Triphenyl Phosphate Research Articles

Analysis of potential human accumulation differences and mechanisms of environmental new flame retardants: Based on in vitro experiments and theoretical calculations.

Hundreds of new flame retardants (NFRs) are widely used, causing environmental pollution and threating human health. In this study, based on the interaction of NFRs and human serum albumin (HSA), we assessed the differences in potential human accumulation of 8 NFRs including 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), tetrabromobisphenol A bis(dibromopropyl ether) (TBBPA-DBPE), 2,4,6-tribromophenol (TBP), pentabromophenol (PBP), tri-n-butyl phosphate (TnBP), triphenyl phosphate (TPP), Tri(2-chloroethyl) phosphate (TCEP), and Tri(1,3-dichloro-2-propyl) phosphate (TDCP). All NFRs could bind to HSA and cause slight damage to its structure, suggesting their potential human accumulation ability. Notably, the binding pocket of site 1 was larger than that of site 2, so TBBPA-DBPE with a larger molecular volume exhibited a preference for binding to site 1 and other NFRs with smaller volume bound to site 2. Binding constant (KA) analysis revealed that TBP and PBP had strongest potential human accumulation ability (KA: 6.35×106-7.84×106L/mol), followed by TnBP, TPP, TCEP, and TDCP (KA: 3.50×104-7.80×104L/mol), while TBBPA-DBPE and TBECH presented the lowest ability (KA: 5.84×103-8.05×103L/mol). Theoretical calculations demonstrated that the magnitude of KA was attributed to the molecular volume and the size and distribution of NFRs' molecular surface electrostatic potential (MSEP). TBP and PBP with smaller molecular volumes exhibited evenly distributed positive and negative MSEP, facilitating their entry into the binding site and interact with HSA. In summary, this study elucidates the influence of pollutants' volume and the size and distribution of MSEP on the binding sites and KA, providing a crucial theoretical basis for understanding the pollutants' potential human accumulation, which contributes to the screening and monitoring of new environmental pollutants.

Evaluation of the effect of triphenyl phosphate on hemp fiber‐reinforced polycarbonate composites for 3D printing applications

Evaluation of the effect of triphenyl phosphate on hemp fiber‐reinforced polycarbonate composites for <scp>3D</scp> printing applications

Assessing the chemical interactions and biological effects of a petrochemical and bio-based plastic with a common plastic flame retardant and solvent.

Microplastic pollution remains a persistent environmental challenge for aquatic environments. Yet, health impact assessments of microplastics focus largely on the polymers themselves. It is important to understand the chemical behaviour and biological effects of both plastics and chemicals associated with their production, such as additives and solvents. Here, the individual and interactive chemical behaviour and biological impacts of two microplastics and two associated chemicals are assessed: polyvinyl chloride (PVC), a traditional petroleum-based plastic; polyhydroxyalkanoate (PHA) a novel bio-based plastic; triphenyl phosphate (TPhP), a common plastic flame retardant; and a widely use solvent dimethyl sulfoxide (DMSO). Thermogravimetric analysis and Nuclear Magnetic Resonance revealed no significant polymer chemical adsorption and desorption of TPhP or DMSO nor any evidence of reaction products between TPhP and DMSO. Biological assays on a freshwater fish host-parasite system, assessed fish growth, feeding, disease resistance and parasite survival. Both microplastics, the TPhP and solvent DMSO individually and interactively had no significant impact on fish growth. However, PVC alone and PHA+TPhP + DMSO significantly inhibited feeding behaviour of fish and increased mortality. Fish exposed to the solvent DMSO alone experienced the highest disease burdens. Interestingly, off-host survival of parasitic worms exposed to DMSO or TPhP + DMSO was higher than unexposed control worms. This study highlights the complex effects of microplastics and plastic associated chemicals on biological systems, and that novel bio-based plastics are not necessarily 'better' especially when associated with the same chemicals. Industry must be required to declare which chemicals are used in the manufacture of plastic products.

Exposure to triphenyl phosphate during pregnancy: The role of gut-bile acids-liver axis on lipid metabolism in male offspring.

The widespread use of Triphenyl phosphate (TPhP) as a substitute flame retardant in various commercial products has raised global concerns for its health risks. Previously, we found that gestational and lactational TPhP exposure disturbed lipid metabolism and gut microbiota in offspring sex-dependently. In this study, we further explored the prenatal TPhP exposure on lipid metabolism in male offspring, and the role of gut-bile acids-liver axis in it. The results showed that gestational TPhP exposure would induce hyperlipidemia in male offspring, it dose-dependently increased the weight of body and liver, levels of serum lipid, and enlarged lipid droplets in white adipose tissue. The expression of lipid metabolism-related genes was significantly changed in the liver and adipose tissue. The gut microbiome of male offspring was also altered, with different profiles between the low and high dose treatment group. Target bile acids (BAs) metabolites analysis revealed a significant increased levels of primary BAs cholic acid (CA), but decreased levels of chenodeoxycholic acid (CDCA), and decreased levels of the secondary BAs deoxycholic acid (DCA), hyodeoxycholic acid (HDCA), ursodeoxycholic acid (UDCA), and lithocholic acid (LCA) in TPhP treatment group. Measurements of gene expression along the gut-BAs-liver axis showed that the TPhP treatment group had an increase in cholesterol-7alpha-hydroxylase (CYP7A1) and a decrease in apical sodium-dependent bile acid transporter (ASBT), with only the low-dose group exhibiting an increase in carbohydrate response element binding protein (ChREBP). Correlation and mediation analysis highlighted associations of Burkholderiaceae in low-dose treatment group and Erysipelotrichaceae in high dose group with lipid metabolism and BAs metabolites. No consistent correlations were observed in two treatment group. Additionally, Mantel tests did not reveal a consistent correlation between the microbiome network community and lipid metabolism or the gut-bile acids-liver axis. Overall, our findings indicate that gestational TPhP exposure induces hyperlipidemia in male offspring, and while the gut-BAs-liver axis plays a role, other mechanisms warrant further investigation.

The effect of synergists on the inhibition of detoxification enzyme activities and acaricide sensitivity in Rhizoglyphus robini.

The saffron bulb mite, Rhizoglyphus robini Claparede (Acari: Acaridae), is the most important pest of the saffron crop in Iran. This pest attacks and feeds on saffron corms. For this reason, the corms are treated with acaricides before planting. The high activity of detoxification enzymes in arthropods may reduce their pesticide sensitivity. Diethyl maleate (DEM) is an inhibitor of glutathione S-transferases (GSTs), piperonyl butoxide (PBO) is an inhibitor of cytochrome P450 monooxygenases, and triphenyl phosphate (TPP) is an inhibitor of esterase activity. A filter paper method was used to determine the efficiency of these synergists in inhibiting the activity of detoxifying enzymes of R. robini. Adult mites were treated with these three synergists for 6, 12, 24, and 48 h, respectively. The activity of each detoxifying enzyme was measured and compared to the control treatment, and the inhibition percentage was calculated each time. The results showed that DEM reduced GST activity by 59.9% after 48 h, PBO inhibited cytochrome P450 activity by 30%, and TPP suppressed esterase activity by 38.5%. The most statistically significant inhibition occurred 24 h after pretreatment with each synergist. Bioassays with 24 h pretreatment showed that the sensitivity of R. robini to propargite increased by 1.6 times with PBO, 1.7 times with TPP, and 2.5 times with DEM. In conclusion, synergists and efficient inhibition of detoxifying enzymes can play a significant role in increasing the sensitivity of agricultural pests to pesticides and can be considered in managing pesticide resistance.

Organophosphate flame retardants and their metabolites in paired dog food and urine: Pet exposure through food consumption.

Companion dogs are exposed to various chemicals. However, our understanding of the sources and pathways of chemical exposure in pets remains limited. In this study, we collected urine samples from 47 dogs and corresponding samples of the food they consumed to analyze the concentrations and dietary exposure to organophosphate flame retardants (OPFRs) and their metabolites (mOPFRs). Triphenyl phosphate (TPHP) and its metabolite, diphenyl phosphate (DHPH), were the predominant compounds detected in dog food and urine samples. The concentration of mOPFRs in urine decreased as body weight increased; however, neither sex nor age significantly influenced mOPFR levels in dog urine. The estimated daily intake of OPFRs (343ng/kg bw/day) through food consumption (EDIfood) was comparable to the previously reported levels of polycyclic aromatic hydrocarbons (324ng/kg bw/day) and higher than those of pesticides (214ng/kg bw/day), parabens (120ng/kg bw/day), and polychlorinated biphenyls (103ng/kg bw/day). By calculating the ratio of EDIfood to the cumulative daily intake based on urinary mOPFR concentrations, it was found that dietary sources contributed to 66% of the total TPHP exposure in dogs. This finding was further supported by Spearman's correlation analysis between parent OPFR concentrations in dog food and mOPFR levels in urine (p<0.01), indicating that dietary intake may be one of the most significant exposure pathways for OPFRs in dogs. To the best of our knowledge, this is the first study to investigate the levels of OPFR exposure in paired dog food and urine samples.

Prenatal Triphenyl Phosphate Exposure and Hyperlipidemia in Offspring: Role of Trophoblast-Derived Extracellular Vesicle PPARγ.

Triphenyl phosphate (TPhP) is a widely used organophosphate flame retardant, the health risks of TPhP are a global concern. In this study, we found that prenatal TPhP exposure at human relevant concentration induced hyperlipidemia in male offspring, it increased serum levels of triglyceride, total cholesterol, and low-density lipoprotein cholesterol. Placental trophoblast-derived extracellular vesicles (T-EVs) could transport to the fetus through maternal-fetal circulation. TPhP significantly upregulated the protein level of peroxisome proliferator activated receptor γ (PPARγ) in T-EVs. Similar to TPhP, gestational exposure to T-EVs isolated from TPhP exposed mice placentae induced the same effects. While, gestational intervention with GW9662 (PPARγ inhibitor) or GW4869 (EVs secretion inhibitor) would alleviate the disturbed lipid metabolism induced by TPhP. Meanwhile, in vitro experiments verified that TPhP upregulated PPARγ in HTR8/SVneo cells derived EVs, and these EVs promoted adipogenesis in preadipocyte 3T3-L1 cells. Knock down of PPARγ in HTR8/SVneo could alleviate the adipogenensis effects of EVs derived from TPhP exposed HTR8/SVneo cells. These results demonstrate that TPhP exposure induces hyperlipidemia in male offspring by upregulating PPARγ in T-EVs. Our study provides new insights into the metabolic disruptive effects of TPhP, and emphasizes the mediating effects of placental T-EVs on gestational environmental stress in fetal development.

Two detoxification enzyme genes, CYP6DA2 and CarFE4, mediate the susceptibility to afidopyropen in Semiaphis heraclei.

Semiaphis heraclei is an important economic pest affecting Caprifoliaceae and Apiaceae plants, and chemical control is still the main effective control method in the field. Afidopyropen is a new type of pyridine cyclopropyl insecticide, which can effectively control piercing-sucking mouthparts pests and is suitable for pest resistance management. However, the detoxification mechanism of S. heraclei to afidopyropen is still poorly cleared. The insecticidal activity of afidopyropen against S. heraclei and the enzyme activity assay and synergism bioassay were evaluated. The detoxification enzyme genes were obtained by transcriptome and validated by quantitative real-time PCR (RT-qPCR). Furthermore, RNA interference was used to study the functions of detoxification enzyme genes. The activities of cytochrome P450 monooxygenases (P450s) and carboxylesterases (CarEs) were significantly increased under afidopyropen treatment. The toxicity of afidopyropen against S. heraclei was significantly increased after application the inhibitors of piperonyl butoxide and triphenyl phosphate. Sixteen P450 genes and three CarE genes were identified in the transcriptome of S. heraclei. The RT-qPCR results showed that eleven P450 genes and two CarE genes were significantly upregulated under afidopyropen treatment, and the expression of CYP6DA2 and CarFE4 was upregulated by more than 2.5 times. The expression pattern of CYP6DA2 and CarFE4 was further analyzed in different developmental stages of S. heraclei and knockdown of CYP6DA2 and CarFE4 significantly increased the susceptibility of S. heraclei to afidopyropen. The results of this study uncover the key functions of CYP6DA2 and CarFE4 in the detoxification mechanism of S. heraclei to afidopyropen, and provide a theoretical basis for the scientific use of afidopyropen in the field.

Rap1 and mTOR signaling pathways drive opposing immunotoxic effects of structurally similar aryl-OPFRs, TPHP and TOCP.

Aryl organophosphorus flame retardants (aryl-OPFRs), commonly used product additives with close ties to daily life, have been regrettably characterized by multiple well-defined toxicity risks. Triphenyl phosphate (TPHP) and tri-o-cresyl phosphate (TOCP), two structurally similar aryl-OPFRs, were observed in our previous study to exhibit contrasting immunotoxic effects on THP-1 macrophages, yet the underlying mechanisms remain unclear. This study sought to address the knowledge gap by integrating transcriptomic and metabolomic analyses to elucidate the intricate mechanisms. During individual omics analyses, we unfortunately only obtained highly similar results for both TPHP and TOCP, failing to identify the key reasons for their differences. These results revealed comparable disturbances induced by both compounds, including disruptions in nucleic acid synthesis and energy metabolism, blocking ADP to ATP conversion by reducing TCA cycle intermediates, consequently leading to ATP depletion. However, through integrative analysis, specific pathways affected by each compound were successfully identified, shedding light on their unique effects. TPHP reduced GTP levels necessary for Rap1 activation, thereby inhibiting phagocytosis and adhesion of THP-1 macrophages. Conversely, TOCP stimulated the mTOR signaling pathway, enhancing phosphorylation of downstream proteins S6K, RHOA, and PKC, consequently promoting immune responses. This study not only clarified the distinct immunotoxic mechanisms of TPHP and TOCP but also provided critical insights into how structural variations in aryl-OPFRs can lead to markedly different immune responses, thereby informing future risk assessments and regulatory strategies for these compounds.

Fire-retardant and thermally conductive polyacrylonitrile-based separators enabling the safety of lithium-ion batteries.

Lithium-ion batteries (LIBs) have broad application prospects in many fields because of their high energy density. However, the poor heat resistance of polyolefin membranes and uneven lithium deposition result in battery failure and even infamous thermal runaway behavior. To improve the intrinsic safety of batteries, fire-retardant, thermally conductive, electrospinning strategies are employed to acquire a functional polyacrylonitrile (PAN) nanofiber separator (PAN@FBN/TPP) containing modified boron nitride (FBN) and triphenyl phosphate (TPP). Compared with those of the Celgard separator, the porosity, contact angle, and electrolyte uptake of the Celgard separator are greatly improved. Moreover, the designed separator shows excellent thermal stability without shrinkage when heated at 220°C. The char residue at 800°C is 43.7wt%, which is much greater than that of the Celgard separator (∼0.26wt%). The maximal peak heat release rate (PHRRmax) is only 30% that of the Celgard separator. The improvement in heat resistance laid a solid foundation for the preparation of high-safety LIBs. The advantages of a uniform pore size distribution and extremely high porosity provide abundant active sites and convenient channels for Li+ migration. The cell with the PAN@FBN/TPP separator shows excellent cycle stability and rate performance. Owing to the high heat resistance of PAN and the excellent flame-retardant capability of FBN, the LIBs presented the highest self-heating temperature (T0) and thermal runaway temperature (T1) and the smallest maximum temperature (Tmax) and heat release rate (HRRmax) in the safety performance test; compared with those of commercial separator batteries, the above thermal safety parameters increased by 16.9%, 6.5%, 21.8% and 81.5%, respectively. Overall, this work may provide an effective way to fabricate LIBs with high thermal safety.

Phosphorous flame-retardant concentration in Finnish daycares dust and children’s exposure

Children in daycare centers are exposed to various chemicals present in indoor dust, including organophosphorus flame retardants (OPFRs). This study analyzed OPFR levels in dust from 18 daycare centers in Tampere, Finland, to assess children’s exposure through dust ingestion, inhalation, and dermal absorption. The OPFRs measured included tris(2-chloroisopropyl) phosphate (TCIPP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), triphenyl phosphate (TPHP), and 2-ethylhexyl diphenyl phosphate (EHDPP). The median concentrations (μg/g) were significantly higher than those reported in similar studies, with TCIPP (265.27), TDCIPP (31.11), TPHP (12.18), and EHDPP (4.24). These elevated levels are possibly due to fire safety regulations in Finland, that have resulted in the extensive use of flame retardants in various materials. The Margin of Exposure (MOE) calculations, which compared total exposure to oral Reference Doses (RfD), indicated that most OPFRs did not pose a significant risk to children, with MOEs generally above 1000. However, TCIPP had the lowest MoE, suggesting a potential health risk at higher exposure levels.

Organophosphate flame retardants associated with increased oxidative stress biomarkers and elevated FeNO levels in general population of children: The Hokkaido study

Our previous study found that exposure to higher organophosphate flame retardants (PFRs) was associated with increased prevalence of wheeze and type 2 inflammation among school-aged children. It remains unclear whether PFR exposure elevates oxidative stress in these general pediatric population, thereby potentially contributing to the development of allergic diseases. This study examined the associations between individual and mixture exposure to PFRs and oxidative stress in children aged 9–12 years (n = 423). The oxidative stress biomarkers included 4-hydroxynonenal (4-HNE) and hexanoyl-lysine (HEL) for lipid peroxidation, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) for DNA damage. We also examined the mediation effects of oxidative stress on the relationships between PFR exposure and health outcomes: wheeze and type 2 inflammation biomarkers, including fraction of exhaled nitric oxide (FeNO) and blood eosinophils. Higher concentrations of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), Σ triphenyl phosphate (ΣTPHP), Σ tris(2-butoxyethyl) phosphate (ΣTBOEP), and Σ 2-Ethylhexyldiphenyl phosphate (ΣEHDPHP) metabolites were significantly associated with higher levels of 4-HNE. Elevated concentrations of TDCIPP, ΣTPHP, and ΣTBOEP were positively associated with HEL. Higher ΣTPHP and ΣTBOEP were positively associated with 8-OHdG. The PFR mixture was positively associated with all three oxidative stress biomarkers according to the Quantile g-computation and Bayesian kernel machine regression models. Oxidative stress biomarkers mediated 11.4 % to 15.3 % of the association between PFRs and FeNO ≥35 ppb. PFR exposure was positively associated with oxidative stress markers of DNA damage and lipid peroxidation, which may contribute to elevated type 2 inflammation among school-aged children. These findings, identified in the general pediatric population at low exposure levels, highlight the need for ongoing attention to the allergic symptoms posed by PFR exposure.

Emerging and legacy organophosphate flame retardants in the tropical estuarine food web: Do they exhibit similar bioaccumulation patterns, trophic partitioning and dietary exposure?

Emerging organophosphate flame retardants (E-OPFRs) are a new class of pollutants that have attracted increasing attention, but their bioaccumulation patterns and trophodynamic behaviors in aquatic food webs still need to be validated by comparison with legacy OPFRs (L-OPFRs). In this study, we simultaneously investigated the bioaccumulation, trophic transfer, and dietary exposure of 8 E-OPFRs and 10 L-OPFRs in a tropical estuarine food web from Hainan Island, China. Notably, the Σ10L-OPFRs concentration (16.1-1.18 × 105 lipid weight (lw)) was significantly greater than that of Σ8E-OPFRs (nondetectable (nd) - 2.82 × 103 ng/g lw) among the investigated organisms, and they both exhibited similar trends: fish<mollusk<crustacean. Significant biomagnification was found only for triphenyl phosphate (TPHP, an L-OPFR) with a trophic magnification factor (TMF) of 1.55, whereas other E- and L-OPFRs showed limited trophic transfer potential. Storage lipid was the dominant adsorption phase for most E-OPFRs and L-OPFRs on the basis of the fugacity approach. The water content controls the main trophic partitioning for the L-OPFRs of triethyl phosphate (TEP) and tris(2-chloroethyl) phosphate (TCEP) in the food web. Storage lipid and structure protein are equally important for 2,2-bis(chloromethyl)-propane-1,3-diyltetrakis(2-chloroethyl) biphosphate (V6, an emerging OPFR). The investigation of metabolites and the biotransformation rate (K M) confirmed the role of biotransformation in offsetting trophic transfer for both legacy and emerging OPFRs. Furthermore, the hazard quotients (HQs) were found to be <1 for South China residents for both the E- and L-OPFRs, but the health risks of these two kinds of OPFRs should be given sustained attention.

Cresyl diphenyl phosphate (a novel organophosphate ester) induces hepatic steatosis by directly binding to liver X receptor α: From molecule action to risk assessment

Cresyl diphenyl phosphate (CDP), a novel organophosphate ester (OPE), has been increasingly detected in various environmental and human samples. However, its toxicity, mechanisms, and health risks remain largely unknown. In this work, we investigated CDP-induced hepatic steatosis through Liver X Receptor α (LXRα) pathway across the molecular interactions, signaling pathways, cell functions, animal effects, and population risks, and compared them to triphenyl phosphate (TPHP) and tricresyl phosphate (TCRP). Receptor binding results showed that all three OPEs bound to LXRα directly in the order of TCRP > CDP > TPHP. Docking results suggested that the three aryl groups played an essential role in the binding of these chemicals to LXRα. They also activated LXRα-mediated lipogenesis pathway and promoted lipid accumulation in HepG2 cells. The intracellular concentration and LXRα-bound concentration of the chemicals in HepG2 cells followed a consistent order of CDP > TCRP > TPHP. In mice, exposure to CDP activated LXRα-mediated de novo lipogenesis pathway, leading to hepatic steatosis. Risk assessment results suggested that few populations (5.38 %) face a LXRα-mediated hepatic steatosis risk from CDP exposure. Collectively, our results demonstrate that CDP could bind to LXRα, activate the subsequent de novo lipogenesis pathway, inducing hepatic steatosis, and increasing adverse health risks.

First Evidence of Novel Organothiophosphate Esters as Prevalent New Pollutants in Dust from Automotive Repair Shops Discovered by High-Resolution Mass Spectrometry.

The occurrence of organophosphorus compounds has garnered global concern due to their widespread production and potential environmental risks. Limited structural information has hindered a comprehensive understanding of their composition. By characteristic fragmentation-based nontarget analysis, the occurrence and composition of organothiophosphate esters (OTPEs), which are antiwear additives in lubricant oils that have received little attention previously, were investigated in dust from automotive repair shops and surrounding buildings. Fourteen OTPEs were tentatively identified, including four triarylphosphorothionates, six O,O-dialkyl phosphorothioates, and four O-alkyl O-alkyl sulfone phosphorothioates, among which four OTPEs were further confirmed by authentic standards or an industrial product. Triphenyl phosphorothioate (TPhPt) and tris(2,4-di-tert-butylphenyl) phosphorothioate (AO168=S) were prevalently detected in automotive repair shops with median concentrations of 230 and 246 ng/g, respectively, closely comparable to triphenyl phosphate (TPhP, median concentration: 302 ng/g). O,O-Dihexyl phosphorothioate (DHPt), O,O-dioctyl phosphorothioate (DOPt), O-hexyl O-hexyl sulfone phosphorothioate (DHSPt), and O-octyl O-octyl sulfone phosphorothioate (DOSPt) were the abundant analogues in automotive repair shops with semiquantitative median concentrations in the range of 119-1.05 × 103 ng/g. Hierarchical cluster analysis showed that OTPEs exhibited similar distribution patterns across automotive repair shops, indicating that these chemicals had similar sources. Moreover, the concentrations of OTPEs were usually higher in automotive repair shops than that in surrounding buildings, suggesting a motor vehicle related emission source. To our knowledge, 12 out of the 14 detected OPTEs were reported in the environment for the first time. The discovery of these OTPEs expanded the scope of known organophosphorus pollutants, highlighting the potential contaminants of OTPEs from lubricant oils for automotive and industrial applications.

Synthesis of Polyphosphate Flame Retardant Bisphenol AP Bis(Diphenyl Phosphate) and Its Application in Polycarbonate/Acrylonitrile-Butadiene-Styrene.

The flame retardant bisphenol AP bis(diphenyl phosphate) (BAPDP) is synthesized from triphenyl phosphate and bisphenol AP via transesterification, producing a polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with a high flame retardancy and thermal stability. In this study, flame-retardant PC/ABS blends with various BAPDP contents are prepared, and their flame retardancy is studied using the limit oxygen index, vertical combustion, thermogravimetric analysis, and cone calorimeter testing. With a BAPDP content of 20 wt%, the product exhibits a limiting oxygen index of 25.4% and achieves the UL-94 V-0 grade, with a thermal deformation temperature of 72.6 °C. BAPDP improves the flame retardancy of the PC/ABS blends and exhibits fewer adverse effects on the thermal deformation temperature than other commercial flame retardants at the same concentration.

A new green rigid polyurethane foam based on modified palm oil: Preliminary study of their potential for marine buoy applications

AbstractThis study demonstrates a new green rigid polyurethane (PU) based on modified palm oil (MPO) for marine buoy applications. The bio‐polyol based on palm oil was synthesized using hydrogen peroxide and formic acid. The foam formation was by kinetic foaming reaction. The MPO‐based PU foams made with increased water content had closed cells that grew larger with water content to provide a low‐density foam. The resistance to flammability of PU foam was improved by adding triphenyl phosphate (TPP). The PU foam with increased TPP content had enlarged cells, increased water absorption and decreased compressive strength. In addition, carbon black (CB)‐containing foam had uniform, large foam cells, comparatively high density, higher compressive strength, and low water absorption. Moreover, a high CB content gave shorter extinguishing time for PU foam. The PU foams were investigated for buoyancy and compared with a commercial PU foam buoy. The commercial buoy had lower density, providing better‐floating performance than PU foam. Interestingly, CB_8 had an elevated density, but low water absorption rate, similar to the commercial buoy PU foam. The investigations showed that the PU foam from MPO is eco‐friendly, and the buoyancy performance of that foam is improved on adding TPP or CB.

Association of joint exposure to organophosphorus flame retardants and phthalate acid esters with gestational diabetes mellitus: a nested case-control study

BackgroundOrganic phosphate flame retardants (OPFRs) and phthalate acid esters (PAEs) are common endocrine-disrupting chemicals that cause metabolic disorders. This study aimed to assess the association between joint exposure to OPFRs and PAEs during early pregnancy in women with gestational diabetes mellitus (GDM).MethodsSeven OPFRs and five PAEs were detected in the urine of 65 GDM patients and 100 controls using gas chromatography-tandem triple quadrupole mass spectrometry (GC-MS). The association of OPFRs and PAEs with GDM was assessed using logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models.ResultsLevels of dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dimethyl phthalate (DMP), tris (2-butoxyethyl) phosphate (TBEP), tributyl phosphate (TBP), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tri-ortho-cresyl phosphate (TOCP), and triphenyl phosphate (TPHP) increased in the GDM group, and the OPFRs and PAEs, except for BBP and TMCP, were associated with GDM in the logistic regression analysis. In the WQS model, the mixture of OPFRs and PAEs was significantly positively associated with GDM (OR = 3.29, 95%CI = 1.27–8.51, P = 0.014), with TDCPP having the highest WQS index weight. BKMR analysis reinforced these results, showing that the overall association of joint exposure to the OPFRs and PAEs with GDM increased at exposure levels of the 55th to 75th percentiles. Independent exposure to TDCPP (OR = 1.42, 95%CI = 1.09–1.86, P = 0.011) and TBEP (OR = 1.29, 95%CI = 1.04–1.60, P = 0.023) were associated with an increased risk of GDM.ConclusionsEnvironmental exposure to OPFRs and PAEs is significantly associated with GDM. These findings provide evidence for the adverse effects of exposure to OPFRs and PAEs on the health of pregnant women.

Photoelectrocatalytic degradation of organophosphate esters using tio2 electrodes produced from 3d-printed ti substrates.

3D printed electrode substrates with novel geometries may significantly improve the efficacy of photoelectrocatalysis for degradation of recalcitrant pollutants such as organophosphate flame retardants (OPFRs). However, the 3D printed substrates often have an irregular topology that can lead to a less uniform arrangement of nanotubes following anodisation. This study investigated the effect of polishing 3D-printed Ti substrates prior to anodisation to form TiO2 nanotube array electrodes, and their subsequent applicability for photoelectrocatalytic treatment of OPFRs in water matrices. Polished and non-polished electrodes exhibited differences in morphology in terms of average roughness, (0.38 and 3.10µm, respectively), leading to more uniform TiO2 nanotubes of the former. Water contact angle measurements revealed the non-polished electrode was super-hydrophilic and the polished electrode hydrophilic (water contact angles of 6.4˚ and 16.1˚, respectively). Despite these differences, the polished and non-polished electrodes exhibited very similar electrochemical responses. In fact, the purity and electrical conductivity of water matrices affected the photoelectrocatalytic performance more than the electrode morphology. The purified water (PW) matrix facilitated the highest degradation/removal of OPFRs, compared to tap water matrices. In particular, individual OPFR degradation levels in PW were 74% ± 9, 37% ± 10, 33% ± 9, 31% ± 11 and 3% ± 5 for triphenyl phosphate, tris(butyl) phosphate, tris(isobutyl) phosphate, tris(2-butoxyethyl) phosphate and tris(2-chloroisopropyl) phosphate, respectively. The removal of OPFRs was relative to their reactivity to hydroxyl radicals, which was higher for the aryl then alkyl straight-chain and then chlorinated compounds. This study reveals that polishing of electrode substrates is not required for the preparation of effective photoelectrocatalytic reactors to treat recalcitrant pollutants (e.g. OPFRs), Importantly, future development of novel high-profile 3D printed electrode will not be hindered by the requirement to polish the substrates prior to anodisation.

Electrochemical degradation of aromatic organophosphate esters: Mechanisms, toxicity changes, and ecological risk assessment

Aromatic organophosphate esters (AOPEs), including triphenyl phosphate (TPHP), tricresyl phosphate (TCP), and 2-ethylhexyl diphenyl phosphate (EHDPP), pose significant health and ecological risks. Electrochemical advanced oxidation process (EAOP) is effective in removing refractory pollutants. In this study, the degradation performance and detoxication ability of AOPEs by EAOP were investigated. Hydroxylation, oxidation, and bond cleavage products were identified as major degradation products (DPs) due to the reaction with ·OH and O₂·-. Toxicity assessments using ecological structure activity relationship (ECOSAR) model and flow cytometry (FCM) revealed the cytotoxicity and aquatic toxicity for DPs were significantly decreased. 16S rRNA gene sequencing of sediment exposure to AOPEs and DPs were applied to assess ecological toxicity, and results showed reduced bacterial richness and diversity with EHDPP and TCP, while TPHP slightly enhanced richness. AOPEs and DPs altered bacterial genera involved in carbon, nitrogen, sulfur cycling and organic compound degradation. Bacterial community assembly suggested elevated stochastic processes and reduced ecotoxicity, confirming AOPEs can be effectively detoxified by 10-min EAOP treatment. Molecular ecological network analysis indicated increased complexity and stability of bacterial communities with DPs. These findings comprehensively revealed the toxicity of AOPEs and their DPs and provided the first evidence of effective degradation and detoxification by EAOP from ecotoxicological perspective.