Four Chemical Trends Will Shape the Next Decade's Directions in Perfluoroalkyl and Polyfluoroalkyl Substances Research

Abstract

Per- and polyfluoroalkyl substances (PFAS) represent a versatile group of ubiquitously occurring chemicals of increasing regulatory concern. The past years lead to an ever expanding portfolio of detected anthropogenic PFAS in numerous products encountered in daily life. Yet no clear picture of the full range of individual substance that comprise PFAS is available and this challenges analytical and engineering sciences. Authorities struggle to cope with uncertainties in managing risk of harm posed by PFAS. This is a result of an incomplete understanding of the range of compounds that they comprise in differing products. There are analytical uncertainties identifying PFAS and estimating the concentrations of the total PFAS load individual molecules remain unknown. There are four major trends from the chemical perspective that will shape PFAS research for the next decade. Mobility: A wide and dynamic distribution of short chain PFAS due to their high polarity, persistency and volatility.Substitution of regulated substances: The ban or restrictions of individual molecules will lead to a replacement with substitutes of similar concern.Increase in structural diversity of existing PFAS molecules: Introduction of e.g., hydrogens and chlorine atoms instead of fluorine, as well as branching and cross-linking lead to a high versatility of unknown target molecules.Unknown “Dark Matter”: The amount, identity, formation pathways, and transformation dynamics of polymers and PFAS precursors are largely unknown.These directions require optimized analytical setups, especially multi-methods, and semi-specific tools to determine PFAS-sum parameters in any relevant matrix.

Hyphenated High Performance Liquid Chromatography–Tandem Mass Spectrometry Techniques for the Determination of Perfluorinated Alkylated Substances in Lombardia Region in Italy, Profile Levels and Assessment: One Year of Monitoring Activities During 2018

“…Such compounds are widely used in everyday life, for example in adhesives, polishes, paints, waxes, textiles, in stain/water/grease repellents in carpets and clothing or in cooking utensils such as non-stick coatings [7][8][9]. In addition, former research suggests that the impact of exposure from consumer products is usually lower than the impact of exposure to contaminated drinking water or food, such as fish [10,11].…”

The role of analytical chemistry in exposure science: Focus on the aquatic environment

“…More than 3000 PFASs have been marketed (Wang et al, 2017). Although in recent years many new anthropogenic PFASs have been detected (Xiao, 2017;Gebbink et al, 2017;Barzen-Hanson et al, 2017) a clear picture of the full range of individual substances is still lacking and reveals the need to investigate in depth the occurrence of fluorinated compounds in the environment Kotthoff and Bücking (2018).…”

Regulation of Persistent Chemicals in Hazardous Waste: A Case Study of Washington State, USA

“…For example, some short‐chain per‐ and polyfluoroalkyl substances (PFAS, e.g., perfluorobutanoic acid [PFBA]) and lower chlorinated polychlorinated biphenyls (PCBs, e.g., PCB‐11) are still persistent and toxic but more mobile (i.e., more polar and hydrophilic) and less bioaccumulative (i.e., less nonpolar and hydrophobic) than their longer chain or higher chlorinated analogs, respectively (Rodenburg et al 2015; Wang et al 2015). As a result, a chemical classification scheme has been proposed, based on persistence, mobility, and toxicity (PMT) (Reemtsma et al 2016; EC 2017; Kotthoff and Bucking 2018; Arp and Hale 2019; Rudel et al 2020). Although PBT frameworks have existed for decades, the concept of PMT was introduced in more recent years (especially in relation to the aquatic environment), contributing to the proposed incorporation of PMT criteria into EU chemical regulation (e.g., REACH) (Rudel et al 2020).…”