burning behaviour of upholstered furniture and their willingness to sponsor this effort. The opportunity to work with many of the most prominent fire researchers and furniture experts has been extremely rewarding. All the expertise of these scientists has resulted in many research results that are presented here. The article only gives the main findings and conclusions of the project, namely the presentation of the fire safety design procedure of the CBUF project. Other articles will deal with specific modelling topics and an extensive description of the project can be found in the final CBUF report EUR 16477 EN.

Notes: Partial substitution of ammonium polyphosphate (APP) by manganese dioxide (MnO2) in polyamide 6 (PA-6) fire retarded with 20% of APP strongly increases the fire retardant effect. ‘Linear pyrolysis’ experiments, which are modified cone calorimeter tests, show an increase in the amount and an improvement of the shielding properties of the intumescent char formed on the surface of burning polymer. The enhancement of the yield of aliphatic-aromatic char stable to oxidation was observed in thermogravimetry under air. The fire retardant action of an APP/MnO2 mixture in PA-6 is twofold. On the one hand, this additive promotes involvement of the polymer in the charring and, on the other, the formed manganese phosphate glasses improve the thermo-insulating properties of the intumescent char on the surface of burning PA-6.

Notes: Based on the CFAST model, this paper describes a two-layer zone model developed to predict the environment in a multi-compartment structure subjected to a fire. The predictive equations, fire sub-processes and algorithm are concisely described. In order to validate the model and program a series of experimental data obtained from Cooper's work at NIST were selected for comparison with numerical results, and the comparison is fundamentally favourable. This paper presents an example of this comparison, including the results simulated by the CFAST zone model (Version 1.6). It is shown from the comparison that this model predicts better results than that of the CFAST for these cases, and convection heat transfer may be underestimated in the two models. It is also shown that C.W. Gear's stiffly stable method is feasible in numerically integrating the governing equation set. Additionally, this model is applied to conduct a parameter sensitivity analysis for a two-room fire, and some informative results are given and discussed.

Notes: No Abstract

Notes: In this paper an overview is given of several methods for quantitative analysis of FTIR spectra. Each method has its particular advantages and disadvantages. Therefore, depending on the gas component to be analysed in smoke gas spectra, an optimal choice of method has to be made. This choice depends on several different aspects:• Is the spectral band of interest free of interfering components?• Does the absorption-concentration relation show strong deviations from Beer's law?• Are significant baseline corrections necessary?• Does the applied model need to warn for the presence of unexpected components?• Is it sufficient to use only a few wavenumbers or is a full-spectrum method necessary?It will not be easy to make the appropriate choice. However, in some cases, statistics can help, in others, a good rule of thumb is to keep the choice as simple as possible. © 1996 by John Wiley & Sons, Ltd.

Notes: Quasi-steady-state heat fluxes absorbed on the calorimeter surface in ten vertical 0.1 m high×1 m wide zones were measured by means of water calorimetry. The calorimeter surface also included an array of intrinsic thermocouples to measure surface temperatures, and an array of Schmidt - Boelter radiometers for a second, more responsive, method of heat flux measurement. The pool fire environment characterization was done with measurements from velocity probes, directional flame thermometers (DFTs), and thermocouples. The initial measurements with a 1 m×1 m water cooled vertical flat plate calorimeter located 0.8 m above and inside a 6 m×6 m JP-4 pool fire are described. Water calorimetry measured absorbed surface heat fluxes of about 65-70 kW m-2 with a gradual decrease with increasing height above the pool. Intrinsic thermocouple measurements recorded typical calorimeter surface temperatures of about 500°C, with spatial variations of ±150°C. Gas velocities across the calorimeter face averaged 3.4 m s-1 with a predominant upward component, but with an off-vertical skew. Analysis of data collected in the fire environment in the vicinity of the calorimeter was performed to characterize the fire environment and to determine the input parameters required to calibrate analytical models. For this test, the emissive power distribution near the plate was essentially linear. Flux measurement in the fire environment ranged from 75 kW m-2 to 175 kW m-2. With temperature and heat flux data, effective absorption coefficients were determined by using a two-flux method to solve the inverse problem. The results show that the optical thickness increases with increasing distance from the calorimeter surface. The effective absorption coefficient is approximately 0.8 m-1 in the vicinity (0 - 1.85 m) of the calorimeter and is approximately 2 m-1 in the vicinity (1.85 - 2.8 m) of the plume centerline. The observed decrease in heat flux on the calorimeter surface with increasing vertical height is consistent with analytical fire models derived for constant temperature surfaces. Results from several diagnostics also indicated trends and provided additional insight into events that occurred during the fire. Some events are correlated, and possible explanations are discussed.

Notes: Samples of unscoured, scoured, bleached and mercerized cellulosic fabrics were treated with dimethylol urea (DMU). It was observed that this treatment imparted to the fabrics flame retardant (FR) characteristics. These observations were interpreted in terms of the fact that DMU reacts bifunctionally with glucopyronosyl hydroxyls in such a way that a three-dimensional (hence more stable) structure develops in addition to the possibility of release of acid residues within the flaming zone.

Notes: Nailed joints with wood members were exposed simultaneously to standard fire and constant load. Different loads were applied in the range of 0.1 to 0.6 of the estimated failure load at normal temperature. Measurements of the rate of charring and the temperature were used to determine the temperature profiles and further to estimate the reduction in the strength properties. The test results are compared with calculations based on the theory of K. W. Johansen. Three different relations between the reduction of embedding strength and the temperature were investigated. For one of these relations, the theory agrees well with the results obtained in the fire tests. The results of the calculations also show that there is a considerable reduction of the embedding strength during the first period of fire.

Notes: The purpose of this study is to evaluate the effect of different oil contaminants on the spontaneous ignition behavior of cotton fabric. A series of treated fabrics with different oil contamination percentages was investigated and compared. Measurements were designed and carried out to determine the average time-to-ignition and to study the thermal behavior of systems containing cellulose. The results showed that the time-to-ignition of the contaminated samples has notably decreased, particularly at relatively low temperatures (350-450°C). However, at higher temperatures such effects became insignificant. Differential Thermal Analysis measurements were used to explain the mechanism by which the oils affect the thermal behavior of the sample. The heat evolved due to the oxidation of the oil content is sufficient to increase the rate of cotton depolymerization at the expense of the dehydration mechanism. In other words, the heat evolved promotes the formation of volatiles which are not char precursors.

Notes: The study compares five new intumescent additive mixtures and a carbonizing additive system with the ammonium polyphosphate-pentaerythritol system and additive formulations previously developed in laboratory in terms of fire retardancy of polypropylene-based formulations. The mixture of diammonium pyrophosphate and polyols produced by agrochemical industry xylitol and d-sorbitol (carbonization agent) are FR additive mixtures of interest for polyolefins. Moreover, the FR performance of the mixture of ammonium polyphosphate and polyamide-6 is reported. It is proposed that boric acid salts have to be developed as precursors for carbonization catalytic species. A thermal analysis study shows that FR performances and amounts of carbonaceous materials resulting from the thermal degradation of the additive mixtures are not related. An additional compilation of previous spectroscopic studies by the laboratory confirms that the intumescent process results from the formation of polyaromatic species and that FR systems maintain acidic species in a relatively high temperature range. An ESR study discusses the presence of π radicals in the protective coating formed using the additive systems. It provides information on the size of the carbonaceous structures in the materials and the presence of crystalline phases in the coating. Finally, the participation of free radicals in the formation of chemical bonds between the materials produced from the additives and the products of the degradation of the polymer is discussed.

Notes: The Fourier Transform infrared spectrometer method is developed by VTT Fire Technology in Finland, and is described by NORDTEST as NT FIRE 047. The method takes gas samples from the ventilation duct of a cone calorimeter, and is used to perform dynamic quantitative or qualitative measurements. This is an important step in the direction of continuous measurements of gas components in fire smoke. A lot of effort, knowledge and funds are required for a proper calibration and use of this equipment. The experience with application and interpretation of the test method is reviewed in regard to mounting, calibration and use of the equipment. The work concludes that the NORDTEST NT FIRE 047 test method needs to be revised and completed in the sections on apparatus, calibration routines, analysis procedure and expression of results. The missing information and details can lead to differences in application of the method. Until a revised document appears, frequent communication between laboratories can eliminate these differences.

Notes: Fire prevention, detection, and suppression requirements for spacecraft are based on those established for terrestrial and aircraft systems. In the weightless (or microgravity) environment of an orbiting spacecraft, however, the buoyant upward flow typical of fires in terrestrial environments is nearly absent; and this feature profoundly influences fire characteristics and responsive safety strategies. This paper reviews the findings of microgravity-combustion research that are relevant to techniques of spacecraft fire safety. These practical applications are further illustrated by descriptions of some fire-safety requirements and design features of the Shuttle and those in progress for the International Space Station.

Notes: Autoignition temperature and heat of combustion are two important parameters in determining the oxygen compatibility of materials. This study investigates the autoignition temperature of 32 polymers at an elevated oxygen pressure of 10.3 MPa and reports their heat of combustion. © 1996 by John Wiley & Sons, Ltd.

Notes: The philosophy behind research into personal protection from flame and intense heat for UK military personnel is addressed. The threat is examined as are methods of measurement and assessment. Finally an overview of the novel techniques which are being pursued at the Science and Technology Division is given. © British Crown Copyright 1996/MOD.

Notes: Dust explosion hazard exists in plants and facilities wherever combustible dusts are handled. The minimum ignition temperature of dust clouds is an important factor requiring special attention for the design of any explosion preventive measures. The present paper is confined to a study of the minimum ignition temperature of the cloud of polyethylene, an organic dust. This parameter was determined using the Godbert-Greenwald furnace apparatus for different particle sizes and dust concentrations. Some preliminary experiments were carried out for determination of minimum explosive concentrations of polyethylene dust to specify experimental conditions for determination of minimum ignition temperature. The experimental results, particularly variation of minimum ignition temperature with particle size and dust concentration, have been explained on the basis of a two-stage ignition involving devolatilization of solid particles into gaseous intermediates and homogeneous combustion of these gaseous components. A model was also developed for determining the minimum ignition temperature of polyethylene dust simulating conditions in the test furnace and this will be presented in a separate paper.

Notes: The thermal decomposition of azobisisobutyronitrile (AIBN) has been studied under fully adiabatic conditions in a sealed bomb using an accelerating rate calorimetry technique (ARC). Data relating to temperature, pressure and time have been discussed. AIBN decomposes exothermally and the onset of decomposition occurs at 56.19°C. The reaction reaches its maximum at 112.28°C. During this temperature range, the self-heat rate, and the time to maximum rate of the reaction were evaluated. The experimental data have been also treated to evaluate the activation energy of the potential runaway reaction.

Notes: This paper discusses the predicted results obtained from models developed to determine the effects of furnace depth (2.5 m and 0.5 m), type of furnace lining material type (fireclay brick, insulating firebrick and ceramic fibre insulation) and type of fuel (gas or liquid) on fire severity in fire resistance test furnaces using the CAN/ULC-S101, ASTM E119 and ISO 834 time-temperature relationships. The type of fuel used in the furnace and the type of furnace wall lining material significantly affected the heat absorbed by the test specimen while the furnace depth effect was minimal when the furnace was lined with ceramic fibre insulation. Factors to improve the repeatability and reproducibility of the fire severity in fire resistance test furnaces are provided.

Notes: The fire retardancy properties of hardboard treated with ammonium hydrogen carbonate (AHC) and sodium bromide were investigated by measuring their ignition time and flame temperature. An increase in ignition time and lowered flame temperature were observed with increased flame retardant (FR) concentration. AHC was found to be less effective as a fire retardant for this material. © 1996 by John Wiley & Sons, Ltd.