The government is proposing to halt the importation, manufacture and use of three groups of PFAS chemicals by July 2025.

And while the move has been welcomed, the wastewater and packaging industries fear that without a much more aggressive approach, manufacturers will simply switch to thousands of others that won't be banned.

There's no firm estimate of how many man-made PFAS chemicals actually exist. The Australian government says more than 4000, but the United States estimates almost 15,000.

Some have been in heavy use since the 1940s, valued for their heat, water and stain repelling properties, and they can be found in everything from carpets, clothes and furniture to food packaging, cookware, cosmetics and sunscreen.

They are extremely slow to break down, if they do at all, and science shows they can accumulate in plants and animals and are now detectable everywhere on earth, even the most remote locations.

They are in the air, in water and soil. They're in the food chain. And they are in human bodies, including the umbilical cords of unborn children.

Their human health effects are contested.

But a recent high-level report to the US government outlined evidence of an association between PFAS exposure and some types of cancers, liver problems, lower birth weights and thyroid disorders.

Few PFAS chemicals have been well studied but most are considered moderately to highly toxic, the European Union's environment agency says.

Australia's wastewater and packaging industries are pleased authorities are beginning to act, saying there's no doubt it will help reduce the nation's contamination burden.

But they also want far more than what's currently on the table.

Rob Tinholt is chair of the Australian and New Zealand Biosolids Partnership which supports the sustainable reuse of a wastewater treatment by-product.

Biosolids are essentially treated and dried sewage sludge - a mud-like residue that reflects everything Australian industries and households use and put down the drain or sewer.

Because PFAS chemicals are present in consumer products, and in use by industry, they are also present in biosolids which are spread on Australia's farmlands as fertiliser.

The partnership warns the presence of PFAS in biosolids is a major threat to the long-term viability of the waste solution.

"Biosolids is a significant resource for Australia, but could also become a significant waste burden as a result of PFAS contamination," it wrote in a recent submission to the government.

Australia produces almost 1.5 million wet tonnes of biosolids per year and the vast majority of that is reused in agriculture, landscaping, forestry or mine rehabilitation.

If biosolids can't satisfy safety thresholds for land application, that could result in "a significant diversion of biosolids into landfill facilities, which we estimate will not have the physical capacity to receive those biosolids," Mr Tinholt warns.

The recent report to the US government, written by the National Science and Technology Council, notes the transfer of PFAS from soils into crops and animal feed is a topic of ongoing investigation.

But available data indicates PFAS in agriculture primarily originates from the entry of contaminated soil, water or air to agricultural operations.

And it says the use of recycled materials contaminated with PFAS, including biosolids used for fertiliser, increases exposure in livestock and crops.

Mr Tinholt says the obvious solution is better source control, and the partnership wants the phase-out to be expanded to all PFAS chemicals.

If that doesn't occur, he fears product manufacturers will simply pivot to chemicals not covered by the proposed ban.

It's a concern shared by the Australian Packaging Covenant Organisation, which is working with industry on a voluntary phase-out of PFAS in fibre-based food packaging.

That's happening alongside federal packaging reforms that will deal with the use of harmful chemicals such as PFAS.

The organisation is particularly worried about what's actually present in food packaging.

In 2021, the organisation tested fibre-based packaging for 28 identifiable PFAS chemicals.

"While we found medium to high levels of total fluorine - indicative of PFAS - in 21 out of 74 samples, we did not find any of the 28 PFAS tested for," it said.

"This indicates that we do not have a high level of visibility over the exact PFAS used in packaging, meaning a broader approach should be taken to PFAS phase-outs."

The biosolids partnership also doesn't want to wait until 2025 for the bans to kick in, and says the government should start keeping a public register of products known to contain PFAS and require PFAS content to appear on all product labels so consumers can make informed decisions.

Geoff Latimer writes Hazardous Waste in Australia reports for the federal government and says there's no putting the PFAS genie back in the bottle.

"There is nothing we can do about legacy uses of PFAS products," he said.

"The bio-accumulative nature of PFAS means they are an intergenerational problem. Human history tells us that chemicals with chronic effects tend to keep their secret hidden until they've been in widespread use for perhaps decades, as is the case with PFAS."

While source control is an obvious part of limiting future PFAS harms, he notes the challenges when no one can definitively say how many there are.

The solutions are more tangible for contaminated waste and must be focused on effective containment given the ability of PFAS to further leach and spread through environments and animal and plant life.

"Wastewater treatment plants produce biosolids that act like sponges to adsorb PFAS, which can further exacerbate the problem through direct application to agricultural land," he said.

"Even thermal treatment methods like thermal desorption (or) offgas destruction might not be as destructive as we would hope."

The government proposes to classify PFOA, PFOS and PFHxS as schedule seven chemicals considered "likely to cause serious or irreversible harm to the environment with no essential uses".

Australia's advice is more cautious on human health risks than other jurisdictions including the European Union's environment agency, which warns PFAS can lead to health problems such as liver damage, thyroid disease, obesity, fertility issues and cancer.

The federal government's Expert Health Panel for PFAS notes scientific evidence is scarce but there are consistent reports of an association with "several health effects" considered to be within normal population ranges.

It says there is "limited to no evidence of human disease or other clinically significant harm resulting from PFAS exposure".

The Albanese government said it was focusing on the PFAS that are of greatest global concern when it comes to human and environmental health as a first step.

It said Australia's environment ministers had agreed to pursue new mandatory design standards to regulate harmful chemicals out of packaging.

Environment Minister Tanya Plibersek was contacted for comment.

Australian Associated Press