&EPA United States Environmental Protection Agency Emerging Contaminants- Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) May 2012 EMERGING CONTAMINANTS FACT SHEET - PFOS and PFOA At a Glance * Fully fluorinated compounds that are human-made substances and not naturally found in the environment. * Used as a surface-active agent and in variety of products, such as fire fighting foams, coating additives and cleaning products. * Does not hydrolyze, photolyze or biodegrade under environmental conditions and is extremely persistent in the environment. * Studies have shown it has the potential to bioaccumulate and biomagnify in wildlife. * Readily absorbed after oral exposure and accumulates primarily in the serum, kidney, and liver. * Toxicological studies on animals indicate potential developmental, reproductive and systematic effects. * Health-based advisories or screening levels for PFOS and PFOA have been developed by both the EPA and the states. * Standard detection methods include high-performance liquid chromatographyand tandem mass spectrometry (MS/MS). * Common water treatment technologies include activated carbon filters and reverse osmosis units. Introduction An "emerging contaminant" is a chemical or material that is characterized by a perceived, potential or real threat to human health or the environment or by a lack of published health standards. A contaminant may also be "emerging" because a new source or a new pathway to humans has been discovered or a new detection method or treatment technology has been developed (DoD 2011). This fact sheet, developed by the U.S. Environmental Protection Agency's Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the emerging contaminants perfluorooctane sulfonate (PFOS) and perfluorooctanoicacid (PFOA), including physical and chemical properties; environmental and health impacts; existing federal and state guidelines; detection and treatment methods; and additional sources of information. PFOS and PFOA are extremely persistent in the environment and can be transported long distances in air. As a result, they are widely distributed across the higher trophic levels and are found in soil, air and groundwater at sites across the United States. The toxicity and bioaccumulation potential of PFOS and PFOA indicate a cause of concern for the environment and human health. This fact sheet is intended for use by site managers faced with addressing PFOS and PFOA at cleanup sites or in drinking water supplies and for those in a position to consider whether these chemicals should be added to the analytical suite for site investigations. What are PFOS and PFOA? »> PFOS and PFOA are fully fluorinated, organic compounds and are the largest made perflourinated chemicals (PFCs) (ATSDR2009). »> PFOS is a perfluoralkyl sulfonate that is commonly used as a simple salt (such as potassium, sodium, or ammonium) or incorporated into larger polymers (EFSA2008; EPA2009a). »> PFOA is a perfluoralkyl carboxylate that is produced synthetically as its salts. Ammonium salt is the most widely produced form (EFSA 2008; EPA2009a). »> PFOS synonyms include 1-Octanesulfonicacid, 1-Octanesulfonicacid, Heptadecafluoro-, 1-Perfluorooctanesulfonicacid, Heptadecafluoro-1- octanesulfonicacid, Perfluoro-n-octanesulfonicacid, Perfluoroctanesulfonicacid, and Perfluoroctylsulfonicacid (ATSDR2009; UNEP2005). »> PFOA synonyms include pentadecafluorol -octanoic acid, pentadecafluoro-n-octanoicacid; pentadecaflurooctanoicacid; perfluorocaprylic perfluoroctanoicacid; perfluoroheptanecarboxylic acid; and octanoic acid (ATSDR 2009). United States Environmental Protection Agency Solid Waste and Emergency Response (5106P) EPA 505-F-11-002 May 2012 Disclaimer: The U.S. EPA prepared this fact sheet from publicly available sources that were available at the time the fact sheet was published; additional information can be obtained from the source documents. This fact sheet is not intended to be used as a primary source of information and is not intended, nor can it be relied on, to create any rights enforceable by any party in litigation with the United States. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. 1 ------- Emerging Contaminants Fact Sheet - PFOS and PFOA What are PFOS and PFOA? (continued) They are stable chemicals made of a long carbon chain that is both lipid- and water-repellent. Because of the unique amphiphilic character, PFOS and PFOA are used as surface-active agents in various high-temperature applications and for applications in contact with strong acids or bases (ATSDR 2009; UNEP 2005). They are used in a wide variety of industrial and commercial products such as textiles and leather products; fire fighting foams, metal plating, the photographic industry, photolithography, semi- conductors, paper and packaging, coating additives, cleaning products, and pesticides (OECD 2002; EFSA 2008). They are human-made compounds and do not naturally occur in the environment (ATSDR 2009; UNEP 2006). PFOS and PFOA can be formed by environmental microbial degradation or by metabolism in larger organisms from a large group of related substances or precursor compounds (ATSDR 2009; Condor etal. 2010; UNEP 2006). The 3M Company, the primary manufacturer of PFOS, completed a voluntary phase-out of PFOS production in 2002 (ATSDR 2009; UNEP 2007). PFOS chemicals are no longer manufactured in United States. However, they can be imported and used for specific limited uses (EPA 2009a). PFOA is primarily manufactured for use as an aqueous dispersion agent, as ammonium salt, in the manufacture of fluoropolymers, which are used in a wide variety of mechanical and industrial components. They are also produced unintentionally by the degradation of some fluorotelomers (EPA 2009a). As part of the EPA's PFOA stewardship program, eight companies committed to reduce global facility emission and product content of PFOA and related chemicals by 95 percent in 2010 and eliminating emission and product content by 2015 (ATSDR 2009; EPA 2012). Exhibit 1: Physical and Chemical Properties of PFOS and PFOA (ATSDR 2009; Brooke et al. 2004; Cheng et al. 2008; EFSA 2008; EPA 2002; UNEP 2006) Property CAS Number Physical Description (physical state at room temperature and atmospheric pressure) Molecular weight (g/mol) Water solubility (mg/L at 25°C) Melting Point (°C) Boiling point (°C) Vapor pressure at 20 °C (mm Hg) Air water partition coefficient (Pa.mJ/mol) Octanol-water partition coefficient (log Kow) Organic-carbon partition coefficient (log Koc) Henry's law constant (atm m3/mol) Half-Life PFOS (Potassium Salt) 2795-39-3 White Powder 538 (potassium salt) 570 (purified), 370 (freshwater), 25 (filtered seawater) >400 Not measurable 2.48X10"b < 2 X1 0'° Not measurable 2.57 3.05 x 10"9 Atmospheric: 114 days Water: > 41 years (at 25° C) Photolytic: > 3.7 years Sonolysis: 20 to 63 minutes •dzjjZjfl 335-67-1 White powder/waxy white solid 414 9.5X10J(purified) 45 to 50 188 0.017 Not available Not measurable 2.06 Not measurable Atmospheric: 90 days Water: > 92 years (at 25° C) Photolytic: > 349 days Sonolysis: 20 to 63 minutes Notes: g/mol - grams per mole; mg/L - milligrams per Pa m3/mol - pascal-cubic meters per mole; atm m3/mol liter; C - degree Celsius; mm Hg - millimeters of mercury; - atmosphere-cubic meters per mole. ------- Emerging Contaminants Fact Sheet - PFOS and PFOA What are the environmental impacts of PFOS and PFOA? During past manufacturing processes, large amounts of PFOS and PFOA were released to the air, water and soil in and around fluorochemical facilities (ATSDR 2009; UNEP 2006). PFOS and PFOA have been detected in a number of U.S. cities in surface water and sediments downstream of former production facilities, wastewater treatment plant effluent, sewage sludge, and landfill leachate (EPA 2002; OECD 2002). PFOS and PFOA are chemically and biologically stable in the environment and resistant to biodegradation, atmospheric photooxidation, direct photolysis, and hydrolysis. As a result, these chemicals are extremely persistent in the environment (ATSDR 2009; EFSA 2008). No transformation of PFOS or PFOA has been observed in soil, sediment, sludge, water or biota systems. Progressive shortening of PFOS and PFOA has been observed in the atmosphere (Conderetal. 2010). Low acid dissociation constants (pKa) ranging from -3 to 4 suggest that PFOS and PFOA are strong acids and exist predominately in the anionicform in the environment (Conder et al. 2010). As a result of the chemical stability of PFOS and PFOA and the low volatility of these substances in ionic form, these substances are persistent in water and soil (ATSDR 2009). Additionally, PFOS and PFOA can be transported long distances in air because of their high atmospheric half-lives (ATSDR 2009; UNEP 2005). Monitoring data, including at sites remote from known point sources, have shown highly elevated levels of PFOS and PFOA throughout the northern hemisphere and indicate that long-range transport has occurred (ATSDR 2009; UNEP 2005; 2007). The wide distribution of the chemicals in high trophic levels increases the potential for bioaccumulation and bioconcentration. Because of their persistence and long-term accumulation, higher trophic level wildlife such as fish, piscivorous birds, and Arctic biota can continue to be exposed to PFOS and PFOA (EPA 2006; UNEP 2006). PFOS exhibits a higher tendency to bind to organic matter and bioaccumulate compared to PFOA due to its longer perfluoroalkyl chain length (Conderetal. 2010). PFOS has been shown to bioaccumulate and biomagnify in wildlife species such as fish and piscivorous birds. The biomagnification factor ranges from 1.4 to 17 kilogram per kilogram (kg/kg) in predatory birds and mammals (Moermond et al. 2010; UNEP 2006). PFOS is the only PFC that has been shown to accumulate to levels of concern in fish tissue. The estimated kinetic bioconcentration factor in fish ranges from 1,000 to 4,000 (EFSA 2008; MDH 2011). PFOS and PFOA have not been reported at the EPA's National Priorities List (NPL) sites; however, it is unknown how many of the current or former NPL sites have been evaluated for the presence of these chemicals (ATSDR 2009). What are the health effects of PFOS and PFOA? Studies have found small quantities of PFOS and PFOA in the blood samples of humans and wildlife nationwide, indicating that exposure to the chemicals is widespread (3M 2000; EPA 2006). Potential pathways, which may lead to widespread exposure, include ingestion of food and water, use of commercial products, or inhalation from long- range air transport (ATSDR 2009; EPA 2009a; MDH 2011). Based on the limited information available, fish and fishery products seem to be one of the primary sources of human exposure to PFOS. The maximum permissible concentration (MPC), based on consumption offish by humans as the most critical route, is 0.65 nanograms per liter (ng/L) for freshwater (Moermond et al. 2010). Toxicology studies show that PFOS and PFOA are readily absorbed after oral exposure and accumulate primarily in the serum, kidney, and liver. No further metabolism is expected (EFSA 2008; EPA 2006; EPA 2009a). PFOS and PFOA have a long half-life of about 4 years in humans. This continued exposure could increase body burdens to levels that would result in adverse outcomes (ATSDR 2009; EPA 2009a). ------- Emerging Contaminants Fact Sheet - PFOS and PFOA What are the health effects of PFOS and PFOA? (continued) Acute- and intermediate- duration oral studies in rodents have raised concerns about potential developmental, reproductive, and other systematic effects of PFOS and PFOA (Austin et al. 2003; ATSDR 2009; EPA 2006). Results of a study indicate that exposure to PFOS can affect the neuroendocrine system in rats (Austin et al. 2003). Both PFOS and PFOA have a high affinity for binding to B-lipoproteins and liver fatty acid- binding protein. Several studies have shown that these compounds can interfere with fatty acid metabolism and may deregulate metabolism of lipids and lipoproteins (EFSA 2008; EPA 2009a). The EPA has not classified PFOS or PFOA as to carcinogenicity (ATSDR 2009). The chronic exposure to PFOS and PFOA can lead to the development of tumors in the liver of rats; however, more research is needed to determine if there are similar cancer risks for humans (ATSDR 2009; OECD 2002). Epidemiologic studies have shown an association between PFOS exposure and bladder cancer; however, further research is needed (EPA 2006; OECD 2002). The EPA is currently assessing PFOS to establish the reference dose/reference concentration (RfD/RfC), which will be made available to the public through the Integrated Risk Information System (IRIS) (EPA 2011b). Are there any federal and state standards and guidelines for PFOS and PFOA? The EPA has not established a minimal risk level (MRL) for PFOS or PFOA because human studies to date are insufficient to determine with a sufficient degree of certainty that the effects are either exposure-related or adverse (ATSDR 2009). The EPA finalized two Significant New Use Rules (SNURs) in 2002, requiring companies to inform the EPA 90 days before they manufacture or import 88 identified PFOS-related substances (EPA 2008; UNEP2006). In 2007, the SNURs were amended to include 183 additional PFOS-related substances with carbon chain lengths of five carbons and higher (EPA 2006; UNEP 2007). The SNURs allow for the continuation of a few limited, highly technical uses of PFOS where there are no alternatives available, and which are characterized by very low volume, low exposure, and low releases (ATSDR 2009; EPA 2006). In January 2009, the EPA's Office of Water established a provisional health advisory (PHA) of 0.2 micrograms per liter (ug/L) for PFOS and 0.4 ug/L for PFOA to protect against the potential risk from exposure of these chemical through drinking water (EPA 2009b; EPA 2011 a). EPA Region 4 recommended a residential soil screening level of 6 milligrams per kilogram (mg/kg) for PFOS and 16 mg/kg for PFOA (EPA 2009c). Minnesota has established a health risk limit of 0.3 ug/L for PFOS and PFOA in drinking water (MDH 2011). New Jersey has established a preliminary drinking-water guidance value of 0.04 ug/L for PFOA (NJDEP 2007). North Carolina has established an interim maximum allowable concentration of 2 ug//L for PFOA in drinking water (NCDENP 2008). The EPA intends to propose actions in 2012 under the Toxic Substances Control Act (TSCA) Section 6 to address the potential risks from long-chain PFCs such as PFOS and PFOA. TSCA Section 6 provides authority for EPA to ban or restrict the manufacture (including import), processing and use of these chemicals (EPA 2009a). What detection and site characterization methods are available for PFOS and PFOA? Detection methods for environmental samples are primarily based on high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS) (ATSDR 2009). HPLC-MS/MS has allowed for more sensitive determination of individual PFOS and PFOA in air, water, and soil (ATSDR 2009). ------- Emerging Contaminants Fact Sheet - PFOS and PFOA What detection and site characterization methods are available for PFOS and PFOA? (continued) Both liquid chromatography (LC)-MS/MS and gas chromatography-mass spectrometry (GC-MS) can be used to identify the precursors of PFOS and PFOA (EFSA 2008). The development of LC - electrospray ionization (ESI) MS and LC-MS/MS has improved the analysis of PFOS and PFOA (EFSA 2008). Sample preparation methods include solvent extraction, ion-pair extraction, solid-phase extraction, and column-switching extraction (ATSDR2009). Air samples maybe collected using high-volume air samplers that employ sampling modules containing glass-fiber filters and glass columns with a polyurethane foam (EFSA 2008). Reported sensitivities for the available detection methods include low picograms (pg) per cubic meter (pg/m3) levels in air, high pg/L to low nanogram (ng)/L levels in water, and high pg per gram (pg/g) to low ng/g levels in soil (ATSDR 2009). What technologies are being used to treat PFOS and PFOA? Because of their unique physiochemical properties (strong fluorine-carbon bond and low vapor pressure), PFOS and PFOA resist most conventional treatment technologies such as direct oxidation and biodegradation (Hartten 2009; Vectis et al. 2009). The optimal treatment method depends on the concentration of PFOS and PFOA, background organic and metal concentration, available degradation time, and other site-specific conditions (Vectis et al. 2009). Both activated carbon filters and reverse osmosis units have been shown to be effective at reducing PFCs in water at levels typically found in drinking water (below 0.2 ug/L); however, incineration of the concentrated waste is required for complete destruction of PFOS and PFOA (Hartten 2009; MDH 2008; Vectis et al. 2009). Alternative technologies studied for PFOS and PFOA degradation include photochemical oxidation and thermally-induced reduction (Hartten 2009; Vectis et al. 2009). Studies have also evaluated the use of sonochemical degradation to treat PFOS and PFOA in groundwater (Cheng et al 2008; Vectis et al. 2009). Where can I find more information about PFOS and PFOA? 3M Company (3M). 2000. "Determination of serum half-lives of several fluorochemicals." Agency for Toxic Substance and Disease Registry (ATSDR). 2009. "Draft Toxicological Profile for Perfluoroalkyls." www.atsdr.cdc.qov/toxprofiles/tp200.pdf Austin, M.E., Kasturi, B.S., Barber, M., Kannan,K., MohanKumar, P.S., and MohanKumar, S.M. 2003. "Neuroendocrine effects of perfluorooctane sulfonate in rats." Environ Health Perspect. Volume 111(12). Pages 1485to1489. www.ncbi.nlm.nih.gov/pmc/articles/PMC1241651/ Brooke D., Footitt, A., and Nwaogu, T.A. 2004. Environmental Risk Evaluation Report: Perfluorooctane Sulfonate (PFOS). Cheng, J., Vecitis, C.D., Park, H., Mader, B.T., and Hoffmann, M.R. 2008. Sonochemical Degradation of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoate (PFOA) in Landfill Groundwater: Environmental Matrix Effects. Environ. Sci. Technol. Volume 42 (21). Pages 8057 to 8063. Conder, J.M., Wenning, R.J., Travers, M., and Blom, M. 2010. Overview of the Environmental Fate of Perfluorinated Compounds. Network for Industrially Contaminated Land in Europe (NICOLE) Technical Meeting. 4 November 2010. Hartten, A.S. 2009. "Water Treatment of PFOA and PFOS." DuPont Corporate Remediation Group. www.epa.gov/oppt/pfoa/pubs/Water%20Treatment %20Methods%20Hartten%200ct16-09.pdf Minnesota Department of Health (MDH). 2008. "MDH Evaluation of Point-of-Use Water Treatment Devices for Perfluorochemical Removal. Final Report Summary." www.health.state.mn.us/divs/eh/wells/waterquality/ poudevicefinalsummary.pdf ------- Emerging Contaminants Fact Sheet - PFOS and PFOA Where can I find more information about PFOS and PFOA? (continued) MDH. 2011. Perfluorochemicals (PFCs) in Minnesota. www.health.state.mn.us/divs/eh/hazardous/topics/ pfcs/index.html Moermond, C., Verbruggem E., and Smit, C. 2010. Environmental risk limits for PFOS: A proposal for water quality standards in accordance with the Water Framework Directive. www.rivm.nl/bibliotheek/rapporten/601714013.pdf New Jersey Department of Environmental Protection (NJDEP). 2007. Determination of PerfluorooctanoicAcid (PFOA) in Aqueous Samples. Final Report. http://slic.nistatelib.org/slic files/diqidocs/w329/w3 292007.pdf North Carolina Department of Environment and Natural Resources (NCDENP). 2008. Recommended Interim Maximum Allowable Concentration for PerfluorooctanoicAcid. Organization for Economic Cooperation and Development (OECD). Environment Directorate. 2002. "Hazard Assessment of Perfluorooctane Sulfonate (PFOS) and its Salts." www.oecd.orq/dataoecd/23/18/2382880.pdf United National Environment Programme (UNEP). 2005. "Perfluorooctane sulfonate proposal." Stockholm Convention on Persistent Organic Pollutants Review Committee. Geneva, 7-11 November 2005. UNEP. 2006. "Risk profile on perfluorooctane sulfonate." Stockholm Convention on Persistent Organic Pollutants Review Committee. Geneva, 21 November 2006. UNEP. 2007." Risk Management Evaluation on Perfluorooctane Sulfonate." Stockholm Convention on Persistent Organic Pollutants Review Committee. Geneva, 19-23 2007. U.S. Department of Defense (DoD). 2011. Emerging Chemical & Material Risks. http://www.denix.osd.mil/portal/paqe/portal/ CMRMD/ECMR U.S. Environmental Protection Agency (EPA). 2002. Hazard Assessment of Perfluorooctanoic Acid and its Salts. www.ewq.org/files/EPA hazard full.pdf EPA. 2006. PFAS-Proposed Significant New Use Rule, 40CFR721. U.S. Federal Register: Vol. 71 (No 47), March 10, 2006. www.qpo.gov/fdsvs/pkq/FR-2006-03-10/pdf/E6- 3444.pdf EPA. 2008. Significant new uses of chemical substances. U.S. Environmental Protection Agency. Code of Federal Regulations. 40 CFR 721. EPA. 2009a. Long-Chain Perfluorinated Chemicals (PFCs) Action Plan. EPA. 2009b. Provisional Health Advisories for PerfluorooctanaoicAcid (PFOA) and Perfluorooctyl Sulfonate (PFOS). EPA Region 4. 2009c. Soil Screening Levels for PerfluorooctanaoicAcid (PFOA) and Perfluorooctyl Sulfonate (PFOS). Memorandum. EPA. 2011 a. PerfluorooctanoicAcid (PFOA) and Fluorinated Telomers. Related EPA Actions. www.epa.gov/oppt/pfoa/pubs/activities.htmltfnerl EPA. 2011 b. Perfluorooctane Sulfonate (PFOS) - IRIS Assessment. http://cfpub.epa.gov/si/si public record report.cfm ?dirEntrvlD=133328 EPA. 2012. Perfluorooctanoic acid (PFOA) and Fluorinated Telomers. www.epa.gov/oppt/pfoa/ European Food Safety Authority (EFSA). 2008. "Perfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) and their salts." The EFSA Journal Volume 6 (53), Pages 1 to 131. Vectis, C.D., Park, H., Cheng, J.,and Mader, B.T. 2009. "Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)." Frontiers of Environmental Science & Engineering in China. Volume 3(2), Pages 129 to151. Contact Information If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, by phone at (703) 603-8712 or by email at cooke.marvt@epa.gov. ------- |