Urethane Foam Health Effects | livestrong The overall toxicity of polyurethane materials followed a similar trend to their HCN yields; with flexible foams generally being the least toxic, rigid foams being slightly more toxic and polyisocyanurate foams being the most toxic. Rigid foam decomposed between 200 and 410C, while flexible foam decomposed between 150 to 500C. Further fragmentation of these molecules led to the production of HCN, acetonitrile, acrylonitrile and a range of olefinic fragments. When a liquid fuel gives off enough vapors so that it can be . For any larger fire there will always be a significant yield of CO, HCN (from nitrogen containing materials), hydrocarbons and smoke. Cyanide gas. 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. A sample of rigid polyurethane foam was heated in a static tube furnace with an air flow of 50mlmin1 at a range of temperatures from 600 to 1200C and the yield of HCN was quantified. However, the yield of CO was lower in both the non-flaming and flaming combustion. The highest concentration these compounds were formed at occurred at a decomposition temperature of 350400C which indicated no new degradation steps had occurred beyond 350C. 11) ultimately giving well-ventilated flaming. Potential Chemical Exposures From Spray Polyurethane Foam 1982), the authors exposed male Fisher 344 rats in a 200L exposure chamber to the fire effluent from the flaming and non-flaming combustion of both materials. The full-scale test showed good accordance with the SSTF data considering the inherent unreliability of large-scale testing. STM wrote the manuscript and produced all of the images used in figures. Chambers et al. Busker RW, Hammer AH, Kuijpers WC, Poot CAJ, Bergers WWA, Bruijnzeel, PLB (1999) Toxicity testing of combustion products of polyurethane and polyvinylchloride. The polyester fabric produced 9293mgg1 of CO when burned with very little difference in the flaming or non-flaming conditions. 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. 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). This char can decompose further, leaving behind a residue at >800C, to produce simple organic fragments and some polycyclic aromatic hydrocarbons (PAHs). Fire and Materials 31:p495521, Bott B, Firth JG, Jones TA (1969) Evolution of toxic gases from heated plastics. The full size ISO 9705 test resulted in well-ventilated flaming ( 0.260.5) due to the relatively large volume of air and relatively small sample size. CO yields are generally very low for well-ventilated conditions (in the absence of halogens) but increase considerably under-ventilated combustion conditions. p 1-30. Early work by Voorhees (1975) identified what they described as extreme toxicity of the combustion products of a phosphate fire retarded polyurethane foam. HCN also causes rapid incapacitation, preventing escape, and then, with CO, contributes to death from asphyxiation. 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. 1982), and a three . Journal of Applied Polymer Science 63:p4774, Rein G, Lautenberger C, Fernandez-Pell AC (2006) Application of Genetic Alogorithms and Thermogravimetry to Determine the Kinetics of Polyurethane Foam in Smoldering Combustion. The sample is a 7575mm square solid sheet and the standard for smoke measurement states that the results are only valid at the thickness tested (typically 14mm). Fire retardants, such as gas-phase free radical quenchers, have been reported to increase the yields of CO in well-ventilated conditions by preventing the oxidation of CO to CO2. Short chains with high functionality results in highly cross-linked polyurethane polymers which is characteristic of rigid foams. DiNenno) Fourth Edition. Off-gassing is the unpleasant odor caused by volatile . Unlike carbon monoxide which remains primarily in the blood (as COHb), the cyanide ion is distributed throughout the extra-cellular fluid of tissues and organs (ISO 13571 2007). Polyurethane foams based on polyether polyols will have a lower decomposition temperature in air than polyester polyol based foams. Almost all unwanted fires are diffusion flames, with inefficient mixing of fuel and oxygen(as opposed to the "premixed" flames found in burner/combustion systems). The polyisocyanurate, on the other hand, produced slightly more HCN than the rigid foam (17mgg1 vs 12mgg1). Isocyanates also react with themselves in various ways to produce dimers, trimers and completely new functional groups. 7) (Avar et al. Burning foam will emit mainly carbon monoxide, carbon dioxide and small traces of other toxic gases, such . In addition to the more common process of adding cross-linking reagents during the production process, cross-linkages in polyurethanes can be the result of the high reactivity of the isocyanate precursors. A large number of studies have been performed over the last 50years to understand the thermal decomposition of polyurethane materials, and as a result of this the mechanism of their decomposition in inert-atmospheres is fairly well understood. 23. CO and HCN are the main asphyxiants produced during the combustion of polyurethanes and there have been a large number of studies published regarding their yields. Gaithersberg, MD, Babrauskas V, Twilley WH, Janssens M, Yusa S (1992) Cone calorimeter for controlled-atmosphere studies. As the main reactive group that isocyanates react with, polyols are a major component of the resulting polyurethane product. Correspondence to 2013). Interscience Publications, London, Purser DA (2008b) Chapter 2: SFPE Handbook of Fire Protection Engineering (Ed. But the amount & rate of release are affected . Most polyurethanes are cross-linked to some degree and decompose without melting. (PDF) The fire toxicity of polyurethane foams - ResearchGate Building renovations, demolition, or building disassembly done years later can disturb spray foam insulation. 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). The Steady state tube furnace apparatus, ISO/TS 19700. This is when flame retardant chemicals were added to the foam or coverings to stop the furniture from burning so ferociously. Download resource During flaming combustion of polyurethane foams, the yield of toxicants can be directly related to the fuel/air ratio, expressed as an equivalence ratio (). While the link between CO yield and equivalence ratio is well established, the yield of HCN in ventilation limited conditions shows more complicated behaviour for polyurethanes. Polyurethane foam when burned gives off - wiehoch.com Again, above 600C the compound and any yellow smoke present was decomposed into smaller volatile fragments. However, many people fail to escape from fires because of the incapacitating effect of smoke (obscuring visibility) and its irritant components which cause pain, preventing breathing and escape or reason death occurred. 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. 2023 BioMed Central Ltd unless otherwise stated. VOCs and Other Toxic Chemicals in Mattresses: What to Know Memory foam is a type of polyurethane foam. The average combined yield of isocyanates recovered was 0.869mgg1 and the average yield of amines and aminoisocyanates was 0.321mgg1. The guidelines above for choosing a safer mattress or non toxic mattress topper can help determine which . During polymerisation, isocyanates undergo a number of distinct reactions. 2012). Animal studies provide most of what we know about the dangerous effects of toxic substances. (1969) reported the decomposition of rigid polyurethane foams in both nitrogen and air to assess the production of CO, HCN and NH3. eds. The most widely used fire-test apparatus, stipulated in smoke regulations in most countries of the developed world, is the smoke density chamber as described inISO 56592 2012, andshownschematically in Fig. However, it does suggest that yield of toxic products is effected by covering the foam with another material during flaming combustion. They attributed the different decomposition mechanisms to the physical form of the polyurethane foam, rather than to any chemical differences. Fire Safety Journal 40:439465, Aneja A (2002) Chapter 2, Structureproperty Relationships of Flexible Polyurethane Foams, PhD. The authors reported GC/MS analysis of the condensed phase products obtained. 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. 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. 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. 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. TNO Report. The author acknowledged that there is a range of contradictory results available in the literature regarding their fire toxicity. 1). 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. Equation2 represents the generally accepted case that there are only two significant asphyxiant fire gases, CO and HCN. Thermosets are cross-linked polymer molecules which, on heating, do not melt but will eventually decompose. 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. Rubber Chemistry and Technology 32(2):p337345, Article The authors asserted that fire retarding flexible polyurethane foam did not increase its acute or chronic toxicity when compared to non-fire retarded flexible foam. Fire Sci Rev 5, 3 (2016). Google Scholar, Schartel B, Hull TR (2007) Development of fire-retarded materials - interpretation of cone calorimeter data. According to Tim Rodrique, the director of the DFS, investigators suspect that the fires were caused by the exothermic reaction that results from the mixing of the two chemicals used to make . The initial decomposition of the foam, at >300C, results in the volatilisation of isocyanates, amines and Woolleys yellow smoke, leaving behind polyols in the condensed phase. As with all foams, memory foam compresses under pressure. PDF The fire toxicity of polyurethane foams - SpringerOpen But many products or materials continue off-gassing even after the "new smell" has gone awaythe fumes are just much more subtle. 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. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. In general, isocyanate (R-NCO) exposure causes irritation to the skin, mucous membranes, eyes and respiratory tract (NIOSH 1989). Michal (1982) reported a similar trend at a fixed air flow rate. When polyurethane foam insulation burns it gives off toxic gasses, very high temperatures and large amounts of thick, black smoke. Experimental data reported a 28% recovery of DAT which supports the proposed decomposition mechanism. Fire and Materials 5(4):p133141, Christy M, Petrella R, Penkala J (1995) Controlled-atmosphere cone calorimeter. 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. Rigid MDI based foams are primarily used for insulation in the construction industryand can also be found in the transport industry. The most commonly reported adverse health effects after airborne isocyanate exposure is asthma due to sensitisation (Piiril et al. The overall toxicity of the polyisocyanurate foam shows a clear increase as the fire became more under-ventilated, while the rigid polyurethane foam showed a slight decrease at 1.242.00. However, once one of the groups forms a urethane or urea, the activating effect on the other isocyanate is reduced, as ureas and urethanes are weaker activating groups than isocyanates. 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). NBSIR 832719. UPDATED 8/16/2011 The Massachusetts Division of Fire Safety (DFS) is investigating the causes of three house fires that were ignited while insulation contractors were installing spray polyurethane foam. 2008), where inhaled isocyanates rapidly form conjugates with epithelial lung cell proteins (Wisnewski et al. 4 Equation3 uses a similar principle to equation1 to estimate the combined effect of all irritant gases. The use of 13C labelling by Chambers et al. 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. The applied heat flux must be large enough for burning to continue at oxygen concentrations as low as 5%. Equation 2 calculates the FED of the major asphyxiants, CO and HCN, but without taking oxygen depletion or CO2 driven hyperventilation into account. Under well-ventilated flaming (<0.8), the yields of CO2 and NO2 were at their highest, while the yields of CO and HCN were at their lowest. Before you take it for a test drive, make sure to give your new mattress time to off-gas in a well-ventilated environment. An understanding of the relative reaction rates is vital in controlling the production of the polymer and producing the desired physical properties (Herrington & Hock 1998). In ventilation controlled fires (such as those occurring in a room, buildingor other enclosure), the yields of these gases from the flaming combustion of polyurethane foams generally follow the same trend. This was observed by Levin et al. Fire Technology 51:p318, Blomqvist P, Lonnermark A (2001) Characterization of the combustion products in large-scale fire tests: comparison of three experimental configurations. (1999) used the controlled atmosphere cone calorimeter, but argues correctly,in the authors' opinion,that an instantaneous effective global equivalence ratio PML 1998-A97. TDI is primarily used in the production of flexible foams, which are used in the furniture and interior industries. Journal of Fire and Materials 4:p5058, Farrar DG, Hartzell GE, Blank TL, Galster WA (1979) Development of a protocol for the assessment of the toxicity of combustion products resulting from the burning of cellular plastics, University of Utah Report, UTEC 79/130; RP-75-2-1 Renewal, RP-77-U-5. One analysis of fire victims' blood showed a trend of declining COHb and a rise in cyanide concentrations (Anderson et al. Int Anesthesiol Clin 33:181, Kimmerle G (1976) Toxicity of Combustion Products with Particular Reference to Polyurethane. International Association for Fire Safety Science, Ravey M, Pearce EM (1997) Flexible Polyurethane foam. The authors acknowledged that they did not include isocyanates in their calculations. Only the SSTF has a heated reaction zone which replicates the hot layer. Journal of Fire Sciences 8:p6379, BS 6853 (1999) Code of practise for fire precautions in the design and construction of passenger carrying trains. 2012). 8 and Table3. Fire and Materials 6:p1315, Neviaser JL, Gann RG (2004) Evaluation of Toxic Potency values for Smoke from Products and Materials. NBSIR 822532. However, the presence of Cu2O reduced the HCN generated by the flexible polyurethane foam by 70-90% at low temperatures. 1992), shown in Fig. 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. 1984a). (2006) and also Garrido and Font (2015). McKenna, S.T., Hull, T.R. Fire Technology 51:p213217, Blais M, Carpenter K (2015) Flexible Polyurethane Foams: A comparative measurement of toxic vapors and other toxic emissions in controlled combustion environments of foams with and without fire retardants. A summary of the bond decomposition temperatures in polyurethanes is shown in Table2 (Gharehbagh & Ahmadi 2012). The polyurethanes used were elastomers based on TDI, which could potentially have differing decomposition mechanisms to their foam counterparts. Levin et al. Stec and Hull (2011) presented material-LC50 data for rigid polyurethane foam and polyisocyanurate foam, calculated using rat lethality data from ISO 13344 (1996). 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). The radiant heat flux in the ISO/TS 19700 apparatus has been measured (Stec et al. Smouldering was forced by an electrically heated resistance wire embedded in the sample and a load cell measured the mass of the sample throughout the experiment. As fires grow, they become ventilation controlled, and fires in enclosures such as buildings rapidly change from well-ventilated to under-ventilated. The cone calorimeter (ISO 56601 2002) is probably the most widely used apparatus for measurement of flammability properties such as ignitability and heat release rate (Schartel & Hull 2007). This is due to the concentration of oxygen directly under a flame being close or equal to 0% (Schartel & Hull 2007). Polyurethanes are named from the presence of theurethane (also known as carbamate) functional group (Fig. Isocyanate structure also affects the reactivity of the isocyanate group. Irritant gases cause pain and breathing difficulties, leading to incapacitation, such that the victim can no longer effect their own escape (ISO 13571 2012). Toxic Materials in Foam Mattresses? Are We Safe? Free of VOCs and HAPs. The toxic product yields may be quantified from the gas concentrations and mass feed rate during the steady state burn period. 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. Polyurethane is widely used, with its two major applications, soft furnishings and insulation, having low thermal inertia, and hence enhanced flammability. The two main families of polyols used are polyether polyols and polyester polyols (Fig. The yields of some of the most toxic gases from unwanted fires (such as CO, HCN and some organic irritants) have been demonstrated to be directly related to the combustion conditions (Purser 2002). In particular, the ventilation condition has a . The rigid polyurethane foam yielded ~55mgg1 CO and ~0.5mgg1 of HCN. Both types of foam yielded very similar products at temperatures above 600C. This slight decrease is probably within the limits of experimental error, as it does not follow the general trend shown by most materials. NIST performed the experimental burn tests 1 on 4-inch (10-cm) thick by 4 ft x 4 ft (1.2 m x 1.2 m) wide polyurethane foam slabs. Babrauskas V, Lawson JR, Walton WD, Twilley WH (1982) Upholstered Furniture Heat Release Rates Measured with a Furniture Calorimeter. These VOCs come mainly from the polyurethane used in the mattress, but also from other chemicals used in flame retardants and plastics, the researchers said. Appropriate formulation affords a degree of control over the cross-linking in the polymer without the need for additional cross-linking agents. Preliminary calculations suggested that 27% of the TDI should be recovered as DAT. While this may occur to some degree, it is generally accepted that the majority of the diisocyanates produced in the decomposition of polyurethanes are either volatilised or converted into their amine derivative and then volatilised. Does the foam give off toxic fumes if burned? By using infrared analysis, the authors were able to detect a range of compounds at each step, as summarised in Fig. The non-flaming decomposition of polyurethanes in air or nitrogen can be summarised effectively usinga generalised mechanism based on the available literature (Fig. 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. Equation Levin BC, Fowell AJ, Birky MM, Paabo M, Stolte A, Malek D (1982) Further development of a test method for the assessment of the acute inhalation toxicity of combustion products. Polymer Degradation and Stability 98:535541, Anderson RA, Watson AA, Harland WA (1981) Fire Deaths in the Glasgow Area: I General Considerations and Pathology. Reliable rate of heat release, fire effluent toxicity and smoke generation data are all essential components of such an assessment. For the range of materials investigated, the authors also noted that those containing fire retardants (including the CMHR-PUF and PIR) resulted in a higher recovery fraction of fuel N as HCN. Refer to MSDS. Woolley WD, Wadley AI, Field P (1972) Studies of the thermal decomposition of flexible polyurethane foams in air. It can be used for testing samples 100100mm and up to 50mm thick, in both the horizontal and vertical orientation. Foam: Fire Hazard and Fire Barrier | Monolithic.org Similarly, well-ventilated fires are generally small, and of low toxicity. Damage was most severe to the exterior. The uptake, distribution, metabolism and excretion of cyanide is much more complex than for CO and quantifying CN- in fire victims is more expensive and not routinely undertaken. 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). Toxicology 115:7, Henneken H, Vogel M, Karst U (2007) Determination of airborne isocyanates. The half-scale ISO 9705 experiments showed a wider range of ventilation conditions up to ~2.0. 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). In addition totheir flammability, polyurethanes form carbon monoxide, hydrogen cyanide and other toxic products on decomposition and combustion. Isocyanates should be considered when assessing the fire toxicity of polyurethane foams, due to their acute irritating effects and chronic effects associated with exposure. (1986) investigated the toxicity of flexible polyurethane foam and a polyester fabric both separately and together. This value decreased to 18mgg1 at ~2.0. It gives off toxic gasses and smoke, which makes it difficult to evacuate and put out a fire. Unfortunately, your body heat appears . Woolley WD, Fardell PJ, Buckland IG (1975) The Thermal Decomposition Products of Rigid Polyurethane. Similarly to the trend reported by Stec and Hull (2011) in well-ventilated conditions, this can be attributed to gas phase free radical quenching in the material by the chlorine present in both the CMHR-PUF and PIR (2.53% and 3.56% chlorine by weight, respectively).
Loss Of Appetite, Nausea Fatigue Diarrhea Headache, Irwindale Police Department, Articles P