Production Of Chloride Research Articles

Simulation of an allyl chloride production process via the propylene chlorination route in ChemCAD simulator

Allyl chloride is typically used to make intermediates for downstream derivatives such as resins and polymers, and in the production of epichlorohydrin. The present work describes the simulation and conceptual design of an allyl chloride production process via the propylene chlorination route in ChemCADÒ simulator, to know the mass and energy balances of the intermediate and final streams, the operating and design parameters of some equipment, and other results of interest. The production process consists of a fired heater, a fluidized bed reactor, a waste heat boiler, six shell and tube heat exchangers, two compressors, a gas-liquid absorber and four distillation columns. About 1.336,307 kg/h of allyl chloride are produced at the distillate of the last distillation column with a purity of 99,92%, while pure propylene, 2-chloropropene and an aqueous solution of HCl 32,4 wt. % are also obtained as byproducts. A first-of-its-kind simulation model was obtained in ChemCADÒ, which could be employed for further optimization studies and productivity increment analysis.

Enhancing Vinyl Chloride Product Yield By Optimizing Operating Conditions In Plug Flow Reactor With Al2O3 Catalyst

Vinyl chloride (VC) is a colorless stable gas produced through a complex process with many interactions in reaction and separation. This study aims to improve mass and energy efficiency in vinyl chloride production through process simulation with HYSYS V.11. The process was modified using a plugged flow reactor (PFR) with an Al2O3 catalyst and a simplified distillation column. The method involves recycling the liquid product from the distillation column back to the mixing unit as a feed. The results show that energy efficiency improves with the reduction of the reactor's heat flow requirement from 1.009×107 kJ/h, and to 4.689×106 kJ/h, and distillation of the 2.82×106 kJ/h to 1.368×106 kJ/h. Mass efficiency also increased, with vinyl chloride yields rising by 118%, from 2572 kg/h to 3045 kg/h. In conclusion, these process modifications have succeeded in reducing energy consumption and increasing production significantly, making the process more efficient and energy friendly. Further research is suggested to optimize the use of waste heat. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis, characterization and measurement of antimicrobial activity of (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)- heptabenzenecyclononadecaphan-6,15-diliene and its palladium(II) chloride complex

To synthesize the Schiff base with the desired properties, a transition from a monomeric molecule to a macrocyclic structure was made. For this purpose; (oxy)-dibenzaldehyde dibenzaldehyde derivative, (oxy)bis(N-prop)-1-en-2-yl-aniline derivative, (oxy)-dianiline derivative and (sulfanediyl)-dianiline compounds were obtained at the end of four different reaction processes. In the last step of these reactions, a macrocyclic compound (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)-heptabenzenecyclononadecaphan- 6,15-diene Schiff base was obtained by condensation method. As a result of the reaction of this product with PdCl2, (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)-heptabenzenecyclononadecaphan-6,15-dylene palladium(II) chloride product was obtained and a new biologically active metal complex was synthesized. Their structures were identified by characterizing them according to elemental analysis (CHN), thermal analysis, PXRD, conductivity measurements, FT-IR, and UV-vis spectra. Spectral data confirmed the structure of azomethine (-C=N-) and phenolic OH groups with a nitrogen atom of the metal-coordinated ligand and the presence of metal ions. As a result of this information, a tetrahedral geometry was suggested for the Pd(II) complex. Antimicrobial activities of the synthesized metal complex were tested. Pd(II) complex showed the highest cytotoxicity (MIC value 11.25±0.14 µg/mL) effect, comparable to other cis-platinum-based drugs.

Improving Process Design for Reaching Energy Efficiency, Environmentally Friendly, and Producing High Purity Methyl Chloride of Dehydrochlorination Process of Methanol and Hydrogen Chloride

Methyl chloride, also known as chloromethane, plays a vital role in producing various industrial goods. The current demand for methyl chloride in Indonesia exceeds production levels, making the design of a methyl chloride plant essential. This research focuses on improving methyl chloride production economically and operationally by exploring plant design using simulations that emphasize energy efficiency and high purity. The objective of this research is to develop a process design for producing methyl chloride from methanol and hydrogen chloride, aiming for energy efficiency, an environmentally friendly factory, and high-purity methyl chloride products. The research employed an iterative simulation method to compare the basic and modified processes for methyl chloride production. The process involved constructing a simulation model using Aspen HYSYS, analyzing the simulation results using Aspen Energy Analyzer V12, and iteratively adjusting process parameters until achieving the desired performance or results. The research findings indicate that the methyl chloride modification process exhibits a lower energy requirement compared to the methyl chloride base process. Moreover, the modification process demonstrates minimal carbon emissions, establishing it as a sustainable and environmentally friendly design. Additionally, the methyl chloride produced in the modification process achieves a higher percentage of purity. In the initial process, the methyl chloride purity stood at 98.17%, while in the modified process, it saw an elevation to 99.35%. Considering these three aspects, the modification process is conclusively more efficient than the basic process system. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

A new targetry system for cyclotron production of pharmaceutical grade indium-111 radioisotope

Abstract The aim of this research is to present a new, fast, simple, low-cost and innovative method for the production and purification of pharmaceutical grade indium-111 chloride for use in nuclear medicine.In the previous methods for cyclotron production of indium-111 radioisotope, besides the need for high amount of enriched cadmium, in electrodeposition of enriched cadmium on copper backings for target preparation and its chemical dissolution step, impurities of isotopes of copper and zinc enter the final product. So, radiolabeling of such products was hard or impossible with some molecules. In this research, due to the proper selection of the target isotope, enriched cadmium-112, and the optimal proton bombardment energy, only very low amount radioisotopic impurities were produced and observed in the sample solution. After the separation process, the amounts of zinc-65 and indium-114 were less than the standard permissible amounts in indium-111 radiopharmaceuticals. The concentration of cadmium impurities in the final product was less than 0.1 ppm. The radionuclidic purity of the sample was confirmed by gamma ray spectroscopy, and it was found to be suitable for use in preclinical studies.

Machine Learning Framework for the Methyl Chloride Production Process

We report a framework for calculating the exergy and energy losses in the hydrochlorination of the methanol process for a methyl chloride production unit. Machine learning-based predictive maintenance models are identified to assess plant toxicity. The proposed novel framework integrates Hyprotech Systems (HYSYS) and machine learning models. It optimizes the operating conditions of the chloromethane plant. Both supervised and unsupervised machine learning models such as Bayesian Ridge regression (BRR), Nearest Neighbors regression (KNR), and Stochastic gradient descent regression (SGD) are used to forecast energy and exergy destruc¬tion. Among these models, the BRR exhibits exceptional accuracy in predicting thermodynamic losses, notably achieving an R2 value of 0.998. Thereby, an integrated framework could serve as a valuable diagnostic tool for assessing real-time plant data to enhance plant opera¬tional efficiency.

A common phthalate replacement disrupts ovarian function in young adult mice

Di-2-ethylhexyl terephthalate (DEHTP) is a replacement for its structural isomer di-2-ethylhexyl phthalate (DEHP), a known endocrine disrupting chemical and ovarian toxicant. DEHTP is used as a plasticizer in polyvinyl chloride products and its metabolites are increasingly found in biomonitoring studies at levels similar to phthalates. However, little is known about the effects of DEHTP on the ovary. In this research, we tested the hypothesis that DEHTP is an ovarian toxicant and likely endocrine disrupting chemical like its isomer DEHP. The impact of environmentally relevant exposure to DEHTP and/or its metabolite mono-2-ethylhexyl terephthalate (MEHTP) on the mouse ovary was investigated in vivo and in vitro. For the in vivo studies, young adult CD-1 mice were orally dosed with vehicle, 10 µg/kg, 100 µg/kg, or 100 mg/kg of DEHTP for 10 days. For the in vitro studies, isolated untreated ovarian follicles were exposed to vehicle, 0.1, 1, 10, or 100 µg/mL of DEHTP or MEHTP. Follicle counts, hormone levels, and gene expression of steroidogenic enzymes, cell cycle regulators, and apoptosis factors were analyzed. In vivo, DEHTP exposure altered follicle counts compared to control. DEHTP exposure also decreased expression of cell cycle regulators and apoptotic factors compared to control. In vitro, follicle growth was reduced compared to controls, and expression of the cell cycle regulator Cdkn2b was increased. Overall, these results suggest that DEHTP and MEHTP may be ovarian toxicants at low doses and should be subjected to further scrutiny for reproductive toxicity due to their similar structures to phthalates.

Passerini and thiol-ene reactions: A facile, green, and efficient route to high-performance bio-based plasticizers

The increasing global demand for sustainable alternatives to petroleum-based plasticizers, particularly in poly(vinyl chloride) (PVC) products, has intensified the exploration of bio-based options derived from renewable resources such as plant oils. Traditional bio-based plasticizers, while promising, often suffer from limitations such as low molecular weight, high volatility, and poor compatibility with PVC, thereby restricting their practical applications. To surmount this hurdle, we introduce a novel synthetic route combining the Passerini reaction with the thiol-ene click reaction, aimed at producing high-performance plant oil-based plasticizers (POPs) with enhanced ester content and molecular weight. This method offers significant advantages over traditional methods, including low reaction temperatures (≤40 ​°C), ultrahigh yield (95 ​%) when using ethanol as the solvent, and precise control over ester content. Furthermore, the key findings demonstrate that the designed and synthesized POP (bio-content, 69 ​%) produced using this method exhibits outstanding overall performance, such as excellent migration resistance, good compatibility with PVC, and high thermal stability compared to traditional plasticizers. This facile, green, and efficient method may significantly advance the adoption of bio-based plasticizers, establishing them as a viable alternative to petroleum-based counterparts.

Multi-Objective Optimization and Design for Industrial Vinyl Chloride Reactor by Hybrid Model

The acetylene conversion rate and vinyl chloride production capacity are the main economic indexes for vinyl chloride synthesis, and the reaction temperature is an important operating parameter to prevent the Hg active component from being loss. These three factors have not been taken into consideration simultaneously in the traditional optimization process, making it difficult to achieve optimization targets perfectly for industrial application. To overcome this problem, an efficient strategy framework was proposed based on a hybrid model. Compared with conventional paradigms, the proposed framework could not only reduce computational expense but optimize these two economic indexes with a constrained reaction temperature simultaneously. In addition, a machine learning method was used to conduct a feature analysis, which can reveal the potential interaction between different variables so key variables of this reactor could be identified. To demonstrate and verify this framework, multi-objective optimization involving multiple variables with constrained conditions for the industrial reactor was conducted from design and operation perspectives, respectively. The proposed strategy could provide optimal operational direction for the industrial reactor from these design and operation aspects, which contribute to the sustainable and highly efficient process development in this field. For the first section of an industrial vinyl chloride reactor, this strategy could realize significant improvement in the acetylene conversion rate from 81.34% to over 95.00% and in the vinyl chloride production capacity from 2.60 to above 3.40 mol/h in the operation scenarios, which can meet production requirements. So, the second section of the traditional reactor system is not needed at all.

Controlling (E/Z)-Stereoselectivity of -NHC=O Chlorination: Mechanism Principles for Wide Scope Applications.

Organic halogen compounds are cornerstones of applied chemical sciences. Halogen substitution is a smart molecular design strategy adopted to influence reactivity, membrane permeability and receptor interaction. Chiral bioreceptors may restrict the stereochemical requirements in the halo-ligand design. Straightforward (but expensive) catalyzed stereospecific halogenation has been reported. Historically, PCl5 served access to uncatalyzed stereoselective chlorination although the stereochemical outcomes were influenced by steric parameters. Nonetheless, stereochemical investigation of PCl5 reaction mechanism with carbamoyl (RCONHX) compounds has never been addressed. Herein, we provide the first comprehensive stereochemical mechanistic explanation outlining halogenation of carbamoyl compounds with PCl5; the key regioselectivity-limiting nitrilimine intermediate (8-Z.HCl); how substitution pattern influences regioselectivity; why oxadiazole byproduct (P1) is encountered; stereo-electronic factors influencing the hydrazonoyl chloride (P2) production; and discovery of two stereoselectivity-limiting parallel mechanisms (stepwise and concerted) of elimination of HCl and POCl3. DFT calculations, synthetic methodology optimization, X-ray evidence and experimental reaction kinetics study evidence all supported the suggested mechanism proposal (Scheme 2). Finally, we provide mechanism-inspired future recommendations for directing the reaction stereoselectivity toward elusive and stereochemically inaccessible (E)-bis-hydrazonoyl chlorides along with potentially pivotal applications of both (E/Z)-stereoisomers especially in medicinal chemistry and protein modification.

A joint economic evaluation and FP2O techno-economic resilience approach for evaluation of suspension PVC production

The production of polyvinyl chloride (PVC) involves obtaining a thermoplastic polymer from vinyl chloride monomer (VCM) and ethylene, primarily through the suspension method. This process is vital for manufacturing various products, such as pipes and coatings. However, its high-energy consumption necessitates economic evaluations to assess feasibility. In this work, a dual approach is proposed: a Feedstock-Processing-Product-Operation (FP2O) based techno-economic resilience analysis via sensitivity analysis alongside economic evaluation. The study evaluated a PVC production process with a capacity of 518,400 t/y of VCM over a 15-year plant lifespan. The techno-economic assessment revealed a Total Capital Investment of $609, 882, 203, a Payback Period of 4.22 years, and a Return on Investment of 14.38 %. Positive Net Present Value and a cost/benefit ratio >1 indicate the plant's installation under proposed conditions is favorable. Additionally, the technical-economic resilience analysis identified the process's response to changes in PVC price, raw material costs, and production capacity, guiding improvement actions pre- and post-plant assembly.

Development and prospect of the acetylene production chain based on the process systems engineering: a focus on the polyvinyl chloride production

Abstract With the shortage of international oil resources and rising oil prices, the acetylene chemical industry has been revitalized. As an important basic raw material in the petrochemical industry, it can produce many chemical products and extend the acetylene production chain. Firstly, the production, conversion, and utilization of acetylene are outlined. Subsequently, this paper focuses on reviewing the core production process routes and the corresponding research progress in the acetylene production chain and points out the development trends of the domestic acetylene downstream conversion. Then, considering that acetylene is produced by calcium carbide technology in Ningdong and the extended downstream polyvinyl chloride industry chain is a large energy consumer and the focus of environmental safety monitoring, the entire process from coal-based calcium carbide acetylene production to polyvinyl chloride synthesis is elaborated from the perspective of process systems engineering. The resource utilization status and bottlenecks in the process are declared, and the direction of process improvement and optimization is proposed. Finally, the entire acetylene production chain is briefly analyzed and reviewed.

In-situ activation of persulfate by emplaced magnetite nanoparticles for degradation of 1,2-dichloroethane in porous media

In this study, column experiments were conducted to explore on the method of emplacement of magnetite nanoparticles (MNPs) for in situ activation of persulfate (PS) in sand porous media to degrade 1,2-dichloroethane (DCA), a typical recalcitrant chlorinated compound. Different molar ratios between PS and DCA (0:1, 2:1, 5:1 and 20:1) and mass contents of MNPs in the sand (0 %, 1.9 % and 5.4 %) were tested. In the absence of MNPs, degradation of DCA was negligible for a hydraulic retention time of 7 h. Presence of MNPs at the content of 1.9 % enhanced degradation of DCA and the highest removal efficiency (34.2 %) was observed at the PS-to-DCA molar ratio of 5:1. At the MNPs content of 5.4 %, increase of the PS-to-DCA molar ratio from 2:1 to 20:1 lead to not only increase in DCA removal efficiency but also substantial enhancement in chloride production, indicating that high PS concentration could cause significant degradation of the Cl-containing intermediates. In contrast to MNPs, Fe3O4 solids with much larger size (∼1 μm) were much less effective in activating PS for DCA removal even at a significantly higher content in the medium. The transport data could be well fitted by the one-site chemical nonequilibrium model, which showed kinetic DCA sorption to the MNPs as a key process for the transport. In the long-term injection experiment, a stable and significant removal of DCA (∼50 %) was observed for 254 days at the MNP content of 1.9 %. The results of this study show the potential of MNPs as a sustainable PS activator in injection-based in situ chemical oxidation for groundwater remediation.

Production of Bio-plasticized Polyvinyl Chloride (PVC) Films Synthesized from Microalgae (Chlorella vulgaris)

Abstract Bio-based plasticizers for PVC films are being explored to replace conventional phthalate-based plasticizers due to the threats they pose to human health and the environment. In the present study, fatty acids from Chlorella vulgaris were extracted via Microwave-assisted Extraction and were epoxidized using esterification and transesterification reactions in a magnetically stirred reactor to produce EFAME plasticizer. FTIR Analysis determined the presence of an epoxy group as the peak C=O stretch (1739.79 cm−1) was detected. PVC films were synthesized at different concentrations of EFAME (30%, 40%, and 60%). At 40% of EFAME, the PVC exhibited high displacement in the tensile strength and elongation at break test, which was used as a basis to produce PVC-A, PVC-B, and PVC-C, and was compared to phthalate-plasticized PVC film, PVC-D. SEM-EDX Analysis verified the presence of PVC and EFAME in the plasticized PVC films as Carbon, Oxygen, and Chlorine elements were detected. PVC A had the lowest weight loss percentage at 40.96% indicating it has developed high migration resistance among the extraction mediums used. DSC analysis confirmed the plasticizing effect of EFAME as the glass transition temperature of bioplasticized PVC films decreased. Using One-way ANOVA, the physicochemical tests of PVC films plasticized with EFAME showed significantly better results than PVC films plasticized by DOP. Thus, the present study indicates that the bio-based plasticizer derived from C. vulgaris is a better and a potential alternative for phthalates in plasticizing PVC films.

Effects of di-(2-ethylhexyl) phthalate and its metabolites on transcriptional activity via human nuclear receptors and gene expression in HepaRG cells

Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in polyvinyl chloride products. DEHP exposure in humans is of great concern due to its endocrine-disrupting properties. In this study, we characterized the agonistic activities of DEHP and its five metabolites, mono-(2-ethylhexyl) phthalate (MEHP), 5OH-MEHP, 5oxo-MEHP, 5cx-MEPP and 2cx-MMHP against human nuclear receptors, peroxisome proliferator-activated receptor α (PPARα), pregnane X receptor (PXR), and constitutive androstane receptor (CAR) using transactivation assays. In the PPARα assay, the order of the agonistic activity was MEHP >> 5cx-MEPP >5OH-MEHP, 5oxo-MEHP >2cx-MMHP > DEHP, with DEHP significantly inhibiting MEHP-induced PPARα agonistic activity. This finding was compared to the results from in silico docking simulation. In the PXR assay, DEHP showed PXR agonistic activity more potent than that of MEHP, whereas the other metabolites showed little activity. In the CAR assay, none of the tested compounds showed agonistic activity. Moreover, the expression levels of PPARα-, PXR-, and CAR-target genes in HepaRG cells exposed to DEHP or MEHP were investigated using qRT-PCR analysis. As a result, exposure to these compounds significantly upregulated PXR/CAR target genes (CYP3A4 and CYP2B6), but not PPARα target genes (CYP4A11, etc.) in HepaRG cells. Taken together, these results suggest that direct PXR and/or indirect CAR activation by several DEHP metabolites may be involved in the endocrine disruption by altering hormone metabolism.

Enhancing predictive monitoring of ethylene oxychlorination reactor states through spatiotemporal coupling analysis

The production of polyvinyl chloride (PVC) encounters challenges stemming from the temporal and spatial coupling characteristics inherent in the fixed bed ethylene oxychlorination process. Consequently, the implementation of enhanced safety measures and risk reduction strategies becomes imperative. This study introduces a pioneering methodology leveraging a spectral temporal graph neural network. By leveraging reactor temperature data, spatial variable decoupling facilitated by the Fourier transform, and a self-attentive mechanism within graph neural networks, the proposed approach adeptly forecasts future reactor states. The model's seamless alignment with the physical knowledge of reaction processes, validated through the adjacency matrix and hotspot region identification, underscores its efficacy in ensuring process safety and mitigating operational risks in PVC production. Empirical findings further validate the effectiveness of the approach, with predictions demonstrating an error margin of less than 0.5°C in forecasting future reactor temperatures.

Synthesis and Characterization of Diacylthiourea and Diacylthioureato Cu(I) Complexes

A series of six disubstituted diacylthioureas 1,3‐ and 1,4‐C6H4[C(O)NHC(S)NR1R2]2 (L1‐6) were synthesized with varied Rn substituents (R1 = R2 = Et for L1‐2; R1 = R2 = Bn for L3‐4; R1 = iPr and R2 = Ph for L5 (1) and L6 (2)). Treatment of Ln with Cu(I) halide precursors CuX(PPh3)3 (X = Cl, Br, I) produced the discrete binuclear adducts Ln[CuX(PPh3)2]2 (3‐11 and 14‐16; n = 1‐3 and 6) by binding to Cu(I) centres via the monodentate‐S mode. In contrast, L4 and L5 yielded only the chloride products of binuclear L4[CuCl(PPh3)2]2 (12) and mononuclear L5CuCl(PPh3)2 (13), respectively, with one S arm in the latter remaining dangling, while bromide or iodide analogues were not available for L4 and L5, possibly due to the steric hindrance imposed by larger halide anions or bulky isopropyl substituents. The reactions of Ln with nitrate [Cu(NO3)(PPh3)2]led to the double‐deprotonation of ligand protons to generate dianions Ln' (1,3‐/1,4‐C6H4[C(O)NC(S)NR1R2]22‐) and led to the consequent formation of binuclear diacylthioureato Cu(I) complexes Ln'[Cu(PPh3)2]2 (n=1 (17), 2 (18), 4 (19)) via the κ‐O,S‐bidentate mode. The obtained ligands and complexes were spectroscopically and structurally characterized. These Cu(I) products (3‐19) were experimentally used as catalysts for the oxidation of 1‐phenylethanol.

Intelligent prediction of incipient fault in vinyl chloride production process based on deep learning

With the development of industrial information technology, deep learning (DL) has been successfully applied in chemical process fault detection. However, the features of incipient faults could not be more evident at the initial stage, which makes it difficult for deep learning to fully mine the feature probability information, resulting in poor performance of incipient fault monitoring. This paper proposes an intelligent predictive model based on mechanistic modeling to predict incipient faults and determine optimal response times for vinyl chloride production (VCP) processes. Firstly, a dynamic simulation of the VCP production process is performed to obtain datasets of early faults. Secondly, data dimensionality reduction is performed by cleverly combining spearman ranking correlation coefficient (SRCC) and slow feature analysis (SFA). Then, a long short-term memory network (LSTM) with attention mechanism (AM) is built to predict the future trends of key variables. Finally, the optimal response time for different types of incipient faults is determined by comparing the effectiveness of various control schemes. Compared with traditional methods, the R2 of the proposed prediction model corresponding to different step sizes can reach 99.7%, 99.5%, 99.2%, and 98.7%. In addition, the response times for single and parallel faults are 2 and 2.5 h, which helps to control and eliminate potential incidents in advance.

Characterization of corrosion mechanism and traditional soldering treatment of a composite bronze lamp from the Greco-Roman period of Egypt

This paper presents a study of treatment by soldering for a unique bronze oil lamp combined with Eros and dog figurines. In this object, there are two types of soldering; the first is ancient, used to join the three pieces together, and the other is used in conservation treatments to stop the degradation of the object. Soft solders have been a modern method of repair, with its historical use as the original joining technique demonstrating its general durability and effectiveness. Optical microscopy, portable X-ray fluorescence, and micro-Raman spectroscopy were used to identify the soldering treatment, the chemical composition of the alloy, and the corrosion products. Investigation techniques showed the use of a modern tin-lead alloy as soft soldering in past interventions to treat cracks and fill losses. Cracks propagated due to soil pressures and ongoing corrosion processes, as well as the combined action of tensile forces and the surface-active molten solder. The ancient solder used to attach the dog and Eros to the lamp was a hard solder. The three pieces were made of high-leaded tin bronze, with Pb contents ranging from 10.5 to 13 wt%. The chloride and sulfate corrosion products detected by µ-RS were more aggressive in the object structure. The corrosion products of the soft solder consisted mostly of lead and tin oxides, basic carbonates, and sulfates.

A common phthalate replacement disrupts ovarian function in young adult mice.

Di-2-ethylhexyl terephthalate (DEHTP) is a replacement for its structural isomer di-2-ethylhexyl phthalate (DEHP), a known endocrine disrupting chemical and ovarian toxicant. DEHTP is used as a plasticizer in polyvinyl chloride products and its metabolites are increasingly found in biomonitoring studies at levels similar to phthalates. However, little is known about the effects of DEHTP on the ovary. In this research, we tested the hypothesis that DEHTP is an ovarian toxicant and likely endocrine disrupting chemical like its isomer DEHP. The impact of environmentally relevant exposure to DEHTP and/or its metabolite mono-2-ethylhexyl terephthalate (MEHTP) on the mouse ovary was investigated in vivo and in vitro. For the in vivo studies, young adult CD-1 mice were orally dosed with vehicle, 10 µg/kg, 100 µg/kg, or 100 mg/kg of DEHTP for 10 days. For the in vitro studies, isolated untreated ovarian follicles were exposed to vehicle, 0.1, 1, 10, or 100 µg/mL of DEHTP or MEHTP. Follicle counts, hormone levels, and gene expression of steroidogenic enzymes, cell cycle regulators, and apoptosis factors were analyzed. In vivo, DEHTP exposure increased primordial follicle counts at 100 µg/kg and 100 mg/kg and decreased primary follicle counts at 100 mg/kg compared to control. DEHTP exposure also decreased expression of cell cycle regulators and apoptotic factors compared to control. In vitro, follicle growth was reduced by 1 µg/mL DEHTP and 1, 10, and 100 µg/mL MEHTP compared to controls, and expression of the cell cycle regulator Cdkn2b was increased. Steroid hormone levels and steroidogenic enzyme gene expression trended toward decreases in vivo, whereas progesterone was significantly increased by exposure to 100 µg/mL MEHTP in vitro. Overall, these results suggest that DEHTP and MEHTP may be ovarian toxicants at low doses and should be subjected to further scrutiny for reproductive toxicity due to their similar structures to phthalates.