Table 4.
PFAS thermal degradation by‐products reported
| Reference | Parent PFAS | Treatment temperature | Atmosphere | Fluorinated by‐products notedA |
|---|---|---|---|---|
| NRC Alaska (2019) | PFOS and PFOA (measured in contaminated soil sample) |
425–815°C (kiln) 980–1,200°C (secondary combustion) |
Oxidizing | PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFDoA, PFTeA, PFBS, FOSA, PFUnA, PFHxS, PFOS, NMeFOSAA, NEtFOSAA, 6:2 FTS |
| Major (2019) | PFOA, PFOS, PFHxS, PFNA, PFBS, and PFHpA | 1,000°C | Oxidizing | PFBA, PFBS, PFPeA, PFHxA, PFHxS, PFHpA, PFOA, PFOS, PFNA, PFDA, PFUnA, PFDoA |
| Watanabe et al. (2018) | PFOA, PFHxA, PFOS (on GAC) | 700°C | Reducing | Incomplete balance suggests volatile organofluoro compounds |
| Watanabe et al. (2016) |
PFOA, PFHxA (on GAC) PFOS (on GAC) |
800°C 900°C 1,000°C 700–1,000°C |
Reducing |
PFPeA, PFBA PFBA None None |
| García et al. (2007) | PTFE |
750°C 850°C 950°C 1,050°C |
Oxidizing |
CF4, C2F6, benzoyl fluoride CF4, C2F6 CF4, C2F6, C3F6, benzenepentafluoro CF4, C2F6, benzenepentafluoro |
| Yamada et al. (2005) |
Fluorotelomer‐based acrylic polymer (C0.33H0.40O0.04F0.19Cl0.04) Treated polyester fiber (2% F by weight) |
600°C 1,000°C 725°C |
Oxidizing |
Flurobenzene, difluorobenzene, ·CF3, ·CF2CH=CH2 ·CF3, ·CF2CH=CH2 ·CF3 |
| Krusic et al. (2005) | PFOA |
307°C 355–385°C |
Vacuum |
Perfluoro‐1‐heptene 1‐H‐perfluoroheptane, perfluoro‐1‐heptene |
| Krusic and Roe (2004) | Ammonium PFOA | 196–234°C | Vacuum | 1‐H‐perfluoroheptane |
| Ellis et al. (2003) | PTFE | 550°C | Oxidizing | fluoroacids |
| Taylor and Yamada (2003) | PFOS |
600°C 900°C |
Oxidizing |
CF4 or C2F6 (postulated), 1,1‐difluroethene CF4 or C2F6 (postulated) |
| Ellis et al. (2001) | PTFE | 500°C | Oxidizing | Tetrafluoroethene, hexafluoropropene, trifluoroacetate, cyclo‐octafluorobutane, CF3(CF2)nCOOH, CF3O(CF2)mCOOH, monofluoracetic acid, difluoroacetic acid |
| Conesa and Font (2001) | PTFE | 700°C | Oxidizing | C2F2, C2F4, CF4, CHF3, CH2F2, C2F6, ·CFO, CH2F2, cyclo‐C4F8, C3F3 |
| Reducing | same | |||
| Simon and Kaminsky (1998) | PTFE | 500–600°C | Reducing | Trifluroethylene, hexafluroproprene, cyclo‐octafluorobutane |
| Jun et al. (1995) | PTFE | 510–600°C | Reducing | Tetrafluoroethylene, hexafluroproprene, cyclo‐octafluorobutane |
| Baker and Kasprzak (1993) | PTFE | 400°C |
Oxidizing Reducing |
Tetrafluoroethylene, hexafluropropylene, trifluoroacetyl fluoride, fluoroform, perfluoroisobutylene hexafluropropylene, perfluoroisobutylene |
| Blake and Tomlinson (1971) | Fluoroacetic acid | 295–382°C | Vacuum | Fluoroacetyl fluoride |
| Sheppard and Sharts (1969), Kissa (2001) | Perfluoroalkanoic acid | 550°C | Not identified | Perfluoroalkenes, hydrogen fluoride |
| Perfluoroalkanoic potassium salt | 165–200°C | Perfluoroalkenes | ||
| Scheel et al. (1968) | PTFE | 550°C | Reducing | Carbonyl fluoride |
| Lewis and Naylor (1947) | PTFE | 600–700°C | Reducing | Tetrafluoroethylene |
Compound acronym definition can be found in the source reference.