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Ground Water and Drinking Water

Drinking Water Health Advisories for PFOA and PFOS

Health Advisories

EPA has established health advisories for PFOA and PFOS based on the agency’s assessment of the latest peer-reviewed science to provide drinking water system operators, and state, tribal and local officials who have the primary responsibility for overseeing these systems, with information on the health risks of these chemicals, so they can take the appropriate actions to protect their residents. EPA is committed to supporting states and public water systems as they determine the appropriate steps to reduce exposure to PFOA and PFOS in drinking water. As science on health effects of these chemicals evolves, EPA will continue to evaluate new evidence.

To provide Americans, including the most sensitive populations, with a margin of protection from a lifetime of exposure to PFOA and PFOS from drinking water, EPA has established the health advisory levels at 70 parts per trillion. 

  • What's a health advisory?

    Health advisories provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. EPA's health advisories are non-enforceable and non-regulatory and provide technical information to states agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination. EPA’s health advisory level for PFOA and PFOS offers a margin of protection for all Americans throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water.

  • What health effects are the basis for the health advisories?

    EPA’s health advisories are based on the best available peer-reviewed studies of the effects of PFOA and PFOS on laboratory animals (rats and mice) and were also informed by epidemiological studies of human populations that have been exposed to perfluoroalkyl substances (PFASs). These studies indicate that exposure to PFOA and PFOS over certain levels may result in adverse health effects, including developmental effects to fetuses during pregnancy or to breastfed infants (e.g., low birth weight, accelerated puberty, skeletal variations), cancer (e.g., testicular, kidney), liver effects (e.g., tissue damage), immune effects (e.g., antibody production and immunity), thyroid effects and other effects (e.g., cholesterol changes). To learn more about the underlying studies for the health advisories, see EPA’s Health Effects Support Documents for PFOA and PFOS.

  • Read more questions and answers

    Is EPA going to establish a national drinking water standard for PFOA and PFOS?

    EPA is evaluating PFOA and PFOS as drinking water contaminants in accordance with the process required by the Safe Drinking Water Act (SDWA). To regulate a contaminant under SDWA, EPA must find that it: (1) may have adverse health effects; (2) occurs frequently (or there is a substantial likelihood that it occurs frequently) at levels of public health concern; and (3) there is a meaningful opportunity for health risk reduction for people served by public water systems.

    EPA included PFOA and PFOS among the contaminants for which water systems are required to monitor under the third Unregulated Contaminant Monitoring Rule (UCMR 3) in 2012. Results of this monitoring effort can be found on the publicly-available National Contaminant Occurrence Database (NCOD). EPA updates the information approximately quarterly. In accordance with SDWA, EPA will consider the occurrence data from UCMR 3, along with the peer reviewed health effects assessments supporting the PFOA and PFOS Health Advisories, to make a regulatory determination on whether to initiate the process to develop a national primary drinking water regulation.

    In addition, EPA plans to begin a separate effort to determine the range of perfluoroalkyl substances (PFAS – the group of chemicals of which PFOA and PFOS are a part) for which an Integrated Risk Information System (IRIS) assessment is needed. The IRIS Program identifies and characterizes the health hazards of chemicals found in the environment. IRIS assessments inform the first two steps of the risk assessment process: hazard identification, and dose-response. As indicated in the 2015 IRIS Multi-Year Agenda, the IRIS Program will be working with other EPA offices to determine the range of PFAS compounds and the scope of assessment required to best meet Agency needs. More about this effort can be found at https://www.epa.gov/iris/iris-agenda.

    Should I be worried about other perfluoroalkyl substances (PFASs) in drinking water?

    These health advisories are specifically for PFOA and PFOS and do not apply to other perfluoroalkyl substances (PFASs). The Agency is continuing to gather information about other PFAS. In addition to monitoring for PFOA and PFOS under EPA’s third Unregulated Contaminant Monitoring Rule (UCMR 3), systems also monitored four other PFASs. Results of this monitoring effort can be found on the publicly-available National Contaminant Occurrence Database (NCOD). EPA updates the information approximately quarterly. The last update reflects results received as of April 1, 2016. EPA expects the complete dataset from UCMR 3 to be available by mid-2016. Visit the NCOD.

    How can I find out if there are elevated levels of PFOA or PFOS in my drinking water supply?

    Customers that are served by a public water system can contact their local water supplier and ask for information on PFOA and PFOS in their drinking water, and are encouraged to request a copy of their Consumer Confidence Report. This report lists the levels of contaminants that have been detected in the water, including those by EPA, and whether the system meets state and EPA drinking water standards. If you are concerned about the possibility of PFOA or PFOS in your drinking water and you are served by a private well, EPA recommends testing your drinking water. In addition, EPA recommends that residents reach out to their local public health department for more information.

    The most recent Consumer Confidence Report can be obtained from your drinking water utility, by visiting their website or contacting them for a copy. Some public water systems upload their Consumer Confidence Report to EPA’s website at: epa.gov/ccr. Information about private wells can be found here: epa.gov/privatewells.

    Also, if your public water system participated in collecting monitoring data for UCMR3, you can find information about your system in the National Contaminant Occurrence Database (NCOD).

    I live in a community with elevated PFOS/PFOA levels. Who do I call to get more information about what my utility is doing to address the elevated levels?

    Contact your local water supplier to find out more about PFOA and PFOS in your drinking water. If you don't know who your local water supplier is, the information should be included in your latest water bill.

    I get my tap water from a private well. How can I find out if PFOA and PFOS are in my water?

    If you are concerned about the possibility of PFOA or PFOS in your drinking water and you are served by a private well, EPA recommends testing your drinking water. Laboratory analysis is necessary to determine if your water contains perfluorinated chemicals. Qualified testing labs can analyze a sample of your water to determine whether perfluorinated chemicals are present and at what concentrations. In some locations, regulators or manufacturers of PFOA or PFOS have set up programs to measure perfluorinated chemicals in groundwater. Your local water or health department or drinking water system should know if there is such a program in your area. In addition, EPA recommends that residents reach out to their local public health department or state who may be able to help provide support for testing or to seek such support from a responsible party. If no program has been established or support is not available in your area, you can pay to have independent testing done at a qualified testing lab (typical cost is several hundred dollars per sample). More information about private wells can be found here: epa.gov/privatewells.

    Are the health advisory levels appropriate for all children (regardless of age)?

    Yes, the 70 parts per trillion health advisory levels offer a margin of protection for children regardless of age. The health advisory levels are based on developmental effects to a fetus or breastfed infant resulting from exposures that occur during pregnancy and lactation (nursing) and are also protective, over a lifetime of exposure to drinking water at these levels, for all other health effects (non-cancer and cancer).

    My water has PFOA or PFOS in it at levels above the health advisory. Should I be concerned about my health?

    If you are concerned about potential health effects from exposure to PFOA and/or PFOS above the health advisory level, contact your doctor or health care professional.

    Can a person drink tap water containing PFOA or PFOS at or below the level of the health advisory every day of their life and not expect adverse health effects from these chemicals?

    This health advisory level offers a margin of protection for all Americans from adverse health effects for a lifetime of exposure to PFOA and PFOS in drinking water at this level.

    Can PFOA and/or PFOS be boiled out of my water?

    No; PFOA and PFOS cannot be removed by heating or boiling water. However, there are steps you and your drinking water system can take to limit your exposure.In some cases, drinking water systems may be able to reduce concentrations of perfluoroalkyl substances, including PFOA and PFOS, by closing contaminated wells or changing rates of blending of water sources. Alternatively, public water systems can treat source water with activated carbon or high pressure membrane systems (e.g., reverse osmosis) to remove PFOA and PFOS from drinking water. These treatment systems are used by some public water systems today, but should be carefully designed and maintained to ensure that they are effective for treating PFOA and PFOS. In some communities, entities have provided bottled water to consumers while steps to reduce or remove PFOS or PFOA from drinking water or to establish a new water supply are completed.

    Home drinking water treatment units are typically certified by independent third party organizations against ANSI (American National Standards Institute) standards to verify their contaminant removal claims. Some home filters remove impurities using activated carbon and reverse osmosis, which are the same technologies utilized by public water supply systems to remove PFOA and PFOS. However, there currently are no ANSI protocols for testing home treatment systems to verify that these devices effectively remove PFOA and PFOS or how frequently the filters should be changed in order to maintain removal efficiency. NSF International is currently developing such protocols.

    How does a utility reduce or remove PFOA or PFOS from water?

    A number of options are available to drinking water systems to lower concentrations of PFOA and PFOS in the drinking water supply. In some cases, drinking water systems may be able to reduce concentrations of perfluoroalkyl substances, including PFOA and PFOS, by closing contaminated wells or changing rates of blending of water sources. Alternatively, public water systems can treat source water with activated carbon or high pressure membrane systems (e.g., reverse osmosis) to remove PFOA and PFOS from drinking water. These treatment systems are used by some public water systems today, but should be carefully designed and maintained to ensure that they are effective for treating PFOA and PFOS. In some communities, entities have provided bottled water to consumers while steps to reduce or remove PFOA or PFOS from drinking water or to establish a new water supply are completed.

    Many home drinking water treatment units are certified by independent accredited third party organizations against American National Standards Institute (ANSI) standards to verify their contaminant removal claims. NSF International (NSF®) has developed a protocol for NSF/ANSI Standards 53 and 58 that establishes minimum requirements for materials, design and construction, and performance of point-of-use (POU) activated carbon drinking water treatment systems and reverse osmosis systems that are designed to reduce PFOA and PFOS in public water supplies. The protocol has been established to certify systems (e.g., home treatment systems) that meet the minimum requirements. The systems are evaluated for contaminant reduction by challenging them with an influent of 1.5±30% μg/L (total of both PFOA and PFOS) and must reduce this concentration by more than 95% to 0.07 μg/L or less (total of both PFOA and PFOS) throughout the manufacturer’s stated life of the treatment system. Product certification to this protocol for testing home treatment systems verifies that devices effectively reduces PFOA and PFOS to acceptable levels.

    Do systems with high levels of PFOA or PFOS have to take immediate action by treating the water or providing bottled water?

    EPA’s recommended actions for drinking water systems are as follows:

    Steps to Assess Contamination

    If water sampling results confirm that drinking water contains PFOA and PFOS at individual or combined concentrations greater than 70 parts per trillion, EPA recommends that water systems quickly undertake additional sampling to assess the level, scope and localized source of contamination to inform next steps

    Steps to Inform

    If water sampling results confirm that drinking water contains PFOA and PFOS at individual or combined concentrations greater than 70 parts per trillion, water systems should promptly notify their State drinking water safety agency (or with EPA in jurisdictions for which EPA is the primary drinking water safety agency) and consult with the relevant agency on the best approach to conduct additional sampling.

    Drinking water systems and public health officials should also promptly provide consumers with information about the levels of PFOA and PFOS in their drinking water. This notice should include specific information on the risks to fetuses during pregnancy and breastfed and formula-fed infants from exposure to drinking water with an individual or combined concentration of PFOA and PFOS above EPA’s health advisory level of 70 parts per trillion. In addition, it should identify options that consumers may consider to reduce risk such as seeking an alternative drinking water source, or in the case of parents of formula-fed infants, using formula that does not require adding water.

    Steps to Limit Exposure

    A number of options are available to drinking water systems to lower concentrations of PFOA and PFOS in the drinking water supply. In some cases, drinking water systems may be able to reduce concentrations of perfluoroalkyl substances, including PFOA and PFOS, by closing contaminated wells or changing rates of blending of water sources. Alternatively, public water systems can treat source water with activated carbon or high pressure membrane systems (e.g., reverse osmosis) to remove PFOA and PFOS from drinking water. These treatment systems are used by some public water systems today, but should be carefully designed and maintained to ensure that they are effective for treating PFOA and PFOS. In some communities, entities have provided bottled water to consumers while steps to reduce or remove PFOA or PFOS from drinking water or to establish a new water supply are completed.

    Many home drinking water treatment units are certified by independent accredited third party organizations against American National Standards Institute (ANSI) standards to verify their contaminant removal claims. NSF International (NSF®) has developed a protocol for NSF/ANSI Standards 53 and 58 that establishes minimum requirements for materials, design and construction, and performance of point-of-use (POU) activated carbon drinking water treatment systems and reverse osmosis systems that are designed to reduce PFOA and PFOS in public water supplies. The protocol has been established to certify systems (e.g., home treatment systems) that meet the minimum requirements. The systems are evaluated for contaminant reduction by challenging them with an influent of 1.5±30% μg/L (total of both PFOA and PFOS) and must reduce this concentration by more than 95% to 0.07 μg/L or less (total of both PFOA and PFOS) throughout the manufacturer’s stated life of the treatment system. Product certification to this protocol for testing home treatment systems verifies that devices effectively reduces PFOA and PFOS to acceptable levels.

    Besides drinking water, how else can people be exposed to PFOA and PFAS?

    The chemicals PFOA and PFOS were widely used to make carpets, clothing, fabrics for furniture, paper packaging for food and other materials that are resistant to water, grease or stains. They were also used for firefighting at airfields and in a number of industrial processes. Most people have been exposed to these chemicals through consumer products, but drinking water can be an additional source of exposure in communities where these chemicals have contaminated water supplies. Between 2000 and 2002, PFOS was voluntarily phased out of production in the U.S. by its primary manufacturer. In 2006, eight major companies voluntarily agreed to phase out their global production of PFOA and PFOA-related chemicals, although there are a limited number of ongoing uses. Scientists have found PFOA and PFOS in the blood of nearly all the people they tested, but these studies show that the levels of PFOA and PFOS in blood have been decreasing.

    Must EPA Method 537 be used to analyze drinking water samples, outside the scope of UCMR 3, for PFOA and PFOS?

    EPA’s Unregulated Contaminant Monitoring Rule (UCMR 3) required that Method 537 be used to analyze UCMR 3 samples for PFOA, PFOS, and four other PFASs. With the exception of a small number of public water systems (PWSs) that are carrying out repeat/delayed UCMR 3 sample collection in 2016, UCMR 3 monitoring is complete. Those who are now monitoring for PFOA/PFOS in drinking water are generally doing so outside the scope of UCMR 3. As such, EPA’s drinking water program does not have any particular requirements (including a method specification) for the “non-UCMR” monitoring.

    For the following reasons, EPA has a degree of familiarity with (and confidence in) Method 537: it was developed with particular attention to potential for interference; it has been through multi-lab validation; and it was used to support analysis of samples from approximately 5000 PWSs under UCMR 3. Other methods may be appropriate for the analysis of PFASs in drinking water but they have not been evaluated by EPA’s Office of Water. Those considering alternative methods should consider the degree to which method performance has been evaluated and documented, as well as the degree to which the method capabilities align with data quality objectives.

    Must approved/certified/accredited laboratories be used to analyze drinking water samples, outside the scope of UCMR 3, for PFOA and PFOS?

    Laboratories wishing to analyze UCMR 3 samples for PFOA, PFOS and the other PFASs were initially assessed by EPA and, where appropriate, approved to support UCMR 3 monitoring. EPA provided oversight of those labs during the core period of UCMR 3 monitoring. With the few exceptions noted above (involving delayed and/or repeat sampling in 2016), UCMR 3 monitoring is generally complete and the concept of “approved to support UCMR 3” is no longer applicable.

    PFOA and PFOS are not regulated contaminants. Unless/until PFASs become regulated in drinking water, EPA’s drinking water program does not have any particular requirements (including the use of particular laboratories) for the “non-UCMR” monitoring.

    States generally certify/accredit laboratories that support drinking water compliance monitoring (i.e., for regulated contaminants). EPA is aware that some states also offer (and others plan to offer) programs for laboratories that wish to be certified/accredited to analyze drinking water samples using Method 537. EPA is also aware that entities who carry out ISO 17025 accreditation (“ILAC signatories”) offer such service for laboratories conducting non-regulatory monitoring (such as PFAS monitoring outside the scope of UCMR 3). Lastly, EPA is aware that DOD plans to establish a PFAS laboratory accreditation program. EPA will continue its efforts to make the certification/accreditation community aware of the ongoing interest in PFAS analyses.

    Does EPA have advice for those who are finding it difficult to find a commercial laboratory that will perform PFAS analyses for drinking water samples?

    Laboratory capacity has historically grown to meet demand, though there may be temporary challenges with laboratory availability as that capacity develops. EPA encourages interested parties to look broadly for laboratories that measure PFASs in drinking water, considering, for example, the network of laboratories across the country that supported UCMR 3 monitoring (see https://www.epa.gov/sites/production/files/2015-10/documents/lablist.pdf for the list of those labs). Please recognize that some may no longer be performing Method 537 or may not currently be accepting PFAS samples. Likewise, be aware that laboratories beyond those approved to support UCMR 3 may now be performing commercial PFAS analyses. The American Council of Independent Laboratories has recently surveyed their membership about PFAS capability/capacity and has indicated that significant laboratory capacity is currently available. EPA will continue its efforts to make the laboratory community aware of the ongoing interest in PFAS analyses.

    When interpreting drinking water analytical data, what is EPA’s recommendation for handling “non-detect” values for PFOS and PFOA?

    Because PFOA and PFOS are not regulated contaminants, EPA looks to states and water systems to decide how to interpret drinking water monitoring data. As a point of comparison, we note that EPA took the following approach when assessing the UCMR 3 PFOA/PFOS results relative to the 2016 Health Advisories:

    • EPA treated results below the UCMR minimum reporting levels (MRLs) [20 ppt PFOA; 40 ppt PFOS] as “zero”
    • EPA used MRL (not detection limit) as our reference point because we have greater confidence in the analytical accuracy for values at/above the MRL
    • EPA calculated the sum of the PFOA and PFOS results and then rounded to the nearest 10 ppt (e.g., 70 ppt versus 74 ppt; 80 ppt versus 76 ppt).

    Does EPA recommend particular minimum reporting levels for PFOA and PFOS drinking water analyses?

    EPA uses UCMR 3 MRLs in assessing the results from that program. EPA set the MRLs for UCMR 3 after looking at the performance of multiple laboratories that conducted “lowest concentration” MRL (“LCMRL”) studies to determine how low they could reliably measure, and EPA vetted those MRLs through the notice-and-comment UCMR 3 rulemaking. EPA set the UCMR 3 MRLs such that we would have high confidence that a capable analyst/lab could meet those levels. EPA is aware that some laboratories are able to reliably measure PFAS in drinking water at lower levels. States or others who may be leading the collection of PFAS data may wish to establish lower MRLs if convinced that the labs supporting sample analyses can meet data quality objectives (in which case there should be a clear, documented rationale for the lower MRLs). Method 537 includes a process for a lab to confirm that it is capable of meeting the established MRL (see section 9.2.5 MINIMUM REPORTING LEVEL (MRL) CONFIRMATION).

    What is “Modified Method 537” and can it be used effectively for analysis of drinking water samples?

    EPA is aware of multiple laboratories that are offering analysis for PFOA, PFOS, and other PFASs by a technique described as “Modified Method 537,” particularly for other (non-drinking) media (e.g., soils, ambient water). Since there is no standardized description of this modified technique, EPA cannot address its performance in a general manner. One laboratory’s modified method may be quite different from another’s, and each laboratory’s technique may be quite different from Method 537, as validated and published by EPA. Those designating the use of particular methods should evaluate their appropriateness relative to their goals and data quality objectives.

Basic Information

Technical Information

Provisional Health Advisories and Draft Health Effects Documents

Technical documents

Peer Review