Discovering Novel Fluorotelomer Ethoxylate Homologues and Analogues in Antifog Products and Indoor Dust

Recent studies have reported the
presence of 6:2 fluorotelomer
ethoxylates (FTEOs) as an emerging group of perfluoroalkyl and polyfluoroalkyl
substances. However, the environmental relevance of additional FTEO
homologues and analogues remains rarely investigated. Through a combination
of suspect screening and homologue-based nontargeted analysis, we
identified a total of 60 FTEO homologues and 30 perfluoroalkyl ether
ethoxylate (PFAEE) homologues in commercial antifog products. They
included homologue groups of 4:2 FTEOs (n = 16),
6:2 FTEOs (n = 17), 8:2 FTEOs (n = 12), 10:2 FTEOs (n = 8), 12:2 FTEOs (n = 7), perfluorobutyl ether ethoxylates (n = 15), and perfluorohexyl ether ethoxylates (n =
15). Among them, 4:2 FTEOs, 6:2 FTEOs, and perfluorobutyl ether ethoxylates
were also frequently detected in house dust (n =
120) collected from South China, with semiquantified concentrations
measured to be 30.4, 36.0, and 55.3 ng/g. Among each homologue group,
the composition profiles of individual homologues with different numbers
of repeated ethoxy units resembled between antifog products and house
dust. A toxicological priority index (ToxPi) approach revealed the
highest risk of 6:2 FTEOs among all of the identified FTEOs and PFAEEs,
although the risks from other groups should not be overlooked. Collectively,
our work reveals the complexity of diverse FTEO homologues and reports
the presence of PFAEEs for the first time in indoor environments,
raising the need for further investigating their sources, environmental
distribution, and potential human exposure.