Australia could soon tighten regulations on permitted levels of “permanent chemicals” in drinking water, with guidelines proposing significant reductions.

The National Health and Medical Research Council released draft guidelines Monday recommending much lower limits for four PFAS compounds, reflecting growing concerns about their potential health risks.

PFAS are a class of thousands of synthetic chemicals used in common products, from nonstick cookware to firefighting foams and stain-resistant fabrics.

They are notoriously persistent in the environment and can take decades or longer to break down, earning them the label “forever chemicals.”

PFAS can accumulate in human and animal tissues, leading to widespread exposure through contaminated water, food, and even air. Their presence in drinking water is of particular concern due to their potential long-term health effects.

Dr Ian Musgrave, a senior lecturer at the University of Adelaide, said PFAS are “highly fat-soluble compounds that are very slow to break down”.

“They persist in the environment and can accumulate in the human body. It can take five years for half an ingested dose of PFAS to be eliminated.

The draft guidelines propose stricter limits based on evidence linking PFAS exposure to various health problems. The limit for PFOA, used in the manufacture of products such as Teflon, would increase from 560 nanograms per liter (ngl) to 200 ngl.

This reduction is based on evidence of the carcinogenic properties of PFOA. In December 2023, the International Agency for Research on Cancer classified PFOA as a human carcinogen, placing it in the same category as other known carcinogens such as alcohol and air pollution.

Likewise, the limit for PFOS, once a main ingredient in Scotchgard fabric protectants, would be reduced from 70 ngl to just 4 ngl. This change stems from new research highlighting the potential effects of PFOS on bone marrow.

The guidelines also set new limits for the PFAS compounds PFHxS and PFBS based on their impact on thyroid function. The proposed limit for PFHxS is 30 ngL, while PFBS, which has been used as a replacement for PFOS at Scotchgard since 2023, would be capped at 1,000 ngl.

“The proposed guidelines are quite reasonable and within the ranges suggested by other regulatory agencies around the world, with the exception of the United States – whose guidelines for some compounds are lower but based more on politics and not scientific evidence of danger,” said Oliver Jones, professor of chemistry at RMIT University.

Although the proposed limits for PFOS are consistent with the United States’ draft guidelines, Australia’s limit for PFOA remains higher than that of the United States.

In the United States, regulators aim for zero concentrations of carcinogenic compounds, while Australia takes a “threshold model” approach, meaning regulators believe health risks are mitigated as long as concentrations chemicals remain below a threshold.

According to the board’s chief professor, Steve Wesselingh, the limits were determined using animal studies in the absence of high-quality human studies to guide the process.

“It is not unusual for guideline values ​​to vary from country to country,” said Professor Wesselingh, explaining that different countries use different methodologies and scientific criteria to set safety limits for substances such as PFAS.

The board chose to create individual limits for each PFAS compound rather than a combined limit, citing the large number of PFAS chemicals and the limited toxicology data available for most of them.

Water quality management in Australia is overseen by the federal and state governments.

According to Dr. David Cunliffe, senior water quality advisor, developing individual guideline values ​​for specific PFAS compounds ensures that drinking water safety measures are based on the best available science.

Despite the proposed stricter limits, experts say the public should not be overly concerned about PFAS in their drinking water.

Dr Daniel Deere, water and health consultant at Water Futures, said Australia has relatively little PFAS contamination in its public water supplies.

It said alternative water sources, such as bottled water, household filtration systems or rainwater tanks, are useless unless individuals are specifically informed by local authorities of the PFAS contamination in their area.

Professor Stuart Khan, Head of the School of Civil Engineering at the University of Sydney, said: “Australians can continue to be confident that Australia’s drinking water guidelines incorporate the latest and greatest scientific evidence. strong to support drinking water safety. »

The board’s review of limits for PFAS in drinking water has been ongoing since late 2022. The current guidelines, last updated in 2018, are being revised in response to growing evidence of risks to health related to PFAS.

The draft guidelines will remain open for public comment until November 22, 2024, allowing scientists, stakeholders and the public to provide feedback before final limits are established.