A critical review of the application of polymer of low concern and regulatory criteria to fluoropolymers

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a group of fluorinated substances that are in the focus of researchers and regulators due to widespread presence in the environment and biota, including humans, of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Fluoropolymers, high molecular weight polymers, have unique properties that constitute a distinct class within the PFAS group. Fluoropolymers have thermal, chemical, photochemical, hydrolytic, oxidative, and biological stability. They have negligible residual monomer and oligomer content and low to no leachables. Fluoropolymers are practically insoluble in water and not subject to long-range transport. With a molecular weight well over 100 000 Da, fluoropolymers cannot cross the cell membrane. Fluoropolymers are not bioavailable or bioaccumulative, as evidenced by toxicology studies on polytetrafluoroethylene (PTFE): acute and subchronic systemic toxicity, irritation, sensitization, local toxicity on implantation, cytotoxicity, in vitro and in vivo genotoxicity, hemolysis, complement activation, and thrombogenicity. Clinical studies of patients receiving permanently implanted PTFE cardiovascular medical devices demonstrate no chronic toxicity or carcinogenicity and no reproductive, developmental, or endocrine toxicity. This paper brings together fluoropolymer toxicity data, human clinical data, and physical, chemical, thermal, and biological data for review and assessment to show that fluoropolymers satisfy widely accepted assessment criteria to be considered as "polymers of low concern" (PLC). This review concludes that fluoropolymers are distinctly different from other polymeric and nonpolymeric PFAS and should be separated from them for hazard assessment or regulatory purposes. Grouping fluoropolymers with all classes of PFAS for "read across" or structure-activity relationship assessment is not scientifically appropriate. Integr Environ Assess Manag 2018;14:316-334. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

The concept of essential use for determining when uses of PFASs can be phased out

“…3,54,62 The safety evaluation of these devices for use in humans was discussed by Henry et al (2018). 63 Aer review, multiple regulatory agencies have concluded that the use of PFASs in these products, including in devices implanted into patients' bodies, does not pose an appreciable risk because the uoropolymers are not bioavailable. [63][64][65] It is however unclear whether impurities of uoropolymer processing aids such as PFOA and HFPO-DA were included in the regulatory reviews.…”

The Concept of Essential Use for Determining When Uses of PFASs Can Be Phased Out

“…Another use of fluoropolymers is as coatings in catheters, stents and needles to reduce friction and improve clot resistance and to provide protein-resistance in filters, tubing, o-rings, seals, and gaskets used in kidney dialysis machines and immunodiagnostic instruments 3,54,62 . The safety evaluation of these devices for use in humans was discussed by Henry et al (2018). 63 After review, multiple regulatory agencies have concluded that the use of PFASs in these products, including on devices implanted into patients' bodies, does not pose an appreciable risk because the fluoropolymers are not bioavailable [63][64][65] .…”

“…The safety evaluation of these devices for use in humans was discussed by Henry et al (2018). 63 After review, multiple regulatory agencies have concluded that the use of PFASs in these products, including on devices implanted into patients' bodies, does not pose an appreciable risk because the fluoropolymers are not bioavailable [63][64][65] . It is however unclear whether impurities of fluoropolymer processing aids such as PFOA and HFPO-DA were included in the regulatory reviews.…”

A review: advancements in fluoro-based polymers for aggrandizing anti-galling and wear resistant characteristics

“…Hence fluorine-based polymers are recognized as great value-added molecules owing to their versatile unique feature particularly low value of refractive index, cohesive energy, surface energy and relative permittivity, and high value of thermal resistance, high chemical stability, resistance against UV, concentrated mineral acids, alkalis, and aging [76][77][78]. The tradename of commercially available Fluoropolymers has been tabulated in Table 5.…”

“…Although these coatings served the purpose of improved anti-galling properties but the fluorine present in them act as a biotransformation precursor i.e. it results in the metabolism imbalance in human body and sometime can result in trauma as during austere conditions fluoro-polymers gets degrade and releases hydrofluoric acids [77,172].…”