The authors noted that a large number of the data available relating to the test conditions were vague or completely undefined. (2006) and also Garrido and Font (2015). Table1 shows the relative reactivity of isocyanates with nucleophiles at 25C without the presence of a catalyst. Causes of UK fire deaths from 1955 to 2013 (UK Fire Statistics 2013). Michal (1982) reported a similar trend at a fixed air flow rate. Combustion Science and Technology 183(7):p627644, Saunders JH (1959) the Reactions of Isocyanates and Isocyanate Derivatives at Elevated Temperatures. Known as "solid gasoline" in the insurance industry, once a polyurethane fire starts, it usually results in a total loss of property and loss of life, according to Federated Insurance. The yields of acid gases and nitrogen-containing products depend upon the proportion of the appropriate elements in the materials burned and the efficiency of conversion. . ISO 13571 (2007) considers the four major hazards from fire which may prevent escape (toxic gases, irritant gases, heat and smoke obscuration). (3) Polyurethane foam mattresses, dubbed "solid gasoline", can give off toxic fumes that may be linked to short- and long- term health conditions. However, instead of finding my answer I found seemingly endless reports on websites claiming that memory foam gives off potentially toxic fumes. They produce a strong odor for awhile after manufacture. FEC model from ISO 13571. In the UK, the rapid rise in fire deaths, in particular those from smoke toxicity, between the late 1950s and the early 1980s has been attributed to the rapid growth in low cost polyurethane foam furniture, with superior comfort and lower cost than the natural fillings that preceded it. However, due to the poor reproducibility of smoke chamber experiments, the tendency for it to give very low HCN yields, and the fact that the experiment is well-ventilated, the reported toxicity is likely much lower than in a real fire situation. Terms and Conditions, The higher flammability of these new furniture products took people by surprise, and has been blamed for an increased number of serious fires and a tripling of fire deaths over 20years (Fig. Carbon monoxide binds to the haemoglobin in red blood cells resulting in the formation of carboxyhaemoglobin (COHb), with stability 200 times greater than that of oxyhaemoglobin, impeding the transport of oxygen from the lungs to the cells in the body. Conversely, nitric oxide gas at low concentrations(~20 ppm) has been used to aid breathing in the treatment of respiratory disorders (Kavanagh & Pearl 1995). The general approach, described in ISO 13571 (2012), is to ensure that the available safe escape time (ASET) before escape routes become obscured by smoke and/or filled with toxic gases, exceeds the required safe escape time (RSET). Is Polyurethane Foam Toxic, And Should You Avoid it? - The Safe Parent Memory foam is a type of polyurethane foam. Routes of entry in this case are inhalation, ingestion (saliva), and skin absorption. These polyols will fragment and volatilise as the temperature increases, leaving behind a char (>600C). The PIR foam produced similar HCN yields to the CMHR-PUF until 1.5, after which it increased more rapidly to give a yield of 20mgg1 at ~1.75. SP Swedish National Testing and Research Institute, Bors, Hietaniemi J, Kallonen R, Mikkola E (1999) Burning characteristics of selected substances: Production of heat, smoke and chemical species. The general approach in generating toxic potency data from chemical analysis is to assume additive behaviour of individual toxicants, and to express the concentration of each as its fraction of the lethal concentration for 50% of the population for a 30min exposure (gas-LC50). However, while the char produced when the polymer was heated at 370C contained only 20% of the total nitrogen from the polymer, 40% of that (8% of the total nitrogen in the polymer) was recovered as HCN when the char was burned at 600C. Toxic Materials in Foam Mattresses? Are We Safe? The CACC and SDC show reasonable agreement for well-ventilated burning, but fail to replicate the more hazardous under-ventilated fire conditions. 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. 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. Off-gassing is the unpleasant odor caused by volatile . NBSIR 822532. . Bench-scale methods used for generation of toxic fire effluentsideally should be capable of reproducing individual fire stages or combustion conditions, for input into models of combustion toxicity. As polyurethane foams have very low thermal inertia, application of heat or a small flame can be enough to ignite them. These nucleophiles include amines, alcohols, carboxylic acids, thiols, water, ureas and urethanes (Aneja 2002). Elemental analysis of the polymers showed that the CMHR-FPUR contained 8.22% nitrogen by weight and the PIR contained 6.15% nitrogen by weight. The heating of polyurethanes in an inert-atmosphere results in the progressive rupturing of bonds as a function of temperature. STM would like to acknowledge the University of Central Lancashire for provision of a studentship. 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. 1982) to that of a large scale test room. Additionally, assorted nitrogenous organics were detected in the tar including aniline, quinoline, pyridine, benzonitrile, indole and acridine derivatives with more than 50% of the tar nitrogen being bound as 4-[(4-aminophenyl)methyl]aniline (the amino analogue of MDI). The authors suggested that the presence of oxygen does not affect the mechanisms by which CO and HCN are produced. The chemistry of polyurethane foams and their thermal decomposition are discussed in order to assess the relationship between the chemical and physical composition of the foam and the toxic products generated during their decomposition. However, during the combustion of polyurethane foams, the HCN yield is notably higher when the fire progresses from smouldering to flaming combustion. Fire Res 1:p1121. Some of these methods attempt to address the transition through the fire stages by monitoring the formation of toxic gases as a function of time, as the oxygen concentration falls, and the fire condition changes from well-ventilated to under-ventilated. The full-scale test showed good accordance with the SSTF data considering the inherent unreliability of large-scale testing. The sample is spread evenly in a silica boat over a length of 800mm and fed into a tube furnace at a typical rate of 1gmin-1 with flowing airat a rate of 2-10 L min-1. The rigid polyurethane foam yielded ~55mgg1 CO and ~0.5mgg1 of HCN. The samples tested included both commercial rigid polyurethane foam and polyisocyanurate foam. Asphyxiant or narcotic gases cause a decrease in oxygen supplied to body tissue, resulting in central nervous system depression, with loss of consciousness and ultimately death. The average combined yield of isocyanates recovered was 0.869mgg1 and the average yield of amines and aminoisocyanates was 0.321mgg1. Test methods, such as the steady state tube furnace (ISO/TS 19700) and the controlled atmosphere cone calorimeter (ASTM E 1354), facilitate ventilated controlled conditions which give yields of CO and HCN comparable to those observed in under-ventilated post-flashover compartment fires. The polyester based polyurethane began to decompose at 284C with a secondary decomposition step at 359C. By using this website, you agree to our Foams Under Laboratory Conditions, Fire Research Note, No 1039. 1985 and Levin et al. Work by Ravey and Pearce (1997) on the decomposition of a polyether based flexible polyurethane foam suggested that up to 360C the decomposition of the foam was achieved by two main mechanisms. https://doi.org/10.1186/s40038-016-0012-3, DOI: https://doi.org/10.1186/s40038-016-0012-3. Self-addition reaction of two isocyanates to produce a uretidione, Self-addition reaction of three isocyanates to produce a isocyanurate ring, Reaction of two isocyanates to produce a carbodiimide. Secondary air is added in a mixing chamber to give a total gas flow of 50Lmin1. The difference in the decomposition of rigid and flexible polyurethane foams was investigated by Chun et al. 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). While the data presented is a useful compilation of toxic potency data from the available literature before 2004, the report does not take into consideration the conclusions of individual authors, the exact specifics of the test condition, and the validity of the results. (2007) assessed the toxic product yields of a flexible polyurethane foam that was designed for use in hospital mattresses. When formed at the site, there is a potential for a completed-operations exposure. Although the authors intended for the bench scale test methods and the large scale test to represent post-flashover room fires, the tests resulted in CO and HCN yields that suggested the combustion conditions were not under-ventilated (Table7). 2 Before you take it for a test drive, make sure to give your new mattress time to off-gas in a well-ventilated environment. The reaction of a urethane with another isocyanate will produce an allophanate (Scheme5). A review by Paabo and Levin (1987) found that there is no difference in the decomposition products of rigid and flexible polyurethane foams at high temperatures regardless of their differing degradation mechanisms at lower temperatures. The authors noted that the yields of CO during the well-ventilated testing were higher than expected for both materials, and attributed this to the possible presence of gas phase free radical quenchers, such as halogens or phosphorous containing flame retardants, which would reduce the conversion of CO to CO2 (Schnipper & Smith-Hansen 1995). The guidelines above for choosing a safer mattress or non toxic mattress topper can help determine which . Each method is described briefly in the following section. 2011). HCN analysis was performed using infrared (IR) spectroscopy using a short path-length gas cell, which is a questionable method for the quantification of HCN due to its poor IR absorption, high potential for interferences and a poor limit of detection. 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 formation of the toxicant in question was the result of an unusual reaction of the polyol in the foam, trimethylol propane, with the phosphate fire retardant in the gas phase. PDF Fire Properties of Polyvinyl Chloride In addition, asphyxiation can also occur as a result of lowered oxygen concentration, and is affected by the carbon dioxide concentration. A polyether polyol (i) and a polyester polyol (ii). Manage cookies/Do not sell my data we use in the preference centre. 1984a). 3) (Aneja 2002). 1982), and a three . A "combustion modified high resilience" flexible polyurethane foam (CMHR-PUF) and a polyisocyanurate (PIR) foam were analysed a steady state tube furnace apparatus. In a report from the same laboratory, Braun et al. Progressive changes in the composition of a static specimen (for example due to char formation) provide additional complexity. Do memory foam mattresses give off toxic fumes? The transport industries have adopted the smoke density chamber (SDC) ISO 56592 (2012) and ASTM E662, for quantification of toxic product yields (Fire Test Procedure Code 2010; CEN/TS 455452 2009) using simple pass/fail chemical detection (e.g. Three Massachusetts Home Fires Linked to Spray-Foam Installation (such as polyurethane foam) burn slower (have a lower (HRR) than higher-density materials (cotton padding) of similar makeup. It is usually used in isomeric mixtures of varying ratios, with 80:20 2,4 to 2,6 being the most commonly used (Fig. These fires are large, relative to the enclosure, and produce greater volumes of effluent, affecting occupants over a much wider part of any building.

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