Table 2.
Hierarchical overview of the nonpolymer perfluoroalkyl substances, compounds for which all H atoms on all C atoms in the alkyl chain attached to the functional group have been replaced with F
| Classification and chemical structure | CnF2n+1R, where R = | Examples | Uses | |
|---|---|---|---|---|
| Perfluoroalkyl acids (PFAAs) | Perfluoroalkyl carboxylic acids (PFCAs)a | -COOH | Perfluorooctanoic acid (PFOA), C7F15COOH | Surfactant |
| Perfluoroalkyl carboxylates (PFCAs)a | -COO− | Perfluorooctanoate (PFOA), C7F15COO− | ||
| Perfluoroalkane sulfonic acids (PFSAs)b | -SO3H | Perfluorooctane sulfonic acid (PFOS), C8F17SO3H | Surfactant | |
| Perfluorobutane sulfonic acid (PFBS), C4F9SO3H | ||||
| Perfluoroalkane sulfonates (PFSAs)b |  |
Perfluorooctane sulfonate (PFOS), 
|
||
Perfluorobutane sulfonate (PFBS), 
|
||||
| Perfluoroalkane sulfinic acids (PFSIAs)b | -SO2H | Perfluorooctane sulfinic acid (PFOSI), C8F17SO2H | Intermediate environmental transformation product | |
| Perfluoroalkyl phosphonic acids (PFPAs)c | -P(=O)(OH)2 | Perfluorooctyl phosphonic acid (C8-PFPA) C8F17P(=O)(OH)2 | Surfactant | |
| Perfluoroalkyl phosphinic acids (PFPIAs)c | -P(=O)(OH)(CmF2m+1) | Bis(perfluorooctyl) phosphinic acid (C8/C8-PFPIA) C8F17P(=O)(OH)(C8F17) | Surfactant | |
| Perfluoroalkane sulfonyl fluorides (PASFs)b | -SO2F | Perfluorooctane sulfonyl fluoride (POSF), C8F17SO2F | Major raw material for surfactant and surface protection products | |
| Perfluorobutane sulfonyl fluoride (PBSF), C4F9SO2F | ||||
| Perfluoroalkane sulfonamides (FASAs)b | -SO2NH2 | Perfluorooctane sulfonamide (FOSA), C8F17SO2NH2 | Major raw material for surfactant and surface protection products | |
| Perfluoroalkanoyl fluorides (PAFs)b | -COF | Perfluorooctanoyl fluoride (POF), C7F15COF | Major raw material for PFOA made by the ECF process; raw material for surfactant and surface protection products | |
| Perfluoroalkyl iodides (PFAIs) (Telomer A)c | -I | Perfluorohexyl iodide (PFHxI), C6F13I | Major raw material for surfactant and surface protection products | |
| Perfluoroalkyl aldehydes (PFALs) and aldehyde hydrates (PFAL·H2Os)c | -CHO and -CH(OH)2 | Perfluorononanal (PFNAL), C8F17CHO | Intermediate environmental transformation product | |
a
Substances originating by either electrochemical fluorination (ECF) or fluorotelomer processes;
b
Substances originating by the ECF process;
c
Substances originating by the fluorotelomer process.