Health & Environmental Research Online (HERO)


GenX Chemicals (CASRN 13252-13-6 and CASRN 62037-80-3)


153 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Degradation of hexafluoropropylene oxide oligomer acids as PFOA alternatives in simulated nanofiltration concentrate: Effect of molecular structure

Authors: Bao, Y; Cagnetta, G; Huang, Jun; Yu, G (2020) HERO ID: 6302277

[Less] Hexafluoropropylene oxide (HFPO) oligomer acids are an important class of perfluorooctanic acid (PFOA) . . . [More] Hexafluoropropylene oxide (HFPO) oligomer acids are an important class of perfluorooctanic acid (PFOA) alternatives used in fluoropolymer production. Their chemical structure presents a periodical -CF3 branch and oxygen bridge. In particular, hexafluoropropylene oxide dimer, trimer and tetramer acid (HFPO-DA, HFPO-TA and HFPO-TeA) have been globally detected in waters, and are thought to exert an even greater potential ecological risk than PFOA. Moreover, different to PFOA, HFPO-DA has been demonstrated to be strongly oxidation-resistant, and thus its removal is more challenging. In this study, the degradability of HFPO-TA and HFPO-TeA, as well as a perfluoropolyether carboxylic acid without a -CF3 branch (TeA-w), was investigated. Unlike HFPO-DA, HFPO-TA and HFPO-TeA could be oxidized under UV/persulfate, which was attributed to the changed molecular configuration and weakened protective effect of the -CF3 branch on a-carbon atoms against SO4- attack. As a result, the oxidability of these HFPO acids increases with the number of oxygen bridges (i.e. HFPO-TeA > HFPO-TA > HFPO-DA). However, oxidation is found to be a risky approach for HFPO-TA and HFPO-TeA removal owing to significant generation and accumulation of HFPO-DA. On the contrary, HFPO-TA and HFPO-TeA were effectively degraded without accumulation of (by)products in a strong reductive system (UV/sulfite). HFPO oligomer acid degradation in both oxidative and reductive systems always follows a similar pathway; namely, HFPO-TeA -> HFPO-TA -> HFPO-DA. Nanofiltration is potentially one of the best available technologies for HFPO oligomer removal from drinking water, but safe concentrate disposal should be a consideration. Given this, we performed degradation of HFPO-DA/TA/TeA mixture in simulated nanofiltration concentrate. More than 99.7% of the three substances were removed within 60 min, and a complete fluoride recovery was obtained 120 min later. This corroborated that reduction by UV/sulfite is a potential complementary technology for nanofiltration in drinking water deep treatment aimed at removing HFPO oligomer acid contamination.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Activation of human nuclear receptors by perfluoroalkylated substances (PFAS)

Authors: Behr, AC; Plinsch, C; Braeuning, A; Buhrke, T (2020) Toxicology In Vitro 62:104700. HERO ID: 6305866

[Less] Perfluoralkylated substances (PFAS) such as perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic . . . [More] Perfluoralkylated substances (PFAS) such as perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic acid (PFOS) are used to produce, e.g., surface coatings with water- and dirt-repellent properties. These substances have been shown to be hepatotoxic in rodents, and the mechanism of action is mostly attributed to the PFAS-mediated activation of the peroxisome proliferator-activated receptor alpha (PPARα). In the present study, we investigated by using luciferase-based reporter gene assays whether PFOA, PFOS and six alternative PFAS can activate, in addition to PPARα, eight other human nuclear receptors. All tested PFAS except for perfluorobutanesulfonic acid (PFBS) were able to activate human PPARα. Perfluoro-2-methyl-3-oxahexanoic acid (PMOH) and 3H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP) were weak agonists of human PPARγ. The other human nuclear receptors (PPARδ, CAR, PXR, FXR, LXRα, RXRα and RARα) were not affected by any PFAS tested in this study. Although PMOH was more effective than PFOA in stimulating PPARα in the transactivation assay, it was less effective in stimulating PPARα-dependent target gene expression in human HepG2 hepatocarcinoma cells. Notably, any effect observed in this in vitro study only occurred at concentrations higher than 10 μM of the respective PFAS which is in all cases several magnitudes above the average blood concentration in the Western population. Thus, the results suggest that nuclear receptor activation may only play a minor role in potential PFAS-mediated adverse effects in humans.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Epigenetic toxicity of PFOA and GenX in HepG2 cells and their roles in lipid metabolism

Authors: Wen, Y; Mirji, N; Irudayaraj, J (2020) Toxicology In Vitro 65:104797. HERO ID: 6302274

[Less] Perfluorooctanoic acid (PFOA), an extremely persistent perfluoroalkyl substance (PFAS), and 2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy) . . . [More] Perfluorooctanoic acid (PFOA), an extremely persistent perfluoroalkyl substance (PFAS), and 2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX), its shorter chain alternative, have been implicated in hepatocellular damage with unusual fat deposit and liver enlargement. In this study we explored the underlying mechanisms of PFOA and GenX induced hepatocellular damage. Liver hepatocellular carcinoma cell line HepG2 was used as a model to study induced liver inflammation in vitro at the cellular, genetic, and epigenetic levels. HepG2 cells were exposed to PFOA or GenX for 48 h and the DNA and RNA were extracted and analyzed. mRNA expression of PFOA exposed cells showed that the cell cycle genes were affected significantly, as well as the ten-eleven translocation methylcytosine dioxygenases (TETs) and the essential lipid metabolism genes. However, GenX did not have as significant an effect on the expression levels. Global methylation levels of HepG2 cells was found to be inversely proportion to PFOA exposure levels and had corresponding trends with mRNA expression of most genes of interest. Upon comparison, the global methylation level of GenX decreased and then increased. Our work points to the fact that PFOA induced epigenetic changes may play a major role in lipid metabolism gene regulation contributing to higher levels of epigenetic toxicity than GenX.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Evaluation of Maternal, Embryo, and Placental Effects in CD-1 Mice following Gestational Exposure to Perfluorooctanoic Acid (PFOA) or Hexafluoropropylene Oxide Dimer Acid (HFPO-DA or GenX)

Authors: Blake, BE; Cope, HA; Hall, SM; Keys, RD; Mahler, BW; Mccord, J; Scott, B; Stapleton, HM; Strynar, MJ; Elmore, SA; Fenton, SE (2020) Environmental Health Perspectives 128:27006. HERO ID: 6305864

[Less] BACKGROUND: Perfluorooctanoic acid (PFOA) is a poly- and perfluoroalkyl substance (PFAS) . . . [More] BACKGROUND: Perfluorooctanoic acid (PFOA) is a poly- and perfluoroalkyl substance (PFAS) associated with adverse pregnancy outcomes in mice and humans, but little is known regarding one of its replacements, hexafluoropropylene oxide dimer acid (HFPO-DA, referred to here as GenX), both of which have been reported as contaminants in drinking water.

OBJECTIVES: We compared the toxicity of PFOA and GenX in pregnant mice and their developing embryo-placenta units, with a specific focus on the placenta as a hypothesized target.

METHODS: Pregnant CD-1 mice were exposed daily to PFOA (0, 1, or ) or GenX (0, 2, or ) via oral gavage from embryonic day (E) 1.5 to 11.5 or 17.5 to evaluate exposure effects on the dam and embryo-placenta unit. Gestational weight gain (GWG), maternal clinical chemistry, maternal liver histopathology, placental histopathology, embryo weight, placental weight, internal chemical dosimetry, and placental thyroid hormone levels were determined.

RESULTS: Exposure to GenX or PFOA resulted in increased GWG, with increase in weight most prominent and of shortest latency with GenX exposure. Embryo weight was significantly lower after exposure to PFOA (9.4% decrease relative to controls). Effect sizes were similar for higher doses ( PFOA and GenX) and lower doses ( PFOA and GenX), including higher maternal liver weights, changes in liver histopathology, higher placental weights and embryo-placenta weight ratios, and greater incidence of placental abnormalities relative to controls. Histopathological features in placentas suggested that PFOA and GenX may exhibit divergent mechanisms of toxicity in the embryo-placenta unit, whereas PFOA- and GenX-exposed livers shared a similar constellation of adverse pathological features.

CONCLUSIONS: Gestational exposure to GenX recapitulated many documented effects of PFOA in CD-1 mice, regardless of its much shorter reported half-life; however, adverse effects toward the placenta appear to have compound-specific signatures. https://doi.org/10.1289/EHP6233.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Elevated levels of per- and polyfluoroalkyl substances in Cape Fear River Striped Bass (Morone saxatilis) are associated with biomarkers of altered immune and liver function

Authors: Guillette, TC; Mccord, J; Guillette, M; Polera, ME; Rachels, KT; Morgeson, C; Kotlarz, N; Knappe, DRU; Reading, BJ; Strynar, M; Belcher, SM (2020) Environment International 136:105358. HERO ID: 6302271

[Less] Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals of concern that persist in the . . . [More] Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals of concern that persist in the environment. Environmental monitoring revealed high concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) and other novel PFAS in the lower Cape Fear River; however, there is limited information on PFAS exposures and effects of this contamination on aquatic biota. Serum concentrations of 23 PFAS in Striped Bass (Morone saxatilis) from the Cape Fear River (n = 58) and a reference population from an aquaculture laboratory on the Pamlico/Tar watershed (n = 29) were quantified using liquid chromatography and high-resolution mass spectrometry, and correlations between PFAS concentrations and health-related serum biomarkers were evaluated. Perfluorooctane sulfonate, the predominant PFAS in Cape Fear River Striped Bass serum, was detectable in every sample with serum concentrations reaching 977 ng/mL. Perfluorononanoic and perfluorodecanoic acid were also detected in all samples, with perfluorohexanesulfonic acid present in >98% of the samples. HFPO-DA (range <0.24-5.85 ng/mL) and Nafion byproduct 2 (range <0.2-1.03 ng/mL) were detected in 48% and 78% of samples, respectively. The mean total PFAS concentration found in domestic Striped Bass raised in well-water under controlled aquaculture conditions was 40 times lower, with HPFO-DA detected in 10% of the samples, and Nafion byproduct 2 was not detected. The elevated PFAS concentrations found in the Cape Fear River Striped Bass were associated with biomarkers of alterations in the liver and immune system.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Environmental contamination and human exposure to PFASs near a fluorochemical production plant: Review of historic and current PFOA and GenX contamination in the Netherlands

Authors: Gebbink, WA; van Leeuwen, SPJ (2020) Environment International 137:105583. [Review] HERO ID: 6305899

[Less] Fluorochemical production plants (FPP) are primary emission sources of per- and polyfluoroalkyl substances . . . [More] Fluorochemical production plants (FPP) are primary emission sources of per- and polyfluoroalkyl substances (PFASs) to the local environment. An FPP located in the Netherlands has historically used perfluorooctanoic acid (PFOA) for fluoropolymer production and is currently using GenX (HFPO-DA; 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionic acid) as a replacement. This study reviewed existing data from open access reports and peer reviewed publications on the environmental presence of PFOA and GenX in environmental matrices such as surface water, groundwater, soil and vegetation. Published data on human exposure to PFOA and GenX (i.e. via drinking water and food as well as blood monitoring) were reviewed in order to assess the influence of the FPP on contamination of the local population. Concentrations in environmental and human exposure samples were compared to (inter)national quality standards or risk limits. The data showed higher PFOA and GenX concentrations in surface water, groundwater, soil and vegetation samples taken close to point sources, and the highest observed concentrations exceeded these standards and limits (except for PFOA in soil). Drinking water and food also contained higher PFOA and GenX concentrations in samples taken close to point sources compared to samples further away. Tolerable daily intake (TDIs) for both PFASs were exceeded, however, only in a maximum exposure scenario. Blood monitoring of the local population near the FPP, and FPP workers, confirmed high exposure can occur as blood concentrations of several individuals exceeded the safe level. This paper provides a comprehensive overview on PFOA and GenX contamination close to point sources in the Netherlands.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Legacy per- and polyfluoroalkyl substances (PFASs) and alternatives (short-chain analogues, F-53B, GenX and FC-98) in residential soils of China: Present implications of replacing legacy PFASs

Authors: Li, J; He, J; Niu, Z; Zhang, Y (2020) Environment International 135:105419. HERO ID: 6302272

[Less] With the worldwide regulation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), . . . [More] With the worldwide regulation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), the alternatives (short chain analogues and emerging per- and polyfluoroalkyl substances, PFASs) have gradually attracted global attention. This study analysed the replacing of legacy PFASs in China using PFASs data from residential soils, which might be good environmental indicators of their present usage. The total concentrations of 21 PFASs ranged from 244 to 13564 pg/g, and PFOA was the dominant compound among the studied PFASs, with a concentration of 354 ± 439 pg/g. Serious PFASs pollution in residential soils mainly occurred in Eastern Coastal China as a result of locally developed industry and economies. Weak but significant correlations were found between PFASs and environmental and socioeconomic factors, suggesting that various factors determine PFASs contamination in residential soils. The concentration and detection frequency (DF) of short-chain analogues (C < 8) (375 ± 509 pg/g and 100%), and F-53B (216 ± 306 pg/g and 98.9%) were higher than those for PFOS (193 ± 502 pg/g and 85.4%), indicating that these compounds have been widely used as PFOS alternatives and their consumption has already exceeded that of PFOS in China. In addition, GenX (the PFOA alternative) had a concentration and DF of 19.1 ± 104 pg/g and 40.5%, respectively. These values were much lower than those for PFOA (354 ± 439 pg/g and 96.6%), indicating GenX consumption is still limited at the national scale of China, despite its use as a PFOA replacement. Moreover, the low concentration and DF of FC-98 (2.31 ± 11.1 pg/g and 27.0%) indicate that its consumption might be negligible. Our study demonstrated that short chain analogues and emerging alternatives have become the dominant PFAS pollutants in Chinese residential soils, and further studies need to be conducted to understand their toxicity and environmental risks.

Technical Report
Technical Report

Annex XV report: Proposal for identification of a substance of very high concern on the basis of the criteria set out in REACH Article 57

Author: ECHA (2019) The Netherlands: ECHA. HERO ID: 5883637

[Less] 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid, its salts and its acyl halides (covering any . . . [More] 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid, its salts and its acyl halides (covering any of their individual isomers and combinations thereof), further denoted as HFPO-DA, are identified as substances of very high concern in accordance with Article 57(f) of Regulation (EC) 1907/2006 (REACH) because in water under environmental conditions these substances exist in the form of 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate, for which there is scientific evidence of probable serious effects to the environment and human health which give rise to an equivalent level of concern to those of other substances listed in points (a) to (e) of Article 57 of REACH.

Technical Report
Technical Report

Support document for identification of 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionic acid, its salts and its acyl halides (covering any of their individual isomers and combinations thereof) as substances of very high concern because of their hazardous properties which cause probable serious effects to human health and the environment which give rise to an equivalent level of concern to those of CMR1 and PBT/vPvB2 substances (article 57f)

Author: ECHA (2019) The Netherlands: ECHA. HERO ID: 5883639


The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Adsorption behavior and mechanism of emerging perfluoro-2-propoxypropanoic acid (GenX) on activated carbons and resins

Authors: Wang, Wei; Maimaiti, A; Shi, H; Wu, R; Wang, Run; Li, Z; Qi, D; Yu, G; Deng, S (2019) HERO ID: 5024248

[Less] As a typical alternative to perfluorooctanoic acid (PFOA), perfluoro-2-propoxypropanoic acid (GenX) . . . [More] As a typical alternative to perfluorooctanoic acid (PFOA), perfluoro-2-propoxypropanoic acid (GenX) has been detected worldwide in aquatic environment and attracted great concerns recently, but their adsorptive removal from water is not clear. In this study, the adsorption behavior and mechanism of GenX on granular activated carbon (GAC), powdered activated carbon (PAC), anion-exchange resins (IRA400 and IRA67) were compared. The particle size of activated carbon (AC) affected the initial adsorption rate but exhibited little influence on the adsorption capacity for GenX. The initial adsorption kinetics of GenX on the three granular adsorbents (GAC, IRA67 and IRA400) followed the intraparticle diffusion-controlled adsorption. IRA67 had the highest adsorption capacity of 3.22 mmol/g for GenX, higher than IRA400 (2.78 mmol/g) and much higher than the two ACs (0.79 mmol/g). When GenX was co-removed with perfluorooctanoic acid (PFOA) in competitive system, the adsorbed amounts of GenX on the four adsorbents decreased significantly, and adsorbed GenX was replaced by PFOA with increasing time. The small adsorbent size could speed up the replacement process, and the polyamine group on the resins was more prone to producing this effect than the quaternary ammonium group. PAC was more suitable for GenX removal at low pH, while IRA400 was better used at high solution pH. The spent AC and resins were successfully regenerated in the ethanol and NaCl solution, respectively, and their regeneration efficiency was significantly enhanced in hot water. The adsorption mechanisms including anion exchange, electrostatic interaction and hydrophobic interaction were involved in the GenX adsorption.