Per- and polyfluoroalkyl substances (PFAS) are a large family of chemicals that contain carbon, fluorine and other elements. Historically, the industry referred to these chemicals as perfluorinated compound chemicals or PFC. However, since this acroynym also refers to perfluorinated carbons, it has fallen out of fashion as a term for PFAS compounds. While perfluoroctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the most commonly discussed forms, PFAS is an incredibly broad class, encompassing many thousands of varieties.
So what do these diverse substances have in common? All PFAS compounds contain a chain of carbon atoms bonded to fluorine atoms, but the exact number of atoms varies depending on the specific chemical. In perfluoroalkyl substances for instance, all the carbons except the last in the chain are attached to fluorine atoms. For polyfluoroalkyl substances, on the other hand, at least one (but not all) of the carbons in the chain are attached to fluorine atoms. The number of carbon atoms contained within a compound’s perfluorinated chain distinguishes it as either long-chain PFAS (seven or more carbon atoms) or short-chain PFAS (less than seven atoms).[1]
Another key feature of PFAS is that they are manmade fluorinated compounds which are not naturally found in the environment. Their production first began in the 1940s for primarily industrial applications such as additives to coatings, but their use soon expanded to firefighting foams and finally to everyday items like non-stick cookware and cosmetics. As PFAS became more popular, concerns grew surrounding their potential impact on people, wildlife and the planet.
The problem of PFAS in the environment
PFAS are famously stable—and that creates serious problems for public health when they escape their intended applications. Their extreme chemical stability and low volatility make PFAS highly persistent in the environment and mobile in both the atmosphere and major bodies of water. As a result, they are dubbed “forever chemicals”; substances that do not break down or stay easily contained, accumulating in ecosystems and our bodies with potentially toxic results.
Researchers have found compelling evidence linking high concentrations of PFAS within human and animal bodies to a variety of health concerns; from developmental issues in children to impaired endocrine function and increased risk of certain cancers.[2] In general, long chain PFAS are more acutely toxic, though short chain varieties have still been shown to cause potentially damaging cell changes.[3] Over-accumulation of PFAS in water, air and soil can have equally damaging effects on flora and fauna that last for decades, if not more.[4] With this in mind, governments and international environmental agencies have been steadily introducing restrictions on the production and use of forever chemicals with the aim of eventually making society PFAS-free—and this trend shows no signs of slowing down.
How do regulators view PFAS?
PFOA and PFOS were listed under the Stockholm Convention on Persistent Organic Pollutants (POPs) and as a consequence, are restricted under the EU POPs Regulation. Another, less widely used sub group—perfluorohexanesulfonic acid (PFHxS), its salts and PFHxS-related compounds—are also listed under the POPs Regulation Annex I, following a similar restriction outlined in Annex A to the Stockholm Convention, published in June 2022.[5] In addition to the substance groups listed above, C9-C14 PFCAs are currently banned or restricted in the EU market.[6]
Over 10,000 substances are currently under review according to the ECHA’s updated REACH legislation, with a major new raft of guidance—including a Universal PFAS Restriction Proposal—estimated to be published by the end of 2026.[7] Further information on the restriction process can be found in the new ECHA chemicals database.[8]
Separate from the EU’s investigations, UK REACH similarly oversees and restricts the use of specific PFAS, while other related UK laws require wastewater management companies and industrial processors to monitor and manage levels of PFAS contaminants.[9],[10]
What Are The Main PFAS Compounds Found in Water?
Industrial and municipal wastewater can carry a variety of pollutants that not only pose a risk to human health, but also impact the ecology of the rivers, streams, lakes, and groundwater tables that they eventually flow into. There are hundreds of different PFAS compounds that can then find their way into drinking water supplies, but the group detailed below are considered the main suspects for PFAS treatment. It’s important to note that this list is non-exhaustive and that precise treatment requirements will vary between individual drinking water purification, industrial wastewater treatment and ground remediation projects.
No | Acronym(s) | Description |
1 | PFBA | Perfluorobutanoic Acid |
2 | PFPeA | Perfluoropentanoic acid |
3 | PFHxA | Perfluorohexanoic acid |
4 | PFHpA | Perfluoroheptanoic acid |
5 | PFOA | Perfluorooctanoic acid – linear and branched |
6 | PFNA | Perfluorononanoic acid |
7 | PFDA | Perfluorodecanoic acid |
8 | PFUnA; PFUdA; PFUnDA | Perfluoroundecanoic acid |
9 | PFDoA; PFDoDA | Perfluorododecanoic acid |
10 | PFTrDA;PFTriA | Perfluorotridecanoic acid |
11 | PFTeA; PFTeDA | Perfluorotetradecanoic acid |
12 | PFHxDA | Perfluorohexadecanoic acid |
13 | PFODA | Perfluorooctadecanoic acid |
14 | PFBS | Perfluorobutane sulfonic acid |
15 | PFPeS | Perfluoropentane sulfonic acid |
16 | PFHxS | Perfluorohexane sulphonic acid – linear and branched |
17 | PFHpS | Perfluoroheptane sulfonic acid |
18 | PFOS | Perfluorooctane sulfonic acid – linear and branched |
19 | PFNS | Perfluorononane sulfonic acid |
20 | PFDS | Perfluorodecane sulfonic acid |
21 | PFUnDS | Perfluoroundecane sulfonic acid |
22 | PFDoS; PFDoDS | Perfluorodecane sulfonic acid |
23 | HFPO-DA (Gen-X) | Hexafluoropropylene oxide-dimer acid or perfluoro-2-propoxypropanoic acid – (FRD 903) |
24 | HFPO-TA | Hexafluoropropylene oxide trimer acid |
25 | DONA:ADONA | 4,8-dioxa-3H-Perfluorononanoic acid |
26 | PFMOPrA | Perfluoro-3-methoxypropanoic acid |
27 | NFDHA | Perfluoro-3,6-dioxaheptanoic acid |
28 | PFMOBA | Perfluoro-4-methoxybutanic acid |
29 | PFECHS | Perfluoroethylcyclohexane Sulphonate |
30 | 3:3 FTCA | 3-Perfluoropropyl Propanoic acid |
31 | 5:3 FTCA | 5:3 Fluorotelomer carboxylic acid |
32 | 7:3 FTCA | 2H,2H,3H,3H-Perfluorodecanoic acid |
33 | PFEESA | Perfluoro(2-ethoxyethane)sulphonic acid |
34 | 6:2 Cl-PFESA;9Cl-PF3ONS | 6:2 chlorinated polyfluoroalkyl ether sulfonate |
35 | 8:2 Cl-PFESA;11Cl-PF3OUdS | 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid |
36 | 4:2 FTSA; 4:2 FTS | 4:2 Fluorotelomer sulfonic acid |
37 | 6:2 FTSA; 6:2 FTS | 6:2 Fluorotelomer sulfonic acid |
38 | 8:2 FTSA; 8:2 FTS | 8:2 fluorotelomer sulfonic acid |
39 | FBSA; PFBSA | Perfluorobutane sulfonamide |
40 | FHxSA | Perfluorohexane sulfonamide |
41 | FOSA (PFOSA) | Perfluorooctane sulfonaminde – Linear and branched |
42 | MeFOSA; N-MeFOSA | N-methylperfluorooctane sulfonamide – Linear and branched |
43 | EtFOSA; N-EtFOSA | N-ethyl perfluorooctane sulfonamide – Linear and branched |
44 | MeFOSE | N-methylperfluorooctanesulfonamidoethanol |
45 | EtFOSE | N-ethyl-N-(2-hydroxyethyl)-perfluorooctanesulfonamide |
46 | NMeFOSAA; MeFOSAA; MePFOSAA | 2-(N-Methylperfluorooctanesulfonamido) acetic acid |
47 | NEtFOSAA; EtFOSAA; EtPFOSAA | N-ethyl perfluorooctane sulfonamido acetic acid |
48 | MePFBSA | N-methylperfluor-n-butanesulfonamide |
49 | MePFBSAA | N-methylperfluor-n-butanesulfonylamide acetic acid |
50 | PFTrDS | perfluorotridecan sulfonic acid |
51 | 10:2 FTS | 10:2 fluorotelomer sulfonic acid |
52 | 6:2 diPAP | 6:2 fluorotelomer phosphate diester |
53 | 6:2/8:2 diPAP | 6:2/8:2 fluorotelomer phosphate diester |
54 | 8:2 diPAP | 8:2 fluorotelomer phosphate diester |
How can Chemviron help you manage PFAS removal?
With its powerful adsorption, purification and recycling properties, activated carbon is one of the best strategies for tackling PFAS contamination in a range of water sources. For optimal effectiveness, the carbon treatment approach must be tailored to the specific type of PFAS contaminants, their range of concentrations, and the final treatment objective based on local regulations and internationally agreed limits. Harnessing more than 80 years of technical excellence, Chemviron is here to offer the solutions and technical expertise needed to remove commonly found PFAS compounds, efficiently and effectively.
To learn more about how our activated carbon solutions and tailored end-to-end services can support your operations, get in touch here:
[1] Li, H., Dong, Q., Zhang, M., Gong, T., Zan, R., & Wang, W. (2023). Transport behavior difference and transport model of long- and short-chain per- and polyfluoroalkyl substances in underground environmental media: A review.. Environmental pollution, 121579 . https://doi.org/10.1016/j.envpol.2023.121579.
[2] Sunderland, E., Hu, X., Dassuncao, C., Tokranov, A., Wagner, C., & Allen, J. (2018). A Review of the Pathways of Human Exposure to Poly- and Perfluoroalkyl Substances (PFASs) and Present Understanding of Health Effects. Journal of exposure science & environmental epidemiology, 29, 131 – 147. https://doi.org/10.1038/s41370-018-0094-1.
[3] Ateia, M., Maroli, A., Tharayil, N., & Karanfil, T. (2019). The overlooked short- and ultrashort-chain poly- and perfluorinated substances: A review.. Chemosphere, 220, 866-882 . https://doi.org/10.1016/J.CHEMOSPHERE.2018.12.186.
[4] Evich, M., Davis, M., McCord, J., Acrey, B., Awkerman, J., Knappe, D., Lindstrom, A., Speth, T., Tebes-Stevens, C., Strynar, M., Wang, Z., Weber, E., Henderson, W., & Washington, J. (2022). Per- and polyfluoroalkyl substances in the environment. Science, 375. https://doi.org/10.1126/science.abg9065.
[5] https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:JOL_2023_198_R_0004
[6] https://eur-lex.europa.eu/eli/reg/2021/1297/oj
[7] https://echa.europa.eu/-/echa-announces-timeline-for-pfas-restriction-evaluation
[8] https://echa.europa.eu/registry-of-restriction-intentions/-/dislist/details/0b0236e18663449b
[9] https://www.dwi.gov.uk/pfas-and-forever-chemicals/
[10] https://www.gov.uk/government/publications/interim-position-statement-on-the-approach-to-pmt-concept-to-support-uk-reach-risk-management-of-pfas/interim-approach-to-the-pmt-concept-to-support-uk-reach-risk-management-of-pfas