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 (<i>n</i> = 16), 6:2 FTEOs (<i>n</i> = 17), 8:2 FTEOs (<i>n</i> = 12), 10:2 FTEOs (<i>n</i> = 8), 12:2 FTEOs (<i>n</i> = 7), perfluorobutyl ether ethoxylates (<i>n</i> = 15), and perfluorohexyl ether ethoxylates (<i>n</i> = 15). Among them, 4:2 FTEOs, 6:2 FTEOs, and perfluorobutyl ether ethoxylates were also frequently detected in house dust (<i>n</i> = 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.