Scientists are disturbed by the rise of what is now the most rampant “forever chemical” on the planet, with air-conditioning and refrigeration believed to be propelling its rapid accumulation in human blood, drinking water, household dust, plant-based food, rain and the oceans.
Experts are calling for urgent research into trifluoroacetic acid (TFA), which has recently been linked to toxic effects on reproduction, as levels increase “exponentially” across the globe.
An artist’s impression of the TFA molecular structure, and industrial usages in fridges and air-conditioning.Credit: Matt Davidson
Professor Hans Peter Arp, from the Norwegian University of Science and Technology, said scientists were shocked by the extent of TFA’s spread after developing new methods to sample for it in recent years.
“It’s accumulating irreversibly, and we don’t know what blood levels we’re going to reach before it peaks. It’s going to be decades from now. We are disturbed by that.”
The soaring levels of TFA have been largely tied to the use of fluorinated gases in air-conditioning and refrigeration.
They were introduced in the 1990s as industry scrambled to find replacements for chlorofluorocarbons, which had gouged a hole in the ozone layer.
Fluorinated gases have since been rolled out globally in the air-conditioning units of cars, trucks and large office buildings, along with commercial refrigerators in supermarkets, food processing factories, wineries and greenhouses.
Professor Brett Paull is leading efforts to monitor for TFA in Australia. Credit: Peter Mathew
As the gases are expelled into the atmosphere, TFA returns to the earth in rain, where it accumulates in bodies of water.
Chinese scientists uncovered a 17-fold increase in TFA concentrations in surface waters around Beijing over a decade, and a four-fold increase in dust over four years.
Similar results have been echoed in ice cores in northern Canada, and in rainfall in Germany.
There has not been any publicly available widespread monitoring for TFA in Australia, but Professor Brett Paull from the University of Tasmania said it would “absolutely” be present in water supplies.
“Once it’s in the water system and in precipitation, then of course it’s going to be into every living thing,” he said.
‘It’s everywhere now and increasingly so. Somebody should be paying attention.’
Professor Brett Paull, University of Tasmania
TFA does not break down in the environment. This is one of the traits that has seen the Organisation for Economic Co-operation and Development (OECD) classify it as a “forever chemical”, an umbrella term for a family of thousands of per- and polyfluoroalkyl substances (PFAS) that are nearly indestructible.
PFAS lurk in dozens of household products like frying pans and contact lenses, but recent data from European regulators indicates fluorinated gases account for about 63 per cent of all forever chemicals usage.
They deliver the man-made refrigerants sector around $US8 billion ($11.9 billion) in annual revenue. Key players include global chemical giants like Daikin, Honeywell and Chemours, a spin-off of Dupont, according to Grand View Research.
But the sector is now facing an existential challenge after five European countries submitted a proposal last year for a sweeping ban on forever chemicals, including refrigerants.
Makers of natural refrigerants are urging Australian regulators to follow suit, warning that fluorinated gases pose the twin threats of greenhouse gas emissions and forever chemicals pollution.
Leading TFA expert Professor Martin Scheringer warns not enough is known about the chemical’s potential risk to humans.
The fluorinated gases industry has been lobbying for an exemption from the European ban and has played down the risks posed by TFA.
They claim it does not meet the criteria to be classified as a forever chemical and will not harm human health at current environmental levels.
But Professor Martin Scheringer, from Masaryk University in the Czech Republic, said those arguments ignore the “alarming” speed at which TFA has been accumulating.
“The levels will eventually breach guidelines set for safe consumption of drinking water and TFA is practically impossible to remove from water,” Scheringer said.
Professor Arp called for urgent research into TFA’s toxicity.
“For the scientific community, I want to see all hands on deck,” he said.
Refrigerants Australia, representing manufacturers of fluorinated gases, pointed out that the European Chemicals Agency was years off making a determination on any prospective ban, and the issues were proving complex.
“Of course, we do not want to see harm to the environment and to human health,” said executive director Greg Picker.
“At the same time, managing a transition away from those PFAS where possible, reducing release to the environment where there are critical uses will require sophisticated policy and regulatory approaches.”
‘It’s everywhere’
Forever chemicals are prized for their water-repelling and stain-fighting properties, but there has been mounting scientific concern over their effects on health, including links to cancer, immune system dysfunction and high cholesterol.
TFA is deemed a forever chemical by the OECD but not by authorities in the United States.
Levels of TFA began their sharp ascent in the 1990s and are expected to continue to balloon in coming decades.
Arp said that often, TFA was already the forever chemical showing up in the highest concentrations in water and human blood.
A recent study of European waterways showed TFA accounted for more than 98 per cent of PFAS found, while a German study revealed that it contributed more than 90 per cent of forever chemical pollution in drinking water.
TFA was detected in 97 per cent of blood samples in a 2019 Chinese study, while a US study found it in 95 per cent of drinking water samples.
TFA pollution has also been linked to the use of pesticides and pharmaceuticals.
Wave of concern
There was a short-lived flurry of research into TFA from the late 1980s, when one study revealed it accumulated in the amniotic fluid of pregnant mice and another flagged its potential toxicity to the fetus.
Recent revelations of TFA’s spread have sparked a new wave of scientific interest.
In 2021, an industry-led study revealed TFA caused severe fetal malformations in rabbits.
Pharmaceuticals giant Bayer notified the European Food Safety Authority about its findings under laws requiring companies to report information regarding potentially harmful or unacceptable effects of their products.
‘The scientific understanding of a chemical’s toxicity increases – often massively – over time.’
Professor Martin Scheringer, Masaryk University
The German Chemical Agency cited the study when proposing that TFA should be classified as toxic to reproduction. Research is under way to determine if the findings are applicable to humans.
The Pesticide Action Network Europe noted that eye abnormalities in rabbits bore similarities to those discovered in rats exposed to other banned types of PFAS.
Some material safety data sheets acknowledge that TFA causes reproductive toxicity in animals but say its toxicological effects “have not been fully investigated”.
Refrigerants Australia pointed this masthead to a 2022 scientific report which found the increases of TFA are “not expected to pose a significant risk to humans or the environment at the present time”
The report, by an expert panel advising the Montreal Protocol, which manages the use of man-made refrigerants, concluded that “no harm is anticipated” based on projected releases of TFA.
But the findings have been contentious in the scientific community.
Scheringer argued a proper risk assessment could not be carried out while there was a poor understanding of human exposure to TFA and its toxicity. He said potential connections with a myriad of human diseases first needed to be explored.
“This is a formidable task and often only very limited toxicity data are available for a chemical such as TFA,” he said.
“The scientific understanding of a chemical’s toxicity increases – often massively – over time.”
Paull said scientists were concerned effects would be uncovered in years to come.
Woolworths is transitioning from man-made to natural refrigerants to reduce the risks from greenhouse gases and forever chemicals. Credit: Oscar Colman
“By the time you leave it for a decade or two it’s too late because you can’t take it out,” he said.
Paull is seeking to investigate TFA levels in waters, soils, sediments and plants.
“It’s everywhere now and increasingly so,” he said. “Somebody should be paying attention”.
Slipping the net
TFA particles are too small to be trapped by most drinking water filters. The only technology effective at removing them is reverse osmosis, but such filters are costly to install and maintain.
Natural refrigerants include ammonia, hydrocarbons, carbon dioxide and water. Manufacturers argue they perform the same or better than man-made alternatives, without the environmental risks.
The vast majority of domestic refrigerators now use natural refrigerants and there are signs that the clothes dryer market is following suit, according to the European Chemicals Agency.
“There are technologies already available that are proven and tested,” said Selwyn Wallace, who runs an Australian business manufacturing hydrocarbon-based refrigerants.
Forever chemicals have been detected in-airconditioning units.Credit: Getty Images/iStockphoto
“There’s no need for all these forever chemicals.”
Woolworths started scaling up its use of natural refrigerants to lower its greenhouse gas emissions, but now considers reducing risks from PFAS a secondary benefit.
Since 2017, all new Woolworths supermarkets have been built with natural refrigerant systems, while older supermarkets undergoing renovations are upgrading their systems to use natural refrigerants.
The City of Parramatta introduced provisions in its development control plan to encourage the use of natural refrigerants in the CBD in 2022, extending those to the wider local government area a year later.
George Haydock, who runs a Sydney-based natural refrigerants company, has been lobbying councils to make the change.
“When people become educated, we can move forward,” Haydock said.
Picker warns natural refrigerants carry safety risks: hydrocarbons are associated with the risk of fires, ammonia is toxic, and carbon dioxide is an asphyxiant.
“There are also environmental, energy efficiency, operational costs and a range of other issues to be managed,” Picker said.
“We will need access to all the refrigerants in our kit bag to meet environmental, energy, safety and cost requirements of the Australian community.”
Forever chemicals in commercial refrigeration and air-conditioning.Credit: Getty Images
Picker said there were thousands of sources of forever chemicals that can escape into the environment via landfills and groundwater.
“Focusing on emissions to atmosphere alone is misleading and subject to significant uncertainty,” he said.
He noted that refrigerants do not need to be released into the atmosphere and said containment should be part of the solution.
Get to the heart of what’s happening with climate change and the environment. Sign up for our fortnightly Environment newsletter.