The rain jacket in the hall closet. The non-stick pan on the stove. A fast-food wrapper from last night's dinner. The mascara in the bathroom drawer. For most of us, these are ordinary things, but they all sit inside a much larger story about a class of synthetic chemicals that have become almost impossible to avoid in modern life.

Per- and polyfluoroalkyl substances, the family collectively known as PFAS, were first created in 1938 when a DuPont chemist named Roy Plunkett accidentally discovered polytetrafluoroethylene, the slippery compound that became Teflon [1]. That single invention spawned a sprawling chemical universe: the U.S. National Library of Medicine's PubChem database lists more than 7 million PFAS-related structures, although regulators in practice focus on a much smaller subset, with the U.S. Environmental Protection Agency's DSSTox database listing around 14,735 unique PFAS structures for prioritisation [1]. PFAS show up in waterproof jackets, yoga pants, carpets, mobile phone screens, food packaging, firefighting foam, electrical insulation, and cosmetics [1].

What PFAS are, and where they hide

The chemistry that makes PFAS so useful is also the reason they are so persistent. The carbon-fluorine bond is one of the strongest in organic chemistry, which is why a non-stick pan slides an egg off without butter and why a rain jacket shrugs off a downpour. It is also why these compounds do not break down under normal environmental conditions [2]. PFOA, one of the most studied PFAS, has been found in the blood of more than 98% of Americans sampled in the National Health and Nutrition Examination Survey [2], and its cousin PFOS has a half-life of approximately 3-5 years in the human body [3].

PFAS enter our bodies through several routes. The U.S. Centers for Disease Control and Prevention's Agency for Toxic Substances and Disease Registry lists contaminated drinking water, food grown in PFAS-impacted soil, food packaging, household dust, and breast milk among the main pathways [4]. For most people in the general population, drinking water and diet do most of the work; for people living near airports, military bases, or certain industrial sites, local contamination can dominate.

Three product categories deserve a closer look. The PTFE coating on a modern Tefal or Teflon pan is, by itself, considered biologically inert at normal cooking temperatures [5]. PFOA, the bigger historical worry, was a processing aid used in coating manufacture and has been phased out by major brands since 2013 [6]. The current picture, for now, is that a post-2013 non-stick pan used on medium heat is a low-risk item. Degraded or older pans, or any pan heated above roughly 260°C, are a different matter [5].

Food packaging is a more meaningful, ongoing source of dietary exposure. Greaseproof wrappers, fast-food boxes, and microwave popcorn bags have historically used PFAS coatings to resist oil, and the chemicals can migrate into the food they touch. Cosmetics and textiles carry their own version of the same problem: "long-lasting," "waterproof," and "stain-resistant" are cues worth treating as PFAS red flags. The same chemistry that keeps mascara from smudging keeps a school uniform from staining, and it does not wash out.

What the health science says in 2026

PFAS research has matured a great deal since the early 2010s, and the picture in 2026 is clearer than it used to be, though still not complete. The strongest consensus, according to ATSDR's 2025 clinical guidance, is that PFAS exposure is associated with increased cholesterol, decreased antibody response to vaccines (especially in children), and an increased risk of kidney and testicular cancers [7]. The same agency lists ulcerative colitis, thyroid disease, pregnancy-induced hypertension, decreased fertility, and low birthweight as outcomes with credible supporting evidence [7].

The caution here is the word "associated." For most of these outcomes, the epidemiological evidence is strong enough to trigger regulatory action, but the science is still moving on dose-response at the very low levels most people carry in their blood. The International Agency for Research on Cancer took the strongest step to date in November 2023, classifying PFOA as Group 1, "carcinogenic to humans," the same category as asbestos and tobacco smoke [8]. PFOS remains in Group 2B, "possibly carcinogenic to humans," with reclassification under discussion [8].

PFOA and PFOS themselves are legacy compounds. PFOA was phased out under the U.S. EPA's Stewardship Program between 2006 and 2015, with a 95% reduction by 2010 and full elimination by 2015 [2], and PFOS was listed under the Stockholm Convention on Persistent Organic Pollutants in 2009 [9]. Their replacements, including the GenX family of perfluoroether acids (HFPO-DA), are now themselves turning up in drinking water and showing similar toxicity in animal studies [10].

The 2024 EPA drinking water rule, and the 2026 pivot

On 10 April 2024, the EPA finalised the single most important regulatory development for U.S. consumers: the first-ever national, legally enforceable drinking-water standard for six PFAS. Those headline numbers are stark. The Maximum Contaminant Level for both PFOA and PFOS was set at 4.0 parts per trillion, the lowest level the agency has ever set for any drinking-water contaminant [11]. Individual MCLs of 10 ppt were set for PFHxS, PFNA, and HFPO-DA, with a Hazard Index of 1 for any mixture of two or more of the four compounds PFHxS, PFNA, HFPO-DA, and PFBS [11]. Maximum Contaminant Level Goals for PFOA and PFOS were set to zero, a signal that non-cancer health effects can occur at any detectable level [11].

The compliance timetable has shifted. As originally written, public water systems were required to complete initial monitoring by 2027 and reach full compliance with all MCLs by 2029 [11]. Then, on 18 May 2026, the EPA announced a proposed rule that would push the PFOA and PFOS compliance deadline to 2031 and, more dramatically, would rescind the PFHxS, PFNA, HFPO-DA, and Hazard Index components altogether [11]. As of mid-2026, the standard is in genuine regulatory flux, and consumers should treat the headline 4 ppt number as the current floor, not the final word. About 100 million people in the U.S. are served by water systems that will be required to take action under the rule [11], supported by $1 billion in dedicated Bipartisan Infrastructure Law funding and roughly $4 billion in broader drinking-water investment [11].

Australia, on a parallel track

The Australian story is similar in shape and predates the EPA rule by more than a decade. Aqueous film-forming foam, known as AFFF, has been the dominant firefighting foam at airfields, refineries, and military bases since the 1960s, and almost every significant contamination site traces back to it [12]. The Australian Department of Defence has confirmed more than 90 PFAS contamination sites nationally [13].

The most studied cluster sits at RAAF Base Williamtown, about 30 km north of Newcastle, where AFFF use from the 1970s to the early 2000s contaminated groundwater and surface water across a wide investigation zone. A 2017-2018 Australian Government health study found elevated PFAS levels in residents who lived within that zone [14]. A class action by affected residents was settled against the Australian Department of Defence for A$212.5 million in 2022 [14], and Hunter Water's installation of granular activated carbon (GAC) treatment at the Tomago and Grahamstown water treatment plants in 2018-2019 is one of the clearest success stories so far, holding PFAS below the new Australian guideline values in the regional drinking supply [14][15].

Katherine in the Northern Territory, downstream of RAAF Base Tindal [13], and Oakey on Queensland's Darling Downs, adjacent to the Oakey Army Aviation Centre [16], are the other two most-cited sites, both with active blood-testing programs for residents in defined zones and ongoing GAC filtration in place.

What a person can realistically do

The honest answer, for now, is that total avoidance of PFAS is not possible for most people. The compounds are too widely distributed in air, dust, food, and water for any individual choice to be a complete solution. A few practical steps do reduce exposure, though. An NSF/ANSI 58 certified reverse-osmosis system or an NSF/ANSI 53 certified carbon filter is the most effective point-of-use option for PFOA and PFOS; standard pitcher filters do not reliably remove them. U.S. water utilities are required to publish annual PFAS monitoring results, and Australian water utilities publish quarterly data in affected areas. If your supply is above the relevant guideline, switch to filtered or bottled water for drinking and cooking.

Scepticism about stain and water claims on consumer goods is also warranted. "Waterproof," "greaseproof," "stain-resistant," and "long-lasting" on clothing, cosmetics, and food packaging are the most reliable PFAS tells. Choose untreated alternatives where you can. On the cookware front, a modern, post-2013 non-stick pan used on medium heat is a low-risk item; older pans, or any pan showing flaking or used on high heat, are worth replacing with stainless steel, cast iron, or enamel-coated cast iron.

The regulatory picture is evolving quickly, too: the EPA's 2026 proposed changes, state drinking-water standards, and the Stockholm Convention's slow expansion of listed compounds (PFOA was added in 2019) are all worth following.

The science is still moving, and so is the regulation. The era of treating PFAS as an industrial curiosity is over, and the cleanup will take decades. In the meantime, the most useful consumer frame is the one regulators use: reduce legacy PFAS exposure where you can, and watch your local tap-water data more closely than the labels on your jacket.