Table 2.
Nonpolymer PFAS toxicity, physical, and chemical properties
| Nonpolymer PFAS | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Perfluoroalkyl substances | Polyfluoroalkyl substances | ||||||||
| Description | Perfluoroalkyl acids (PFAA) | Fluorotelomer alcohols | |||||||
| Substance | PFBA | PFHxA | PFOA | PFBS | PFOS | Hexafluoropropylene oxide (HFPO) dimer acid, ammonium salt | 2,2,3‐trifluoro‐3‐[1,1,2,2,3,3‐hexafluoro‐3‐(trifluoromethoxy) propoxy]propanoic acid | 6:2 FTOH | 8:2 FTOH |
| CAS number | 375‐22‐4 | 307‐24‐4 | 335‐67‐1 | 375‐73‐5 | 1763‐23‐1 | 62037‐80‐3 | 919005‐14‐4 | 647‐42‐7 | 678‐39‐7 |
| Structure |
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| Chain length | Short | Short | Long | Short | Long | Short | Short | Short | Long |
| Molecular weight | 214.0384 | 314.0534 | 414.069 Da | 300.11 | 500.13 | 347.084 | 378.07 | 364.1 | 464.12 |
| Physical state, description | Liquid | Colorless liquid | White to off‐white powder | Colorless liquid | Liquid | Clear, colorless liqud | Clear, colorless liquid | Clear, colorless to pale yellow liquid | Waxy solid |
| Boiling point | 120 to 121 °C | 157 °C | 192 °C | 210 to 212 °C | 249 °C | 108 °C | 183 °C | 171 °C | NDA |
| Melting point | −17.5 °C | NDA | 54.3 °C | NDA | NDA | 183 to 184 °C | NDA | 78 °C | NDA |
| Vapor pressure | 5866 Pa at 56 °C | 263.9 Pa at 25 °C (est) | 4.21 Pa at 25 °C | 3.57 Pa at 25 °C (est) | 0.2667 Pa at 25 °C | 2910 Pa at 20 °C | 32 Pa at 20 °C | 26.6645 Pa at 25 °C | 31 Pa at 25 °C |
| Stability (hydrolysis, photolysis, oxidation, thermal, biological) | Stable | Concentrations decreased by 0.8% after 106 d of solar irradiation; no other data | Stable | NDA | NDA | Stable | Stable | NDA | NDA |
| Water solubility (USP 2011) | 2.14 × 105 mg·L−1 at 25 °C | In water, 15 700 mg·L−1 at ambient temperature | 9.50 × 103 mg·L−1 at 25 °C | In water, 344 mg·L−1 at 25 °C (est) | 3.2 × 10−3 mg·L−1 at 25 °C (est) | >1000 g·L−1 at 20 °C | 100% Soluble in water | “insoluble” 18.8 mg·L−1 | 140 µg·L−1 at 25 °C |
| Log K OW | Not applicable | 3.48 (est) | 4.81 (est) | 1.82 (est) | 4.49 (est) | NDA | 1.89 | 4.54 | NDA |
| Particle size µm | NDA | NDA | NDA | NDA | NDA | Dried solid 76% >105 microns; 24% < 105 microns | NDA | NDA | NDA |
| Acute Dermal LD50 | NDA | Low (>2000 mg/kg) | Low (>2000 mg/kg) | Low (>2000 mg/kg) | NDA | Low (5000 mg/kg) | Low (5000 mg/kg) | Low (5000 mg/kg) | NDA |
| Skin irritant, Y or N | Y, corrosive | Y | Y | N | N | Y | Y, mild | Y | NDA |
| Eye irritant, Y or N | Y (serious damage) | Y | Y | Y | Y | Y | Y | Y | NDA |
| Skin sensitizer, Y or N | NDA | N | N | N | NDA | N | Y | N | NDA |
| 90‐d animal feeding study (no effect dose) | 6 mg/kg‐day | 50 mg/kg‐day | 0.06 mg/kg‐day | 200 mg/kg‐day | 0.4 mg/kg‐day | 0.1 mg/kg‐day | 10 and 100 mg/kg‐day for males, females | 5 mg/kg‐day | 5 mg/kg‐day |
| Mutagen, Y or N | NDA | N | N | N | N | N | N | N | N |
| Caused tumors in lab rats, Y or N | NDA | N | Y | NDA | Y | Y | NDA | NDA | NDA |
| Half‐life in humans | 69 to 87 h | <28 d | 3.3 to 3.8 y | 24 to 46 d | 5.4 to 5.9 y | 2.3 h | 23 ± 11 d | NDA | NDA |
| References | (Ding and Peijnenburg 2013; NICNAS 2015; ChemSpider 2018; Sigma Aldrich 2018a; ATSDR 2018) | (Savu 1994; USEPA 2012; Environ 2014; Zhao L et al. 2014; ChemSpider 2016; Luz et al. 2019) | (Kennedy et al. 2004; Butenhoff et al. 2004; Yalkowsky et al. 2010; Bhhatarai and Gramatica 2011; USEPA 2012; Haynes 2014) | (Kosswig 2000; Lewis 2012; USEPA 2012; Sigma Aldrich 2015) | (Ashford 1994; Lewis 2012; USEPA 2012) | (Biegel et al. 2001; Caverly Rae et al. 2015; Beekman et al. 2016; Hoke et al. 2016; ECHA 2019b; PubChem. 2019) | (Gordon 2011; Wang et al. 2013; ECHA 2020) | (Daikin 2007, 2009a, 2009b) | (Ladics et al. 2008; Climate and Pollution Agency, Norway 2010) |
PFAS = per‐ and polyfluoroalkyl substances; PFAA = perfluoroalkyl acids; PFBA = perfluorobutanoic acid; PFHxA = perfluorohexanoic acid; PFOA = perfluorooctanoic acid; PFBS = perfluorobutane sulfonic acid; HFPO = hexafluoropropylene oxide; FTOH = fluorotelomer alcohol; NDA = no data available.