Directly Fluorinated Containers as a Source of Perfluoroalkyl Carboxylic Acids

Abstract

Direct fluorination of plastics is performed to impart chemical resistance via exposure of polyethylene to fluorine gas to produce a fluorine-modified surface layer. Leaching experiments were performed on a directly fluorinated container under various conditions and with different matrices, including foodstuffs. The average sum of per-and polyfluoroalkyl substances (PFAS) concentrations measured from extraction of a fluorinated container was 63.75 ± 13.2 ng/g plastic. Seven-day leaching experiments of fluorinated containers with water, methanol, and acetone produced sums of PFAS concentrations that ranged from 0.99 to 66.92 ng/g plastic. Leaching experiments with food matrices produced sums of PFAS concentrations ranging from 2.66 to 7.19 ng/g plastic. A subset of samples subjected to leaching at elevated temperatures generated sums of PFAS concentrations up to 830% higher. In all experiments, short-chain perfluoroalkyl carboxylic acids (PFCAs) were detected in the highest frequencies and concentrations with analyte concentration decreasing as chain length increased. An estimate for PFAS released into food ranged from 0.77 to 2.68 ng/kg body weight per week, showing ingestion of food stored in these containers could be a significant source of exposure. Based on the large number of applications where directly fluorinated containers find use, the observation of PFAS migration suggests use regulations are warranted, and future studies should explore their fate when disposed or recycled.

Evaluation of Per- and Polyfluoroalkyl Substances Leaching from Biosolids and Mitigation Potential of Biochar through Undisturbed Soil Columns

“…The major employer for the community that generated biosolids applied to the Outagamie site was a food packaging company. PFOA has been measured in leachate from both directly fluorinated and nonfluorinated food containers . Although manufacturing and import of PFOA ceased through the U.S. EPA toxic substances control act, PFOA manufactured or imported before 2020 may still be in use .…”

“…PFOA has been measured in leachate from both directly fluorinated and nonfluorinated food containers. 45 Although manufacturing and import of PFOA ceased through the U.S. EPA toxic substances control act, PFOA manufactured or imported before 2020 may still be in use. 46 Perfluorinated carboxylic acids may also be produced during direct fluorination of high density polyethylene material; however, mostly short-chain PFAS are produced.…”

Per- and Polyfluoroalkyl Substances in Food Packaging: Migration, Toxicity, and Management Strategies

“…As has been shown for many types of polymers used as FCMs, unreacted monomers, reaction intermediates, and degradation products migrate from polymers, especially after extended use and/or under certain conditions (e.g., high temperature). 12,42,43,176 In addition to lowering PFAS exposure to consumers, government regulations and voluntary initiatives limiting or banning the use of PFASs in FCMs/FCAs may contribute to positive knock-on effects both up and down the supply chain. One could expect these actions to reduce exposure for people working in fluorochemical manufacturing facilities and/or at facilities where PFAS-containing FCMs are used, made, and disposed of.…”

“…PFASs are known to be found in food packaging and other food contact articles (FCAs) used in the production, processing, transport, handling, and storage of foods . Like many other food contact chemicals (FCCs), PFASs have been shown to migrate from different food contact materials (FCMs), such as paper and board and plastics, into food, allowing for exposure of the general public. − Many current legal frameworks covering FCMs require the risk assessment of individual chemicals present in FCMs; however, to date there is no overview of the range of PFASs actually used in FCMs and whether they have been assessed for their risks at all. Furthermore, the presence of PFASs in FCMs raises particular concerns with regards to their life cycle, as the production of PFASs and PFAS-containing materials causes occupational exposure , and their disposal leads to contamination of groundwater and drinking water via landfill leachate. , Disposal of FCMs containing PFASs via recycling and/or incineration also may lead to environmental contamination and human exposure .…”

Aqueous Leaching of Ultrashort-Chain PFAS from (Fluoro)polymers: Targeted and Nontargeted Analysis

“…13 Progress by our groups and others using ion chromatography−mass spectrometry (IC-MS) and 19 F nuclear magnetic resonance (NMR) 14−16 now enable these measurements. Side-chain fluorinated polymers 17−20 and directly fluorinated high-density polyethylene (HDPE) 21,22 have been identified as sources of small-molecule PFAS like PFCAs, but fluoropolymers as sources of small-molecule PFAS are less understood. Evidence from the PFAS research community suggests that fluoropolymers may be sources of small-molecule PFAS due to, for example, the need for delay columns in high-performance liquid chromatography (HPLC) systems and the avoidance of polytetrafluoroethylene (PTFE) septa on autosampler vials.…”