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Xing Y, Ge Y, Lu S, Yang T, Peng X. Dimethylcyclosiloxanes in Mobile Smart Terminal Devices: Concentrations, Distributions, Profiles, and Environmental Emissions. Toxics 2024; 12:287. [PMID: 38668510 PMCID: PMC11053745 DOI: 10.3390/toxics12040287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024]
Abstract
Dimethylcyclosiloxanes (DMCs) are utilized as vital monomers in the synthesis of organosilicon compounds, integral to the manufacture of mobile smart terminal devices. Toxicological studies have revealed potential endocrine-disrupting activity, reproductive toxicity, neurotoxicity, and other toxicities of the DMCs. This study investigated the concentrations and composition profiles of seven DMCs, including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), and octadecamethylcyclononasiloxane (D9) in three types of mobile smart terminal device components (silicone rubber, adhesive, and plastics). Environmental emissions of DMCs from silicone rubber materials were also estimated to improve the recognition of their potential fate within the environment. D5-D9 were widely present in silicone rubber and adhesives with detection rates ranging from 91-95.5% and 50-100%, respectively, while D3 and D4 were more frequently detected in plastics, both showing a detection rate of 61.1%. Silicone rubber had the highest total DMCs (∑7DMCs) and a concentration of 802.2 mg/kg, which were dominated by D7, D8, and D9. DMCs detected in adhesives were dominated by D4, D5, and D6. The estimated emission of ∑DMCs released into the environment in China from silicone rubber used in mobile smart terminal devices exceeds 5000 tons per year. Further studies are needed on the presence of DMCs in various commodities and environmental media to assess their ecological and human health impacts, as well as the toxicological effects of D7-D9 for the appropriate regulation of these chemicals.
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Affiliation(s)
- Yuanna Xing
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiming Ge
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Shaoyou Lu
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Tao Yang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianzhi Peng
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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Clewell H, Greene T, Gentry R. Dermal absorption of cyclic and linear siloxanes: a review. J Toxicol Environ Health B Crit Rev 2024; 27:106-129. [PMID: 38375664 DOI: 10.1080/10937404.2024.2316843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Cyclic and linear siloxanes are compounds synthesized from silicon consisting of alternating atoms of silicone and oxygen [Si-O] units with organic side chains. The most common cyclic siloxanes are octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), while the most common linear siloxanes are high molecular weight polydimethylsiloxanes (PDMS) and low molecular weight volatile linear siloxanes known as hexamethyldisiloxane (L2), octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5). These compounds (1) exhibit low dermal toxicity, (2) are generally inert and non-reactive, and (3) are compatible with a wide range of chemicals offering beneficial chemical properties which include the following: wash-off or transfer resistance from the skin, sun protection factor (SPF) enhancement, emolliency in cleaning products). Because of these properties, these compounds are incorporated into multiple consumer products for use on the skin, such as cosmetics and health-care products, with over 300,000 tons annually sold into the personal care and consumer products sector. Because of their widespread use in consumer products and potential for human dermal exposure, a comprehensive understanding of the dermal absorption and overall fate of siloxanes following dermal exposure is important. This review summarizes available data associated with the dermal absorption/penetration as well as fate of the most commonly used siloxane substances.
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Affiliation(s)
- Harvey Clewell
- Ramboll Americas Engineering Services, Inc, Winston-Salem, NC, USA
| | - Tracy Greene
- Ramboll Americas Engineering Services, Inc, Monroe, LA, USA
| | - Robinan Gentry
- Ramboll Americas Engineering Services, Inc, Monroe, LA, USA
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Niu H, Su X, Li Q, Zhao J, Hou M, Dong S, Yan X, Sun J, Feng J. Dimethylsiloxanes in dust from nine indoor microenvironments of Henan Province: Occurrence and human exposure assessment. Sci Total Environ 2023; 903:166546. [PMID: 37625713 DOI: 10.1016/j.scitotenv.2023.166546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
Dimethylsiloxanes (MSs) are widely used in daily life and industry, with indoors being the main release site. Detecting the levels of MSs in indoor dust is essential for assessing the risks of human exposure. In this study, the content of MSs (D3-D8 and L3-L16) was quantified in indoor dust samples from nine microenvironments of Henan Province. The detection frequency of the targets ranged from 5.00 % to 100 %. The sum concentration of dimethylsiloxanes (TSi) was in a range of 463-3.32 × 104 ng·g-1 (median: 1.92 × 103 ng·g-1). The sum concentration of linear dimethylsiloxanes (TLSi) from all microenvironments was higher than the sum concentration of cyclic dimethylsiloxanes (TCSi), which was consistent with previously reported results. D7 and D8 were the main cyclic dimethylsiloxane, which had similar sources based on Spearman correlation analysis (p < 0.001). Moreover, D8 was detected with high levels in indoor dust for the first time, which warrants further exploration. L8-L16 were the main linear dimethylsiloxanes, which may have been due to their widespread use in electronic equipment and office equipment. The Spearman analysis found that total organic carbon (TOC) in indoor dust had weak effect on MSs. Additionally, relatively high MS levels were recorded in high people-flow working microenvironments. Accordingly, the exposure doses of MSs via indoor dust intake were estimated for different age groups using the model of worst-case exposure and median concentration. Toddlers had the highest EDIs (95th percentile concentration, 90.7 ng·kg-1-bw·d-1) to MSs.
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Affiliation(s)
- Haoran Niu
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Xianfa Su
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Qian Li
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Jiahui Zhao
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Manyun Hou
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Shuying Dong
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Xu Yan
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Jianhui Sun
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China
| | - Jinglan Feng
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China.
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Liu YQ, Wang ZW, Hu CY. Progress in research on the safety of silicone rubber products in food processing. Compr Rev Food Sci Food Saf 2023. [PMID: 37183940 DOI: 10.1111/1541-4337.13165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/24/2023] [Accepted: 04/15/2023] [Indexed: 05/16/2023]
Abstract
Silicone rubber (SR) is widely used in the food processing industry due to its excellent physical and chemical properties. However, due to the differences in SR product production formulas and processes, the quality of commercially available SR products varies greatly, with chemical and biological hazard potentials. Residual chemicals in SR, such as siloxane oligomers and 2,4-dichlorobenzoic acid, are non-intentionally added substances, which may migrate into food during processing so the safe use of SR must be guaranteed. Simultaneously, SR in contact with food is susceptible to pathogenic bacteria growing and biofilm formation, like Cronobacter sakazakii, Staphylococcus aureus, Salmonella enteritidis, and Listeria monocytogenes, posing a food safety risk. Under severe usage scenarios such as high-temperature, high-pressure, microwave, and freezing environments with long-term use, SR products are more prone to aging, and their degradation products may pose potential food safety hazards. Based on the goal of ensuring food quality and safety to the greatest extent possible, this review suggests that enterprises need to prepare high-quality food-contact SR products by optimizing the manufacturing formula and production process, and developing products with antibacterial and antiaging properties. The government departments should establish quality standards for food-contact SR products and conduct effective supervision. Besides, the reusable SR products should be cleaned by consumers immediately after use, and the deteriorated products should be replaced as soon as possible.
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Affiliation(s)
- Yi-Qi Liu
- Department of Food Science & Engineering, Jinan University, Guangzhou, Guangdong, China
| | - Zhi-Wei Wang
- Packaging Engineering Institute, Jinan University, Zhuhai, Guangdong, China
| | - Chang-Ying Hu
- Department of Food Science & Engineering, Jinan University, Guangzhou, Guangdong, China
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Alva-Gallegos R, Carazo A, Mladěnka P. Toxicity overview of endocrine disrupting chemicals interacting in vitro with the oestrogen receptor. Environ Toxicol Pharmacol 2023; 99:104089. [PMID: 36841273 DOI: 10.1016/j.etap.2023.104089] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
The oestrogen receptor (ER) from the nuclear receptor family is involved in different physiological processes, which can be affected by multiple xenobiotics. Some of these compounds, such as bisphenols, pesticides, and phthalates, are widespread as consequence of human activities and are commonly present also in human organism. Xenobiotics able to interact with ER and trigger a hormone-like response, are known as endocrine disruptors. In this review, we aim to summarize the available knowledge on products derived from human industrial activity and other xenobiotics reported to interact with ER. ER-disrupting chemicals behave differently towards oestrogen-dependent cell lines than endogenous oestradiol. In low concentrations, they stimulate proliferation, whereas at higher concentrations, are toxic to cells. In addition, most of the knowledge on the topic is based on individual compound testing, and only a few studies assess xenobiotic combinations, which better resemble real circumstances. Confirmation from in vivo models is lacking also.
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Affiliation(s)
- Raul Alva-Gallegos
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Alejandro Carazo
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic.
| | - Přemysl Mladěnka
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
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Sounouvou HT, Lechanteur A, Piel G, Evrard B. Silicones in dermatological topical drug formulation: Overview and advances. Int J Pharm 2022; 625:122111. [PMID: 35973590 DOI: 10.1016/j.ijpharm.2022.122111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/23/2022] [Accepted: 08/10/2022] [Indexed: 10/15/2022]
Abstract
Silicones, more specifically those of the polydimethylsiloxane type, have been widely used in the pharmaceutical industry for decades, particularly in topical applications. In the dermatological field, in addition to provide undeniable textural and sensory benefits, they can play important functions in the physicochemical properties, stability and biopharmaceutical behavior of these formulations. However, despite the notable advances that can be attributed to the family of silicones, the reputation of these compounds is quite bad. Indeed, silicones, even if they derive from sand, are synthetic compounds. Moreover, they are not biodegradable. They flow into our wastewater and oceans, accumulating in the fauna and flora. This obviously raises many concerns in the common imagination. Do silicones represent a danger for our environment? Should the human species worry about long term toxic effects? Are the claimed benefits really that important? After exploring the various applications of silicone excipients in topical dermatological formulations with a special focus on recent advances which open breathtaking prospects for dermatological applications, this paper shed light on the specific challenges involved in preparation of silicone-based drug as well as, the in vivo behavior of these polymers, the toxicological and environmental risks associated with their application.
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Affiliation(s)
- Hope T Sounouvou
- Laboratory of Pharmaceutical Technology and Biopharmacy, CIRM, University of Liège, 4000 Liège, Belgium; Medicinal Organic Chemistry Laboratory (MOCL), School of Pharmacy, Faculté des Sciences de la Santé, Université d'Abomey-Calavi, Campus du Champ de Foire, Cotonou, Benin.
| | - Anna Lechanteur
- Laboratory of Pharmaceutical Technology and Biopharmacy, CIRM, University of Liège, 4000 Liège, Belgium
| | - Géraldine Piel
- Laboratory of Pharmaceutical Technology and Biopharmacy, CIRM, University of Liège, 4000 Liège, Belgium
| | - Brigitte Evrard
- Laboratory of Pharmaceutical Technology and Biopharmacy, CIRM, University of Liège, 4000 Liège, Belgium
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Mojsiewicz-Pieńkowska K, Krenczkowska D, Bazar D, Wielgomas B, Cal K, Kaliszan M. Comparative study of the percutaneous permeation and bioaccumulation of the cyclic siloxane using frozen-thawed and nonfrozen ex vivo human skin. Toxicol In Vitro 2022; 82:105379. [PMID: 35561954 DOI: 10.1016/j.tiv.2022.105379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 04/06/2022] [Accepted: 05/06/2022] [Indexed: 11/25/2022]
Abstract
Literature shows contradictory information regarding the effect of freezing the excise skin ex vivo on the diffusion of substances into the skin. Few studies indicate that storing the human or animal skin in a frozen state decreases the barrier properties after thawing. Therefore, to understand the properties of frozen skin, we evaluated the effect of storage of ex vivo human skin (2 weeks at -20 °C) on the penetration of stratum corneum and permeation into deeper skin layers (epidermis, and dermis) as well as to the receptor fluid by octamethylcyclotetrasiloxane (D4) a representative test compound of cyclic siloxanes. The main research were preceded by checking the integrity of nonfrozen ex vivo human skin in comparison to the frozen-thawed one by using the Electrical Resistance technique (ER) and the fluorescence microscopy. Samples collected in the skin absorption experiment were analyzed by gas chromatography equipped with a flame ionization detector (GC-FID). The results of this study demonstrated that freezing of excised ex vivo human skin at -20 °C for up to 14 days does not alter the permeability of D4 in a statistically significant manner. Thus, our results confirmed the validity of using skin storage conditions for testing the penetration and permeation of xenobiotics recommended by the OECD, EMA, and WHO guidelines.
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Affiliation(s)
- Krystyna Mojsiewicz-Pieńkowska
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. Józefa Hallera 107, 80-416 Gdańsk, Poland.
| | - Dominika Krenczkowska
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. Józefa Hallera 107, 80-416 Gdańsk, Poland
| | - Dagmara Bazar
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. Józefa Hallera 107, 80-416 Gdańsk, Poland
| | - Bartosz Wielgomas
- Department of Toxicology, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. Józefa Hallera 107, 80-416 Gdańsk, Poland
| | - Krzysztof Cal
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. Józefa Hallera 107, 80-416 Gdańsk, Poland
| | - Michał Kaliszan
- Department of Forensic Medicine, Faculty of Medicine, Medical University of Gdańsk, ul. Dębowa 23, 80-204 Gdańsk, Poland
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Mojsiewicz-Pieńkowska K, Stachowska E, Krenczkowska D, Bazar D, Meijer F. Evidence of Skin Barrier Damage by Cyclic Siloxanes (Silicones)-Using Digital Holographic Microscopy. Int J Mol Sci 2020; 21:ijms21176375. [PMID: 32887477 PMCID: PMC7504040 DOI: 10.3390/ijms21176375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 08/31/2020] [Indexed: 11/16/2022] Open
Abstract
Cyclic siloxanes (D4, D5, D6) are widely used in skin products. They improve skin sensory properties and alleviate dry skin, but there is still one report (published 2019), which regards their effects on the destruction of the skin barrier, by using fluorescence microscopy and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). A new skin-imaging technique, digital holographic microscopy (DHM), was used for the first time to investigate the impact of D4, D5, and D6 on the skin barrier. We observed irreversible damage of the stratum corneum due to the interaction with cyclic siloxanes. These substances changed: (a) the first level of the skin barrier through destabilization of the intercellular lipid lamellae and destruction of the corneocyte structure (measured with axial nanometer resolution), (b) the second level by collapse of not only corneocytes but also of a significant part of the clusters, leading to the loss of the stratum corneum integrity and formation of the lacunae, (c) the third level as an effect of the change in the surface geometrical topography of the stratum corneum and disruption of the integrity of this skin layer, measured with lateral micrometer resolution. DHM allowed also to identify an important pathway for substances to penetrate into the skin through canyons surrounding the clusters. Our investigations provide advanced information for understanding the mechanisms by which various substances pass the skin barrier, including uncontrolled diffusion into the skin.
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Affiliation(s)
- Krystyna Mojsiewicz-Pieńkowska
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, al. gen. Józefa Hallera 107, 80-416 Gdańsk, Poland; (D.K.); (D.B.)
- Correspondence: ; Tel.: +48-58-3491656
| | - Ewa Stachowska
- Department of Metrology and Measurement Systems, Faculty of Mechanical Engineering and Management, Poznan University of Technology, ul. Piotrowo 3, 60-965 Poznan, Poland; (E.S.); (F.M.)
| | - Dominika Krenczkowska
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, al. gen. Józefa Hallera 107, 80-416 Gdańsk, Poland; (D.K.); (D.B.)
| | - Dagmara Bazar
- Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, al. gen. Józefa Hallera 107, 80-416 Gdańsk, Poland; (D.K.); (D.B.)
| | - Frans Meijer
- Department of Metrology and Measurement Systems, Faculty of Mechanical Engineering and Management, Poznan University of Technology, ul. Piotrowo 3, 60-965 Poznan, Poland; (E.S.); (F.M.)
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