Health & Environmental Research Online (HERO)


PFHxA (307-24-4)


338 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

Addendum to Iwai and Hoberman (2014)-Reassessment of developmental toxicity of PFHxA in mice

Authors: Iwai, H; Hoberman, AM; Goodrum, PE; Mendelsohn, E; Anderson, JK (2019) International Journal of Toxicology 38:183-191. HERO ID: 5097907

[Less] This article presents a supplemental data analysis and evaluation of the findings from an oral (gavage) . . . [More] This article presents a supplemental data analysis and evaluation of the findings from an oral (gavage) combined developmental and perinatal/postnatal reproduction toxicity study of the ammonium salt of perfluorohexanoic acid (CASRN: 21615-47-4) in Crl: CD-1(ICR) mice. The original study has been cited as supporting a lowest-observed-adverse-effects level of 175 mg/kg/d and no-observed-adverse-effects level of 35 mg/kg/d for developmental effects from perfluorohexanoic acid (PFHxA, CASRN: 307-24-4) in mice. The statistical analysis reported in 2014 was accurate in terms of quantifying statistical significance within phase 2 of the study. However, given the low incidence of findings, the purpose of this article is to extend the analysis and interpretation of findings by pooling the control group information from both phases of the same study, comparing the study findings to the incidence rates for stillbirths and postpartum viability for this species and strain of mouse observed for similar studies conducted by the same laboratory, and evaluating data on the incidence and range of spontaneous eye abnormalities reported in the literature. Based on this supplemental evaluation, the original study supports a NOAEL of 175 mg/kg/d for PFHxA in mice, which is a factor of 5-fold higher than previously reported. Furthermore, to the extent that this study may be considered in the selection of a point of departure for PFHxA in mice, it is noted that 175 mg/kg/d for maternal exposure is an unbounded NOAEL for developmental effects, meaning that the study did not establish a dose at which developmental effects may occur.

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

Toxicokinetics of perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) in male and female Hsd:Sprague dawley SD rats following intravenous or gavage administration

Authors: Dzierlenga, AL; Robinson, VG; Waidyanatha, S; Devito, MJ; Eifrid, MA; Gibbs, ST; Granville, CA; Blystone, CR (2019) Xenobiotica 1-11. HERO ID: 5916078

[Less] Poly- and perfluorinated alkyl substances (PFAS) are environmentally persistent chemicals associated . . . [More] Poly- and perfluorinated alkyl substances (PFAS) are environmentally persistent chemicals associated with many adverse health outcomes. The National Toxicology Program evaluated the toxicokinetics (TK) of several PFAS to provide context for toxicologic findings.Plasma TK parameters and tissue (liver, kidney, brain) concentrations are reported for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA) or perfluorodecanoic acid (PFDA) after single-dose administration in male and female Hsd:Sprague-Dawley® (SD) rats.Generally, longer Tmax and elimination half-lives, and slower clearance f, were correlated with longer chain length. Male rats administered PFOA had a prolonged half-life compared to females (215 h vs. 2.75), while females had faster clearance and smaller plasma area under the curve (AUC). Females administered PFHxA had a shorter half-life (2 h vs. 9) than males and faster clearance with a smaller plasma AUC, although this was less pronounced than PFOA. There was no sex difference in PFDA half-life. Female rats administered PFDA had a higher plasma AUC/dose than males, and a slower clearance. PFDA had the highest levels in the liver of the PFAS evaluated.Profiling the toxicokinetics of these PFAS allows for comparison among subclasses, and more direct translation of rodent toxicity to human populations.

Data/Software
Data/ Software

ChemView

Author: U.S. EPA (2019) [Searchable database to access health and safety data about a chemical known and assessed by EPA.]. [Database] HERO ID: 2991004

[Less] Use this database to get information on chemical health and safety data received by EPA and EPA's assessments . . . [More] Use this database to get information on chemical health and safety data received by EPA and EPA's assessments and regulatory actions for specific chemicals under the Toxic Substances Control Act (TSCA). ChemView contains no confidential business information (CBI).

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

Perfluorohexanoic acid toxicity, part I: Development of a chronic human health toxicity value for use in risk assessment

Authors: Luz, AL; Anderson, JK; Goodrum, P; Durda, J (2019) Regulatory Toxicology and Pharmacology 103:41-55. HERO ID: 5080589

[Less] Perfluorohexanoic acid (PFHxA) is a short-chain, six-carbon perfluoroalkyl acid (PFAA) and is a primary . . . [More] Perfluorohexanoic acid (PFHxA) is a short-chain, six-carbon perfluoroalkyl acid (PFAA) and is a primary impurity, degradant, and metabolite associated with the short-chain fluorotelomer-based chemistry used globally today. The transition to short-chain fluorotelomer-based products as a cornerstone in replacement fluorochemistry has raised questions regarding potential human health risks associated with exposure to fluorotelomer-based substances and therefore, PFHxA. Here, we present a critical review of data relevant to such a risk assessment, including epidemiological studies and in vivo and in vitro toxicity studies that examined PFHxA acute, subchronic, and chronic toxicity. Key findings from toxicokinetic and mode-of-action studies are also evaluated. Sufficient data exist to conclude that PFHxA is not carcinogenic, is not a selective reproductive or developmental toxicant, and does not disrupt endocrine activity. Collectively, effects caused by PFHxA exposure are largely limited to potential kidney effects, are mild and/or reversible, and occur at much higher doses than observed for perfluorooctanoic acid (PFOA). A chronic human-health-based oral reference dose (RfD) for PFHxA of 0.25 mg/kg-day was calculated using benchmark dose modeling of renal papillary necrosis from a chronic rat bioassay. This RfD is four orders of magnitude greater than the chronic oral RfD calculated by the U.S. Environmental Protection Agency for PFOA. The PFHxA RfD can be used to inform public health decisions related to PFHxA and fluorotelomer precursors for which PFHxA is a terminal degradant. These findings clearly demonstrate that PFHxA is less hazardous to human health than PFOA. The analyses presented support site-specific risk assessments as well as product stewardship initiatives for current and future short-chain fluorotelomer-based products.

Technical Report
Technical Report

NTP technical report on the toxicity studies of perfluoroalkyl carboxylates (perfluorohexanoic acid, perfluorooctanoic acid, perfluorononanoic acid, and perfluorodecanoic acid) administered by gavage to Sprague Dawley (Hsd:Sprague Dawley SD) rats

Author: NTP (2019) (Toxicity Report 97). Research Triangle Park, NC: National Toxicology Program. HERO ID: 5400977


Archival Material
Archival Material

28-day evaluation of the toxicity (C20613) of perfluorohexanoic acid (PFHxA) (307-24-4) on Harlan Sprague-Dawley rats exposed via gavage

Author: NTP (2018) Available online at https://tools.niehs.nih.gov/cebs3/views/?action=main.dataReview&bin_id=3879. [Website] HERO ID: 4309149

[Less] On 05 April 2018 indirect bilirubin measurements were added to the clinical chemistry tables. No changes . . . [More] On 05 April 2018 indirect bilirubin measurements were added to the clinical chemistry tables. No changes were made to existing data.

Archival Material
Archival Material

TOX-97: Perfluorohexanoic acid (307-24-4), perfluorooctanoic acid (335-67-1), perfluorononanoic acid (375-95-1), perfluorodecanoic acid (335-76-2), WY-14643 (50892-23-4). Chemical Effects in Biological Systems (CEBS)

Author: NTP (2018) Available online at https://manticore.niehs.nih.gov/cebssearch/publication/TOX-97. (Apr 4, 2018). [Website] HERO ID: 4309651


Data/Software
Data/ Software

Chemistry Dashboard

Author: U.S. EPA (2018) Washington, DC: U.S. Environmental Protection Agency. HERO ID: 4575224


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

Plasma concentration of 14 perfluoroalkyl acids (PFAAs) among children from seven cities in Guangdong, China

Authors: Zhang, R; Ye, J; Wei, Q; Li, M; Xu, K; Li, Z; Lin, W; Liu, P; Chen, R; Ma, A; Zhou, Z (2018) Science of the Total Environment 616-617:1469-1476. HERO ID: 4238457

[Less] The toxicity and persistence of perfluoroalkyl acids (PFAAs) in humans have drawn growing concerns, . . . [More] The toxicity and persistence of perfluoroalkyl acids (PFAAs) in humans have drawn growing concerns, particularly for children. However, data regarding the concentrations of PFAAs in children are limited. In this study, we measured the concentrations of 14 PFAAs in plasma samples collected from 1192 children aged 0-7years from 7 cities in Guangdong Province: Guangzhou, Shenzhen, Foshan, Dongguan, Zhaoqing, Zhongshan and Zhanjiang. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected in >99.5% of the analysed samples. PFOS had the highest median concentration (23.6ng/mL) in the total samples, followed by PFOA (2.8ng/mL). The median concentrations of the other PFAAs were lower than 0.4ng/mL. The concentrations of perfluorohexanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluorododecanoic acid, perfluorohexane sulfonate, PFOA and PFOS in children from Foshan were significantly higher than those found in other cities (p<0.001). Negative correlations between most of the PFAA concentrations and age (r=-0.06--0.45) were found in all children. Weak to moderate correlations (r=0.080-0.698) were observed between all PFAA concentrations. Our findings indicated a high exposure of children to PFAAs in the early life-stage. The exposure sources and pathways of PFAAs in different regions are different. Considering a lack of information on the exposure pathways and health status, more studies are needed to evaluate the exposure resources and assess the health risk of PFAA exposure in children.

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

Interactions of perfluoroalkyl substances with a phospholipid bilayer studied by neutron reflectometry

Authors: Nouhi, Y; Ahrens, L; Kabayama, HH; Hughes, NAV; Campana, M; Gutfreund, P; Palsson, GK; Vorobiev, AA; Hellsing, MS (2018) Journal of Colloid and Interface Science 511:474-481. HERO ID: 4234858

[Less] The interactions between perfluoroalkyl substances (PFASs) and a phospholipid bilayer (1,2-dimyristoyl-sn-glycero-3-phosphocholine) . . . [More] The interactions between perfluoroalkyl substances (PFASs) and a phospholipid bilayer (1,2-dimyristoyl-sn-glycero-3-phosphocholine) were investigated at the molecular level using neutron reflectometry. Representative PFASs with different chain length and functional groups were selected in this study including: perfluorobutane sulfonate (PFBS), perfluorohexanoate (PFHxA), perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctane sulfonate (PFOS), and perfluorooctane sulfonamide (FOSA). All PFASs were found to interact with the bilayer by incorporation, indicating PFAS ability to accumulate once ingested or taken up by organisms. The interactions were observed to increase with chain length and vary with the functional group as SO2NH2(FOSA)>SO2O-(PFOS)>COO-(PFNA). The PFAS hydrophobicity, which is strongly correlated with perfluorocarbon chain length, was found to strongly influence the interactions. Longer chain PFASs showed higher tendency to penetrate into the bilayer compared to the short-chain compounds. The incorporated PFASs could for all substances but one (PFNA) be removed from the lipid membrane by gentle rinsing with water (2mLmin-1). Although short-chain PFASs have been suggested to be the potentially less bioaccumulative alternative, we found that in high enough concentrations they can also disturb the bilayer. The roughness and disorder of the bilayer was observed to increase as the concentration of PFASs increased (in particular for the high concentrations of short-chain substances i.e. PFHxA and PFBS), which can be an indication of aggregation of PFASs in the bilayer.