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The Grenfell Tower fire in central London, started within a flat, engulfed the whole 24 storey building in flames, killed 72 people and spread toxic effluent via the plume and particulate deposits. Soil samples from 6 locations up to 1,2 km from the Tower, together with semi-burnt fire debris and char samples, were collected 1 and 6 months after the fire. Additionally, dust samples and condensates were collected from a flat 160 m away from the Tower after 17 months. Samples were analysed for common potentially toxic components of fire effluents and synthetic vitreous fibres. Samples collected within 140 m of the Tower showed, amongst other toxicants, polychlorinated dibenzo-p-dioxin concentrations 60 times greater than UK urban reference soil levels; benzene levels were 40 times greater; levels of 6 key polycyclic aromatic hydrocarbons (PAHs) were approximately 160 times greater. PAHs levels are approximately 20 times greater than those reported from nearby Hyde Park before the fire. To explain the presence of these pyrogenic contaminants char and partially burnt debris were also collected and analysed. Benzene, PAHs, isocyanates and phosphorus flame retardants were found. Hydrogen cyanide and synthetic vitreous fibres were present in both soil and debris. Particulate and pyrogenic contamination in the immediate vicinity is clearly evident, and may have leached out of fire debris, char and dust. Further analysis of the area around the Tower is necessary to understand potential health risks. • Pyrogenic contamination in the immediate vicinity of the Tower was clearly evident. • PCDD/Fs, PAHs, and benzene levels were greater than UK urban reference soil levels. • Hydrogen cyanide and synthetic vitreous fibres were present in both soil and debris. • Isocyanates, flame retardants, PAHs and benzene were found in char and debris. • Further analysis around the Tower is necessary to understand possible health risks. [ABSTRACT FROM AUTHOR]

In this study, we described the synthesis of the derivatives of thiosemicarbazide, dicarboximide, 1,2,4-triazole-5-thione and 4-oxo-1,3-thiazolidine. Two different dicarboxylic acid anhydrides reacted with 4-substituted-3-thiosemicarbazide, and derivatives of thiosemicarbazide and dicarboximide were obtained. Next, cyclization reaction of dicarboximide derivatives in alkaline media was used to prepare 1,2,4-triazole-5-thione. The 4-oxo-1,3-thiazolidine was synthesized by the reaction of dicarboximide with ethyl bromoacetate. All obtained derivatives were analysed by 1H and 13C NMR spectra, and for one compound, the X-ray crystallography was done. Antimicrobial, antiviral and in vitro evaluations of cytotoxicity were examined. According to the preliminary antiviral screening, compounds 3 and 4 presented the antiviral activity against HSV-1 and CVB3. Additionally, compound 3 shows selective in vitro toxic effect against human epithelial cells FaDu, without affecting normal animal cell line (Vero). The same derivatives 3 and 4 also displayed a wide spectrum of antimicrobial activity against reference microorganisms and indicated both antibacterial and antifungal potential activities. [ABSTRACT FROM AUTHOR]

Reaction of phenoxyacetic acid hydrazide with isocyanate was used to the synthesis of new semicarbazide derivatives. Cyclization of these compounds in a 2% aqueous solution of sodium hydroxide led to formation of 1,2,4-triazole-3-one. The chemical structure of synthesized compounds was confirmed by elemental analysis and spectroscopic methods (1H and 13C NMR). On the basis of the NMR, spectra were found that cyclic compounds 1,2,4-triazole exist in the -one form. Moreover, all derivatives were examined for their in vitro activity against some species of bacteria. New compounds presented mild or moderate antimicrobial activity only against reference Gram-positive bacteria. Two derivatives (one semicarbazide and one triazole) showed bactericidal or bacteriostatic activity. [ABSTRACT FROM AUTHOR]

Fire toxicity is the largest cause of death and injury from unwanted fires, yet it is the least well studied area of fire science and engineering. Fire toxicity increases by factors up to 50, as the fire becomes under-ventilated. This has proved difficult, but not impossible, to replicate in a controlled way on a bench-scale. Clear correlations have been observed between the stoichiometric equivalence ratio, and the yields of the major asphyxiants, carbon monoxide and hydrogen cyanide. In addition, irritant components of fire effluents, which have an instantaneous effect, can incapacitate fire victims, trapping them in a fire. However, the longer term toxicants present in fire effluents, such as the carcinogenic polycyclic aromatic hydrocarbons, and the microscopic particulates which result from their agglomeration are probably responsible for hundreds or thousands more deaths than the acute asphyxiants and irritants. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) have attracted considerable interest due to their unique physical, chemical, optical and electrical properties opening avenues for a large number of industrial applications. They have shown potential as fire retardant additives in polymers, reducing heat release rate and increasing time to ignition in a number of polymers. Relevant work on the types, properties and applications has been reviewed particularly considering their application in fire situations. There are concerns over the health risks associated with CNTs and many papers have likened CNTs to the health problems associated with asbestos. There are contradictions relating to the toxicity of CNTs with some papers reporting that they are toxic while others state the opposite. Directly comparing various studies is difficult because CNTs come in many combinations of size, type, purity levels and source. CNTs can potentially be released from polymers during the combustion process where human exposure may occur. While this review has shed some light regarding issues relating to toxicity under different fire scenarios much more thorough work is needed to investigate toxicity of CNTs and their evolution from CNT–polymer nanocomposites in order to reach firm conclusions. [ABSTRACT FROM AUTHOR]

Newly obtained derivatives ofN-substituted amides of 3-(3-ethylthio-1,2,4-triazol-5-yl)propenoic acid were analyzed by reversed phase high performance liquid chromatography and thin layer chromatography using the RP-18 phase as stationary phase and the mixtures of methanol, water and ammonium buffer as mobile phase. Based on the relationships between the retention factors (logkandRM) and the concentration of organic modifier in water (ϕ), the lipophilicity chromatographic parameters (logkWandRMW) were obtained by the extrapolation method. Lipophilicity parameter was experimentally determined using seven standard solutes with knownlogPOWvalues, which were analyzed under the same chromatographic conditions as tested compounds. The calculatedlogPparameters using ALOGPs software were computed. In order to confirm the validity of these chromatographic methods, the relationships between the chromatographic lipophilicity parameters and calculatedlogPparameters were prepared. [ABSTRACT FROM PUBLISHER]

Abstract: Standard industry formulations of flame retarded aliphatic polyamides, meeting UL 94 V-0, have been burned under controlled conditions, and the yields of the major asphyxiants, carbon monoxide (CO) and hydrogen cyanide (HCN) have been quantified. Although both the combination of aluminium phosphinate and melamine polyphosphate, and the combination of brominated polystyrene and antimony oxide, inhibit combustion reactions in the gas phase, this study shows that the phosphorus causes a much smaller increase in the CO and HCN yields than antimony-bromine. The mechanisms of CO and HCN generation and destruction are related to the flame inhibition reactions. Both CO and HCN form early in the flame, and the OH radical is critical for their destruction. Crucial, in the context of the flame inhibition mechanism, is the observation that the phosphorus system reduces the H and O radical concentrations without a corresponding decrease in the OH radical concentration; conversely, the bromine system reduces all three of the key radical concentrations, H, O and OH, and thus increases the fire toxicity, by inhibiting decomposition of CO and HCN. Moreover, while the phosphorus flame retardant is effective as an ignition suppressant at lower temperatures (corresponding to early flaming), this is effect “switches off” at high temperatures, minimising the potential increase in fire toxicity, once the fire develops. Since flame retardants are most effective as ignition suppressants, and at the early stages of flaming combustion, while most fire deaths and injuries result from toxic gas inhalation from more developed fires, it is clearly advantageous to have an effective gas phase flame retardant which only causes a small increase in the toxic product yields. [Copyright &y& Elsevier]

The properties of 21 1,2,4-triazoles, relevant to their pharmacokinetics, were investigated using experimental methods and in silico calculations. The lipophilicities of the compounds were determined experimentally using reversed-phase chromatography and liquid chromatography with micellar mobile phases, or they were calculated in silico from their molecular structures. In the reversed-phase technique, an octadecylsilyl, immobilized artificial membrane and immobilized cholesterol were used as the stationary phases. Biological descriptors of compounds, i.e. log BB, log KHSA, Caco -2, and fu,brain, were determined in silico by using ACD/Percepta software. Principal component analysis was used to indicate similarities between chromatographic, partitioning, and biological variables. Highly significant relationships were determined to exist between the chromatographic parameters and the biological descriptors, especially for log BB and log KHSA. The chromatographic parameters measured on the cholesterol column were recommended for use in predicting the lipophilic and biological properties of the 1,2,4-triazoles that were tested. [ABSTRACT FROM AUTHOR]

The novel N-(substituted-thioureido)aminobicyclo dicarboximide and 3,4-disubstituted 1,2,4-triazolino-5-thione were synthesized and their antimicrobial and antituberculosis activities were examined. Selected dicarboxylic acid anhydrides were used to obtain derivatives of thiosemicarbazide and dicarboximide. Dicarboximides were also cyclized in the presence of an alkaline solution giving 1,2,4-triazolino-5-thione. The chemical structure of all compounds was confirmed by IR, 1H NMR, 13C NMR, the X-ray crystallography ( 6, 11) and elemental analysis. Antimicrobial and antituberculosis activities of the derivatives were measured. [ABSTRACT FROM AUTHOR]

A fire experiment conducted in a British 1950s-style house is described. Measurements of temperature, smoke, CO, CO2, and O2 were taken in the Lounge, stairwell, and front and back bedrooms. The front bedroom door was wedged open, while the door to the back bedroom was wedged closed. Contrary to expectations and despite the relatively small fire load, analysis and hazard calculations show permeation of toxic fire gases throughout the property with lethal concentrations of effluent being measured at each sampling point. A generally poor state of repair and missing carpets in the upper story contributed to a high degree of gas and smoke permeation. The available egress time was calculated as the time before the main escape route became impassable. Given known human responses to fire, such an incident could have caused fatalities to sleeping or otherwise immobile occupants. [ABSTRACT FROM AUTHOR]

In a reaction of hydrazides of cyclohexylacetic acid1and phenylacetic acid2with isothiocyanates, respective thiosemicarbazide derivatives3–18were obtained. Further cyclization with 2% NaOH led to the formation of 5-(cyclohexylmethyl/benzyl)-4-substituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones19–34. Structures of all new products were confirmed by analytical and spectroscopic methods. All compounds were screened for their in vitro activity against some species of bacteria and fungi. [Supplementary materials are available for this article. Go to the publisher's online edition ofPhosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.] [ABSTRACT FROM AUTHOR]

Abstract: Aryl polyetheretherketones (PEEK) show remarkable thermal stability and low flammability, with an onset of decomposition at around 600 °C, and 60% char formation in the cone calorimeter at 60 kW m−2. However, at lower heat fluxes, and in other small-scale flammability tests, it is difficult to obtain consistent results. PEEK polymer has been modified with different types of carbon nanotubes (CNT), leading to modest improvements in the burning behaviour at addition levels between 0.1 and 1%. The characterisation of the composites indicated satisfactory dispersion, modest enhancements in mechanical properties and thermal stability, and reductions of peak heat release rate for the best performing formulations. Significant differences in thermal stability and burning behaviour were observed as a function of the nature of the CNTs, and the loading level within the polymer. [Copyright &y& Elsevier]

Background Renalase is a novel flavin adenine dinucleotide-dependent amine oxidase that is secreted by the kidney. It circulates in the blood and modulates the cardiac function and systemic blood pressure. Insufficiency of renalase in patients with chronic kidney disease may explain the frequent occurrence of hypertension among patients with end-stage renal disease (ESRD) and an increased risk of cardiovascular events in this group. The aim of the study was to assess the relationship of two renalase gene polymorphisms with hypertension in dialysed patients. Methods Rs2576178 polymorphism was genotyped in 369 patients, rs10887800 polymorphism was genotyped in 421 dialysed patients, using polymerase chain reaction (PCR) and subsequent cleavage with Msp I and Pst I restriction endonucleases. Results Genotype distribution and allele frequencies of rs2576178 polymorphism were compared in the following subgroups of patients: dialysed patients with hypertension: ESRD HY + (n = 200) and dialysed patients without hypertension: ESRD HY − (n = 169). There was a significant difference in the frequency of the G allele carriers. G allele carriers were associated with a 1.55 times higher risk of hypertension [odds ratio (OR) = 1.55; 95% confidence interval (CI): 1.023–2.357, P = 0.039]. Distribution of genotypes and frequencies of alleles of rs10887800 polymorphism were compared in the following subgroups of patients: ESRD HY + (n = 278) and ESRD HY − (n = 143). The G allele carriers were recognized with a significantly higher frequency in ESRD HY + patients (0.46 in ESRD HY + versus 0.37 in ESRD HY − ) [OR = 1.76; 95% CI: (1.159–2.667, P = 0.008)]. Conclusions Our results are the first to suggest an association between renalase gene polymorphisms analysed and hypertension in dialysed patients. It may be an important step towards gaining a deeper insight into cardiovascular pathophysiology. Furthermore, it might provide an optimal treatment and better prognosis for patients with chronic kidney disease. [ABSTRACT FROM AUTHOR]

Abstract: Ethylene-vinyl acetate (EVA) copolymers compounded with mineral filler fire retardants, such as aluminium hydroxide (ATH) and magnesium hydroxide (MH) represent an important class of fire-safe materials, especially as PVC replacements in the cable industry. The thermal decomposition of these materials has been investigated in the presence or absence of montmorillonite nanoclay using simultaneous thermal analysis (STA) interfaced to a Fourier transform infrared spectrometer (FTIR) for analysis of volatiles. STA-FTIR spectra were deconvoluted to give profiles of individual species'' evolution as a function of temperature, in order to identify the individual processes involved. The first step of the degradation, the loss of acetic acid by chain stripping, has been shown to be accelerated by the presence of clay but changed to a loss of acetone by mineral filler fire retardants. This is ascribed to the catalytic properties of the freshly formed alumina and magnesia surfaces. The products of the second step of decomposition are also changed by the various additives. [Copyright &y& Elsevier]

Abstract: Gaseous fire effluents contain a mixture of components, some of which are present in toxicologically significant proportions, together with water vapour and particulate matter, representing a significant challenge to the analyst. The most useful information is obtained from fire gases at about 180°C where water and most organic species are volatile. Despite this, it is often necessary to sample and measure fire effluents for prediction of fire toxicity, estimation of the environmental impact of fires, and to understand their behaviour. Gas phase Fourier Transform Infrared (FTIR) spectroscopy has the potential to measure almost all volatiles on a continuous basis during fire. This paper considers the key parameters, which must be carefully measured and controlled in order to obtain reliable calibration data. It evaluates a number of techniques designed for calibrating an FTIR spectrometer for use in fire gas analysis with conclusions on the best system for use for each species and for specific fire tests or experimental scenarios. As few molecules in the gas phase infrared spectrum obey the Beer-Lambert law, a full set of infrared spectra at different concentrations must be obtained for each target analyte, for the actual spectrophotometer—gas cell configuration in use. In some cases, stable standard mixtures are available, and these only have to be quantitatively diluted. In other cases reactive gases such as hydrogen halides must be generated quantitatively in situ, or vapours must be generated from volatile liquids under controlled conditions, in order to obtain calibration spectra. In each case, care must be taken in the design of the sampling line and calibration system, paying particular attention to the temperature, pressure and gas flow. Gas phase FTIR is a powerful analytical tool, but requires a significant investment in time and equipment before quantitative analysis can be undertaken. Unless care is taken to ensure constant temperature and pressure in the sample lines and gas cell, significant errors will result. [Copyright &y& Elsevier]

Abstract: Polypropylene (PP) and Polyamide 6 (PA6) samples, with and without fire retardants (FR) (ammonium polyphosphate in PP, and a mixture of organic aluminium phosphinate and melamine polyphosphate (OP 1311) in PA 6) and nanofillers (NC) were burned under different fire conditions in order to compare their toxic product yields. Fire effluents (CO, smoke and hydrocarbons) were generated using a steady state tube furnace (BS 7900, ISO TS 19700) for the separate materials and fire retarded and nanocomposite modifications of these materials under flaming conditions. Under well-ventilated conditions yields of carbon monoxide (CO) for all PP samples are similar, whereas for PA6 samples much higher yields of CO for PA6 + FR and PA6 + NC are observed. The highest yields of CO occur for both pure polymers in under-ventilated fire conditions when fire retardant and nanoclay are combined together. For PP the smoke is fairly independent of fire condition, but the PP + FR + NC shows less agglomeration. For PA6 the sample containing OP 1311 shows consistently higher smoke yields. For hydrocarbon yields similar effects are observed for both PP and PA6 polymers; the highest yields are for PA6 + NC, except under-ventilated fires where PA6 + FR produce the most; for PA6 + FR + NC samples the lowest yields are observed, compared to either NC or FR formulations. [Copyright &y& Elsevier]

Abstract: A significant element in the cost of a new building is devoted to fire safety. Energy efficiency drives the replacement of traditional building materials with lightweight insulation materials, which, if flammable can contribute to the fire load. Most fire deaths arise from inhalation of toxic gases. The fire toxicity of six insulation materials (glass wool, stone wool, expanded polystyrene foam, phenolic foam, polyurethane foam and polyisocyanurate foam) was investigated under a range of fire conditions. Two of the materials, stone wool and glass wool failed to ignite and gave consistently low yields of all of the toxic products. The toxicities of the effluents, showing the contribution of individual toxic components, are compared using the fractional effective dose (FED) model and LC50 (the mass required per unit volume to generate a lethal atmosphere under specified conditions). For polyisocyanurate and polyurethane foam this shows a significant contribution from hydrogen cyanide resulting in doubling of the overall toxicity, as the fire condition changes from well-ventilated to under-ventilated. These materials showed an order of increasing fire toxicity, from stone wool (least toxic), glass wool, polystyrene, phenolic, polyurethane to polyisocyanurate foam (most toxic). [ABSTRACT FROM AUTHOR]

Abstract: New N-substituted amides of 3-(3-ethylthio-1,2,4-triazol-5-yl)propenoic acid (2–12) were designed and prepared by the condensation reaction of exo-S-ethyl-7-oxabicyclo-[2.2.1]-hept-5-ene-2,3-dicarbonyl isothiosemicarbazide (1) with primary amines. The chemical structure of all compounds was confirmed by IR, 1H NMR, 13C NMR spectra, the X-ray crystallography (for compounds 8, 11, 12) and elemental analysis. Moreover, compounds 9–11 were screened for their anticancer activity. Compounds 9 (in concentrations of 0.32mM and 0.16mM), 10 (in concentrations of 0.28mM and 0.14mM), and 11 (in concentrations of 0.35mM and 0.17mM) were found to be evidently effective in vitro against lung cell line (IC50). The distinctly marked antiproliferative effect of compounds 9 and 10 in breast carcinoma cells in vitro was ascertained. Moreover, the lowest cytotoxicity of compound 9 in concentrations of 0.16mM and 0.03mM against the normal skin fibroblast cell line and breast carcinoma cell in vitro after 24- and 48-h periods of incubation was noticed in this study. [Copyright &y& Elsevier]

Abstract: The steady state tube furnace (Purser furnace, ISO TS 19700) has been developed specifically to replicate the generation of toxic products from real fires under different fire conditions on a bench-scale. Steady state burning is achieved by driving the sample into a furnace of increasing heat flux at a fixed rate and recording the product yields over a steady state period in the middle of the run. The furnace, sample, and effluent dilution chamber temperature profiles are presented to characterise the conditions in the apparatus. The distribution of smoke in the mixing chamber has been investigated to demonstrate the efficiency of mixing in the effluent dilution chamber. The heat flux applied to the sample at various points through the furnace has been measured, showing that conditions vary from those typical of pre-flaming to fully developed fires. An initial investigation of the repeatability and interlaboratory reproducibility has been undertaken, showing acceptable low levels of uncertainty in the toxic product yields. [Copyright &y& Elsevier]

Abstract: Human lymphocyte antigen-G (HLA-G) is an immunosuppressive molecule that induces functional silencing of immune component cells and can be responsible for immunosuppression in patients with multiple myeloma (MM). Immune dysfunction is an important feature of MM and leads to infections as well as may promote disease progression. Ninety-five patients were included in this study. In MM, the sHLA-G levels were increased when compared to healthy volunteers and the levels of sHLA-G correlated with concentration of creatinine. Interestingly, we detected high levels of sHLA-G in patients with renal insufficiency without any malignant disease but levels were lower than in MM. [Copyright &y& Elsevier]

Inhalation of airborne isocyanates is associated with acute asthma attacks and inflammation in the respiratory tract as well as cancer. These highly reactive compounds are used as monomers in various applications such as foams for insulation materials and upholstery furniture and are therefore commonly found in fire smoke from insulation materials, such as rigid polyisocyanurate (PIR) foams. Consequently, there is an increasing concern regarding the potential adverse health effects they may cause during this type of exposure. The aim of this study was to investigate the stability of generated isocyanates from aerobic pyrolysis of PIR after sampling in the derivatization solution as well as after sample preparation to establish the optimal storage conditions and rate of degradation. Both airborne and particle-bound isocyanates were collected, using dibutylamine as derivatization agent in a midget impinger and impregnated filter after the impinger. The rapid degradation of the generated isocyanates after sampling emphasizes the need for a prompt sample preparation and analysis, in particular for the collected mono-isocyanates, as the concentration decreased by 50% within 4–8 h. [ABSTRACT FROM AUTHOR]

The aim of the studies was to evaluate the antiproliferative potential against human tumor cell lines of newly synthetized derivatives containing 4-nitrophenyl group, as well as its impact on developmental toxicity in zebrafish model. We selected 1-(4-nitrobenzoyl)-4-ethylsemicarbazide (APS-1) and 1-[(4-nitrophenyl)acetyl]-4-hexyl-thiosemicarbazide (APS-18) for research. The antiproliferative properties of semicarbazide derivatives were assessed against human cancer cell lines derived from hepatocellular adenocarcinoma (HepG2), renal cell carcinoma (769-P), non-small cell lung cancer (NCI-H1563) and glioblastoma multiforme (LN229) in comparison to the physiological human embryonic kidney (HEK-293) cell line. The influence of the tested substances on the cell cycle and apoptosis was also evaluated. Fish embryo acute toxicity test (FET) was performed based on OECD Guidelines (Test No. 236), and was carried out for the first 5 days post fertilization. The following concentrations of APS-1 and APS-18 were tested: 125–2000 μM and 0.125–1000 μM, respectively. The presented studies on the antiproliferative properties of the new semicarbazide derivatives showed that the compounds APS-1 and APS-18 reduce the viability of human tumor lines. Particularly noteworthy is the strong and selective antiproliferative activity of APS-18 against all neoplastic cell lines, in particular against glioblastoma. Against this tumor line, the compound APS-1 showed an effective inhibitory effect. In the FET we noted that the direct exposure of zebrafish embryos to APS-1 and APS-18 in used range of concentration did not cause morphological abnormalities, including cardiotoxicity. On basis of obtained outcomes it could be concluded that APS-1 and APS-18 may constitute models for further research, design and synthesis of new, safer drugs with more favorable anticancer properties. • Antiproliferative potential against cancer cells were studied. • Impact on developmental toxicity in zebrafish model was examined. • Influence on the cell cycle and apoptosis was also evaluated. • In the FET tested agents did not cause morphological abnormalities. • Compounds APS-1 and APS-18 reduce the viability of human tumor lines. [ABSTRACT FROM AUTHOR]

Firefighters' personal protective equipment (PPE) is a potential source of chronic exposure to toxic contaminants commonly released from fires. These contaminants have also been found in fire stations. However, little research characterises the routes via which fire contaminants travel back to fire stations. The UK Firefighter Contamination Survey provides information on firefighters' PPE provision, decontamination, and storage practices. All serving UK firefighters were eligible to take part in the survey, which comprised 64 questions. A total of 10,649 responses were included for analysis, accounting for roughly 24% of the UK's firefighting workforce. Results revealed that most firefighters (84%) de-robe contaminated PPE/workwear after re-entering the appliance cab. There was a significant decreasing tendency to send PPE for cleaning after every incident with increasing seniority of role, length of service, and fire attendance frequency. Around one third of firefighters cleaned PPE after every incident. A number of issues were linked to external professional cleaning services, e.g. shrinkage, fit, turn-around time, and stock of reserve/pooled PPE. PPE storage was found to be a potential source of cross contamination, with almost half of firefighters (45%) indicating clean and dirty PPE is not stored separately. More than half of firefighters (57%) stored fire gloves (an item sent for professional decontamination by only 19% of firefighters, and never cleaned by 20%) within other items of PPE such as helmets, boots and tunic/trouser pockets. The survey's results can be used to target gaps in decontamination measures within UK Fire and Rescue Services. [ABSTRACT FROM AUTHOR]

Firefighters are exposed to toxic chemicals not only from the fire incidents they attend, but also from their contaminated station and/or personal protective equipment (PPE). Little is currently known about firefighters' awareness, attitudes, and behaviours towards contaminants which was assessed in the UK firefighter contamination survey. Results revealed that lack of training on fire effluents and their health outcomes are strongly associated with increased fire smoke/contaminant exposure. Notably, untrained firefighters were at least twice as likely to: never clean personal protective equipment (PPE) (Crude Odds Ratio, OR 2.0, 1.5–2.7), infrequently send their PPE for professional cleaning (OR 2.0, 1.6–2.4), remain in the workwear (t-shirt etc.) worn while attending a fire incident (OR up to 3.6, 2.3–5.6), and indicate that cleaning at fire stations is not taken seriously (OR 2.4, 2.2–2.6). Firefighters personally viewing contamination as a "badge of honour" (BoH) were at least twice as likely to: remain in contaminated PPE after fire incidents (OR 2.3, 1.4–3.9), eat with sooty hands (OR 2.2, 1.9–2.5), notice soot in the nose/throat (OR 3.7, 2.7–5.2), and smell fire smoke on the body for more than a day after incidents (OR 2.0, 1.6–2.4). They were also more likely to indicate that cleaning at fire stations is not taken seriously (OR 2.5, 2.2–2.9) and that fire stations smell of smoke always/most of the time (OR 2.3, 2.0–2.6). Strong links were also found between belief in the BoH and never cleaning PPE (OR 1.9, 1.4–2.7), and eating while wearing contaminated PPE (OR 1.8, 1.5–2.2). [ABSTRACT FROM AUTHOR]

Firefighters suffer an increased risk of cancer from exposures to chemicals released from fires. Our earlier research has found that fire toxicants not only remain on firefighters' PPE, but are also tracked back to fire stations. The UK Firefighter Contamination Survey assesses firefighters' risk of developing cancer due to occupational exposure to fire toxins. Over 4% of surveyed firefighters were found to have a cancer diagnosis, with the age-specific cancer rate up to 323% higher (35–39 year olds) than that of the general population. Firefighters who had served ≥ 15 years were 1.7 times more likely to develop cancer than those who had served less time. Firefighters were at least twice as likely to be diagnosed with cancer if they noticed soot in their nose/throat (odds ratio (OR) = 2.0, 1.1–3.5), or remained in their PPE for more than four hours after attending a fire incident (OR = 2.3, 1.1–5.2). Also associated with an increased likelihood of cancer was: eating while wearing PPE (OR = 1.8, 1.2–2.7); failing to store clean/dirty PPE separately (OR = 1.3, 1.0–1.7); working in a station that smells of fire (OR = 1.3, 1.0–1.8) or not having designated (separated) clean and dirty areas (OR = 1.4, 1.1–1.7); using an on-site washing machine to launder fire hoods (OR = 1.3, 1.0–1.7); feeling that cleaning is not taken seriously at work (OR = 1.5, 1.2–2.0). [ABSTRACT FROM AUTHOR]

Exposure to trauma, high-stress situations, and disrupted sleep are well known risk factors affecting firefighters' mental health. Little is known about the association between firefighters' exposure to fire contaminants and mental health disorders. The UK Firefighter Contamination Survey assessed firefighters' health and capacity for occupational exposure to contaminants. Participants were invited to anonymously complete its 64 questions online. Logistic regression analyses assessed the associations between self-reported mental health disorders and proxies of contaminant exposure. Results found that firefighters who notice soot in their nose/throat for more than a day after attending fires (Odds Ratio (OR) = 1.8, 1.4–2.4), and those who remain in their personal protective equipment (PPE) for over 4 h after fires (OR = 1.9, 1.2–3.1), were nearly twice as likely to report mental health disorders. Significantly increased odds ratios for all three outcomes of interest (anxiety, depression and/or any mental health disorders) were also found among firefighters who take PPE home to clean. Sleeping problems were reported by 61% of firefighters. These firefighters were 4.2 times more likely to report any mental health disorder (OR = 4.2, 3.7–4.9), 2.9 times more likely to report anxiety (OR = 2.9, 2.4–3.5) and 2.3 times more likely to report depression (OR = 2.3, 1.9–2.8) when compared to firefighters who did not report sleep issues. Effective decontamination measures within UK Fire and Rescue Services, together with firefighters' wellness, may play a crucial role in protecting firefighters' mental health. [ABSTRACT FROM AUTHOR]

Genetic variations in the calpain 10 gene (CAPN10) were previously implicated with increased risk of type 2 diabetes (T2DM). We studied the association of single nucleotide polymorphisms in the CAPN10 gene, SNP -43, SNP -19 and SNP -63, with T2DM and its complications. Overall, we examined 1440 individuals: 880 patients with diabetes and 560 healthy subjects, all Caucasians of Polish origin. All subjects were genotyped for the CAPN10 SNPs by polymerase chain reaction (PCR). The frequencies of alleles, genotypes and haplotypes at three studied loci were similar between the groups. However, the -43 SNP was significantly more frequent in T2DM patients with coexisting cardiovascular disease (CVD) than in patients without CVD (p=0.001). The -43 SNP was still significantly associated with the risk of CVD after adjusting for potential risk factors including male gender, age, BMI, dyslipidemia and hypertension. The odds ratio for G allele for CVD+ versus CVD- patients was 1.89, 95% CI 1.52-2.35. None of the studied SNPs was significantly associated with microvascular diabetic complications. There was a tendency to increased frequency of SNP -43 1/1 homozygotes in patients with diabetic retinopathy (p=0.057). The homozygous haplotype combination 121/121 was more frequent in T2DM patients than in non-diabetic controls (18.4% vs 10.5%, p=0.019). In conclusion, the results of our study suggest the significant association of SNP -43 with the risk of CVD coexisting with T2DM. We also observed that 121/121 haplotype was associated with T2DM in the studied population. [ABSTRACT FROM AUTHOR]

Abstract: Ultradeformable liposomes are stress-responsive phospholipid vesicles that have been investigated extensively in transdermal delivery. In this study, the suitability of ultradeformable liposomes for pulmonary delivery was investigated. Aerosols of ultradeformable liposomes were generated using air-jet, ultrasonic or vibrating-mesh nebulizers and their stability during aerosol generation was evaluated using salbutamol sulphate as a model hydrophilic drug. Although delivery of ultradeformable liposome aerosols in high fine particle fraction was achievable, the vesicles were very unstable to nebulization so that up to 98% drug losses were demonstrated. Conventional liposomes were relatively less unstable to nebulization. Moreover, ultradeformable liposomes tended to aggregate during nebulization whilst conventional vesicles demonstrated a “size fractionation” behaviour, with smaller liposomes delivered to the lower stage of the impinger and larger vesicles to the upper stage. A release study conducted for 2h showed that ultradeformable liposomes retained only 30% of the originally entrapped drug, which was increased to 53% by inclusion of cholesterol within the formulations. By contrast, conventional liposomes retained 60–70% of the originally entrapped drug. The differences between ultradeformable liposomes and liposomes were attributed to the presence of ethanol or Tween 80 within the elastic vesicle formulations. Overall, this study demonstrated, contrary to our expectation, that materials included with the aim of making the liposomes more elastic and ultradeformable to enhance delivery from nebulizers were in fact responsible for vesicle instability during nebulization and high leakage rates of the drug. [Copyright &y& Elsevier]

Abstract: Polyamide 6 (PA 6) and polypropylene (PP) containing fire retardants, nanofillers or a combination of both additives have been investigated using the steady state tube furnace (ISO TS 19700). The samples were tested under three different fire conditions, to determine the effect of additives on the soot production or toxic product yields. The particle size distribution of the soot was investigated with a cascade impactor, and the separated soot fractions examined by SEM. The predicted deposition based on aerodynamic size of particulates in the human respiratory tract shows clear differences between the pure polymer and its additive counterparts. In all ventilation conditions the virgin polymer produces the least amount of soot, both the additives used (fire retardant and nanoclay) increase the amount of soot, mainly within 0.5–1.0 μm range, for each fire condition. A large contribution to the total soot mass originated particles smaller than 0.5 μm. [Copyright &y& Elsevier]

The condensation of endo- S-methyl- N′-(bicyclo[2.2.1]hept-5-ene-2,3-dicarbonyl) isothiosemicarbazide with 12 primary amines was investigated. The molecular structure of all new products ( 3a- 3l) was confirmed by spectroscopic methods, including 1D/2D NMR, IR spectroscopy and mass spectrometry, and an X-ray crystallography of three selected representative amide crystals. The 2,3-disubstitution of norbornene ( endo-bicyclo[2.2.1]hept-5-ene) unit stabilizes overall cisoid orientation of substituents. Spectroscopic and structural analyses indicate that for the series of 12 derivatives the rigid molecular part is endo-bicyclo[2.2.1]hept-5-ene-2-carboxamide fragment. The specific orientation of the 3-(methylthio)-1 H-1,2,4-triazole unit, second substituent to the norbornene skeleton, is correlated with the chemical character of N-amide substituents. Phenyl derivatives stabilize transoid orientation of the N-H and C=O bonds, whereas the alkyl (methylene or methine) spacer promotes cisoid orientation of these bonds and provides possibility for an intramolecular hydrogen bonding. The solid-state IR spectra and X-ray analysis indicate three patterns of intermolecular association in this series of crystals. Hydrogen bonds observed in crystals influence positions of vibrational bands corresponding to ν (3322-3180 cm), ν (1634-1676 cm), and δ (1600-1500 cm). [ABSTRACT FROM AUTHOR]

Abstract: The fire retardance and thermal stability of soybean-based copolymers reactively modified by copolymerization with trimethylsilylstyrene (SiST) and tris-(4-vinylphenylboroxine) (BST) have been compared with those prepared with equivalent amounts of the additive 1,3-diphenyl-1,1,3,3-tetramethyldisiloxane (SiAD) and tris-(phenylboroxine) (BAD) and with the heteroatom-free soybean-based copolymers. The best results are obtained for the boron-containing copolymers. The reactive or additive approach is a significant factor in terms of the level of fire retardance achieved. [Copyright &y& Elsevier]

Due to the variability and ability of tumor to mutate, as well as the heterogeneity of tumor tissue, such drugs are sought that would act selectively and multidirectionally on the cancer cell. Therefore, two newly synthesized semicarbazide structured substances were evaluated for anticancer properties in our study: 1a and 1b. In order to evaluate the cytotoxicity and selectivity of the tested compounds, MTT and Neutral Red uptake assay on cell lines (HEK293, LN229, 769-P, HepG2 and NCI-H1563) and cell cycle analysis were performed. Acute toxicity and cardiotoxicity were also evaluated in the zebrafish model. The tested compounds (1a , 1b) showed cytotoxic activity, with the greatest selectivity noted against the glioblastoma multiforme cell line (LN229). However, compound 1b showed stronger selective activity than 1a. Both of compounds were shown to significantly affect the M phase of the cell cycle. Whereas, the conducted toxicological examination of newly synthesized thiosemicarbazide derivates showed, that direct exposition of Danio rerio embryos to compound 1a , but not 1b , causes a concentration-dependent increase in developmental malformations, indicating possible teratogenic effects. [Display omitted] • Thiosemicarbazide derivatives showed cytotoxicity activity. • 1b (nitrophenylacetyl grouping) had stronger selective activity against tumor cells. • 1a (nitrobenzoyl grouping) had a lower selective activity against tumor cells. • 1a , but not 1b , causes more developmental defects (possible teratogenic effect). [ABSTRACT FROM AUTHOR]

Highlights • First report relating fire properties of construction products to the Grenfell fire. • Flammability increases by factors of 10 to 100 from best to worst products. • Smoke toxicity 15 times greater for polyisocyanurate insulation than mineral wool. • Novel fire growth mechanism shows flaming polyethene drips igniting insulation foam. • Simple models able to predict fire behaviour in BS8414 test costing 100 times more. Abstract The 2017 Grenfell Tower fire spread rapidly around the combustible façade system on the outside of the building, killing 72 people. We used a range of micro- and bench-scale methods to understand the fire behaviour of different types of façade product, including those used on the Tower, in order to explain the speed, ferocity and lethality of the fire. Compared to the least flammable panels, polyethylene-aluminium composites showed 55x greater peak heat release rates (pHRR) and 70x greater total heat release (THR), while widely-used high-pressure laminate panels showed 25x greater pHRR and 115x greater THR. Compared to the least combustible insulation products, polyisocyanurate foam showed 16x greater pHRR and 35x greater THR, while phenolic foam showed 9x greater pHRR and 48x greater THR. A few burning drips of polyethylene from the panelling are enough to ignite the foam insulation, providing a novel explanation for rapid flame-spread within the facade. Smoke from polyisocyanurates was 15x, and phenolics 5x more toxic than from mineral wool insulation. 1 kg of burning polyisocyanurate insulation is sufficient to fill a 50m3 room with an incapacitating and ultimately lethal effluent. Simple, additive models are proposed, which provide the same rank order as BS8414 large-scale regulatory tests. [ABSTRACT FROM AUTHOR]

Four sandwich panel rooms were constructed as prescribed in the ISO 13784-1 test. However, the construction followed normal industry practice, and the panels were also subjected to the kinds of damage typically found in commercial premises, although such damage may not typically be concentrated in such a small room. The fire load was increased to simulate fires actually occurring in commercial premises by stepping up the propane burner output from the usual maximum of 300-600 kW, and by placing a substantial wooden crib in two of the rooms. The results showed significant differences in fire growth rate and burning behaviour between those panels filled with polyisocyanurate (PIR) and those filled with stone wool in both the experiments without and with the wooden crib. Most significantly, the PIR pyrolysis products caused earlier ignition (by radiation from above) of the wooden crib 11 min into the experiment (1 min after the burner was stepped up to 300 kW), whereas the crib ignited 22 min into the test (2 min after the burner had been stepped up to 600 kW, which is beyond the test standard both in time and heat input) for the stone wool panels. This interaction between building and contents is most often ignored in fire safety assessments. After a few minutes, the PIR pyrolysis products that escaped outside the room, from between the panels, ignited. The extra thermal exposure from the PIR-fuelled flames distorted the panels, which in turn exposed more PIR, resulting in large flames on both the inside and outside of the enclosure. From a fire safety perspective this is most important as it shows that with the large fire loads that are commonly found in commercial premises, steel-faced PIR filled panels are not capable of acting as fire barriers, and may support flame spread through compartment walls and ceilings. In addition, the PIR panelled rooms produced very large quantities of dense smoke and toxic effluents, whereas the stone wool panelled rooms produced small amounts of light smoke of lower toxicity. Furthermore, the experiments showed that modifications to the standard test can lead to extremely different outcomes for some of the products. As the modifications simulated real-life situations, it seems important to discuss whether the standard is robust enough for property safety scenarios encountered in industrial premises. [ABSTRACT FROM AUTHOR]

This paper uses fire statistics to show the importance of fire toxicity on fire deaths and injuries, and the importance of upholstered furniture and bedding on fatalities from unwanted fires. The aim was to compare the fire hazards (fire growth and smoke toxicity) using different upholstery materials. Four compositions of sofa-bed were compared: three meeting UK Furniture Flammability Regulations (FFR), and one using materials without flame retardants intended for the mainland European market. Two of the UK sofa-beds relied on chemical flame retardants to meet the FFR, the third used natural materials and a technical weave in order to pass the test. Each composition was tested in the bench-scale cone calorimeter (ISO 5660) and burnt as a whole sofa-bed in a sofa configuration in a 3.4 × 2.25 × 2.4 m 3 test room. All of the sofas were ignited with a No. 7 wood crib; the temperatures and yields of toxic products are reported. The sofa-beds containing flame retardants burnt somewhat more slowly than the non-flame retarded EU sofa-bed, but in doing so produced significantly greater quantities of the main fire toxicants, carbon monoxide and hydrogen cyanide. Assessment of the effluents’ potential to incapacitate and kill is provided showing the two UK flame retardant sofa-beds to be the most dangerous, followed by the sofa-bed made with European materials. The UK sofa-bed made only from natural materials (Cottonsafe ® ) burnt very slowly and produced very low concentrations of toxic gases. Including fire toxicity in the FFR would reduce the chemical flame retardants and improve fire safety. [ABSTRACT FROM AUTHOR]

Dwelling fires have changed over the years because building contents and the materials used in then have changed. They all contribute to an ever-growing diversity of chemical species found in fires, many of them highly toxic. These arise largely from the changing nature of materials in interior finishes and furniture, with an increasing content of synthetic materials containing higher levels of nitrogen, halogen and phosphorus additives. While there is still a belief that carbon monoxide is the major lethal toxic agent in fires, the hydrogen cyanide and acid gases released from these additives are now well-recognised as major contributory causes of incapacitation, morbidity and mortality in domestic fires. Data for the total number of 263 fire death cases in the Mazowieckie region (mainly Warsaw area) of Poland between 2003-2011 for dwellings fires were obtained from pathologists, forensic toxicologists, fire fighters and analysed. Factors contributing to the death such as the findings of the full post mortem examination (age, sex, health status, burns), the toxicological analysis (carbon monoxide, alcohol etc.), and a thorough investigation of the scene (fire conditions, fuel, etc.) were taken into account and are summarised. [ABSTRACT FROM AUTHOR]

Polymer pellets have been burned in 12 large scale tests in under-ventilated conditions in a 2.5 m 3 fire enclosure with attached corridor. The polymers investigated were low density polyethylene (LDPE), polymethyl methacrylate (PMMA), polystyrene (PS), and polyamide 6.6 (PA6.6). The enclosure, based on a scaled-down ISO 9705 room attached to a horizontally divided corridor, has been designed to replicate under-ventilated burning in enclosure fires, while allowing the equivalence ratio to be determined. This provides a more robust, alternative verification of equivalence ratio, based on measured air flow, than the phi meter used in other reported work. Comparison between the yields of carbon monoxide (CO), carbon dioxide (CO 2 ) and hydrogen cyanide (HCN), with values from the same materials from a bench-scale test together with generically similar materials, shows very good agreement, demonstrating the ability of bench-scale apparatuses, such as the steady state tube furnace (ISO 19700) and the fire propagation apparatus (ISO 12136) to replicate the high toxic yields of under-ventilated combustion. Depending on the material, CO yields between 0.1 and 0.25 g/g were obtained for under-ventilated flaming of the four polymers, alongside HCN yields of 0.01–0.02 g/g for PA6.6. [ABSTRACT FROM AUTHOR]

Qualitative results are presented from analysis of volatile and semi-volatile organic compounds (VOCs/SVOCs) obtained through sampling of gaseous effluent and condensed particulates during a series of experimental house fires conducted in a real house. Particular emphasis is given to the 16 polycyclic aromatic hydrocarbons (PAHs) listed by the Environmental Protection Agency due to their potentially carcinogenic effects. The initial fuel packages were either cooking oil or a single sofa; these were burned both alone, and in furnished surroundings. Experiments were performed at different ventilation conditions. Qualitative Gas Chromatography-Mass Spectrometry (GC-MS) analysis found VOC/SVOC releases in the developing stages of the fires, and benzo( a )pyrene – the most carcinogenic PAH – was found in at least one sampling interval in the majority of fires. A number of phosphorus fire retardants were detected, in both the gaseous effluent and particulates, from fires where the initial fuel source was a sofa. Their release during the fire is significant as they pose toxicological concerns separate from those presented by the PAHs. [ABSTRACT FROM AUTHOR]

The effects of cobalt acetate (CoAc), manganese acetate (MnAc), nickel acetate (NiAc) and zinc acetate (ZnAc) as fire retardant additive in intumescent polypropylene (PP) formulations containing PP/ammonium polyphosphate (APP)/pentaerythritol (PER) are reported. The limiting oxygen index (LOI) and vertical burning (UL94) tests and cone calorimetry were used to quantify the enhancement. Environmental chamber rheometry, thermal gravimetric analysis and the morphology of the residual char were used to investigate the mechanism of enhancement. The incorporation of small quantities of metal acetates had a significant influence on the fire behaviour. As an example, 0.7 wt% MnAc improved the UL 94 rating of PP/APP + PER (mass ratio 100/25, with APP/PER = 3/1) sample from V-2 to V-0, while 1 wt% MnAc reduced the peak heat release rate and the total heat release by 18% and 12% in the cone calorimeter. Rheological data, cone calorimetry, and photographs of the residual char showed how the fire retardancy of the systems were affected by the melt viscosity, which depended on the loading of metal acetate. During thermal decomposition, the metal acetates promote the crosslinking of the polymer and the fire retardant, reinforcing the protective intumescent layer. While, the effect is most potent at the optimal metal loadings. At higher MnAc loadings, the benefit of a stronger char is overwhelmed by the adverse effect of crosslinking on the transition char layer. Thus, this paper offers a new insight into the mechanism of the intumescent fire retarded PP system. [ABSTRACT FROM AUTHOR]

Flame retardants are chemical substances that are intended to mitigate fire safety risks posed by a range of goods including furniture, electronics, and building insulation. There are growing concerns about their effectiveness in ensuring fire safety and the potential harms they pose to human health and the environment. In response to these concerns, on 13 June 2022, a roundtable of experts was convened by the UKRI Six Clean Air Strategic Priorities Fund programme 7. The meeting produced a Consensus Statement that summarises the issues around the use of flame retardants, laying out a series of policy recommendations that should lead to more effective fire safety measures and reduce the human and environmental health risks posed by these potentially toxic chemicals. [ABSTRACT FROM AUTHOR]

The aim of this work are experimental and computational structural studies of new derivatives of 1-cyanoacetyl-4-arylsemicarbazide with potential anticancer activity. We considered 10 possible tautomeric forms and ranked them according to their energy of stabilization using quantum chemical calculations with the single point B3LYP DFT method and the basis set 6-311++G(3df, 3pd) of Gaussian09 program. The order of tautomers was identical for all considered compounds with the exception of derivatives 1 , 5 and 10 . Furthermore, we computed HOMO and LUMO orbitals, electrostatic potential maps and non-covalent interaction maps for most stable tautomers. We confirmed the structures of the compounds with application of experimental and computed 1 H, 13 C NMR, IR and Raman spectra. In addition we performed PED analysis in order to assign IR vibrations and computed non-covalent interaction maps. [ABSTRACT FROM AUTHOR]

In recent years, carbon nanotubes (CNTs) have emerged as a promising candidate for improving the flame retardancy of polymer materials, as well as other physical properties. However, few researches have been focused on the influence of this nanoscale material on the combustion toxicity of polymer composites during combustion. In this work, the fire toxicity of polypropylene (PP) composites with intumescent flame retardants (IFRs) and CNTs has been investigated by a Purser Furnace apparatus, which is called steady state tube furnace (SSTF) and enables different fire stages to be created. The Thermo gravimetric analyzer (TGA) and derivative thermo gravimetric analysis (DTG) data indicate that the thermal stability of PP composites was increased by the addition of IFRs or CNTs. However, the SSTF results show that PP samples with IFR or CNTs or both, produced much more carbon monoxide (CO) compared to neat PP during all fire stages, resulting in a much lower CO 2 /CO ratio. Furthermore, an interesting finding is that the effect of CNTs on the smoke production and C x H y yield of the PP samples during the combustion changes with the combustion equivalence ratio. It indicates that the presence of CNTs promote the formation of smoke particulates from hydrocarbon, but this effect only exist when oxygen supply is not adequate. It is also concluded that the air ventilation and combustion temperature play significant roles in the fire effluent production of PP samples and the morphology of soot particulates. [ABSTRACT FROM AUTHOR]

Identification of soot sources is significant in fire investigation and forensic science. In this paper, principal component analysis (PCA) and a back-propagation (BP) neural network model have been used to classify and identify the soot samples from three different kinds of combustible material. Diesel, polystyrene and acrylonitrile butadiene styrene were burnt under the controlled combustion conditions in small-scale burn tests. Based on the matrix data from the GC-MS analysis data, two principal components have been obtained from PCA analysis with the cumulative energy content of 90.21%. Three different kinds of soot sample can be classified with 100% accuracy. A BP neural network model for predicting and identifying the soot source has been further developed. Accurate identification of the unknown samples has been achieved with this trained BP model. This pilot study indicates that PCA and BP neural network methods have potential in the analysis of soot to identify its principle pre-combustion source material. [ABSTRACT FROM AUTHOR]

In this work, GO was functionalizedby a hyper-branched flame retardant,which was synthesized by the reaction of N-aminoethylpiperazine and di(acryloyloxyethyl)methylphosphonate. Subsequently,the resultant functionalized GO (FGO) was incorporated into the cross-linkedpolyethylene (XLPE) to enhance the flame retardancy of the matrix.Transmission electron spectroscopy images indicated that FGO exhibiteduniform dispersion in XLPE matrix and strong adhesion with the matrixby cross-linking, which improved barrier effect due to reduced heatrelease and the free radical transfer between the matrix and graphenenanosheets. The incorporation of FGO into XLPE matrix endowed polymercomposites with flame retardancy and thermal stability. In addition,the homogeneous dispersion of functionalized GO with a hyper-branchedflame retardant in the polymer matrix improved the antioxidation andmechanical properties of XLPE–FGO nanocomposites compared tothe XLPE–GO samples, as demonstrated through the oxidativeinduction temperature and time test, oven aging test and mechanicaltest. [ABSTRACT FROM AUTHOR]

Highlights: [•] A RGO/NiAl-LDH hybrid was synthesized by a simple co-precipitation route. [•] The hybrid showed visible reduction in the PHRR, SPR and COPR of PMMA. [•] The combined effect of RGO/NiAl-LDH contributed to the reduced flammability. [•] This work permits to open a door for potent graphene hybrid in the domains of risk. [ABSTRACT FROM AUTHOR]

The production of carbon monoxide from disposable barbecues in an enclosed room has been investigated. Hazard calculations have shown that lethal concentrations of CO and CO2 can be produced easily. Burning rates and the relative formation of CO and CO2 depend on the ambient oxygen concentration. Smoke does not correlate with CO concentration as it is mostly produced by the combustion of volatile hydrocarbons added to facilitate ignition. In a typical room, this results in smoke clearing before the maximum CO concentration is reached. Smoke obscuration is therefore a poor indicator of the danger posed by CO. This is an important observation for those discovering or attempting to resuscitate or rescue comatose victims. Dilution caused by ventilation is described numerically and has allowed total volumes of CO and CO2 produced to be estimated. [ABSTRACT FROM AUTHOR]

Abstract: Graphene nanosheets coated with Co3O4 and NiO (denoted as GNS–Co3O4 and GNS–NiO) have been facilely synthesized and then melt-mixed with polyamide 6 (PA6) to investigate the fire retardant properties of the composites. The Co3O4 (20–40 nm) and NiO (8–15 nm) nanoparticles are homogeneously dispersed on the graphene surface, which has been demonstrated by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Scanning electron microscopy clearly shows that graphene, GNS–Co3O4 and GNS–NiO are well dispersed in PA6 due to the electrostatic interaction. The visible increment in decomposition temperature and reduction in maximum decomposition rate are observed from thermogravimetric analysis for both PA6/GNS–Co3O4 and PA6/GNS–NiO composites. Testing in the cone calorimeter shows that incorporating GNS–Co3O4 and GNS–NiO confers PA6 with improved fire safety, as evidenced by the obvious delay in time to peak heat release and visible reduction in heat release rate, CO production rate and total smoke production. The result of the smoke density chamber indicates that GNS–Co3O4 and GNS–NiO perform better than bare graphene in inhibiting the smoke emission. The flammable gaseous products are largely reduced with the addition of GNS–Co3O4 and GNS–NiO as revealed from the thermogravimetric analysis/infrared spectrometry. The improvement in the fire safety is mainly due to the combination effect of physical barrier of graphene layers and catalytic carbonization of metal compounds. [Copyright &y& Elsevier]

The retention behavior of biologically active pyrazoles has been determined using RP-18 TLC and IAM chromatography. The experimental parameters of lipophilicity of the studied compounds were determined and compared with calculated partition coefficients obtained by using of different algorithms. The results of lipophilicity-activity relationships and the selected mathematical models (MLR) indicate the important role of lipophilicity in the antibacterial activity of the group of the compounds under consideration. [ABSTRACT FROM AUTHOR]

Abstract: The preparation of a novel fire retardant nanocomposite of poly(ethylene terephthalate) (PET) using nanoscopic α-zirconium phosphate (α-ZrP), by in situ polymerisation was investigated. The novel fire retarded PET nanocomposite, PET-co-DDP/α-ZrP, was synthesized by the direct condensation of terephthalic acid, ethylene glycol, 9,10-dihydro-10[2,3-di(hydroxycarbonyl)propyl]-10-phosphaphenanthrene-10-oxide (DDP) and nano α-ZrP. The morphology, thermal stability and burning behaviour of the nanocomposite with 1wt% α-ZrP loading was investigated. The extent of dispersion of the nanofillers was quantified by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Significant improvements in fire retardant performance were observed for the nanocomposite from limiting oxygen index (increased from 21.2 to 32.6), UL-94 (achieving V-0), and cone calorimetry (reducing both the heat release rate and the total heat released, without reducing the time to ignition). [Copyright &y& Elsevier]