As global production of PFOS and PFOA is eliminated, manufacturers are focused on developing PFAS replacement technologies, including reformulating or substituting longer chain PFAS (e.g. PFOS and PFOA) with shorter-chain perfluoroalkyl or polyfluorinated substances that include, but are not limited to, compounds produced through electrochemical fluorination (ECF) and fluorotelomerization, such as: fluorotelomer alcohols (FTOH), perfluorobutane sulfonyl fluoride (PBSF)-based derivatives (e.g., perfluorobutane sulfonate (PFBS) as a substitute for PFOS) and polyfluoroethers (e.g. GenX, ADONA and F53B used in the manufacture of fluoropolymers) among others.
Studies are suggesting that some of the lower molecular weight PFAS replacement compounds may or more importantly, may not be less hazardous than their long-chain predecessors. Information on the type and extent of environmental contamination by replacement PFAS although is limited, as most are not currently reported as part of the routine suite of PFAS analyzed by contract analytical laboratories.
Three key PFAS replacements being studied are: 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid; dodecafluoro-3H-4,8-dioxanoate; and a combination of 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate and 11-chlororeicosafluoro-3-oxaundecane-1-sulfonic acid. These are commonly referred to as GenX, ADONA and F53B, respectively. Replacement chemicals, like GenX, tend to have fewer carbon atoms in the chain, but have many similar physical and chemical properties as their predecessors PFOS and PFOA (e.g. they repel oil and water).
Industries in the United States have phased out production of PFOA and PFOS because of potential health risks to humans and have begun using replacement PFAS, such as GenX. There is a substantial body of knowledge for managing risk from PFOS and PFOA, but much less knowledge about the replacement PFAS.
In response to increasing interest in PFAS replacement compounds, Bureau Veritas Laboratories has validated methods for the determination of GenX, ADONA and F53B by isotope dilution liquid chromatography coupled with mass spectrometry.
Bureau Veritas has also developed a detailed technical bulletin describing these compounds, required sampling handling and analytical performance specifications (e.g. reporting limits).