Table 1.
Structural category coverage of tested PFAS.
| OECD Category a,b | No. | CF2 | Potential PFAA Precursor? | PFAS-Map Category |
|---|---|---|---|---|
| PFCAs | 14 | lt8 c = 9; gte8 d = 5 | No e | PFAAs |
| PFSAs | 10 | lt8 = 6; gte8 = 4 | No | PFAAs |
| PFECAs | 6 | lt8 = 4; gte8 = 2 | No f | PFAAs |
| n:3 acids | 5 | lt8 = 5 | Yes | FT PFAA precursors |
| xFASA-Es | 4 | lt8 = 1; gte8 = 3 | Yes | PFAA precursors; FASA-based PFAA precursors |
| 1H-PFCAs | 4 | lt8 = 1; gte8 = 3 | Yes | PFAA precursors |
| n:2 FT sulfonic acids | 3 | lt8 = 1; gte8 = 1 | Yes | FT PFAA precursors |
| PF carbonyl halides | 2 | lt8 = 2 | Yes | Others |
| PFESAs | 1 | lt8 = 1 | No | PFAAs |
| PF alkane sulfonyl halides | 1 | gte8 = 1 | Yes | PFAA precursor |
| PF alkane sulfonyl-based nonpolymers | 1 | gte8 = 1 | Yes | PFAA precursors |
| n:2 FT phosphonic acids | 1 | lt8 = 1 | Yes | Others |
a Of the selected PFAS, two propenoic acids were not categorized in the OECD mappings. b Abbreviations: carbon-fluorine chain length: CF2; perfluoro (PF) alkyl acids: PFAAs; PF carboxylic acids: PFCAs; <8 CF2: lt8; ≥8 CF2: gte8; PF alkane sulfonic acids: PFSAs; PF ether carboxylic acids (PFECAs); fluorotelomer: FT; PF alkane sulfonyl amides/amido ethanols: xFASA/Es; perfluoroalkane sulfonamide: FASA; PF ether sulfonic acid (PFESA). c less than 8: lt8. d greater than or equal to 8: gte8. e except for perfluoroundecanoic acid. f except for perfluoro-3-methoxypropanoic acid and perfluoro-3,6-dioxaheptanoic acid.