PFAS chemicals are omnipresent, enduring, and almost certainly in your bloodstream. Here’s a guide to where they come from, why there are concerns about their use and what regulations are in place to help you avoid exposure.
Your raincoat, beading with water. The slippery smooth surface of your non-stick pans. The mascara you carefully slick onto your eyelashes. The new stain-resistant couch you bought for your dogs to sit on. All these objects contain members of the PFAS family of chemicals: molecular structures found in Arctic glaciers, soil, human blood and water supplies. In summer time, as rain skims off the roof of your tent, you might not be thinking about the chemicals falling off the surface and running towards the ocean, invisible to you, yet there they are.
PFAS stands for perfluoroalkyl and polyfluoroalkyl substances, thousands of different chemicals (exactly what counts is debated) that first appeared in the 1930s when a scientist accidentally created one that came to be known as Teflon, which is used in non-stick cookware. This family of chemicals has been used in thousands of products since. The bond in the molecules, between carbon and fluorine, is exceptionally strong. “That means they’re hard to break down, and they last a long time,” says Melanie Kah, an environmental scientist working at the University of Auckland who studies pollution. How long? We don’t actually know; almost all the PFAS chemicals made since widespread production started in the 1940s still exist somewhere with their molecular structure intact.
I ask Kah how PFAS compares to plastic, another long-lasting human-made substance. “Plastic degrades physically and eventually will be oxidised or disintegrate from being exposed to light,” Kah says. “PFAS take so long to degrade that we can’t measure it, that’s why we call them forever chemicals.”
When it comes to plastic’s longevity – how long the sheet of building wrap that was used to build your apartment will be sitting around for, say – people talk in the hundreds of years. But for some PFAS to deteriorate, it might take thousands of years, an order of magnitude more.
For people making electroplated metal or raincoats or food packaging, this longevity is a feature, not a bug. Because of their ultra-strong bonds, PFAS molecules can repel water and oil, which means the fabric on your raincoat gets covered with beads or water, rather than being saturated, or a non-stick pan doesn’t end up having food caked to it. This also means that PFAS is everywhere. “We are continuously exposed to PFAS in our food, water, in stuff we use every day,” Kah says.
As well as longevity, two other factors make PFAS molecules pervasive. First, they’re mobile. “They move around the environment,” Kah explains. The molecules are at home in water and soil, and thus can become part of anything that interacts with these parts of the environment: humans, yes, but also plants and trees, fish and dolphins, insects and plankton. Secondly, PFAS is bioaccumulative: because it’s so long lasting, the amount of it in your bloodstream, say, increases over time, because you get exposed to more of it more quickly than your body can absorb, digest or expel it.
This also means that concentrations can increase up the food chain, which is called biomagnification. If you eat a plant or animal that has absorbed a lot of PFAS, it will increase the concentrations of the chemical in your body. A guaranteed way to get rid of PFAS is to breastfeed or give blood, but this means that the chemicals will simply go into someone else’s body; the government of Jersey has offered expensive bloodletting therapy to residents who have been exposed to extremely high levels of PFAS in their drinking water due to use of firefighting foam on the island. A drug meant to lower cholesterol levels in blood has also been found to reduce the amount of PFAS in highly exposed people by up to 60%.
These qualities make it really hard to tell how and when people get exposed to PFAS. While some specific sources can be identified, it’s difficult to trace exact paths from an object into the environment. Did molecules of PFAS found in seawater off the New Zealand coast drip off a nearby tent last week? Did they float across the sea from a factory in Fiji? Did they disappear down the drain as someone washed a non-stick pan in the 1990s? Is a PFAS molecule in your blood from a very necessary blood donation you received or from water you drank while overseas?
While there is some knowledge about the health impacts of PFAS molecules, it’s difficult to establish causality, because everyone is exposed to them to some extent. “PFAS chemicals aren’t acutely toxic,” Kah says; any health effects will appear over time, making it hard to link exposure to a single event, or even a single type of PFAS out of the thousands of varieties. What is clear, especially in people who have been exposed to large doses of PFAS by working or living in places where the chemicals have been manufactured, is that they can negatively impact immune system function, increase cholesterol levels in blood and impact the endocrine (hormonal) system – meaning menopause might start earlier, for example. Some PFAS chemicals have also been associated with cancer. The persistence of PFAS seems to be key to its health impacts in humans: not that it is immediately poisonous but that it remains in place, potentially interrupting body functions for decades.
Much of the science around which specific chemicals cause which specific outcomes, at which levels of exposure, in which circumstances, remains unclear. Animal testing (with its own raft of issues) has offered some answers, but it’s not clear that the way PFAS molecules bonded to a rabbit’s blood cells or in a lab-grown human tissue sample is the way they would behave in human bodies. “As with other chemicals, it’s good to take a precautionary approach – let’s not wait for it to be proved toxic before we do something,” Kah says. But do what? “It’s practically impossible to achieve a life that isn’t exposed to PFAS chemicals.”
One of the best things you can do to limit PFAS exposure is what most readers of this article will be doing already – living in New Zealand. There are periodically stories about PFAS being detected in water systems, like in Australia last year, and limits for drinking water have been applied in the US. There’s no sign of PFAS in New Zealand’s drinking water, and Kah and her team have shown that wastewater treatment technology is capable of removing PFAS from urban water. New Zealand has never produced any PFAS chemicals, which is another boon; there are no heavily contaminated industrial sites, and an EPA study in 2022 tested 131 groundwater wells around the country, and found there is a very little PFAS contamination in New Zealand water. That said, some Defence Force locations and firefighting training areas have had a lot of firefighting foam sprayed on them before PFAS-containing materials were banned in 2020, and need to be remediated.
The New Zealand government has also taken some actions to reduce PFAS, in some cases ahead of other countries. As well as the firefighting foam, a total ban on PFAS in cosmetics (including imported products) will be implemented from the end of 2026 – although Kah points out that without a clear definition, the cosmetic industry may debate which chemicals should be counted in the ban. New Zealand was one of the first countries to restrict PFAS in cosmetics specifically. Some companies are also reducing their PFAS use; the American outdoor gear corporation Patagonia has said that it will have completely removed PFAS from its products by the end of this year. In removing PFAS, Kah warns that it’s important to avoid “regrettable substitutions”, where one element is replaced with another, potentially more dangerous chemical whose health or environmental impacts are less well known.
An all-of-government working group convened in 2017 to coordinate action on PFAS among different government departments and regional councils is now inactive, a spokesperson for the Ministry for the Environment confirmed to The Spinoff, but could be reactivated if a national-level issue arose. If councils find an area that was contaminated with PFAS before the RMA was enacted in 1991, they can apply for remediation funding from the Ministry for the Environment, which has a specific fund for this purpose.
While there’s little you can do about PFAS you’re exposed to in the environment, you can limit some exposure by switching out products in your daily life: checking skincare and cosmetic projects you already own for PFAS ingredients (waterproof mascara is often filled with chemicals), cooking with pans that don’t have non-stick coatings, using plastic takeaway containers less, avoiding stain-proof clothing, and replacing PFAS-exposed menstrual products or nappies with PFAS-free varieties.
When there are hundreds of other things to be worried about, should PFAS be a priority? Kah laughs when she’s asked this, pointing out that there’s plenty of evidence that stress can be just as bad for your health as exposure to environmental contaminants. Instead, she suggests, learning about PFAS could be a catalyst to think more about industrial processes we usually don’t see. “I’d like people to be curious about the chemicals we use and why we use them, ask what we can live without, and reflect on the substances that have made life more convenient but might have consequences down the line.”