By using infrared analysis, the authors were able to detect a range of compounds at each step, as summarised in Fig. 2007). . The toxic product yields may be quantified from the gas concentrations and mass feed rate during the steady state burn period. 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 (). 6). 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. These isocyanate derived cross-links can include biurets and allophanates (Fig. 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. 1999). The cribs used in the ISO 9705 tests were constructed from PIR sticks which burned rapidly, albeit with minimal damage to the room. EN 2826. But many products or materials continue off-gassing even after the "new smell" has gone awaythe fumes are just much more subtle. The authors did not specify which analytical methods were used in the quantification of the fire gases, only that they were sampled via a sampling bag. At 850C the yield of HCN was higher with 16mgg1 at ~2.0. The average well-ventilated yield of HCN was found to be 4mgg1, while it was 9mgg1 for under-ventilated conditions. This suggests that any amines formed would have reacted with isocyanates in the vapour phase to form ureas, some of which would have condensed to produce the observed waxy white substance. Is Your Mattress Releasing Toxins While You Sleep? - WebMD The NFX generates data intermediate between the well-ventilated and under-ventilated fire conditions. Overall, the report provides access to a large pool of data organised into a material-LC50 and also helps demonstrate that the large majority of data available is for well-ventilated tests. This makes foam mattresses very harmful. 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 rigid polyurethane foam produced slightly more CO than the polyisocyanurate at ~2.0 (240mgg1 vs 225mgg1). As the global usage of polyurethane foams is expected to continue to increase yearly, it is important that the fire community have a clear understanding of the fire toxicity of polyurethane foams and the reasons why they produce significant amounts of toxic gases during combustion. Fire Research Notes 951:p117. In general, isocyanate (R-NCO) exposure causes irritation to the skin, mucous membranes, eyes and respiratory tract (NIOSH 1989). Around 1015% of the nitrogen in the polymer can be converted into HCN with some being released in isocyanates, aminoisocyanates and amines in the fire effluent. The review suggested that the addition of fire retardants did not appear increase the overall combustion toxicity of polyurethane foams. A summary of these structures is shown in Fig. 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. $$ \begin{array}{l}\mathrm{FED}=\left\{\frac{\left[\mathrm{C}\mathrm{O}\right]}{{\mathrm{LC}}_{50,\;\mathrm{C}\mathrm{O}}}+\frac{\left[\mathrm{H}\mathrm{C}\mathrm{N}\right]}{{\mathrm{LC}}_{50,\;\mathrm{H}\mathrm{C}\mathrm{N}}}+\frac{\left[\mathrm{A}\mathrm{G}\mathrm{I}\right]}{{\mathrm{LC}}_{50,\;\mathrm{A}\mathrm{G}\mathrm{I}}}+\frac{\left[\mathrm{O}\mathrm{I}\right]}{{\mathrm{LC}}_{50,\;\mathrm{O}\mathrm{I}}}\dots \right\}\times {\mathrm{V}}_{{\mathrm{CO}}_2}+\mathrm{A}+\frac{21-\left[{\mathrm{O}}_2\right]}{21-5.4}\\ {}{\mathrm{V}}_{{\mathrm{CO}}_2}=1\kern0.36em +\kern0.36em \frac{ \exp \left(0.14\left[{\mathrm{CO}}_2\right]\right)-1}{2}\end{array} $$, $$ \mathrm{FED}={\displaystyle \sum_{t_1}^{t_2}\frac{\left[\mathrm{C}\mathrm{O}\right]}{35\;000}}\;\Delta t+{\displaystyle \sum_{t_1}^{t_2}\frac{ \exp \left(\left[\mathrm{H}\mathrm{C}\mathrm{N}\right]/43\right)}{220}}\;\Delta t $$, $$ \mathrm{F}\mathrm{E}\mathrm{C}=\frac{\left[\mathrm{H}\mathrm{C}\mathrm{l}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{C}\mathrm{l}}}+\frac{\left[\mathrm{H}\mathrm{B}\mathrm{r}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{B}\mathrm{r}}}+\frac{\left[\mathrm{H}\mathrm{F}\right]}{{\mathrm{IC}}_{50,\;\mathrm{H}\mathrm{F}}}+\frac{\left[{\mathrm{SO}}_2\right]}{{\mathrm{IC}}_{50,\;{\mathrm{SO}}_2}}+\frac{\left[{\mathrm{NO}}_2\right]}{{\mathrm{IC}}_{50,\;{\mathrm{NO}}_2}}+\frac{\left[\mathrm{acrolein}\right]}{{\mathrm{IC}}_{50,\;\mathrm{acrolein}}}+\frac{\left[\mathrm{fomaldehyde}\right]}{{\mathrm{IC}}_{50,\;\mathrm{fomaldehyde}}}+{\displaystyle \sum \frac{\left[\mathrm{irritant}\right]}{{\mathrm{IC}}_{50,\;\mathrm{irritant}}}} $$, $$ \mathrm{material}\hbox{-} {\mathrm{LC}}_{50}=\kern0.36em \frac{M}{\mathrm{FED}\times V} $$, https://doi.org/10.1186/s40038-016-0012-3, http://creativecommons.org/licenses/by/4.0/.
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