Health & Environmental Research Online (HERO)


PFHxA (307-24-4)


9 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

A hypothesis-driven weight-of-evidence analysis to evaluate potential endocrine activity of perfluorohexanoic acid

Authors: Borghoff, SJ; Fitch, S; Rager, JE; Huggett, D (2018) Regulatory Toxicology and Pharmacology 99:168-181. [Review] HERO ID: 5017765

[Less] Perfluorohexanoic acid (PFHxA) is a potential impurity and environmental degradation product of C6-based . . . [More] Perfluorohexanoic acid (PFHxA) is a potential impurity and environmental degradation product of C6-based fluorotelomer products. Considering the potential endocrine activity of perfluoroalkyl acids, a hypothesis-driven weight-of-evidence (WoE) analysis was conducted to evaluate the potential endocrine disruptor activity of PFHxA, as defined by World Health Organization (WHO), across estrogen (E), androgen (A), thyroid (T), and steroidogenesis (S) pathways. A comprehensive literature search identified primary and secondary studies across species for review. The ToxCast/Tox21 database provided in vitro data. Studies identified were reviewed for reliability, and relevance, with endocrine endpoints ranked, and lines of evidence evaluated across pathways. Overall, PFHxA showed no endocrine effects in Japanese medaka, juvenile rainbow trout, chickens or reproductive parameters in northern bobwhite with no significant activity in rodent repeated-dose toxicity, lifetime cancer, or reproductive and developmental studies. In vitro, there was weak or negative activity for T transport protein or activation of E, A or T receptors. PFHxA was also negative in vitro and in vivo for disrupting steroidogenesis. Based on this WoE endocrine analysis, PFHxA exposure did not cause adverse effects associated with alterations in endocrine activity in these models, as such would not be characterized as an endocrine disruptor according to the WHO definition.

Technical Report
Technical Report

Environment tier II assessment for short-chain perfluorocarboxylic acids and their direct precursors. CAS registry numbers: 307-24-4, 21615-47-4, 2706-90-3, 68259-11-0, 375-22-4, 336-59-4

Author: NICNAS (2017) Australian Government Department of Health, National Industrial Chemicals Notification and Assessment Scheme. HERO ID: 3860584


Technical Report
Technical Report

Human health tier II assessment for short chain perfluorocarboxylic acids and their direct precursors

Author: NICNAS (2017) Australian Government, Department of Health, National Industrial Chemicals Notification and Assessment Scheme. HERO ID: 3860585


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

Deriving environmental quality standards for perfluorooctanoic acid (PFOA) and related short chain perfluorinated alkyl acids

Authors: Valsecchi, S; Conti, D; Crebelli, R; Polesello, S; Rusconi, M; Mazzoni, M; Preziosi, E; Carere, M; Lucentini, L; Ferretti, E; Balzamo, S; Simeone, MG; Aste, F (2017) Journal of Hazardous Materials 323:84-98. HERO ID: 3748953

[Less] The evidence that in Northern Italy significant sources of perfluoroalkylacids (PFAA) are present induced . . . [More] The evidence that in Northern Italy significant sources of perfluoroalkylacids (PFAA) are present induced the Italian government to establish a Working Group on Environmental Quality Standard (EQS) for PFAA in order to include some of them in the list of national specific pollutants for surface water monitoring according to the Water Framework Directive (2000/60/EC). The list of substances included perfluorooctanoate (PFOA) and related short chain PFAA such as perfluorobutanoate (PFBA), perfluoropentanoate (PFPeA), perfluorohexanoate (PFHxA) and perfluorobutanesulfonate (PFBS), which is a substitute of perfluorooctanesulfonate. For each of them a dossier collects available data on regulation, physico-chemical properties, emission and sources, occurrence, acute and chronic toxicity on aquatic species and mammals, including humans. Quality standards (QS) were derived for the different protection objectives (pelagic and benthic communities, predators by secondary poisoning, human health via consumption of fishery products and water) according to the European guideline. The lowest QS is finally chosen as the relevant EQS. For PFOA a QS for biota was derived for protection from secondary poisoning and the corresponding QS for water was back-calculated, obtaining a freshwater EQS of 0.1╬╝gL(-1). For PFBA, PFPeA, PFHxA and PFBS threshold limits proposed for drinking waters were adopted as EQS.

Book/Book Chapter
Book/ Chapter

Toxicology data for alternative "short-chain" fluorinated substances

Author: Buck, RC (2015) In DeWitt, JC (Ed.), Toxicological Effects of Perfluoroalkyl and Polyfluoroalkyl Substances (pp. 451-477). New York, NY: Springer International Publishing. HERO ID: 3856851

[Less] Per- and poly-fluoroalkyl substances (PFASs) have been manufactured and widely used since the 1950s . . . [More] Per- and poly-fluoroalkyl substances (PFASs) have been manufactured and widely used since the 1950s in numerous industrial and consumer applications. However, various perfluoroalkyl acids (PFAAs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which have been manufactured and sold themselves and are impurities and breakdown products from numerous commercial per- and poly-fluoroalkyl surfactant and polymeric products, have been found widely in the environment. Concerns about the potential environmental impact of "long-chain" PFAAs has led to a substantial phase out of production of PFOS and PFOA and related compounds. Manufacturers have moved to production of alternative products which cannot be transformed in to long-chain PFAAs. This chapter provides an overview of available toxicology data for alternative fluorinated technologies including: short-chain fluorotelomer, short-chain electrochemical fluorination, perfluoropolyether, fluorinated oxetane, per- and poly-fluoroalkyl ether carboxylates and short-chain perfluoroalkyl acids.

Book/Book Chapter
Book/ Chapter

Carcinogenicity of Perfluoroalkyl Compounds

Authors: Kennedy, GL; Symons, JM (2015) In Molecular and Integrative Toxicology (pp. 265-304). HERO ID: 3859920

[Less] This chapter reviews the information available on the carcinogenic potential of perfluoroalkyl acids . . . [More] This chapter reviews the information available on the carcinogenic potential of perfluoroalkyl acids in both animals and humans. Historically, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) have been the most widely used members of this chemical class making these the subject of the largest proportion of the reported studies. Caution needs to be exercised in projecting the biological activities of any of the chemicals in this family based on results from others. For example, considering the three chemicals for which lifetime studies in rats are available, the outcomes were different with no increase in tumors seen with perfluorohexanoic acid (PFHxA), liver adenomas seen with PFOS, and adenomas of the liver, testis, and pancreas seen with PFOA. Mechanistic studies suggest that the liver tumors seen with PFOA reflect the activation of PPARa while the mechanism for tumor formation in the testis and pancreas is less clear. Epidemiologic studies have been reported for several levels of population exposure. Limited evidence of associations with kidney and testicular cancer has been reported in studies among community members exposed to drinking water contaminated by PFOA. Studies in workers exposed to higher levels of both PFOA and PFOS have not shown consistent evidence for an association with any specific cancer type. Studies in populations exposed to low levels of PFOA and PFOS have shown equivocal results for a variety of cancers with no consistent associations. Based on the evidence reported to date, the prospect for developing a carcinogenic outcome following exposure to PFOA and PFOS is remote. For other perfluoroalkyl acids, there is not sufficient evidence regarding their potential carcinogenicity. It should be noted that human exposures to these chemicals is currently quite low and appears to be decreasing.

Technical Report
Technical Report

Draft toxicological profile for perfluoroalkyls

Author: ATSDR (2015) HERO ID: 3859918


Technical Report
Technical Report

Support: Letter from 3M to USEPA regarding mechanistic two-year study of hepatic tumor induction in rats fed ammonium perfluoroalkyl carboxylates dated 101193

Author: Haskell Laboratories (1993) (Doc# 89-941000007). St. Paul, MN: 3M Company. HERO ID: 3797581

[Less] The test substance included ammonium perfluoroalkyl carboxylates (CAS No. 68259-11-0) which contains . . . [More] The test substance included ammonium perfluoroalkyl carboxylates (CAS No. 68259-11-0) which contains 93 to 97% ammonium perfluorooctanoate (CAS No. 3825-26-1), and smaller amounts of ammonium perfluoroheptanoate (CAS No. 6130-43-4) and ammonium perfluorohexanoate (CAS No. 21615-47-4). The test substance was investigated in a mechanistic bioassay investigating extra hepatic tumor induction by compounds which induce peroxisome proliferation. In this mechanistic bioassay, 300 ppm of the test substance was fed to rats as part of their diet for 2-years. In addition to an ad libitum control, a second control group was pair-fed to the 300 ppm test group to control for the effects of reduced body weight. Increased incidences of combined (single, multiple) hepatic adenomas, Leydig cell adenomas, and pancreatic acinar cell adenomas were seen in the 300 ppm test group when compared to either the ad libitum or pair-fed controls. The tumor incidences (liver, testis, pancreas) were outside the historical control incidence range for DuPont Haskell Laboratory. In addition, age- adjustment statistics also support the conclusion that the tumor incidence was elevated for the liver (both controls), pancreas (pair-fed control), and testis (pair-fed control).

Technical Report
Technical Report

Support: letter from 3M to USEPA regarding mechanistic two-year study of hepatic tumor induction in rats fed ammonium perfluoroalkyl carboxylates dated 10/11/93

Author: 3M (1993) (OTS02049264. 89-941000007. TSCATS/441786). St. Paul, MN: 3M Company. [TSCA Submission] HERO ID: 3797537

[Less] The test substance included ammonium perfluoroalkyl carboxylates (CAS No. 68259-11-0) which contains . . . [More] The test substance included ammonium perfluoroalkyl carboxylates (CAS No. 68259-11-0) which contains 93 to 97% ammonium perfluorooctanoate (CAS No. 3825-26-1), and smaller amounts of ammonium perfluoroheptanoate (CAS No. 6130-43-4) and ammonium perfluorohexanoate (CAS No. 21615-47-4). The test substance was investigated in a mechanistic bioassay investigating extra hepatic tumor induction by compounds which induce peroxisome proliferation. In this mechanistic bioassay, 300 ppm of the test substance was fed to rats as part of their diet for 2-years. In addition to an ad libitum control, a second control group was pair-fed to the 300 ppm test group to control for the effects of reduced body weight. Increased incidences of combined (single, multiple) hepatic adenomas, Leydig cell adenomas, and pancreatic acinar cell adenomas were seen in the 300 ppm test group when compared to either the ad libitum or pair-fed controls. The tumor incidences (liver, testis, pancreas) were outside the historical control incidence range for DuPont Haskell Laboratory. In addition, age- adjustment statistics also support the conclusion that the tumor incidence was elevated for the liver (both controls), pancreas (pair-fed control), and testis (pair-fed control).