ISO 19706 (2011) Guidelines for assessing the fire threat to people. Further decomposition occurred about 600C with the fragmentation of the yellow smoke, primarily into hydrogen cyanide and small quantities of acetonitrile, acrylonitrile and benzonitrile. The authors associated this with the effects of the Cu2O catalytically oxidising the HCN into N2, CO2, H2O and a small amount of nitrogen oxides. However, a non-standard modification of the apparatus has been described, enclosing the fire model in a controlled ventilation chamber, in an attempt to replicate oxygen-depleted conditions. Correspondence to Their development continued commercially in Germany, eventually leading to a global multibillion dollar industry (Vilar 2002). 95% of the demand for polyurethanes is situated in North America, Asian-pacific, and European markets; with demand expected to increase in Eastern Europe and South America in the next 1015 years. At high concentrations these acids can cause pulmonary oedema and death (Paul et al. Isocyanurate rings are the most thermally stable in an inert atmosphere and decompose between 270 and 300C. Andersson B, Markert F, Holmstedt G (2005) Combustion products generated by hetero-organic fuels on four different fire test scales. Equation As polyols are prepolymers, their molecular mass is relevant to their application, with flexible foams being derived from 1000 to 6000 daltons and few hydroxyl groups, while those used in rigid foams have short chains from 250 to 1000 daltons with high functionality (312 hydroxyl groups per chain). The presence of both amines and water in the decomposition products of polyurethane foams are discussed in later sections. This causes deterioration in mental and muscular performance. Other common diisocynates include hexamethylene diisocyanate (HDI), 1,5-naphthalene diisocyanate (NDI) and isophorone diisocyanate (IPDI) (Fig. Biurets are the result of the reaction of isocyanates with substituted-urea functional groups and allophanates are formed in small amounts (unless catalysed) by the reaction of isocyanates with urethanes. 4). This can result from exposure to radiant and convected heat; visual obscuration due to smoke; inhalation of asphyxiant gases; and exposure to sensory/upper-respiratory irritants. 8-80, addressing . Taking this into consideration, the steady state tube furnace and the controlled atmosphere cone calorimeter both produced the highest yields of HCN in under-ventilated conditions. Polymer International 53:p15851610. The non-flaming decomposition of non-fire retarded polyurethane foams in air is generally quite well understood and comparable to the inert atmosphere decomposition, in terms of both products and mechanisms.
eff, should be used, rather than an averaged local equivalence ratio, based on the oxygen supply to the chamber, because, in some experiments, substantial secondary flaming occurred outside the test chamber, such that the amount of oxygen available to combustion exceeded the amount that was fed to the enclosed chamber. Short chains with high functionality results in highly cross-linked polyurethane polymers which is characteristic of rigid foams. The authors presented a large set of data for all of the test methods, including a range of test conditions, air flow rates, oxygen concentration, and mass loadings. These reactions make up the basis of polyurethane chemistry and can be used to tailor polyurethanes with a range of properties by varying the structure and ratios of the individual components. Equations2 and 3 have been taken from ISO 13571 (2007). Alongside this, the decomposition of the foam into an amine, alkene and carbon dioxide was also proposed. However, instead of finding my answer I found seemingly endless reports on websites claiming that memory foam gives off potentially toxic fumes. the sum of each of the concentrations multiplied by the exposure time, for each product; upper respiratory tract irritants are believed to depend on the concentration alone (Purser 2007). Centre for Fire and Hazard Science, University of Central Lancashire, Preston, PR1 2HE, UK, Sean Thomas McKenna&Terence Richard Hull, You can also search for this author in (2011) Aerospace series - Burning behaviour of non-metallic materials under the influence of radiating heat and flames - Determination of gas components in the smoke; ABD 0031 Fire-Smoke-Toxicity (FST) Test Specification (Airbus Industries); Boeing BSS 7239, Test method for toxic gas generation by materials on combustion. Thermogravimetric analysis and differential scanning calorimetry (TGA/DSC) showed that the polyether based polyurethane began to decompose at 258C, with a second decomposition stage at 350C (which could be attributed to the fragmentation of the polyether polyol). Respiratory Issues First, polyurethane is a petrochemical resin that contains known . Interscience Publications, London, Purser DA (2008b) Chapter 2: SFPE Handbook of Fire Protection Engineering (Ed. Recent work by Allan et al. Aromatic diisocyanates, which are commonly used in the production of polyurethanes, have a slightly more complicated chemistry compared to monoiscyanates due to the electronic effects of two isocyanate groups. Avar G, Meier WU, Casselmann H, Achten D (2012) Polymer Science: A Comprehensive Reference, Polymer Science: A Comprehensive Reference, 10, p411-441. At a CO concentration of 10 ppm, impairment of judgement and visual perception occur; exposure to 100 ppm causes dizziness, headache, and weariness; loss of consciousness occurs at 250 ppm; and 1000 ppm results in rapid death. The trimerisation results in a highly stable isocyanurate ring which confer additional thermalstability to polyisocyanurates (Scheme7). https://doi.org/10.1186/s40038-016-0012-3, DOI: https://doi.org/10.1186/s40038-016-0012-3. Performing hot work on or near polyurethane foam may lead to potential exposures to isocyanates and other toxic emissions. At 850C the yield of HCN was higher with 16mgg1 at ~2.0. The review refers to a publication by Babrauskas et al. When a liquid fuel gives off enough vapors so that it can be . The flexible foam produced ~175mgg1 of CO and 5mgg1 of HCN. 13) (UK Fire Statistics 2013).
PDF The fire toxicity of polyurethane foams - SpringerOpen While there were some problems, the data does show that the yields of toxicants from the polyurethane foam were generally most representative of post-flashover conditions in the test methods that were designed for ventilation controlled conditions, such as the steady state tube furnace and the controlled atmosphere cone calorimeter. Polyurethane and polyisocyanate both release polyols and isocyanates during blowing, but the rates diminish rapidly over time as the product cures, provided they dialed in the temps & chemical mix correctly. \( \phi =\frac{actual\; fuel\;to\; air\; ratio}{stoichiometric\; fuel\;to\; air\; ratio} \). Foams Under Laboratory Conditions, Fire Research Note, No 1039. The methods of assessment of fire toxicity are outlined in order to understand how the fire toxicity of polyurethane foams may be quantified. However, as fires tend to grow exponentially, they do not produce constant concentrations of asphyxiant gases. 2013). This prompted the authors to perform further studies in order to understand why allowing the foam to smoulder increased the yield of HCN during flaming combustion. The guidelines above for choosing a safer mattress or non toxic mattress topper can help determine which . Additionally, NO was detected during the well-ventilated tests and NH3 during the under-ventilated tests. Int Anesthesiol Clin 33:181, Kimmerle G (1976) Toxicity of Combustion Products with Particular Reference to Polyurethane. The authors intended to compare the HCN yields for the non-flaming and flaming combustion of the foam in a smoke chamber apparatus (as described in Levin et al. Purser model, [AGI] is the concentration of inorganicacid gas irritants, [OI] is the concentration of organic irritants, A is an acidosis factor equal to [CO2]0.05. Causes of UK fire deaths from 1955 to 2013 (UK Fire Statistics 2013). It has been designed to generate data for input to fire hazard assessments, using the methodology in ISO 13344 (1996) and ISO 13571 (2012), particularly in relation to the ISO fire stages. eds. As polyurethane foams have very low thermal inertia, application of heat or a small flame can be enough to ignite them. HCN, in particular, contributes significantly to the overall fire toxicity of polyurethane foams. Various apparatus and protocols for quantifying fire effluent toxicity in different jurisdictions and industries have been critically reviewed (Hull & Paul 2007). Historically, material-LC50 data has been reported directly based on animal lethality testing, however due to the declining use of animal testing in fire toxicity assessment, calculations based on standard lethality data(such as ISO 13344 1996) are more commonly used. The effect of asphyxiants and deep lung irritants depend on the accumulated doses, i.e. Technology, Gaithersburg MD, Babrauskas V, Levin BC, Gann R, Paabo M, Harris RH, Peacock RD, Yusa S (1991b) Toxic potency measurement for fire hazard analysis, special publication 827, National Institute of Standards and Technology. Non-fatal UK fire injuries requiring hospital treatment, 1955-2013 (UK Fire Statistics 2013). The main asphyxiants, carbon monoxide and hydrogen cyanide have been widely studied and are the best understood (ISO 13571 2007). In the gas phase, isocyanates, amines and yellow smoke will begin to decompose at >600C into low molecular weight nitrogen containing fragments (such as benzonitrile, aniline and hydrogen cyanide (HCN)). 2011). The cribs used in the ISO 9705 tests were constructed from PIR sticks which burned rapidly, albeit with minimal damage to the room. $$ \begin{array}{l}\mathrm{FED}=\left\{\frac{\left[\mathrm{C}\mathrm{O}\right]}{{\mathrm{LC}}_{50,\;\mathrm{C}\mathrm{O}}}+\frac{\left[\mathrm{H}\mathrm{C}\mathrm{N}\right]}{{\mathrm{LC}}_{50,\;\mathrm{H}\mathrm{C}\mathrm{N}}}+\frac{\left[\mathrm{A}\mathrm{G}\mathrm{I}\right]}{{\mathrm{LC}}_{50,\;\mathrm{A}\mathrm{G}\mathrm{I}}}+\frac{\left[\mathrm{O}\mathrm{I}\right]}{{\mathrm{LC}}_{50,\;\mathrm{O}\mathrm{I}}}\dots \right\}\times {\mathrm{V}}_{{\mathrm{CO}}_2}+\mathrm{A}+\frac{21-\left[{\mathrm{O}}_2\right]}{21-5.4}\\ {}{\mathrm{V}}_{{\mathrm{CO}}_2}=1\kern0.36em +\kern0.36em \frac{ \exp \left(0.14\left[{\mathrm{CO}}_2\right]\right)-1}{2}\end{array} $$, $$ \mathrm{FED}={\displaystyle \sum_{t_1}^{t_2}\frac{\left[\mathrm{C}\mathrm{O}\right]}{35\;000}}\;\Delta t+{\displaystyle \sum_{t_1}^{t_2}\frac{ \exp \left(\left[\mathrm{H}\mathrm{C}\mathrm{N}\right]/43\right)}{220}}\;\Delta t $$, $$ \mathrm{F}\mathrm{E}\mathrm{C}=\frac{\left[\mathrm{H}\mathrm{C}\mathrm{l}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{C}\mathrm{l}}}+\frac{\left[\mathrm{H}\mathrm{B}\mathrm{r}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{B}\mathrm{r}}}+\frac{\left[\mathrm{H}\mathrm{F}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{F}}}+\frac{\left[{\mathrm{SO}}_2\right]}{{\mathrm{IC}}_{50,\;{\mathrm{SO}}_2}}+\frac{\left[{\mathrm{NO}}_2\right]}{{\mathrm{IC}}_{50,\;{\mathrm{NO}}_2}}+\frac{\left[\mathrm{acrolein}\right]}{{\mathrm{IC}}_{50,\;\mathrm{acrolein}}}+\frac{\left[\mathrm{fomaldehyde}\right]}{{\mathrm{IC}}_{50,\;\mathrm{fomaldehyde}}}+{\displaystyle \sum \frac{\left[\mathrm{irritant}\right]}{{\mathrm{IC}}_{50,\;\mathrm{irritant}}}} $$, $$ \mathrm{material}\hbox{-} {\mathrm{LC}}_{50}=\kern0.36em \frac{M}{\mathrm{FED}\times V} $$, https://doi.org/10.1186/s40038-016-0012-3, http://creativecommons.org/licenses/by/4.0/. New memory foam smell? STM wrote the manuscript and produced all of the images used in figures. The main toxic combustion products can be divided into two classes: asphyxiant gases, which prevent oxygen uptake by cells, with loss of consciousness and ultimately death; and irritant gases which cause immediate incapacitation, mainly by effects on the eyes and upper respiratory tract, and longer term damage deeper in the lung. The review suggested that the addition of fire retardants did not appear increase the overall combustion toxicity of polyurethane foams. thesis, Virginia Tech, p6-40, ASTM E 1354 Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter, ASTM E 662 Standard Test Method for Specific Optical Density of Smoke Generated by Solid Materials. Insulation, like all building products, has an 'embodied' carbon footprint resulting from energy use during the manufacturing process. In the smoke chamber, the highest reported yield during flaming combustion was 1.02mgg1. As a result of this, studies that use ventilation controlled conditions, such as those using the steady state tube furnace (ISO/TS 19700 2013), are more likely to give a realistic representation of these reduced oxygen environment fire conditions. These polyols will fragment and volatilise as the temperature increases, leaving behind a char (>600C). Neviaser and Gann (2004) compiled the toxic potency data for a range of materials including a number of fire retarded and non-fire retarded polyurethane foams. True. DiNenno et al., eds.). While it is evident that the HCN yield increases as a fire becomes more under-ventilated, the link between the nitrogen content of the fuel and the yield of HCN is less clear. 4 The reported yields for the tests performed can be found in Table8. However, when >2.0 the yield of HCN decreased, falling to 10mgg1 at ~2.75. At 1000C the hydrogen cyanide produced accounted for a range of between 3.8 and 7.3% by weight. At lower temperatures, decomposition differs, depending on the composition and physical properties of the polymer, although clear trends can be identified. These fires are large, relative to the enclosure, and produce greater volumes of effluent, affecting occupants over a much wider part of any building. The yields of toxic products followed the expected trend of being higher in the under-ventilated conditions. (1991b) wherein polyurethane containing a phosphate fire retardant caused immediate death of all of the animals. 2008; Kaplan 1987b). Therefore, in certain conditions, polyurethanes foams can reach their auto-ignition temperature and ignite which will significantlyalter the effect the decomposition mechanisms and resulting products. By using this website, you agree to our Polymer Degradation and Stability 98:535541, Anderson RA, Watson AA, Harland WA (1981) Fire Deaths in the Glasgow Area: I General Considerations and Pathology. These yields are comparable to that of the results reported by Blomqvist et al. Apparatus where changes rapidly allow little time for sampling and measurement of mass loss and effluent compositionat a specific value of, with resultant errors and uncertainties. It has been suggested that the reproducibility problems arise from the single point measurement (the tip of the probe may be in the centre of the plume, below it, or if mixing is more efficient, the upper layer may be recirculated through the flame), or the timing of the effluent sampling may cause instabilities (for example an initial proposal to sample after 8min was replaced by a proposal to sample when the smoke density reached its maximum). In the case of flaming combustion, one of the most important factors relating to the toxic product yield is the fuel/air ratio which, as defined earlier, can be expressed as an equivalence ratio (). In this case, the main reason for including isocyanate reactivity data is to explain the reactivity of isocyanates that are released into fire effluent during combustion. International Maritime Organisation, London, Garrido MA, Font R (2015) Pyrolysis and combustion study of flexible polyurethane foam. To a lesser extent, parameters such as temperature and oxygen concentration also affect the yields of toxic products. Acrolein and formaldehyde are formed especially from cellulosic materials under non-flaming decomposition conditions, but products of vitiated combustion contain other organic irritants. P.J. The open cone calorimeter replicates the early well-ventilated stage of flaming where a fire would be too small to produce enough toxicants to cause harm except in very small enclosures. Others, such as the NF X 70100, and the ISO/TS 19700 SSTF use the furnace temperature setting to ensure a consistent radiant heat flux. Using a cup furnace with a 200L sampling chamber (identical in design to the one used in the smoke chamber experiments), a 3.88g sample of foam was heated to just below its ignition temperature (370C) which yielded <1mgg1 HCN. During flaming combustion, many fire retarded flexible polyurethane foams showed similar or slightly higher toxic potency than the non-fire retarded foams in both well-ventilated and under-ventilated conditions. Most fuel nitrogen is released as N2, but in well-ventilated combustion conditions a proportion is released as oxides of nitrogen (mainly NO) and in under-ventilated combustion conditions a proportion is released as HCN (Purser & Purser 2008a). Each of the decomposition steps took place at a lower temperature in air than in nitrogen, which further suggests the direct interaction of oxygen with the foam during decomposition. The radiant heat apparatus, smoke chamber and controlled atmosphere cone calorimeter produced much lower CO yields than would be expected for under-ventilated flaming. EN 2826. Polyether polyols are more resistant to hydrolysis, but less stable to oxidation, while for polyester polyols it is the opposite. However, unlike a real fire, the heat flux remains constant, and so when the oxygen concentration falls, the flame may be extinguished. Relation of LC Rigid polyurethanes primarily produced aromatic compounds in the condensed phase products of decomposition, whereas flexible polyurethanes produced aromatics, alcohols, aldehydes and heterocycles. (1990) also reported increased HCN yields when the sample was allowed to smoulder before flaming in similar apparatus as above. . However, in the field of combustion toxicity testing, this under-ventilated burning is the most difficult to create using bench-scale apparatus. 1982), and a three .
PDF Polyurethanes and Thermal Degradation Guidance The authors tested a rigid polyurethane foam using a NBS cup furnace (as described in Levin et al. Polymer-Plastics Technology and Engineering 45:p95108, Singh H, Jain AK (2009) Ignition, Combustion, Toxicity, and Fire Retardancy of Polyurethane Foams: A Comprehensive Review. The two main market uses for polyurethane are in the furniture and interior industry and the construction industry with 28% and 25% of the market, respectively (Markets & Markets report 2011). Toxicology 115:7, Henneken H, Vogel M, Karst U (2007) Determination of airborne isocyanates. Diesel engines use the principle of _____ to ignite fuel vapor. This value decreased to 18mgg1 at ~2.0. It is generally accepted that the thermal decomposition occurring during flaming combustion is best represented by the thermal decomposition of a material in an inert atmosphere. (1991a) compared a number of test methods. The authors acknowledged that the lower nitrogen recovery fraction for the flexible foam could be due to fuel nitrogen being lost as isocyanates, which are known to escape into the effluent plume, while for rigid foams they are more likely to be trapped in the burning solid (Woolley & Fardell 1977). There is some contradiction the literature as to the effect fire retardants have on the overall toxicity of polyurethane foams. The authors compiled toxicological data from a range of primary online databases and also requests were made to collect unpublished data that were not publically available. In another investigation, using a steady state tube furnace, Blomqvist et al. to FED. Polyol fragments in the gas phase will also begin to decompose at >800C to produce simple organic fragments and PAHs. Polyurethanes are named from the presence of theurethane (also known as carbamate) functional group (Fig. Research predicting the carbon monoxide evolution from flames of simple hydrocarbons, reviewed by Pitts (1995), has shown the importance of the equivalence ratio . Combustion and Flame 146(12):p95108, Rogaume T, Bustamante-Valencia L, Guillaume E, Richard F, Luche J, Rein G, Torero JL (2011) Development of the Thermal Decomposition Mechanism of Polyether Polyurethane Foam Using Both Condensed and Gas-Phase Release Data. Two mechanisms have been identified for the toxic effects of cyanide. The test conditions were designed so that the fire conditions met the ISO 19706 (2007) fire type 2 (well-ventilated flaming fire <0.75) and fire type 3b (post-flashover fire in large or open compartments ~2.0). When formed at the site, there is a potential for a completed-operations exposure. Thermal decomposition of polyurethanes is usually the reverse of polymerisation, resulting in the formation their precursor functional compoundsdiisocyanates, diamines and dihydroxy compounds. In others, under reduced oxygen concentrations, the fuel lifts from the surface, but ignition does not occur (Christy et al. The second results in a brief stimulation, followed by severe depression, of respiratory frequency, also starving the body of oxygen, and causing convulsions, respiratory arrest and death (Alarie 2002). Download resource The reported yields were extremely low for both CO and HCN, as the NBS smoke chamber apparatus is a well-ventilated fire scenario reported to give low HCN yields (Table6). A large majority of the literature indicates that the addition of fire retardants does not increase toxicity of polyurethane foams. (2006) has supported the claim that polyether based polyurethanes are less stable than their polyester based counterparts when decomposed in air. Fire Safety Science 11:p404418, Stec AA, Hull TR, Lebek K (2008) Characterisation of the steady state tube furnace (ISO TS 19700) for fire toxicity assessment. National Fire Protection Association, Quincy, pp 283, Purser DA (2007) The application of exposure concentration and dose to evaluation of effects of irritants as components of fire hazard. Fire Technology 40:p117199, NFPA 269 (2012) Standard test method for developing toxic potency data for use in fire hazard modelling, NFX 70 1001:2006 Fire Tests - Analysis Of Gaseous Effluents - Part 1: Methods For Analysing Gases Stemming From Thermal Degradation, NIOSH (1989) A summaryof health hazard evaluations: Isocyanates, 1989 to 2002, Paabo M, Levin BC (1987) A review of the literature on the gaseous products and toxicity generated from the pyrolysis and combustion of rigid polyurethane foams. The relation of the FED to the material-LC50 is given in equation4. The toxic product yields may be quantified from the gas concentrations and mass feed rate during the steady state burn period. Material composition, temperature and oxygen concentration are normally the most important. This char can decompose further, leaving behind a residue at >800C, to produce simple organic fragments and some polycyclic aromatic hydrocarbons (PAHs). Whether one or other of these mechanisms predominates, or their interrelationship, remains unclear. Substituted ureas decompose between 235 and 250C and carbodiimides decompose between 250 and 280C. In particular, the ventilation condition has a critical effect on the yield of the two major asphyxiants, carbon monoxide and hydrogen cyanide. When the black char was burned at 600C, it yielded 14.95mg of HCN (65mg per gram of char) and the yellow oil yielded 21mg per gram of oil. Additionally, aromatic isocyanates with more steric hindrance are likely to be less reactive (such as the 2 position in 2,4-TDI (Fig. Fire Safety Science - Proceedings of the First International Symposium, p1111-1122, Markets and Markets report (2011) Methylene Diphenyl Diisocyanate (MDI), Toluene Diisocyanate (TDI) and Polyurethane Market (2011 2016): Markets and Markets CH 1596, July 2011, Marsh ND, Gann RG (2013) Smoke Component Yields from Bench-Scale Fire Tests: 4. These fumes could lead to irritation of the eyes, throat, and lungs, and could cause more severe allergic reactions for individuals with chemical sensitivities. Allergy 63:p583591, Pitts WM (1995) The global equivalence ratio concept and the formation mechanisms of carbon monoxide in enclosure fires. The fire toxicity of polyurethane foams. Springer Nature. Aromatic isocyanates are more reactive than aliphatic isocyanates due to the electronic effects of the aromatic ring. Fire and Materials 5(4):p133141, Christy M, Petrella R, Penkala J (1995) Controlled-atmosphere cone calorimeter. 1986).
Off-gassing & Outgassing: What's the Difference? Where is it From National Bureau of Standards, Gaithersburg MD, Barbrauskas V, Singla V, Lucas D, Rich D (2015) Letter to the Editor- Questions about the conclusions in Blais and Carpenter 2013. Building renovations, demolition, or building disassembly done years later can disturb spray foam insulation. 1984a). (2015) questioned their methodology and noted that the authors did not address the release of HCl and its contribution to the acute fire toxicity of the fire retarded foam. Fire Safety Journal 40:439465, Aneja A (2002) Chapter 2, Structureproperty Relationships of Flexible Polyurethane Foams, PhD. The production of HCN and other low molecular weight nitrogenous compounds from the high temperature decomposition of polyurethanes has been reported in the literature in recent years. However, during the combustion of polyurethane foams, the HCN yield is notably higher when the fire progresses from smouldering to flaming combustion. The mechanisms of decomposition are well understood and the decomposition products of both rigid and flexible polyurethane foams are very similar at high temperatures. volume5, Articlenumber:3 (2016) The two main families of polyols used are polyether polyols and polyester polyols (Fig.
Three Massachusetts Home Fires Linked to Spray-Foam Installation Studies have found that infant mattressesespecially those made with polyurethane foam, which contains the hydrocarbon tolueneare a major off-gassing culprit (Boor, et. Once sensitisation has occurred, even extremely low concentrations of airborne isocyanates can trigger fatal asthma attacks (Henneken et al. Cyanide gas. Oxygen depletion can be lethal if the oxygen concentration falls below tenable levels (~6%). These nucleophiles include amines, alcohols, carboxylic acids, thiols, water, ureas and urethanes (Aneja 2002). National Bureau of Standards, Gaithersburg, MD, Levin BC, Paabo M, Birky MM (1983b) Interlaboratory evaluation of the 1980 version of the national bureau of standards test method for assessing the acute inhalation toxicity of combustion products, NBSIR 832678, National Bureau of Standards, Gaithersberg, MD, Levin BC, Paabo M, Fultz ML, Bailey CS (1985) Generation of Hydrogen Cyanide from Flexible Polyurethane Foam Decomposed under Different Combustion Conditions. Polymer Degradation and Stability 93:p20582065, Tewarson A (2002) SFPE Handbook of Fire Protection Engineering, 3rd ed.
Fastest Volleyball Serve 2020,
Candy Bars Named After Baseball Players,
Articles P