Australia to change rules around ‘forever chemicals’ in tap water

Professor Oliver Jones, Professor of Chemistry and Deputy Director of RMIT Water: Effective Technologies and Tools Research Centre

"The NHMRC has released proposed guidelines for four PFAS in drinking water for public consultation. A fifth compound was assessed but no guideline was proposed.

“There are no major changes to existing guidelines except that a value for one of the substances – PFBS – is proposed for the first time, and the limit for PFOS has been lowered from 70 ng/L to 4 ng/L, which I believe to be overcautious.

“The guidelines won’t be final until the public consultation is complete, and the guidelines are adopted by the states and territories.

“These guidelines are not based on new research but on analysis of the extensive existing data on the topic. This a trickier task than it sounds, as a lot of the data in the literature is not suitable on which to base judgements about human health.

“The proposed guidelines are pretty sensible and while they are lower than the previous guidelines, most drinking water in Australia is already below these limits – so you don’t have to worry about your tap water.

“So what are PFAS, and why do we worry about them?

“PFAS are a family of synthetic chemicals based on carbon-fluorine bonds that are used in a vast range of applications. They are often termed 'forever chemicals' because they are very resistant to degradation; the name is also a small chemistry joke, as the F in forever and C in chemicals can also stand for Fluorine and Carbon, respectively. Unfortunately, the term is misleading as it implies that PFAS never break down and that if they get in your body, they are there forever – neither of which are true.

“Much public concern about PFAS comes from emotive films like Dark Waters and documentaries like How to Poison a Planet. However, emotion is not science. Neither are clicks and likes or online influencers. Science is based on testable hypotheses, good data and evidence-based assessment. What the NHMRC have done here is a mostly good application of these principles.

“I am sure some will assume that since the guidelines are not at 0 ng/L – which is an impossible ask – they must have been influenced by ‘big chemical’. But remember that the people who set the guidelines also have to drink the water, as do their families. It’s not logical to assume they would set levels they thought were unsafe.

“We should also remember that the mere presence of something does not mean it will automatically cause harm under normal circumstances. The dose makes the poison; everything is toxic at the right amount, even water. For example, we know you can get skin cancer from too much sun, but that doesn’t mean you will get cancer as soon as you step outside.

“The limits proposed by the NHRMC are in the nanogram per litre range. One nanogram per litre is 1 part per trillion. This is equivalent to 1 second in 31.7 thousand years. So, this is an incredibly small amount, and the risk of PFAS exposure at this level is also incredibly small.

“While some PFAS have been linked to health effects, the concentrations needed to cause such effects are much, much higher than the levels typically found in Australian drinking waters.

“In addition to that, we aren’t sure if the major source of PFAS exposure to most people is water.  If this is the case, spending millions to go from an incredibly small amount to an even smaller amount would not be money well spent and would not improve health outcomes.

“I think the NHMRC have done a pretty good job here, but if people don’t agree, I’d encourage them to provide feedback and make their case to the NHMRC as part of the consultation.”

Oliver Jones is a Professor of Chemistry, Deputy Director of the RMIT Water: Effective Technologies and Tools (WETT) Research Centre and an internationally recognised expert in analytical and environmental chemistry. He is passionate about using science to keep our environment safe.

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