Questions and answers on review of PFAS in drinking water

About PFAS

What is a health-based guideline value for drinking water?

Health-based guideline values indicate the amount of a chemical in drinking water that a person can consume on a daily basis over a lifetime without any appreciable risk to health. The Australian Drinking Water Guidelines are protective of human health and take into account Australia's conditions and context. The health-based guideline values are very conservative, and include a range of uncertainty factors, which always err on the side of caution.

More information on how guideline values are calculated is provided in Chapter 6 of the Australian Drinking Water Guidelines.

What are PFAS?

Per- and poly-fluoroalkyl substances (PFAS) are a class of more than 4,000 manufactured chemicals that are not found naturally in the environment and have been widely used in industrial and consumer products.

There are many types of PFAS, with the best-known examples being perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS). Other examples of PFAS include perfluorobutane sulfonic acid (PFBS) and, more recently, hexafluoropropylene oxide dimer acid and its ammonium salt (GenX chemicals). These individual chemicals are collectively referred to as PFAS in the PFAS Fact Sheet.

The properties and fate of PFAS chemicals are related to their chain length (C_nF_2n+1). For example, PFOA and PFOS are considered to be ‘long chain’ PFAS (C7-C12) because they contain a long chain of carbon atoms that are fully saturated with fluorine. Examples that are considered ‘short chain’ PFAS (C4-C6) include PFBS and GenX chemicals.

Do PFAS contain fluoride?

No. PFAS chemicals share a similar molecular structure: a chain of linked carbon and fluorine (F) atoms. PFAS contain fluorine atoms but do not contain the fluoride ion (F^-), which is a different chemical species.

Do PFAS have anything to do with microplastics?

PFAS do not necessarily have anything to do with microplastics. While PFAS might be present as a residue or contaminant in microplastics, they are separate substances.

Where do PFAS come from and how much of it comes from drinking water?

Exposure to PFAS can occur through many different pathways, not just from drinking water out of the tap. For example, people can be exposed to PFAS through personal care products, food, food packaging, many consumer goods, clothing, air and dust.

There is limited information on how much PFAS we are exposed to through different sources in Australia. Previous estimates of the relative contribution from drinking water to daily intake of PFOS and PFOA range from 2-3% for a community not impacted by a direct pollution source, up to an estimated maximum of 22% and 24% respectively from contaminated water supplies (Thompson et al. 2011).

The Australian Drinking Water Guidelines assume a default value of 10% attributed to drinking water for chemicals that are used commercially or industrially unless indicated otherwise. This proportionality factor (0.1) has been used to calculate the PFAS guideline values in this update in the absence of high-quality evidence for source contribution from Australian drinking water supplies. It is important to note that higher estimates of drinking water exposure to PFAS (for example, 20% used by international agencies such as the US EPA) would result in higher guideline values than those published in the Guidelines. This means that 10% is a more conservative assumption than 20% and has resulted in lower guideline values as shown below:

For example, derivation of PFOA using default value of 10% (0.1) attributed to drinking water:

200 ng/L (equivalent to 0.2 μg/L)(rounded from 227 ng/L) = 1946 ng/kg bw/day x 70 kg x 0.1 over  

2 L/day x 30

For example, derivation of PFOA using default value of 20% (0.2) attributed to drinking water:

500 ng/L (equivalent to 0.5 μg/L)(rounded from 454 ng/L) = 1946 ng/kg bw/day x 70 kg x 0.2 over  

2 L/day x 30

NHMRC Review of PFAS in Drinking Water

What PFAS are included in the revised PFAS Fact Sheet?

The per- and polyfluoroalkyl substances (PFAS) included in the revised fact sheet include:

• perfluorooctanoic acid (PFOA)
• perfluorooctane sulfonic acid (PFOS)
• perfluorohexane sulfonic acid (PFHxS)
• perfluorobutane sulfonic acid (PFBS)
• hexafluoropropylene oxide dimer acid and its ammonium salt (GenX chemicals).

The term ‘GenX chemicals’ is used collectively for hexafluoropropylene oxide dimer acid and its ammonium salt, because they are the primary chemicals used in GenX processing aid technology. This technology was developed as a replacement for PFOA. The term ‘GenX chemicals’ reflects the next generation of fluoropolymer manufacturing processes that aim to be safer and more sustainable.

Why were the 5 PFAS chosen for NHMRC’s review and are they the most relevant for Australia?

NHMRC had a defined scope for the contracted review based on adopting/adapting existing guidance and guidelines. The most prevalent PFAS found in the Australian population to date have been PFOS, PFOA and PFHxS. NHMRC’s 2023-2025 PFAS review relates only to the specific chemical substances of PFOS, PFHxS, PFOA, PFBS and GenX chemicals. The selection of these 5 PFAS were based on the health advisories proposed by the US EPA at the time (June 2022), which prompted the initiation of the NHMRC review. Additional PFAS may be reviewed in future as part of the rolling revision of the Guidelines.

The evidence evaluation report, which underpins NHMRC’s review, notes that other PFAS such as PFBA and PFHxA are commonly detected in environmental media (for example, water, soil, etc.) in Australia. Further, it was noted that an approach to the assessment of these PFAS, as well as PFAS not routinely monitored for in Australia, would be of benefit.

NHMRC contracted an additional review which looked at the different approaches that international jurisdictions used to calculate a single total/sum guideline value for a PFAS mixture in drinking water. Based on the findings from the review (available in the Addendum Report), NHMRC and the Water Quality Advisory Committee had concerns about the feasibility of implementing a guideline value for a PFAS sum/mixture with the current options available, given the limited health evidence available for other PFAS. Therefore, no single total/sum guideline value for a PFAS mixture has been proposed at this time but it may be reconsidered should further evidence and methods become available.

How did NHMRC review the evidence to calculate the guideline values?

NHMRC has designed a streamlined methodological framework to guide the rolling revision of chemical fact sheets in the Australian Drinking Water Guidelines. The methodological framework ensures consistency and alignment with the 2016 NHMRC Standards for Guidelines and international best practice, whilst making efficient use of limited project resources and time.

The methodological framework outlines a staged approach involving a transparent adopt/adapt process for evaluating existing health advice (such as recent international health-based guideline values) in the first instance instead of undertaking a full review of primary studies. This is to reduce duplication of effort and the time needed to review the fact sheet, as many recent reviews undertaken by overseas agencies are available.

In 2023 NHMRC commissioned an independent review of existing guidance/guidelines for PFAS in drinking water from SLR Consulting Australia. The review showed that many overseas guidance/guidelines were suitable to consider for adoption/adaption in Australia as they were informed by recent, well-conducted reviews of the evidence base. The findings of these reviews conducted by other agencies, including the underpinning studies and resulting guidance values published in existing guidance/guidelines, were presented by the reviewer in an Evidence Evaluation Report and Technical Report.

In light of new evidence underpinning the April 2024 US EPA PFAS guidance for PFOA and PFOS, NHMRC commissioned an additional evidence evaluation to review the studies used to determine the PFOA and PFOS maximum contaminant levels in drinking water. The results of the additional review were presented in an Addendum Report.

The results of these reports were considered by NHMRC and the Committee and used, via an evidence-to-decision process, to inform the update of the PFAS Fact Sheet. The draft documents underwent public consultation and 2 rounds of targeted consultation and expert review prior to publication in the Australian Drinking Water Guidelines.

Further information on NHMRC’s review process is available in the Administrative Report.

How do the 2018 health-based guidelines compare to NHMRC’s updated guidance on PFAS in drinking water?

In August 2018, NHMRC published health-based guideline values for 3 PFAS (PFOS + PFHxS and PFOA) in the Australian Drinking Water Guidelines. These values have now been updated with the values published in the Australian Drinking Water Guidelines. NHMRC’s 2018 health-based guideline values for PFAS in drinking water were:

• Total sum of PFOS and PFHxS 70 ng/L
• PFOA 560 ng/L

NHMRC has considered the findings from a review of existing guidance and guidelines for PFAS and updated its PFAS guidance (including health-based guideline values) based on new information for health effects. The updated NHMRC guidance for PFAS in drinking water specifies 4 separate health-based guideline values as follows:

• PFOS: 8 ng/L
• PFHxS: 30 ng/L
• PFOA: 200 ng/L
• PFBS: 1000 ng/L
• GenX: no health-based guideline value is proposed at this time.

Why are there now separate guideline values for PFOS and PFHxS?

In August 2018, when NHMRC published PFAS guidance in the Australian Drinking Water Guidelines based on the tolerable daily intake developed by Food Standards Australia New Zealand (FSANZ), the health-based guideline value for PFOS was set at 70 ng/L. However, due to limited health evidence, a suitable health-based guideline value for PFHxS could not be calculated. As a result, a total sum guideline value for PFOS and PFHxS of 70 ng/L that was likely to be conservative and protective of human health was recommended as an interim measure. 

Since 2018, new health evidence on PFHxS has emerged, which was included in the current NHMRC review of PFAS in Australian drinking water. The evidence supports the establishment of a separate health-based guideline value for PFHxS of 30 ng/L and considered to be protective of human health.

Why were there so many different guideline options in the review reports and how were the final guideline values selected?

NHMRC has developed a streamlined approach for considering guideline values that have recently been reviewed by comparable overseas agencies. This methodological framework is intended to reduce duplication of effort, as many recent reviews undertaken by international agencies are available.

The guideline values found suitable to adopt/adapt based on their administrative and technical guideline development processes were collated by the reviewer and presented for consideration in the Australian context, along with a critical appraisal of the underlying studies. The Water Quality Advisory Committee considered the guideline options presented and made their decisions based on their analysis of the certainty in the underpinning studies, whether the chosen endpoints (the observed harmful health effects in animals) are clinically relevant to humans and which endpoints are considered the most critical and protective of health.

Further details on how the final guideline values were selected are available in the Administrative Report.

Why were the guideline values based on animal studies and not human studies?

The health-based guideline values are underpinned by high quality animal studies that have examined the effect of PFAS exposure in animals. The effects seen in animals have been used to calculate health-based guideline values for humans.

Unlike some other international agencies, NHMRC did not consider the available studies in humans to be sufficiently reliable or appropriate to calculate Australian health-based guideline values for drinking water. This is because these studies had limitations, such as a small sample size, limited information on how the size of the dose affects humans, and potential confounding by other chemicals (for instance, where exposure to other chemicals might have caused the observed effects).

Further information on the evidence review and how the guideline values were calculated is available in the PFAS Fact sheet and in the review reports.

Why was a benchmark dose (BMDL₁₀) used instead of a no observed adverse effect level (NOAEL) in calculating the PFOS guideline value?

As per Section 6.3.3 of the Australian Drinking Water Guidelines, when using doses from animal studies to try and calculate safe levels of chemicals for humans in drinking water, NHMRC often uses a ‘no observed adverse effect level’ (NOAEL). This is the highest amount of a chemical that causes no observable, harmful effects on the animal. If this is not available, a ‘lowest observed adverse effect level’ (LOAEL) may be used, which is the lowest amount of the chemical that causes observable, harmful effects in the animal. When available, a benchmark dose might be used, which uses mathematical modelling to estimate the level at which harmful effects may be observed.

As noted in US EPA guidance, the NOAEL is of little value in describing human dose-response relationships. This is because it doesn’t provide information on the level at which a human starts responding to a chemical. Additionally, a level of a chemical lower than the NOAEL may still not be safe (US EPA 2012). Limitations of the NOAEL/LOAEL approach are well known (see page 4 of the US EPA guidance).

NHMRC, on advice from its expert Water Quality Advisory Committee, agrees with the US EPA that using a benchmark dose (BMDL₁₀) is a better approach for calculating guideline values as it addresses some of the limitations of the NOAEL/LOAEL approach (US EPA 2012). Of the two approaches, using a more statistically robust benchmark dose (BMDL₁₀) led to the calculation of a lower guideline value for PFOS, which means we have adopted a more cautious approach.

More information on the BMDL₁₀, including particular advantages of the benchmark dose approach, is outlined in the enHealth Environmental Health Risk Assessment guidance.

Why did the health-based guideline value for PFOS in drinking water change from 4 ng/L (proposed at public consultation) to 8 ng/L?

During the consultation process, some stakeholders commented on the approach taken to calculate the draft PFOS health-based guideline value for public consultation. This included some stakeholders questioning the US EPA dose-response model used to establish a benchmark dose (BMDL₁₀). A dose-response model describes how much of a health effect (or ‘response’) is created based on an amount (or a ‘dose’) of a chemical. In response to this feedback and on advice from the Water Quality Advisory Committee Chemical Subgroup, NHMRC engaged SLR Consulting Australia (SLR) to undertake an additional PFOS assessment as an extension of SLR’s evidence review.

SLR’s assessment (detailed in Appendix G of the Administrative Report) examined the US EPA dose-response models used to establish the BMDL₁₀ for the PFOS guideline value. On reviewing SLR’s additional assessment, the Water Quality Advisory Committee recommended using the Gamma model that was prioritised in the SLR report, recognising that other potential options were duly considered.

The Gamma model produced a health-based guideline value of 8.49 ng/L, which is rounded to 8 ng/L as per the rounding conventions described in Chapter 6 of the Australian Drinking Water Guidelines.

What consultation did NHMRC undertake on the draft PFAS guidance?

NHMRC developed the PFAS guidance with advice from the Water Quality Advisory Committee. The draft guidance underwent targeted consultation with the enHealth Water Quality Expert Reference Panel (comprising of Australian and State and Territory Government experts on water quality management and public health), the then Department of Health and Aged Care and Food Standards Australia New Zealand. Expert review on the draft guidance was also sought prior to public consultation.

In accordance with Section 13 of the National Health and Medical Research Council Act 1992, the updated draft PFAS guidance was released for public consultation from 21 October to 22 November 2024. Public consultation ensures that NHMRC’s guidance and evidence review processes remain transparent and accountable. NHMRC also sought feedback from other government agencies during the public consultation period.

Following public consultation, all submissions received were considered by NHMRC with advice from the Water Quality Advisory Committee. Revisions were made to the draft PFAS guidance as required. The updated draft PFAS guidance underwent independent expert review and targeted consultation with jurisdictions before final publication in the Australian Drinking Water Guidelines.

Further details on this process, the feedback received and how it was addressed, is provided in the Administrative Report.

Are there conflicts of interest for members of the Committee overseeing the PFAS review? What processes do you have in place to identify potential conflicts of interests of Committee members?

On appointment, all Water Quality Advisory Committee members declared real and perceived interests in line with NHMRC’s Policy on the Disclosure of Interests Requirements for Prospective and Appointed NHMRC Committee Members. Interests declared by Committee members can be found in the Administrative Report and on the Committee webpage and may include commercial interests, financial interests or relationships. NHMRC Executive as well as the Committee as a whole, discussed and assessed whether these interests would affect a member’s ability to make an impartial decision or provide impartial advice.

Throughout the project and at every Committee/Subgroup meeting, members were required to inform NHMRC of any changes to their interests, and management strategies were put in place as needed.

Comparison with international PFAS advice

Should Australians be concerned that Australia’s guideline values for PFAS are higher than some overseas guideline values?

No, Australians should not be concerned about any differences in guideline levels between Australia and other countries.
NHMRC has noted there is community concern regarding the differences between Australian health-based guideline values and other international jurisdictions. However, Australians should not be concerned as it is not unusual for guideline values to vary from country to country. The Australian guideline values are very conservative, and include a range of uncertainty factors, which always err on the side of caution, and are based on comprehensive evaluations of the latest evidence.

Why are some of the Australian drinking water guideline values for PFAS higher than levels in other countries?

Some Australian drinking water guideline values for PFAS are higher than the values adopted by other countries. It is not unusual for guideline values to vary from country to country. NHMRC carefully considered international recommendations and the evidence base they relied on, including those from the United States Environmental Protection Agency (US EPA), when developing the Australian health-based guideline values.

The process NHMRC used to develop the guideline values for each PFAS is explained in detail in the Administrative Report that accompanies the PFAS Fact Sheet.

It should be noted that between jurisdictions there can be differences in the studies selected to underpin the guideline values, and the methods used to calculate guideline values. This can result in different countries and agencies establishing different guideline values.

For example, the US EPA uses a particular approach for setting limits for carcinogens. This led to the setting of non-mandatory goals of zero for PFOS and PFOA which underpinned the regulatory limits established for these two compounds. Other agencies such as the WHO and enHealth (Environmental Health Standing Committee) use a threshold approach for setting numerical (non-zero limits) for carcinogens. As described in the Australian Drinking Water Guidelines, NHMRC applies a similar approach to WHO. This means that NHMRC considers that any concerning health effects would not be expected to occur if the concentration of PFAS remains below the guideline value. Details on how NHMRC calculated the Australian guideline values for select PFAS chemicals can be found in the Fact Sheet and supporting information.

Importantly, Australian drinking water guidelines, including those for PFAS, are established using a conservative approach that always errs on the side of safety. This approach has been adopted for PFAS.

The health-based guideline values are protective of human health and take into account assumptions used for the Australian context in calculating drinking water guideline values.

How has international evidence from published studies/research/articles contributed to NHMRC’s review?

As Australia's leading expert body supporting health and medical research, NHMRC is responsible for providing the community with health advice based on the best available scientific evidence. In order to responsibly advise the community about any health effects of PFAS in drinking water, NHMRC used internationally recognised processes to assess the strength, quality and relevance of the evidence.

While NHMRC maintains a watching brief on new PFAS research, NHMRC does not re-evaluate its advice or issue warning statements in response to individual studies. NHMRC advice is based on a body of evidence and research outcomes (for instance, through evidence reviews) rather than individual studies and uses best practice evidence review methods.

If NHMRC was looking at guidelines to adopt/adapt, why didn’t we just automatically adopt the United States PFAS advice?

NHMRC does not automatically adopt drinking water guideline values from other jurisdictions. Australian guideline values are determined after carefully evaluating the scientific evidence. Where international advice has been updated, NHMRC and the Water Quality Advisory Committee consider the quality of the review used to inform the international advice, the underpinning scientific evidence and whether the advice is relevant to the Australian context.

This is important because other countries, such as the United States, issue public health advice within their own legislative frameworks that might not be relevant or appropriate for Australia. They can also use risk assessment approaches and policies that may differ from those used in Australia and can potentially result in an over- or underestimation of the risks. It is also not unusual for guideline values to vary from country to country due to different methodologies and the choice of endpoints used.

Australia develops its own national guidance and standards for chemicals in drinking water, including PFAS, taking into account Australian conditions and circumstances. As noted above, some other countries (including the US EPA) use a different approach to developing goals and standards to those applied by NHMRC, which applies the chemical risk assessment approach described by enHealth and the World Health Organization (WHO).

The NHMRC review has considered recent PFAS guidance and reviews from a number of international agencies, not just the US EPA (for example, Health Canada, WHO, European Food Safety Authority). In addition, it is international best practice in guideline development to consider any issues with study methods and how they affect the overall confidence in the results when evaluating the evidence. This includes an assessment of factors that affect study quality and reliability, such as sample size and uncertainties that might have affected the study authors’ interpretation of the results. Further, when developing advice, the Water Quality Advisory Committee also undertakes an evidence-to-decision process, which involves consideration of criteria such as benefits and harms, acceptability, feasibility, health equity and resource impacts, and is focused on the Australian context. NHMRC and the Committee consider potential impacts of different guideline values, but ultimately the decision about the health-based guideline recommendations is based on what is considered the best available health evidence. More information on the evidence-to-decision process can be found in the Administrative Report.

How does Australian advice differ to the United States for PFAS regarding carcinogenicity?

The approach used by NHMRC differs from that used by the US EPA for managing potential carcinogens. In the US, when chemicals are classified as potentially causing cancer without clear evidence of a threshold level below which there is no appreciable cancer risk, the default level of exposure is automatically set at zero as a non-enforceable goal. The US EPA determined this was the case for PFOS and PFOA. The US EPA then establishes enforceable standards that are as close as feasible to the non-enforceable goal taking costs into consideration. Feasibility includes considering levels achievable through available technologies and measurable by existing analytical techniques.

Notably the US has not found that PFAS actually causes any human cancer. However, even a potential to cause cancer triggers a default position of zero under US legislation, which can then be adjusted to a more practical level.

Implications of updated NHMRC PFAS advice in Drinking Water

Are NHMRC advice and guideline recommendations mandatory?

No, but the states and territories reference or adopt them, essentially making them mandatory depending on the local legislation. 

The role of NHMRC, as set out in Section 7 of the National Health and Medical Research Council Act 1992, is to inquire into, issue guidelines on, and advise and make recommendations to the Commonwealth as well as the states and territories on matters such as public health and matters relating to the improvement of health. This includes developing nationally consistent, evidence-based advice such as the Australian Drinking Water Guidelines that can be applied by jurisdictions throughout Australia in the context of their own administrative and legislative frameworks.

The Australian Drinking Water Guidelines provide an authoritative reference of what constitutes safe drinking water at the point of human consumption and are underpinned by a risk management framework that encourages site-specific planning for monitoring and treatment based on local conditions.

The Australian Drinking Water Guidelines are adopted or referenced by various levels of government to develop policy, and these government departments have the responsibility to implement and monitor these policies. Management of drinking water depends on the legislated arrangements for water supply within each jurisdiction; for example, in some states, water supply is managed by the one water corporation, whereas in other states it is managed locally by numerous water suppliers. The relevant state/territory health and/or drinking water regulator is responsible for regulating supply and establishing monitoring requirements.

How long do utilities have to comply with the new drinking water guidelines?

Water providers are not legally required to meet the new drinking water guidelines until the finalised guideline values are published in the Australian Drinking Water Guidelines and adopted by each state and territory.

It is expected that it will take time and resources to implement the new PFAS guideline values in Australia, particularly for small water suppliers in areas adjacent to contaminated sites. The US EPA has also acknowledged these challenges. In consultation with state and territory drinking water regulators, water utilities apply a preventative risk-based approach to the management of drinking water quality. If testing of a drinking water supply has identified PFAS concentrations above the drinking water health-based guideline values published in the Australian Drinking Water Guidelines, the water supply will be managed by the local water provider in consultation with the drinking water regulator. Some water supplies may require additional treatment which will take time to plan and construct or to take other actions to comply with the Guidelines.

Does NHMRC need to do a regulatory impact statement for its advice in the Australian Drinking Water Guidelines?

No, NHMRC does not need to provide a regulatory impact statement (RIS), including any cost-benefit evaluation of regulatory alternatives, when reviewing the Australian Drinking Water Guidelines. The Productivity Commission has determined that NHMRC is not required to undertake an RIS as the guidelines do not have a regulatory status.¹ Implementation of the guidelines by the states and territories is at the discretion of each state and territory health authority and/or drinking water regulator, usually in consultation with water suppliers. Each state and territory should consider the need for an appropriate economic analysis such as a cost-benefit evaluation of alternatives, prior to implementation.

¹ Productivity Commission (2000) Arrangements for Setting Drinking Water Standards: International Benchmarking. Commonwealth of Australia, Canberra.

What do changes to the PFAS health-based guideline values mean for other Australian PFAS advice, such as guidance values for food or soil?

The scope of the PFAS Fact Sheet review was to determine whether changes in NHMRC advice in the Australian Drinking Water Guidelines are warranted based on recent changes in international advice.

Further review of guidance values other than drinking water is outside the scope of this review; however, it is noted that there can potentially be impacts on other PFAS guidance values (for example, for food, soil, recreational water quality) if any proposed changes to NHMRC advice are considered, accepted and adapted by other Australian guidelines or agencies.

Will there be a review of the NHMRC advice for PFAS in recreational water?

Yes. NHMRC is currently reviewing the Guidelines for Managing Risks in Recreational Water (2008), which include the current health-based guideline values for PFAS in recreational water.

The scope of the current PFAS review focuses only on the PFAS advice published in the Australian Drinking Water Guidelines. NHMRC will consider the published drinking water guideline values with the Recreational Water Quality Advisory Committee to determine if a change is warranted to existing advice for PFAS in recreational water. Public consultation on the updated Recreational Water Quality Guidelines is anticipated for late 2025.

Why do Australian guideline values differ for different water bodies and water uses (for example, why do the guideline values for drinking water differ from those for ecosystems and recreational waters)?

The purpose of a guideline value is to identify the level of a contaminant that will minimise human health and ecological risks, based on the best available scientific evidence. Guideline values are developed using methods designed to address the specific context of the guideline and the sensitivities of the organisms exposed to the contaminant. For example, aquatic wildlife may experience continuous PFAS exposure from the water they live in, whereas for humans the main sources of PFAS are usually food, consumer products and drinking water. In some cases, ecosystem guidance can be more stringent than human health guidance. This can arise due to some organisms being more sensitive to a contaminant than humans, and the different mechanisms by which PFAS accumulate (such as accumulation from water, sediment, food sources and trophic structures) (NEMP 3.0).

The PFAS National Environmental Management Plan (NEMP) 3.0 sets guideline values to inform site investigations and consideration of environmental management. Ecological guideline values are used to assess and investigate potential risks to aquatic and terrestrial ecosystems.

NHMRC has developed health-based guideline values for PFAS in Australian drinking water (originally published 24 August 2018, updated in June 2025) and recreational water (published 12 August 2019). Health-based guideline values set by NHMRC for recreational water are different to drinking water. This is because people typically swallow less recreational water than they consume drinking water, both in terms of volume and frequency. As this results in a greater amount of drinking water consumed over time, this means that there needs to be a lower level (or health-based guideline value) of PFAS set for drinking water to be safe for daily consumption.

Both drinking water and recreational water guideline values are precautionary and protective of human health. The guideline values include a wide safety margin and are expected to be well below the level at which any negative effects could occur.
Given that PFAS can persist in humans and the environment for long periods and can therefore accumulate in the body over time if exposure at higher levels continues to occur, the Australian Government takes a precautionary approach and recommends PFAS exposure is minimised where possible.

Water quality and PFAS contamination

Is my water safe to drink?

Your water is safe to drink if it meets the Australian Drinking Water Guidelines.

Drinking water supplies that comply with the Australian Drinking Water Guidelines are safe to drink. The Guidelines provide a risk management framework to assure the consistent supply of safe quality drinking water to protect public health and include health-based guideline values for PFAS and other chemicals considering regular consumption over a lifetime.

PFAS levels measured in Australia by water utilities have been generally below (or well below) the current Australian Drinking Water Guidelines. Where elevated PFAS have been found, it has generally been restricted to locations near contaminated sites, such as air defence bases, airports or firefighting training facilities. Concentrations of PFAS, particularly in bores surrounding contaminated sites, can be much higher compared to that of distributed drinking water supplies.

If testing of a drinking water supply has identified PFAS concentrations above the drinking water health-based guideline values published in the Australian Drinking Water Guidelines, the water supply will be managed by the local water provider in consultation with the relevant health authority and/or drinking water regulator. Drinking water safety is the responsibility of the various water supply utilities in the States and Territories. State and Territory Governments regulate drinking water safety through their relevant health authorities and/or drinking water regulators. Monitoring requirements are set by states and territories and PFAS is monitored based on a risk assessment (for instance, monitoring may occur at different intervals in different areas depending on proximity to a contaminated site).

If your water comes from a private bore, well, tank, or other unregulated source and you have concerns that your water supply might not be safe, it is a good idea to talk with your environment protection agency, local health authority or drinking water regulator. You can also visit the Australian Government PFAS Advice page to find who to contact about the most current advice in your location.

Is bathing/showering in tap water safe?

Exposure to PFOS and PFOA during showering and bathing is considered negligible.

How do I know if PFAS is in my drinking water? Is it tested? Who is responsible for testing it and ensuring levels are safe?

Drinking water can be tested to determine if it contains PFAS and to check if it is below the guideline values.

The responsibility for testing drinking water in Australia depends on whether the water comes from a regulated public (or 'town') water supply versus a private supply such as a rainwater tank or private bore.

For regulated supplies, drinking water providers are responsible for testing public drinking water in Australia. In consultation with state and territory drinking water regulators, water utilities apply a preventative risk-based approach to the management of drinking water quality. Water utilities routinely conduct a range of tests to ensure drinking water quality complies with the Australian Drinking Water Guidelines. State and Territory Governments regulate drinking water safety through their relevant health authorities and/or drinking water regulators.

As with other potential threats to water safety, based on the different risks of PFAS in different areas, PFAS testing will vary across water utilities and locations. For more information on PFAS testing of drinking water, contact your drinking water provider.

The responsibility for testing private drinking water supplies, such as rainwater tanks or private bores, lies with the owner of the property and it is up to them to test and ensure the safety of their own water supply.

Where can I find out the levels of PFAS in my drinking water?

There are PFAS monitoring activities occurring across the country. Recent monitoring has shown that most Australian drinking water contains low or negligible concentrations of PFAS, but the existence of water supplies with higher PFAS levels cannot yet be ruled out. Information on the levels detected in Australian drinking water is available on the websites of many Australian water utilities that publish water monitoring data results (for example, Sydney Water, TasWater)

What should be done if PFAS levels are detected higher than the values stated in the Australian Drinking Water Guidelines?

If water testing has identified PFAS concentrations above the drinking water health-based guideline values published in the Australian Drinking Water Guidelines, the water supply will be managed by the local water provider in consultation with the relevant health authority and/or drinking water regulator. 

As for all chemical guideline values, any detections of PFAS above the recommended level should not be viewed as a pass/fail measure but should trigger an investigation of potential sources of contamination so that these can be managed to bring the water supply back under guideline values.

Given the very conservative nature of the health-based guideline values, deviations over a short period do not necessarily mean that the water is unsuitable for consumption. As the guideline values are intended to minimise risk over a lifetime, any short-term exposure to PFAS concentrations above the guideline values are unlikely to change this risk.

What should be done if PFAS levels are detected lower than the levels stated in the Australian Drinking Water Guidelines?

If testing has identified PFAS in the water, but at concentrations below the drinking water health-based guideline values, this water is considered safe to drink from a PFAS perspective.

What monitoring requirements does NHMRC recommend for PFAS?

Monitoring requirements are set by states and territories as the relevant state/territory health and/or drinking water regulator is responsible for regulating supply and establishing monitoring requirements.

NHMRC recommends a site-specific, risk-based approach to monitoring chemicals of concern such as PFAS in drinking water supplies, as outlined in the Australian Drinking Water Guidelines risk management framework. The underpinning principle of this risk-based approach is to know your catchment. This includes assessing the potential pollution sources in the catchment and undertaking monitoring of source waters (for instance, raw waters, pre-treatment), not just post-treatment, in order to determine:

• whether catchment management measures are working
• if new pollution sources have appeared
• if system improvements are needed.

The ability of PFAS to move easily through ground and surface waters, the historical (often undocumented) use of PFAS in the environment for fire-fighting purposes and the potential for ongoing/unexpected contamination from landfill and biosolid applications means that unexpected PFAS detections may sometimes occur.²

A robust set of background monitoring data and regular catchment/land use risk assessments can provide information about the appropriate frequency of monitoring requirements for a particular water supply. This should be in discussion with state/territory health and/or drinking water regulators, who are responsible for establishing monitoring requirements.

Longer term drinking water quality management should focus on selecting the best quality source water (noting the relative risks that may be present from other chemicals), taking into account all constituents, catchment protection, multiple barriers and management of critical control points as outlined in the Framework for Managing Drinking Water Quality (Chapter 3 of the Australian Drinking Water Guidelines).

Given the public interest in PFAS and the need for broader understanding of the risks from PFAS in drinking water, NHMRC suggests that water providers regularly share information with the community on the current risks in their catchment and the findings from background testing. This transparency will assist in providing consumers with reassurance about the water coming out of their taps.

Further information on the monitoring of drinking water supplies is available at Australian Drinking Water Guidelines.

² Solids recovered from wastewater treatment processes and used as fertilizer in agriculture.

What is the health risk if I have consumed drinking water with PFAS above the recommended level?

Given the very conservative nature of the health-based guideline values in the Australian Drinking Water Guidelines, deviations from the guideline values over a short period do not necessarily mean that the water is unsuitable for consumption. The amount by, and the period for, which a guideline value could be exceeded without causing concern will depend on many factors, including the specific PFAS in question.

Importantly, the ANU PFAS study confirmed the findings of the Australian Government Expert Health Panel which determined that a range of public health impacts had been identified in international studies, but the impacts were generally small. The ANU PFAS study examined exposure to, and the potential health effects of, PFAS in three Australian communities impacted by environmental contamination (Katherine (NT), Oakey (QLD) and Williamtown (NSW)). The study found that there were higher levels of psychological distress among people in exposed communities and an association between higher PFAS blood levels and higher cholesterol. However, the evidence for other adverse effects were not consistently observed across the three exposed communities. PFAS exposure in humans has also been associated with effects on kidney function and levels of some hormones. However, these effects are small and largely within ranges seen in the general population.

The NHMRC guideline values include a wide safety margin and are expected to be well below the level at which any negative effects could occur. NHMRC considers that concentrations of PFAS below the guideline value would not result in harm over a lifetime of consumption. As the guideline values are intended to minimise risk over a lifetime, any short-term exposure to PFAS concentrations above the guideline values are unlikely to change this risk.

How can PFAS get into my drinking water?

PFAS are very persistent and mobile in the environment, meaning that they do not break down easily and can travel long distances in water. Therefore, PFAS can remain in water sources for a long time and potentially affect drinking water quality and safety. PFAS can contaminate drinking water sources when they are released from sites where they were used, stored, or disposed of, such as military bases, airports, industrial facilities, landfills, and wastewater treatment plants. PFAS can end up in drinking water directly from contaminated runoff and groundwater infiltration. PFAS contamination of drinking water is typically unrelated to the activity of the water supplier and is usually due to polluting activities in the catchment by other parties. The main factor to consider for contamination of PFAS in drinking water sources is whether drinking water sources are located in the vicinity of potentially contaminating activities.

Do I need to test my drinking water? How would I do this?

You do not need to test your water if it is provided via a water supplier.

It is important to note that households with a reticulated drinking water supply (for instance, supplied through a piped water network) with PFAS levels below the health-based guideline values, do not need to test tap/drinking water at home. It is the responsibility of the drinking water supplier to ensure that drinking water meets the required standards.

For private supplies, it is up to the owner of the property to test and to ensure the safety of their own water supply.

If there are still concerns about water quality and you want to test your water, it should be done by a professional. There is a high risk of contamination of PFAS during sample collection and analysis, including from PFAS residues on sample vials, disposable gloves and other laboratory equipment. This can make the readings inaccurate and potentially overestimate the concentrations in your water sample. Appropriate sampling, storage and transportation are also critical for analysis. PFAS can adsorb to materials used for sampling and analysis, so appropriate materials should be used. PFAS sample collection and analysis should be carried out by trained personnel in line with accepted guidance, using National Association of Testing Authorities (NATA) accredited laboratories and with appropriate quality control samples.

What filter can be used to reduce/remove PFAS in drinking water?

Australian drinking water providers are committed to ensuring that the water they deliver is safe to drink. This includes responding to emerging threats such as PFAS. It is important to note that households with a reticulated drinking water supply with PFAS levels below the health-based guideline values do not need additional home water treatment.

If your private drinking water supply has PFAS above the drinking water guideline value, an alternate source of drinking water should be found while investigations followed by remediation (for instance, the process of restoring contaminated land for safe use) have been completed.

Researchers are still investigating the most effective and efficient approaches to treating PFAS in drinking water. There are many water filters on the market, but not all filters address PFAS, or are effective at removing all PFAS. If you choose to use a filter, care should be taken to ensure that the device has been proven to remove PFAS by independent testing. The following types of filters/techniques are commonly used to remove PFAS in drinking water:

• Granular activated carbon – these filters use carbon to trap chemicals as water passes through them.
• Ion exchange – use resins, tiny beads that act like powerful magnets that attract and hold the contaminated materials from passing through the system.
• Reverse osmosis/high-pressure membrane systems – a process that forces water through an extremely thin barrier that separates chemicals from the water.

These filters/treatment options display varying levels of effectiveness at reducing PFAS. They also need to be properly maintained and replaced. The US EPA has developed a fact sheet about reducing PFAS in your drinking water with a home filter. Advice from a water treatment expert, relevant health authority and/or drinking water regulator should be sought to determine if water treatment units are appropriate for the given context, including whether they are necessary in the first place. In addition, it should be noted that the use of home water filters can potentially reduce the concentrations of beneficial chemicals that are present in drinking water to protect public health (for example, chlorine residuals to prevent bacterial contamination, fluoride to protect oral health).

PFAS are not removed or destroyed by boiling the water.

Do the Australian Drinking Water Guidelines apply to bottled/ packaged water products?

No, the Australian Drinking Water Guidelines do not apply to bottled or packaged water, which are instead subject to the Food Standards Code. Bottled water is subject to different water quality requirements, so water delivered in bottles is not necessarily subject to the same treatment, storage and delivery requirements as drinking water out of the tap. A 2011 study (Thompson et al. 2011) reported PFOS and PFOA concentrations in bottled mineral water to be comparable to many of the other sampled locations across Australia.

What is Australia doing to manage PFAS contamination/ sites?

Unlike in other countries such as the United States, there is no manufacturing of PFAS compounds such as PFOA, PFOS and PFHxS in Australia. In addition, action has been taken to restrict or replace the use of firefighting foams containing PFAS in Australia. In some jurisdictions the use of these foams has been banned. The Australian Government takes a precautionary approach to managing existing PFAS contamination and works to prevent or reduce environmental and human PFAS exposure wherever possible. A large body of work is underway across Australia to manage contamination and prevent further contamination from PFAS and other industrial chemicals of concern.

The Australian Government has developed the draft PFAS National Environmental Management Plan (v3.0) (NEMP), which provides nationally agreed guidance and standards on the investigation, assessment and management of PFAS wastes and contamination in the environment, including preventing of the spread of contamination.

Information on the NEMP can be found on the Department of Climate Change, Energy, the Environment and Water website. Information on the PFAS Taskforce, responsible for whole-of-government coordination and oversight of Australian Government responses to PFAS contamination, is available at Australian Government PFAS Taskforce.

Human Health Effects of PFAS

What are the health effects of PFAS in humans? 

To date the evidence on health effects of PFAS has been uncertain, draws on a mix of animal and human studies, and can be interpreted in different ways depending on the choice of health outcome (endpoints) used, methodologies, assumptions and other factors.

PFAS exposure in humans has been associated with mildly elevated levels of cholesterol (confirmed by the 2021 Australian National University (ANU) PFAS Study), effects on kidney function and on the levels of some hormones. However, these effects are small and largely within ranges seen in the general population. The ANU PFAS study confirmed the findings of the Australian Government Expert Health Panel which determined that a range of public health impacts had been identified in international studies, but the impacts were generally small.

Some human research studies have found associations between people exposed to PFAS and effects on the immune system (for example, decreased antibody formation following administration of certain vaccines). However, these studies have limitations that affect the certainty in the findings and their reliability for use in calculating guideline values (see the PFAS Fact Sheet for more details on these studies).

NHMRC’s PFAS review concluded that the most critical health effects (endpoints) include potential carcinogenicity (for instance, ability to cause cancer) for PFOA, potential bone marrow effects for PFOS and potential thyroid effects for PFHxS and PFBS based on animal studies. These endpoints have been used to calculate health-based guideline values. For more information see the PFAS Fact Sheet published in the Australian Drinking Water Guidelines.

As PFAS persist in humans and the environment, it is recommended that human exposure is minimised as a precaution. NHMRC continues to monitor international activities and emerging evidence on the health effects of PFAS.

For more information on potential health effects of PFAS, refer to the PFAS Taskforce FAQs, the enHealth PFAS guidance statement and their PFAS Fact Sheet.

Do PFAS cause cancer?

Potential associations between PFAS exposure and increased risk of two uncommon cancers, namely testicular and kidney cancer, have been reported in humans. As noted by enHealth (Environmental Health Standing Committee), much of this evidence relates specifically to PFOA, and not PFOS or PFHxS which are more common in Australia. However, studies on these cancers remain conflicting and associations have only been observed in high exposure groups such as workers in international factories where PFOA is produced.

The International Agency for Research on Cancer (IARC) evaluated the carcinogenicity (for instance, ability to cause cancer) of PFOA and PFOS. After reviewing the extensive published literature, the IARC Working Group classified:

• PFOA as carcinogenic to humans (Group 1) based on animal and mechanistic data (how the toxin might cause illness)
• PFOS as possibly carcinogenic to humans (Group 2B), based on mechanistic data.

The IARC evaluation found that for PFOA there was limited evidence for cancer in humans (renal cell carcinoma and testicular cancer) and strong mechanistic evidence in exposed humans and experimental systems. For PFOS, the IARC evaluation found that there was also limited evidence for cancer in experimental animals and inadequate evidence regarding cancer in humans.

The outcome of the IARC evaluation was published in a summary article in The Lancet Oncology (30 November 2023). Full details of the IARC evaluation is available in Volume 135 of the IARC Monographs on the Identification of Carcinogenic Hazards to Humans, available at: IARC Publications Website - Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS). NHMRC’s 2023–2025 review found there was evidence from animal studies (but not human studies) that PFOA may cause cancer. It did not identify evidence that PFOS, PFHxS, PFBS or GenX chemicals cause cancer. However, NHMRC did not find any evidence of genotoxicity or mutagenicity (for instance, causing damage or permanent changes to genetic material) for PFOA, hence the guideline value for PFOA was calculated using a threshold approach. This means that NHMRC considers that any concerning health effects would not be expected to occur if the concentration of PFAS remains below the guideline value. Short-term exposures to higher levels of PFOA are unlikely to change this risk. This threshold approach is consistent with chemical risk assessment approaches used by enHealth and WHO. Further details on how the guideline value for PFOA was calculated are available in the PFAS Fact Sheet.

How can I test whether I’ve been exposed to PFAS?

Humans can be exposed to PFAS present in lots of things such as food, consumer products (for example, solution-treated carpeting, apparel), dust and drinking water.

A blood test can measure the level of PFAS in a person’s blood. If PFAS are detected, this indicates that a person has been exposed to PFAS. However, there is at present insufficient scientific evidence for a medical practitioner to be able to tell a person whether their blood level will make them sick, or if any current health problems are related to the PFAS levels found in their blood. As such, blood tests have no diagnostic or prognostic value.

At a population level, blood tests can inform a community that they have been exposed to PFAS at a level above that of the general population. Monitoring pooled community blood samples over time may help determine the success of exposure reduction measures in reducing blood levels of PFAS.

How can I reduce my exposure to PFAS?

Humans can be exposed to PFAS present in food, consumer products (for example, make up and personal care products, furniture, solution-treated carpeting, apparel, packaged food and drink containers), dust and drinking water. Results of the National Health Measures Survey, conducted by the Australian Bureau of Statistics (ABS) from January 2022 to April 2024, indicate a baseline level of key PFAS (for example, PFOA and PFOS) in the blood of most Australians, arising primarily from the historical use of these chemicals.

Steps that can be taken to reduce exposure are site-specific. For more information on reducing your exposure see the enHealth guidance statement – Per- and polyfluoroalkyl Substances (PFAS).

Your local state or territory health authority is the authoritative source for precautionary health advice on PFAS, including advice on reducing exposure to PFAS. You can find your local health authority from the PFAS Advice page. Your local health authority and/or drinking water regulator will be able to provide general advice on exposure and health effects, as well as information specific to local water supplies.

The Department of Health, Disability and Ageing can also provide general advice about PFAS exposure and potential health effects.

What is the government doing to manage PFAS?

The Australian Government takes a precautionary approach to managing existing PFAS contamination.  We work to prevent or reduce environmental and human PFAS exposure wherever possible.

We consider new evidence to make sure policy and guidance supports positive health outcomes. This work includes:

• Health-based guidance values
• Australian drinking water guidelines
• ANU PFAS health study
• Research through the NHMRC Targeted Call for Research Scheme
• PFAS biomarker testing
• PFAS Guidance statement.

PFAS research

Is NHMRC funding research into PFAS? Has this research contribute to the current NHMRC review?

NHMRC has funded a number of research projects investigating the health effects of PFAS through a Targeted Call for Research (TCR). In 2019, NHMRC funded 9 research applications through the PFAS TCR totalling over $10.8 million. The funding for this research was provided by the Department of Defence and administered by NHMRC.

The aim of the call for research was to encourage research that increased understanding of the acute and long-term potential human health effects from exposure to PFAS and to inform appropriate responses to managing or reducing human exposure to PFAS. The timeframe for completion of these projects ranges from June to December 2025, with progress updated annually.

As the results of these studies were not published within the review period, they have not contributed to NHMRC’s review which considered existing guidance and reviews from overseas jurisdictions. Findings from the TCR studies would need to be peer reviewed, published and considered as a body of evidence rather than as individual studies. More information about NHMRC’s PFAS TCR, including annual progress reports, is available on the TCR into Per- and Poly- Fluoroalkylated Substances webpage.

What other water research is happening on PFAS in Australia?

Australian researchers have been investigating PFAS and water contamination for some time and continue to contribute to the existing body of knowledge on how to manage PFAS contamination.

For example, Water Research Australia (WaterRA) has conducted a series of projects aimed at understanding and mitigating the environmental impacts of PFAS and related contaminants. Among the completed projects, one focused on the fate, behaviour, and ecological implications of fluorinated surfactants (for example, detergents) from wastewater treatment plants. Another involved modelling PFAS exposure and identifying critical trigger points for further investigation in recycled water irrigation applications. Additionally, researchers examined how soil contaminated with PFAS affects the growth responses of Spinacia oleracea (spinach) seedlings, providing valuable insights into the potential effects of these contaminants on food crops. The transformation of biosolids (for instance, solids recovered from wastewater treatment processes and used as fertilizer in agriculture) into other useful end products was also successfully completed, highlighting innovative approaches to waste management and resource recovery.

Current projects are exploring various strategies for addressing PFAS contamination. Research on the fate of PFAS and short-chain PFAS in biosolids-amended soils is ongoing, as is an investigation into techniques for removing emerging contaminants from sewage. Researchers are assessing the effectiveness of different treatments for PFAS in compost materials and biosolids, which may offer solutions for managing these persistent pollutants in organic waste. Together, these projects aim to deepen our understanding of PFAS behaviour and develop effective remediation (for instance, process of restoring contaminated land for safe use) and management strategies. For further details on these projects, contact WaterRA at info@waterra.com.au. WaterRA members can get more details of these projects at Project list - WaterRA.

There is also ongoing work by Australian researchers to develop new treatment technologies that can be scaled up to help remove PFAS from water for communities (for example, Sun et al. 2024).