A new paper in Nature Communications raises a red flag about fluorinated sorbents, a class of emerging materials for removing PFAS from water. The authors find that several of these materials can themselves release PFAS or PFAS-like compounds, potentially creating new contamination risks while attempting to solve existing ones.
These fluorinated sorbents have been promoted as cutting-edge tools for removing PFAS from drinking water by exploiting strong fluorine-to-fluorine (“like attracts like”) interactions. But the authors appear to find that:
- Claims about PFAS removal performance are often based on small-scale laboratory tests conducted under idealized conditions that do not reflect complex, real-world water systems.
- Fluorinated sorbents can release a range of fluorinated chemicals—including leftover starting materials and breakdown products—during their manufacture, use, and disposal.
- These releases could introduce new PFAS exposures into water systems, undermining the very goal of PFAS cleanup.
Designing sorbents that rely on fluorine-fluorine interactions to capture PFAS can lead to continued reliance on persistent fluorinated materials. But are these F-F interactions indispensable in PFAS removal?
While some laboratory studies report enhanced PFAS adsorption through fluorinated sorbents, others show neutral or even negative effects, with fluorinated side chains sometimes reducing binding efficiency or offering no improvement over non-fluorinated materials. Performance gains observed in simplified, pure-water experiments often diminish sharply in complex, real-world water matrices, particularly for short-chain PFAS. Notably, several non-fluorinated metal-organic and covalent organic frameworks have demonstrated comparable or superior PFAS removal by relying on electrostatic attraction, hydrogen bonding, hydrophobic forces, or coordination chemistry instead.
The paper also investigates whether the environmental and human health risks of fluorinated sorbents are fully understood. Obvious inadequacies emerge from the current picture, including the propensity of fluorinated sorbents to release a variety of fluorinated chemicals into the environment during production and end-of-life stages. “The structures, toxicity and persistence of these derivatives… are poorly characterized”, say the authors, and this leaves uncertainty about the nature of the environmental hazard they present.
Arlene Blum, Executive Director of the Green Science Policy Institute, commented:
“When stopping harm from forever chemicals, using more forever chemistry is the wrong kind of fix. Communities deserve PFAS cleanup that reduces long-term exposure across a technology’s full life cycle and protects future generations. Otherwise, we risk solving today’s PFAS problem by creating tomorrow’s.”
