The purpose of this webpage is to provide the ASTSWMO membership with information on Perfluoroalkyl and polyfluoroalkyl substances (PFASs), also known as perfluorinated chemicals (PFASs), which are emerging contaminants of concern. The identification and cleanup of these contaminants may pose unique challenges in State cleanup programs.
There are many chemicals that fall into the generic family of PFASs. This page will predominantly focus on the two most commonly researched PFASs:
PFOS and PFOA compounds are highly soluble in water and typically present as an anion (conjugate base) in solution and have very low volatility due to their ionic nature. Long chain PFASs have low vapor pressure, and aquatic environments are expected to be their primary sink in the environment. These compounds do not readily degrade by most natural processes. They are thermally, chemically, and biologically stable and are resistant to biodegradation, atmospheric photooxidation, direct photolysis, and hydrolysis. The structure of PFASs increase their resistance to degradation: the carbon-fluorine bonds require a lot of energy to break, and the fluorine atoms shield the carbon backbone.
PFASs have been found worldwide in soil, groundwater, surface water, rain, ice caps, air, plants, animal tissue, and blood serum. The highest concentrations found in the environment tend to be associated with direct discharge from industries where PFASs are in use. Fresh waters in the vicinity of these industries have been documented to have concentrations of PFASs ranging from 1 – 1000s parts per trillion (ppt). Oceanic concentrations of PFASs are several orders of magnitude lower, ranging closer to 0.01 – 0.1 ppt. Interestingly, while not volatile, PFASs have been detected in air, sediments, and fauna in the Arctic, despite being geographically separated from any possible human sources .
PFASs are mobile in soil and leach into groundwater. It is not completely understood how the compounds are transported to areas far removed from industrial facilities or consumer products. Three hypotheses have been presented regarding the method of long-range transport of PFASs. One possibility is direct ocean transport of PFASs. The second is that PFASs are transported directly as marine aerosols, which is supported by evidence that surfactants accumulate at the surface of water bodies. In addition, a third hypothesis is that volatile fluorotelomer alcohols travel great distances in the atmosphere and degrade into PFOS and PFOA.
Due to the wide variety of uses of PFASs, it is not difficult to understand how people are exposed to these chemicals. In the 1990s, regulatory agencies called for additional research on PFASs when it was discovered that these substances were found throughout the earth’s environment and were also very commonly found in human blood serum. Research has indicated that humans can be exposed to PFASs through the following routes:
a) Occupational exposure. Levels of PFASs in the blood of people who work where PFASs are manufactured or used are much higher than people from the same area that do not work where PFASs are manufactured or used. Inhalation and dermal contact are the most common exposure entry routes.
b) Non-occupational exposure. PFASs contamination of food and air is likely to be responsible for most non-occupational exposures in industrial nations. Potential exposure routes include:
i. Eating fish from contaminated water bodies;
ii. Eating crops grown in contaminated soils, particularly in agricultural areas that receive amendments of biosolids from wastewater treatment plants (WWTPs). Biosolids from WWTPs become contaminated from the treatment of contaminated wastewaters at the WWTP.
iii. Infant consumption of contaminated breast milk. Breast milk can become contaminated from PFASs in the bloodstream of the mother;
iv. Drinking contaminated water.
v. Inhalation of contaminated air;
vi. Inhalation and ingestion of house dust containing PFASs; and
vii. Direct contact with consumer products that have been treated with PFASs (such as carpets which are treated with PFASs for stain resistance) or which contain residuals from a manufacturing process. Children especially may ingest PFASs through hand-to-mouth transfer from treated carpets.
The unique chemical and physical properties of PFOA and PFOS prevent them from being measured using conventional analysis. For example, their extremely low volatility eliminates the possibility of using gas chromatography/mass spectrometry (GC/MS). As a result, the more complex methodology of liquid chromatography and tandem mass spectrometry (LC/MS-MS) has been proven most reliable for analyzing PFOS and PFOA in biological and environmental samples. This type of analysis has allowed for more sensitive determination of many PFASs, including PFOA and PFOS, in air, water, and soil.
U.S. EPA developed the first reference method for PFASs in drinking water in September 2008. EPA’s Method 537, Version 1.1 was published in September 2009, and is intended for analyzing selected PFASs in drinking water using solid phase extraction with LC/MS-MS. The method has been validated for 14 different perfluorinated alkyl acids and has lowest concentration minimum reporting limits of 2.9 ppt to 14 ppt. Before September 2009, there were no validated test methods or standardized data quality criteria. As a result, most PFC data generated and used in earlier publications was not based on validated methods and therefore cannot be used for comparison with today’s data.
Many reports have been published on the analysis of PFASs in surface waters, but very few report on the contents of PFASs in air or drinking water. Methods for surface water analysis are similar to those used for drinking water analysis. The European Food Safety Authority and ATSDR have compiled and summarized the various analytical technologies available for detecting various PFASs. ASTM has published two methods for analyzing PFASs in environmental media, D7968 – 14 for soil and D7979 – 15 for water, sludge, influent, effluent and wastewater, but neither has been validated yet. Some environmental laboratories have also developed their own LC/MS-MS procedures allowing for the detection of PFASs.The unique chemical and physical properties of PFASs make the use of conventional treatment technologies difficult. For groundwater, the most common treatment is extraction and filtration through granular activated carbon (GAC). This technology has been shown to consistently remove PFOS at µg/L concentrations with an efficiency of 90%; however, it is not as efficient at removing PFOA and other PFASs. Other adsorbents that have been utilized include: powdered activated carbon, polymers, maize-straw-derived ash, alumina, and montmorillonite. Alternative treatment technologies for groundwater include ion exchange, sonochemical treatment and reverse osmosis for groundwater. All of these technologies still require groundwater extraction and exsitu treatment and are more costly than GAC and relatively experimental.
For soil treatment, contaminated soils are usually removed and sent to landfills. Not only is this an expensive remediation alternative it is also inefficient because the contaminants are not destroyed, but just transferred to another location. PFAS contaminated soils can also be incinerated, but only high temperature incinerators will completely destroy PFOS and PFOA.
Studies continue to be conducted to find more efficient, less costly, in-situ treatment technologies.
The workgroup is composed of six Board Members and two ASTSWMO Staff.
Agency for Toxics and Disease Registry (ATSDR), Division of Toxicology and Environmental Medicine. (2009). Toxicological profile for perfluoroalkyls. U.S. Government Printing Office. http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=1117&tid=237.
Darwin, R. L. (2011). Estimated inventory of PFOS-based Aqueous Film Forming Foam (AFFF), 2011 update to the 2004 report entitled “Estimated Quantities of Aqueous Film Forming Foam (AFFF) In The United States”. Prepared for the Fire Fighting Foam Coalition, Inc., Arlington, VA.
Department of Defense (DoD) Instruction 4715.18, Subject: Emerging Contaminants (ECs). (2009) http://www.dtic.mil/whs/directives/corres/pdf/471518p.pdf.
Environment Canada. (2010). Risk management scope for perfluorooctanoic acid (PFOA), and its salts, and its precursors and long chain (C9 – C20) perfluorcarboxylic acids (PFCAs) and their salts and their precursors. Government of Canada.
Environmental Council of States (ECOS) – DoD Sustainability Workgroup, Emerging Contaminants Task Group. (2007). Issue paper on identification and selection of toxicity values/criteria for CERCLA and hazardous waste site risk assessment in the absence of IRIS values. http://www.ecos.org/files/2733_file_FINAL_ECOS_PV_Paper_4_23_07.doc.
ECOS – DoD Sustainability Workgroup. (2008). issue paper on initiation of emerging contaminants characterization and response actions for protection of human health. http://www.ecos.org/files/3278_file_Resource_Triggers_Paper_9_15_08.doc.
European Food Safety Authority (EFSA). (2008). Opinion of the scientific panel in the food chain on perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and their salts. Question No EFSA-Q-2004-163. EFSA Journal 653, 1-131. http://www.efsa.europa.eu/en/scdocs/doc/653.pdf
Federal Aviation Administration (FFA). (2011). National Part 139 CertAlert: Identifying Mil-Spec Aqueous Film Forming Foam (AFFF). https://www.faa.gov/airports/airport_safety/certalerts/media/cert1102.pdf.
Furl, C. & Meredith, C. (2010). Perfluorinated compounds in Washington rivers and lakes. Washington Department of Ecology. Publication Number 10-03-034. Olympia, Washington. https://fortress.wa.gov/ecy/publications/summarypages/1003034.html
Hawley, E.L., Pancrass, T. & Burdick, J. (2012). Remediation technologies for perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Arcadis White Paper.
Houtz, E. F., Higgins, C. P., Field, J.A. & Sedlak, D. I. (2014). Persistence of perfluoroalkyl acid precursors in AFFF-impacted groundwater and soil.” Environmental Science & Technology, 47(15), doi: 10.1021/es4018877. http://www.researchgate.net/publication/252323955_Persistence_of_Perfluoroalkyl_Acid_Precursors_in_AFFF-Impacted_Groundwater_and_Soil.
Huang, Q. (2013). Remediation of perfluoroalkyl contaminated aquifers using an in-situ two layer barrier: laboratory batch and column study. SERDP Project ER-2127. https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER-2127/ER-2127/%28modified%29/30Jun2014
Lindstrom, A.B., Strynar, M.J., & Libelo, E.L. (2011). Polyfluorinated compounds: past, present, and future. Environmental Science & Technology 45, 7954-7961, doi: 10.1021/es2011622. http://pubs.acs.org/doi/ipdf/10.1021/es2011622
Military Specification (MIL)-F-24385, Fire Extinguishing Agent, Aqueous Film Firefighting Foam (AFFF) Liquid Concentrate, Six Percent, For Fresh and Seat Water. November 21, 1969.
Organization for Economic Cooperation and Development (OECD) Environment Directorate. (2002). Hazard assessment of perfluorooctane sulfonate (PFOS) and its salts.’’ www.oecd.org/chemicalsafety/risk-assessment/2382880.pdf
Place, B.J. &J.A. Field. (2013). Identification of novel fluorochemicals in aqueous film-forming foams (AFFF) used by the US military.” Environmental Science & Technology, 46 (13), 7120-7127. Doi: 10.1021/es301465n. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3390017/
Steenland, K., Tinker, S., Frisbee, S., Ducatman, A., & Vaccarino, V. (2009). Association of perfluorooctanoic acid and perfluorooctane sulfonate with serum lipids among adults living near a chemical plant. American Journal of Epidemiology, 170(10): 1268-78, doi: 10.1093/aje/kwp279. http://aje.oxfordjournals.org/content/170/10/1268.abstract.
Strategic Environmental Research and Development Program (SERDP). (2012). FY 2014 Statement of need, environmental restoration program area, in situ remediation of perfluoroalkyl contaminated groundwater. SON Number: ERSON-14-02. https://www.serdp-estcp.org/content/download/15973/182513/version/1/file/FY14+ERSON-14-02+PFOS.pdf
Tseng, N. (2012). Feasibility of biodegradation of polyfluoroalkyl and perfluoroalkyl substances. A thesis submitted in partial satisfaction of the requirements for the degree Master of Science in Civil Engineering. UCLA. http://escholarship.org/uc/item/2x47296b.
U.S. Air Force (USAF), HQ USAF/A7C. (2012). Interim Air Force guidance on sampling and response actions for perfluorinated compounds at active and BRAC installations. Washington, DC.
U.S. Environmental Protection Agency (EPA). (2009a). Provisional health advisories for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Attachment 1 to: http://www.epa.gov/opptintr/pfoa/pubs/Final%20PFOA%20PFOS%20RfD%20memo%2010-28-09.pdf.
U.S. EPA. (2009b). Determination of selected perfluorinated alkyl acids in drinking water by solid phase extraction and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Version 1.1. http://www.epa.gov/nerlcwww/documents/Method%20537_FINAL_rev1.1.pdf.
U.S. EPA. (2009c). The toxicity of perfluorooctanic acid (PFOA) and perfluorooctane sulfonate (PFOS). Memorandum. http://www.epa.gov/opptintr/pfoa/pubs/Final%20PFOA%20PFOS%20RfD%20memo%2010-28-09.pdf
U.S. EPA. (2012). Unregulated Contaminant Monitoring Rule 3. http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/ucmr3. U.S. EPA (2013). Prepublication notice of Final Significant New Rule on perfluoroalkyl sulfonates and long chain perfluoroalkyl carboxylate chemical substances. 40 CFR Parts 9 and 721. EPA-HQ-OPPT-2012-0268; FRL-9397-1. RIN 2070-AJ95. http://www.epa.gov/oppt/pfoa/pubs/pfas.html.
U.S. EPA. (2014). Perfluorooctanoic acid (PFOA) and fluorinated telomers webpage. http://www.epa.gov/oppt/pfoa/pubs/pfas.html.
U.S. EPA. (2015). 2010/2015 PFOA Stewardship Program webpage. http://www.epa.gov/oppt/pfoa/pubs/stewardship/index.html.
U.S. EPA Region 4 (2009). Soil screening levels for perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS).” Memorandum.
U.S. EPA Region 5. (2009). PFOS chromium electroplater study. http://www.epa.gov/opptintr/pfoa/pubs/pfoschromeplaterstudypdf_final.pdf.
U.S. Navy (USN). Assistant Secretary of the Navy (Energy, Installations and Environment). (2014). Perfluorinated compounds (PFCs) – An emerging environmental issue. Memorandum.
Wallington TJ, Hurley MD, Xia J, Wuebbles DJ, Sillman S, Ito A, Penner JE, Ellis DA, Martin J, Mabury SA, Nielsen OJ, & Sulbaek Andersen MP. (2006). Formation of C7F15COOH (PFOA) and other perfluorocarboxylic acids during the atmospheric oxidation of 8:2 fluorotelomer alcohol. Environmental Science & Technology, 40(3): 924-30, doi: 10.1021/es051858x. http://pubs.acs.org/doi/abs/10.1021/es051858x.
Tuve, RL, & E.J. Jablonski. Method of extinguishing liquid hydrocarbon fires. U.S. Patent 3,258,423, filed September 4, 1963, and issued Jun 28. 1966. http://www.google.com/patents/US3258423.
Concawe: Environmental Science for the European Refining Industry (2016). Report no. 8/16 Environmental fate and effects of poly-and perfluoroalkyl substances (PFAS) https://www.concawe.eu/uploads/Modules/Publications/rpt_16-8.pdf