Residents in a small French town have been banned from drinking tap water due to contamination from so-called “forever chemicals”, but one expert says Australians are unlikely to face a similar scenario.

Tests of the water in Saint-Louis, near the Swiss border, showed it had more than four times the recommended limit of per- and poly-fluoroalkyl substances (PFAS), which has been linked to firefighting foam used at the local Basel Mulhouse Freiburg Airport.

That led authorities to order roughly 60,000 residents – infants, and pregnant, breastfeeding and immunocompromised people – to stop drinking the tap water.

PFAS are a group of more than 4000 manufactured and extremely long-lasting chemicals used in a wide range of industrial and consumer products, including firefighting foam, non-stick cookware, waterproof clothing and food packaging.

But they’ve also been linked to a range of health issues, from raised cholesterol levels to some forms of cancer.

France is far from the only nation to find itself battling PFAS levels.

But, according to RMIT chemistry professor Oliver Jones, Australia is unlikely to be hit by water contamination high enough to cause harm.

”The contamination of PFAS in drinking water in Saint-Louis, France is clearly concerning, especially for those directly affected,” he said.

“However, while headlines like ‘PFAS at four times the recommended limit’ sound alarming, the actual limit is incredibly low and in France, no harm has been demonstrated yet.

“A tap water ban or similar situation is unlikely to happen in Australia, except in the event of a serious industrial accident.

“Most potable water supplies in Australia either have no detectable PFAS or concentrations below even the recently introduced guidelines for Australian drinking water.”

Exactly what health issues the chemicals cause, and how serious they can be, is still unknown.

“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,” Australia’s National Health and Medical Research Council (NHMRC) says.

PFAS have been linked to some types of cancer, including kidney, testicular and prostate, but the NHMRC says studies in the area “remain conflicting and associations have only been observed in high exposure groups”.

“We often overlook the fact that the mere presence of something does not mean it will automatically cause harm,” Jones said.

“For example, we know we can get skin cancer from UV light, but that does not mean we will get cancer as soon as we go outside.

“Although there are places in Australia where extensive use of PFAS-containing fire-fighting foams has occurred, for example airports or firefighting training grounds, these areas are known and managed.”