EXPERT REACTION: NHMRC releases updated guidelines for PFAS in drinking water

It is great to see the NHRMC release their highly anticipated PFAS update to Australia’s drinking water guidelines as part of their PFAS review. 

They now suggest the following limits for selected PFAS. 

• PFOA (perfluorooctanoic acid): 200 ng/L 
• PFOS (perfluorooctane sulfonic acid): 8 ng/L 
• PFHxS (perfluorohexane sulfonic acid): 30 ng/L 
• PFBS (perfluorobutane sulfonic acid): 1000 ng/L 
• GenX chemicals (hexafluoropropylene oxide dimer acid and its ammonium salt): no health-based guideline value can be derived at this time 

These aren't all possible PFAS we find in the environment but those the NHMRC believes we are reasonably confident may, possibly, have health effects at high enough concentrations.

While the final value for PFOS is not the previously suggested 4 ng/L limit, 8 ng/L still represents a nearly tenfold reduction from the current guideline. This is a significant shift.

The NHMRC no doubt feel the revised value has been carefully developed to protect human health. However, implementing it won’t come without challenges, particularly as drinking water guidelines are often used to inform other environmental standards. As such this update could have wide-reaching implications across compliance, environmental management, and risk assessment frameworks. 

Non-intended implications are something that needs to be considered for any PFAS regulation. This is because limits for something like drinking water, which we consume and interact with every day, tend to be quite strict, and generally, the lower the limit, the higher the cost to meet it. Limits for things like say soil outside an office block, that we do not interact with much, likely do not need to be as strict as those for water to protect health. 

There is also the question of who pays to treat water to this level. Water companies would have to pass the cost to consumers. This cost would be higher for remote communities with smaller treatment plants than for large cities already using advanced treatment at large scale. This is against the more standard method of recruiting costs from the initial polluter, but this is difficult in the case of PFAS as there are so many possible sources. 

Many people have heard of PFAS as ‘forever chemicals’ because they’re used in non-stick cookware and waterproof clothing. While some types are being phased out and regulated, PFAS are still used in industries and new technologies where their durability is valued, raising concerns about long-term health and environmental impacts.

PFAS don’t break down in the environment and can remain in the human body for decades - often over 35 years. Their persistence, combined with growing evidence linking PFAS exposure to a range of health risks, has raised serious concerns about their long-term impact on both health and ecosystems. Once released, PFAS can accumulate throughout the food chain, making prevention and regulation critical.

Traditional water treatment plants struggle to remove some of these smaller PFAS, such as the recently regulated PFBS, effectively. However, our research team at Monash University has developed a new type of membrane designed to specifically filter out these persistent environmental contaminants from drinking water.

The long-standing collaboration between Monash University, Clean TeQ Water and its graphene-focused subsidiary NematiQ has supported the development and commercialisation of innovative membrane technology.

We are currently working in collaboration with CleanTeQ to test these membranes in real water systems collected from reservoirs in Melbourne, Australia.

These new guidelines recognised that people are increasingly aware of the risks that the various PFAS variants pose to human health, and how long these chemicals persist in the natural environment.

So it is very encouraging to me to see Australia announce stricter PFAS concentration guidelines for drinking water.

That said, there is still much room for us to improve. The PFAS concentration guidelines in countries like the USA and Canada remain far stricter than these new levels released today in Australia.  

The global effort to phase out PFAS is also not helped by the fact each country has slightly different benchmarks for measuring and reporting PFAS variants and concentrations.

We need to be united in recognising the scope of the PFAS problem across the world if we are to be truly successful in removing these chemicals from the environment.

The only change to the PFAS health-based guideline values proposed at public consultation (October 2024) is a revision of the PFOS guideline value to from 4 ng/L to 8 ng/L.

The change is a result of comments from public consultation and an additional analysis of how the US EPA extrapolated animal data to humans, based on the effects of PFOS on bone marrow. The NHMRC has applied a more robust toxicological model as supported by their consultation with toxicology experts. 

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. Australians can continue to feel confidence that the Australian Drinking Water Guidelines incorporate the latest and most robust science to underpin drinking water safety. 

While drinking water safety always comes first, Australians will need to turn our minds to how we afford any necessary drinking water upgrades. In some cases, advanced water treatment processes may be needed and the cost of these advances will necessarily flow through to customer bills. Drinking water cost increases will hit smaller regional communities hardest. 

A great injustice is that this is the opposite of the ‘polluter pays’ principle, in which the clean-up cost would come from the companies and industries that caused the pollution. Passing remediation costs to drinking water suppliers, and therefore on to their customers, is an example of privatising the profits and socialising the costs.

PFAS constitute a class of over 14,000 chemicals that have been extensively used in industrial applications and consumer products around the world and are a serious health concern. For example, the World Health Organization lists perfluorooctanoic acid (PFOA) as a Group 1 carcinogen and perfluorooctane sulfonic acid (PFOS) as a Group 2B carcinogen.

Only four PFAS are considered in the new NHMRC advice. The Australian government needs to investigate the health impacts of a wider range of PFAS and consider inclusion in the drinking water guidelines, as is common in a number of other countries.

International organisations (eg the European Union and the US Centers for Disease Control) have serious health concerns about a much wider range of PFAS than those subject to Australian guidelines. 

Importantly Australians need more advice on how to lower PFAS in their day-to-day lives.

The recent Australian Bureau of Statistics report suggests that PFAS is in the blood of virtually all Australians, yet the vast majority of our drinking water is PFAS-free.  This begs the question: how are we exposed to PFAS, and how do we avoid it?

The government needs to provide funding for research to better understand the health and ecosystem risks posed by a wide range of PFAS; improve our understanding of the environmental fate of PFAS; and develop cost-effective PFAS drinking water technologies.

The National Health and Medical Research Council's (NHMRC) updated draft guidelines on per- and polyfluoroalkyl substances (PFAS) in drinking water mark a significant advancement in Australia's commitment to public health and environmental safety.

By proposing stricter health-based guideline values for key PFAS compounds, such as reducing the permissible level of perfluorooctanoic acid (PFOA) from 560 ng/L to 200 ng/L and perfluorooctane sulfonic acid (PFOS) from 70 ng/L to 4 ng/L, the NHMRC is aligning national standards with the latest scientific evidence on the potential health risks associated with long-term exposure to these persistent chemicals.

These revisions are not merely numerical adjustments; they reflect a proactive approach to mitigating risks linked to PFAS, which have been associated with various health concerns, including cancer and thyroid disorders.

The updated guidelines serve as a critical tool for water regulators and suppliers, ensuring that drinking water across Australia meets safety standards that protect communities now and into the future.

This initiative highlights the importance of continuous review and adaptation of public health policies in response to emerging scientific knowledge.

The newly released Australian Drinking Water Guidelines by the NHMRC represent a significant policy advancement. The current thresholds are lower than previous values, and the range of regulated PFAS substances has expanded. However, when viewed in a global context, it becomes clear that drinking water standards for PFAS vary across countries, with differences including both the specific types of PFAS regulated and the threshold levels set.

Behind each country’s differing working scope lies an unavoidable reality: PFAS is a large chemical group encompassing thousands of substances, which some scientists have referred to as the "PFAS universe." In attempting to grasp the scale of this vast "universe" and its ever-changing dynamics in the socio- and eco-system, we are in fact confronting a magnitude of uncertainty that defies precise measurement.

How we innovate our scientific and regulatory frameworks to adapt to this complexity — and how we engage in environmental learning under conditions of uncertainty — poses a critical challenge for scientists, regulators, industries, and citizens alike.

When PFAS chemicals get into the water, they can spread far and wide, contaminating many places, including South Australia and even Antarctica. This widespread issue calls for global action. Unfortunately, our current water treatment systems and home filters aren’t effective at removing PFAS because these chemicals are incredibly strong and dissolve easily in water (Bayat et al., 2022).  

You’ll find PFAS in many everyday items like sunscreen, make-up, stain-resistant couches, and food packaging such as pizza boxes. This makes monitoring and reporting essential to identify contamination. However, many water utilities don’t regularly test for PFAS, so we need more testing, including more regular water testing and potentially blood tests, to keep track of these chemicals.

Starting in July 2025, the Federal Government will ban the production and importation of certain PFAS substances, including some everyday products. The maximum allowable concentration of PFOS in drinking water is roughly set at eight drops per 20 Olympic-sized swimming pools (WSAA, 2025). Despite this, some guidelines for some PFAS chemicals are still much higher than international standards. For instance, the US has standards that are 50 times stricter than the new proposed standards in Australia (EPA, 2024).

To tackle these 'forever chemicals,' we need more advanced engineering solutions, as conventional treatment methods just aren’t cutting it.

PFAS are one of the most ubiquitous chemical threats, and are found virtually everywhere, from human blood to the Antarctic environment. PFAS stands for per- and polyfluoroalkyl substances, ubiquitously known as the “forever chemicals” due to their near-indestructible nature. And PFAS have been linked to many adverse health effects, including cancer.

The new NHMRC guideline values are important in keeping Australian communities safe and will inform professionals in the field on how and when to act in environmental remediation.

The National Health and Medical Research Council (NHMRC) have now finalised the changes to the drinking water guidelines for levels of the Per- and Polyfluoroalkyl Substances (PFASs). The National Health and Medical Research Council (NHMRC) periodically reviews the safety of chemicals that Australians are exposed to. PFASs have been of public concern as they are highly fat-soluble compounds that are very slow to break down and may have health impacts, although no clear human health impacts have been identified to date.

While PFAS was phased out after 2001 in Australia, and levels of PFAS in Australians are falling, there continues to be a broad effort to ensure exposure to PFAS is reduced. The NHMRC assumed that 10% of our exposure to PFAS comes from drinking water, and modelled their limits based on this exposure.

The new limits are in line with international limits, and although different jurisdictions place different weighting on animal and human evidence, generally the overall limits are similar.

[A table with current, new and international limits is available in images] 

The water levels are part of a larger regulatory approach looking at total PFAS exposure through diet and environment exposure. Australia does not have the same level of industrial exposure the US has, for example, so we do not need as stringent limits to keep our total exposure down. That said, the NHMRC have been very conservative in their approach to ensure high margins of safety.

The good news is that the vast majority of drinking water supplies are well below these levels, and some drinking water sources do not have detectable levels of PFOA, PFOS and PFHxS. Bore water near contaminated sites may have significant levels and will need remediation.