# Forever Chemicals

> "Forever chemicals" is the plain-language name for [PFAS](/learn/ingredients/pfas) - a class of more than 10,000 synthetic compounds built on an unbreakable carbon-fluorine bond. Coined in 2018 by Harvard researcher Joseph Allen, the term captures the single most important fact about these chemicals: they don't break down. Not in soil, not in water, not in the human body. They accumulate over a lifetime in blood and organs, and they're now found in rainwater on every continent - including the Arctic.

**Type:** concepts
**Categories:** air-fryer, cookware-set, water-filter, frying-pan
**Risk Level:** avoid
**Evidence Strength:** strong
**Source:** https://www.r3recs.com/learn/concepts/forever-chemicals

## Reality Check

**Claim:** My air fryer says PFOA-free so it's safe from forever chemicals
**Reality:** PFOA-free is a near-universal claim on all modern cookware and air fryers - it describes a chemical that was phased out of US manufacturing by 2015. It says nothing about whether the basket contains PTFE (a PFAS polymer), GenX (the PFOA replacement with its own emerging concerns), or whether the coating is intact. An 'PFOA-free' PTFE-coated air fryer basket is still a nonstick surface with a forever chemical polymer coating that degrades above 260 degrees Celsius.

## Overview

"Forever chemicals" isn't a scientific term. It's a translation - a way of explaining in ordinary language what chemists mean when they describe the extreme stability of the carbon-fluorine bond at the core of [PFAS](/learn/ingredients/pfas) chemistry. The phrase was coined in 2018 by Joseph Allen, director of Harvard's Healthy Buildings program and an associate professor at the Harvard T.H. Chan School of Public Health. Allen used it in a Washington Post op-ed to explain to a general audience why PFAS contamination was different from other pollution problems - not just widespread, but structurally permanent.

The name stuck because it's accurate. The C-F bond - a single bond between a carbon atom and a fluorine atom - is the strongest bond in organic chemistry. Bond dissociation energy for C-F runs approximately 485-544 kJ/mol, compared to roughly 350 kJ/mol for a carbon-carbon bond and 411 kJ/mol for a carbon-hydrogen bond. No enzyme found in soil microbes, no UV light intensity at the earth's surface, and no biological process in the human body operates with enough energy to break a C-F bond under normal conditions. That's what makes PFAS compounds "forever" chemicals: their persistence isn't a byproduct of their design - it is the design.

The PFAS class covered by the "forever chemicals" umbrella is vast. The EPA recognizes more than 10,000 distinct compounds sharing the basic fluorinated carbon-chain structure. They range from the long-chain compounds like [PFOA](/learn/ingredients/pfoa) and PFOS - the ones with the most extensive health data and the most severe documented effects - to newer short-chain replacements developed specifically to be less bioaccumulative, and from there to PTFE, the polymer used in [nonstick cookware](/category/cookware-set) and [air fryer](/category/air-fryer) baskets. All are PFAS. All qualify as forever chemicals by structure.

## Why the Chemistry Matters

To understand forever chemicals at a practical level, you need to understand one fact about the C-F bond: fluorine is the most electronegative element on the periodic table. When it bonds to carbon, it pulls electron density so powerfully that it creates a dense, stable electron cloud shielding the carbon backbone. That electron shield is what makes PFAS resist heat, repel water and oil, and withstand chemical attack. It's what makes them so useful in nonstick coatings, waterproof fabrics, firefighting foams, and food packaging. And it's exactly what makes them impossible to break down through normal environmental or biological pathways.

When a PFAS molecule enters the environment - in wastewater from a factory, in rain washing off a Gore-Tex jacket, in leachate from a landfill - it doesn't degrade. It moves. Long-chain PFAS like PFOA and PFOS bind to proteins and accumulate in living tissue. Short-chain PFAS are more water-soluble and travel farther in groundwater. Both categories are what chemists classify as POPs: persistent organic pollutants. The Stockholm Convention - the international treaty governing the most hazardous chemicals - has listed PFOA and PFOS as POPs, obligating signatory nations to eliminate their production and use. But eliminating new production doesn't eliminate what's already in the environment. What's in the soil, the water, and human blood will remain for generations.

## From the Lab to the Front Page: Dark Waters and Public Awareness

For most of the 20th century, the story of forever chemicals was buried in corporate documents. 3M began manufacturing PFAS at industrial scale in the 1940s. DuPont used PFOA as a processing aid to manufacture PTFE - the polymer it marketed as Teflon - starting in the early 1950s. Internal research at both companies documented PFAS accumulating in worker blood and causing harm in animal models as early as the 1960s and 1970s. That evidence was never shared with regulators or the public.

The story began to surface in 1999 when attorney Rob Bilott filed suit against DuPont on behalf of a West Virginia farmer whose cattle were dying near a DuPont waste site. Over the following years, Bilott obtained hundreds of thousands of pages of internal DuPont documents showing the company had known for decades that PFOA was contaminating drinking water in communities along the Ohio River. The resulting 2004 settlement created the C8 Health Project - a study of more than 69,000 people living near the Parkersburg, West Virginia plant that became the largest community health study ever conducted on a single chemical. When the independent science panel issued its findings in 2012, it established probable links between PFOA exposure and six diseases: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, elevated cholesterol, and preeclampsia.

Public awareness leapt forward in November 2019 when the film Dark Waters dramatized Bilott's case. The same month, an EWG analysis published alongside the film estimated that PFAS had contaminated drinking water systems serving an estimated 200 million Americans. The combination of a widely-seen film and actionable contamination data was the inflection point - "forever chemicals" moved from an environmental niche concern to a mainstream consumer issue almost overnight. By 2021, every major news organization in the US had run extended coverage. By 2022, brands like REI and Patagonia were voluntarily committing to eliminate PFAS from their products.

## Where Forever Chemicals Are Found

The depth of PFAS contamination is difficult to grasp because it's genuinely global. A 2022 study published in Environmental Science and Technology found that rainwater collected in remote locations - including the Tibetan Plateau and Antarctic ice cores - contained PFAS at levels above EPA health advisory values. The researchers concluded that the global water cycle has distributed PFAS to every corner of the planet, and that the "planetary boundary" for PFAS - the safe limit for the Earth system as a whole - has already been exceeded. There is now no place on Earth with PFAS-free rain.

For families, the practical exposure pathways are more concentrated:

**Nonstick cookware and [air fryers](/category/air-fryer):** [PTFE](/learn/ingredients/ptfe-teflon), the nonstick polymer marketed as Teflon and used in most mainstream air fryer baskets and frying pans, is a PFAS by EPA structural definition. Intact PTFE at normal cooking temperatures is generally considered stable. But PTFE degrades at 260 degrees Celsius (500 degrees Fahrenheit), and air fryer baskets without food as a thermal buffer can approach or exceed that threshold during preheating. Older pre-2015 cookware was also manufactured using [PFOA](/learn/ingredients/pfoa) as a processing aid, and residual PFOA in worn or scratched coatings can migrate into food. The coating damage issue is the most actionable one: a 2022 study in Environmental Science and Technology found that a scratched nonstick pan could release approximately 9,100 plastic and PFAS-containing particles per use.

**Drinking water:** The EPA's 2023 Unregulated Contaminant Monitoring Rule (UCMR5) - the most comprehensive national tap water survey for PFAS ever conducted - detected PFAS above health advisory levels in systems serving an estimated 176 million Americans. Contamination is highest near military installations (from AFFF firefighting foam), former PFAS manufacturing sites, and industrial facilities. But PFAS at lower levels appears in municipal water systems far from any obvious source, carried by rainfall and surface water. Standard pitcher filters like Brita and PUR do not reliably remove PFAS. The only technologies with documented efficacy are reverse osmosis (NSF/ANSI Standard 58, removes 95-99%) and activated carbon block filters (NSF/ANSI Standard 53 or P473, removes long-chain PFAS at 70-99%). Households with pregnant women or young children near any known contamination zone should install verified filtration as a priority. Look for [water filters](/category/water-filter) with specific NSF certification numbers - not just marketing claims.

**Food packaging:** Grease-resistant coatings on fast-food wrappers, microwave popcorn bags, and pizza boxes have historically used PFAS. Migration from packaging into food increases with temperature and fat content - hot, greasy food in treated packaging is the worst-case scenario. The FDA phased out PFAS in paper food-contact packaging in 2025, but supply chain transition takes time and compliance is incomplete.

**Clothing and textiles:** Durable water repellent (DWR) finishes on outdoor gear, rain jackets, and some athletic apparel use PFAS to make fabric water-resistant. Washing PFAS-treated garments releases PFAS microparticles into wastewater. The outdoor industry has been under significant pressure to transition to non-PFAS DWR alternatives, and brands including Patagonia, Arc'teryx, and REI have committed to PFAS-free products by 2025-2026.

**Carpets, upholstery, and stain-resistant treatments:** Scotchgard and similar stain-resistance treatments have used PFAS for decades. 3M voluntarily phased out PFOS-based Scotchgard in 2000 but reformulated with other PFAS. New generation treatments are beginning to shift to non-PFAS chemistry, but older treated carpets continue to shed PFAS into household dust, where young children - who spend more time on the floor and engage in hand-to-mouth behavior - receive higher exposure per unit body weight than adults.

## The Forever Problem: Bioaccumulation

The "forever" in forever chemicals refers not just to environmental persistence but to what happens inside the body. [PFOA](/learn/ingredients/pfoa) has a half-life of approximately 3.5 years in human blood. PFOS has a half-life of approximately 5 years. These figures mean that if all PFAS exposure stopped today, it would take 3.5 years for half the PFOA in your blood to clear - and 5 years for half the PFOS. Because exposure doesn't stop (it's ongoing through water, food, and household sources), the chemicals accumulate over a lifetime. Blood PFAS levels in the US population were highest in surveys from the late 1990s and early 2000s, declined as PFOA and PFOS manufacturing wound down, and have stabilized at levels still detectable in 97% of Americans.

For pregnant women, the bioaccumulation dynamic has a direct fetal consequence. PFAS cross the placenta. Cord blood studies consistently detect PFAS in newborns at 20-30% of maternal serum concentrations. Breast milk is also a transfer pathway. Infants also receive proportionally higher doses per kilogram of body weight than adults from any exposure source - they eat and drink more relative to their size, and they spend more time on floors where household dust concentrates shed PFAS from treated materials.

The immune system effects documented in children are among the most precisely measured PFAS health outcomes. A landmark study published in JAMA in 2012 found that each doubling of serum PFOS in children at age 5 was associated with a 49% reduction in antibody response to diphtheria vaccination. That finding has been replicated for other vaccines including mumps, rubella, and Hib. The National Toxicology Program concluded in its systematic review that PFOA and PFOS are "presumed immune hazards in humans." This means children with higher PFAS exposure may receive meaningfully less protection from standard childhood vaccines.

## Environmental Persistence: Rainwater, Ice, and the Deep Ocean

The global distribution of PFAS illustrates what "forever" means at a planetary scale. PFAS have been detected in:

- Arctic sea ice and snow, thousands of kilometers from any manufacturing facility
- Deep ocean sediment samples from the Mariana Trench
- Antarctic ice cores dating back to the 1950s (coinciding with the start of industrial PFAS production)
- Polar bears, orcas, and bald eagles - apex predators at the top of food chains with no direct human contact
- Remote mountain lakes with no nearby contamination source
- The blood of Indigenous Arctic communities whose primary PFAS exposure pathway is marine mammals that bioaccumulate PFAS through the food chain

The 2022 rainwater study that detected PFAS above EPA health advisories globally concluded that the planetary boundary for PFAS has been transgressed - meaning the safe operating space for the Earth system has been exceeded. This isn't a local pollution problem that can be cleaned up with conventional remediation. It's a permanent feature of the planetary environment, managed going forward by reducing new inputs while the existing load persists in water cycles, sediment, and living tissue indefinitely.

## Can Forever Chemicals Be Destroyed?

For most of the history of PFAS research, the answer was effectively no. But recent years have produced genuine progress on PFAS destruction technologies, driven by the scale of contamination and the economics of Superfund cleanup liability.

**Supercritical water oxidation (SCWO):** Water at temperatures above 374 degrees Celsius and pressures above 218 atmospheres enters a supercritical phase that behaves as both a liquid and a gas. In this state, it can support oxidation reactions with enough energy to break C-F bonds. SCWO systems have been demonstrated at pilot scale for PFAS destruction in concentrated AFFF solutions and contaminated groundwater concentrates. Companies including 374Water (formerly SCWO Systems) and Aquagga have run field demonstrations. The technology works for concentrated PFAS streams but is energy-intensive and not yet cost-effective for dilute contamination in large water volumes.

**Electrochemical oxidation:** Electrochemical treatment using boron-doped diamond electrodes can generate hydroxyl radicals energetic enough to destroy PFAS. Several municipal water utilities have piloted the technology. Like SCWO, it's most practical for concentrated waste streams.

**Sonochemical degradation:** High-intensity ultrasound in water generates localized hot spots with extreme temperatures and pressures (a phenomenon called acoustic cavitation) that can break C-F bonds. Research teams at UC Berkeley and University of Notre Dame have demonstrated near-complete PFAS destruction in laboratory settings. The technology is pre-commercial but advancing.

**Photocatalytic decomposition:** UV light combined with photocatalysts (including bismuth-based materials and specialized TiO2 formulations) can drive PFAS defluorination under specific conditions. A 2022 study in Science demonstrated complete defluorination of PFAS using a combination of UV-365 and bismuth-based photocatalysts in sodium hydroxide solution at room temperature - a potential breakthrough that simplified the energy requirements compared to earlier approaches.

None of these technologies has yet solved the problem of PFAS contamination at the scale it exists. Hundreds of Superfund sites, thousands of contaminated water utilities, and an estimated 200+ million Americans with some level of PFAS exposure in their drinking water represent a remediation challenge orders of magnitude larger than what current destruction capacity can address. The practical message for families: wait for industrial-scale solutions isn't the answer. Reducing exposure at home - through verified water filtration, replacing older nonstick cookware, and choosing PFAS-free products when available - is the actionable near-term response.

## Current Regulatory Landscape

The regulatory response to forever chemicals accelerated sharply between 2022 and 2025, driven by the UCMR5 water data, the Dark Waters cultural moment, and accumulating epidemiological evidence.

**Federal drinking water:** The EPA finalized the first federal Maximum Contaminant Levels for PFAS in April 2024: 4 parts per trillion for PFOA and PFOS, the lowest enforceable standard for any drinking water contaminant in the US. The health goal (MCLG) is zero - the EPA explicitly states no safe level has been established. PFOA and PFOS were also designated Superfund hazardous substances in July 2024, creating cleanup liability at contaminated sites. Water utility compliance deadline is 2029.

**Product regulation:** Minnesota enacted the first state ban on PFAS in nonstick cookware, effective January 2025. Maine has enacted the broadest consumer product law, extending to virtually all product categories by 2032. California, Colorado, New York, Vermont, Connecticut, and Washington have enacted PFAS product restrictions taking effect between 2025 and 2028. The FDA revoked 35 PFAS food contact authorizations in 2024-2025, eliminating most PFAS from paper food packaging.

**International:** The European Chemicals Agency is evaluating a near-universal restriction on all 10,000+ PFAS compounds under REACH, with a Commission decision expected in 2027-2028. If adopted, it would be the broadest chemical restriction ever enacted globally.

**Third-party certification:** NSF International launched NSF Standard 537, a PFAS-free certification for food equipment, in March 2025. This is currently the most rigorous third-party verification available for cookware and food contact materials - it tests for total organic fluorine (TOF) rather than individual named compounds, meaning it catches replacement chemicals that haven't been individually assessed yet.

## Also Known As

- PFAS (Per- and Polyfluoroalkyl Substances) - the scientific term
- PFCs (perfluorinated compounds) - older informal shorthand
- Fluorochemicals - industry terminology
- C8 chemicals - internal DuPont term for PFOA specifically

## Where Found

- Air fryer baskets and crisper plates with PTFE nonstick coating
- Nonstick cookware - frying pans, griddles, baking sheets with PTFE (Teflon) coating
- Drinking water - found in systems serving an estimated 176 million Americans (EPA UCMR5, 2023)
- Food packaging - grease-resistant coatings on fast-food wrappers, pizza boxes, microwave popcorn bags
- Waterproof and water-resistant clothing with DWR (durable water repellent) finishes
- Stain-resistant carpet and upholstery (Scotchgard and similar treatments)
- Firefighting foam (AFFF) - primary source of water contamination near military bases and airports
- Cosmetics - some foundations, mascaras, and sunscreens use PFAS for texture and durability
- Dental floss - several major brands use PTFE-based floss with PFAS detected in testing
- Rainwater - PFAS detected above health advisory levels globally including Arctic and Antarctic

## Health Concerns

The health case against forever chemicals is built on decades of epidemiological data, most of it generated by the C8 Health Project's study of 69,000 people exposed near DuPont's Parkersburg, West Virginia plant, and corroborated by national biomonitoring surveys and independent cohort studies.

**Cancer:** The WHO's International Agency for Research on Cancer classified PFOA as a Group 1 confirmed human carcinogen in December 2023. The primary cancers with established evidence are kidney cancer (relative risk approximately 1.9 in the NCI's PLCO cohort) and testicular cancer (confirmed by the C8 Science Panel). A 2023 Lancet eBioMedicine meta-analysis found PFAS exposure associated with a 56% increased risk of thyroid cancer.

**Immune suppression:** The Grandjean et al. study in JAMA (2012) found each doubling of serum PFOS in children at age 5 was associated with a 49% reduction in antibody response to diphtheria vaccination. The National Toxicology Program concluded PFOA and PFOS are presumed immune hazards in humans. Children with higher PFAS body burdens may receive significantly less protection from standard childhood vaccines.

**Thyroid disruption:** PFAS structurally mimic thyroid hormones and suppress free T4. This is most consequential during the first 20 weeks of pregnancy, when fetal brain development depends entirely on maternal thyroid hormone. Even subclinical maternal thyroid suppression from PFAS exposure during this window has been linked to reduced IQ in children.

**Cardiovascular:** Elevated LDL cholesterol is the most consistently replicated PFAS health effect across epidemiological studies. A meta-analysis found each 1 ng/mL increase in serum PFOA was associated with a 6.8 mg/dL increase in total cholesterol.

**Reproductive and developmental:** PFAS cross the placenta - cord blood studies detect PFAS in newborns at 20-30% of maternal serum concentrations. Documented effects include preeclampsia (odds ratio approximately 2.0 in C8 Science Panel data), low birth weight, reduced fertility, and reduced IQ scores in children with higher prenatal PFAS exposure.

## Regulatory Status

**US Federal (as of 2026):** EPA finalized Maximum Contaminant Levels for PFOA and PFOS at 4 parts per trillion in April 2024 - the lowest enforceable limit for any US drinking water contaminant, with a health goal of zero. PFOA and PFOS were designated Superfund hazardous substances in July 2024. The FDA revoked 35 PFAS food contact authorizations in 2024-2025, phasing out PFAS in paper food packaging. No federal ban on PFAS in cookware exists.

**State Level:** Minnesota banned PFAS in nonstick cookware effective January 2025 - the first state to do so. Maine enacted the broadest law, extending to virtually all consumer products by 2032. California, Colorado, New York, Vermont, Connecticut, and Washington have enacted product-specific restrictions taking effect 2025-2028.

**EU:** The European Chemicals Agency is evaluating a near-universal REACH restriction on all PFAS compounds, with a Commission decision expected 2027-2028. If adopted, it would be the broadest chemical restriction in history.

**Third-party certification:** NSF Standard 537 (launched March 2025) is the most rigorous PFAS-free certification for food equipment, testing total organic fluorine rather than individual compounds. MADESAFE certification explicitly screens for PFAS in baby products and personal care. Neither 'PFOA-free' nor 'PFAS-free' is a federally defined claim without third-party verification.

## Label Guide

**Look for:**
- PTFE-free AND PFAS-free stated together on cookware or air fryers
- NSF 537 PFAS-free certification on food equipment (launched March 2025)
- Ceramic coating with explicit PFAS-free statement - verified sol-gel silica coatings (GreenPan Thermolon, Caraway)
- Stainless steel basket or cooking surface - inherently PTFE-free and PFAS-free
- Cast iron or carbon steel - no coating, no PFAS
- NSF/ANSI Standard 58 certified on water filters (reverse osmosis - removes 95-99% of PFAS)
- NSF/ANSI Standard 53 or P473 certified on water filters (carbon block - removes long-chain PFAS at 70-99%)
- MADESAFE certified on baby products or personal care (explicitly screens for PFAS)

**Avoid / misleading:**
- PFOA-free without PFAS-free - PFOA was phased out of US manufacturing by 2015; this label describes virtually every product in the market and says nothing about PTFE or other PFAS
- Non-stick with no coating material specified - assume PTFE unless stated otherwise
- Diamond, granite, titanium, or marble nonstick - these are PTFE-base coatings with mineral branding
- Non-toxic - an unregulated marketing claim with no legal definition and no PFAS testing requirement
- Forever chemical-free without third-party verification - an unregulated self-claim
- PFAS-free without NSF or MADESAFE certification - meaningful intent but no independent verification

## Who Is At Risk

- Pregnant women - PFAS cross the placenta, suppress maternal thyroid during critical fetal brain development, and are linked to preeclampsia; the first 20 weeks of pregnancy represent the highest-stakes PFAS exposure window
- Fetuses and newborns - cord blood studies detect PFAS at 20-30% of maternal serum concentrations; immune and neurological development are both sensitive to PFAS disruption
- Formula-fed infants in PFAS-contaminated water areas - mixing powdered formula with contaminated tap water concentrates exposure relative to body weight
- Young children - hand-to-mouth behavior amplifies household dust exposure; immune suppression and neurodevelopmental effects documented at serum levels in the current US range
- Residents near military bases, airports, or PFAS manufacturing sites - AFFF contamination at some sites produces serum PFOS levels 6x the national average; private well users have no regulatory protection
- People with older nonstick cookware or air fryers - pre-2015 pans were made with PFOA; scratched or worn coatings on any nonstick surface release significantly more PFAS particles

## What Helps

For cookware and air fryers: choosing ceramic sol-gel coatings (GreenPan Thermolon, Caraway, Our Place), stainless steel, cast iron, or carbon steel eliminates the PFAS variable entirely. For drinking water: NSF/ANSI 58-certified reverse osmosis removes 95-99% of PFAS; NSF 53 or P473-certified carbon block filters remove long-chain PFAS at 70-99%. For food packaging: fresh food and glass or stainless steel containers eliminate the grease-resistant coating exposure pathway. For clothing: PFAS-free DWR alternatives from brands like Nikwax and Holmenkol are commercially available.

## How To Verify

For cookware and air fryers: contact the manufacturer and request third-party test results showing total organic fluorine (TOF) below detectable limits - not just a brand statement. NSF 537 certification is the most rigorous available and can be verified at nsf.org. For water: look up your utility's annual Consumer Confidence Report (legally required to disclose PFAS test results) or use EWG's Tap Water Database at ewg.org/tapwater. For filter effectiveness: search NSF's certified products database by Standard 58 (reverse osmosis) or Standard 53 (carbon block) and verify your specific model number and PFOA/PFOS are listed.

## Timeline

- **1938:** PTFE Discovered — DuPont chemist Roy Plunkett accidentally discovers polytetrafluoroethylene (PTFE), later trademarked as Teflon. 3M purchases the Simons electrochemical fluorination process and begins manufacturing PFAS compounds at industrial scale.
- **1950s-1960s:** Industrial Deployment — PFOA becomes the processing aid used to manufacture PTFE coatings for cookware. PFAS chemicals proliferate across consumer and industrial applications including firefighting foam, waterproof clothing, food packaging, and stain-resistant textiles.
- **1960s-1970s:** Internal Evidence Suppressed — Internal 3M and DuPont studies document PFAS accumulating in worker blood and causing harm in animal models. Evidence is never disclosed to regulators or the public. In 1981, DuPont finds PFOA in the blood of babies born to female plant workers.
- **1999-2004:** Rob Bilott Lawsuit — Attorney Rob Bilott files suit against DuPont, uncovering decades of suppressed internal documents. A 2004 settlement creates the C8 Health Project - a study of 69,000 people near the Parkersburg, WV plant. The science panel's 2012 findings establish probable links to six diseases.
- **2018:** Term 'Forever Chemicals' Coined — Harvard professor Joseph Allen coins the term 'forever chemicals' in a Washington Post op-ed to explain PFAS persistence to a general audience. The phrase spreads rapidly and becomes the dominant consumer-facing description for the PFAS class.
- **November 2019:** Dark Waters and Mainstream Awareness — The film Dark Waters dramatizes Bilott's case. Simultaneously, EWG estimates PFAS in water systems serving 200 million Americans. The combination moves 'forever chemicals' from environmental niche to mainstream consumer concern.
- **December 2023:** PFOA Classified Group 1 Carcinogen — The WHO's International Agency for Research on Cancer upgrades PFOA to Group 1 - confirmed human carcinogen - the same category as tobacco smoke and asbestos. Kidney and testicular cancer are the primary endpoints.
- **April 2024:** First US Drinking Water Limits — EPA finalizes Maximum Contaminant Levels for PFOA and PFOS at 4 parts per trillion - the lowest enforceable standard for any US drinking water contaminant, with a health goal of zero. PFOA and PFOS designated Superfund hazardous substances in July 2024.
- **2025:** Product Bans and New Certification — Minnesota becomes the first state to ban PFAS in nonstick cookware (January 2025). NSF launches NSF 537 PFAS-free certification for food equipment (March 2025). FDA revokes 35 PFAS food contact authorizations, completing the paper packaging phase-out.

## Air Fryers and Forever Chemicals: The Coating Question

Most mainstream air fryer baskets - from Ninja, Cosori, Instant Pot, and others - are coated with PTFE, a PFAS polymer. PTFE begins degrading at 260 degrees Celsius (500 degrees Fahrenheit). Air fryers are higher-risk than open pans because the enclosed cavity and high-speed fan distribute any released particles throughout the cooking chamber. Preheating an empty basket is the highest-risk behavior - without food as a thermal buffer, basket surfaces can approach or exceed the degradation threshold. Scratched baskets release significantly more PFAS particles. PFAS-free alternatives with stainless steel or verified ceramic baskets exist - and are the R3 recommendation for households with young children or pregnant women.

## What This Does Not Cover

The 'forever chemicals' umbrella does not cover all persistent environmental contaminants - PCBs, dioxins, and certain pesticides are also persistent but belong to chemically distinct classes. Within PFAS, 'forever chemicals' is sometimes used colloquially to refer mainly to long-chain PFAS like PFOA and PFOS, when the scientific and regulatory definition of PFAS includes PTFE and thousands of other compounds. The term also doesn't reflect the significant variation in toxicity across the PFAS class - some compounds have decades of health data, others have almost none.

## R3 Bottom Line

- Replace scratched, chipped, or pre-2015 nonstick cookware and air fryer baskets - coating damage dramatically increases PFAS particle release, and pre-2015 products were manufactured using PFOA.
- Filter your drinking water with a verified NSF/ANSI 58-certified reverse osmosis system or NSF 53-certified carbon block filter - standard pitcher filters (Brita, PUR) do not remove PFAS.
- Never preheat an empty nonstick air fryer basket - without food as a thermal buffer, basket surface temperatures can approach the PTFE degradation threshold.
- Read 'PFOA-free' as a marketing baseline, not a safety signal - it describes a chemical phased out in 2015 and says nothing about PTFE content, replacement compounds, or independent testing.

## FAQ

### Who coined the term 'forever chemicals' and when?

Joseph Allen, director of Harvard's Healthy Buildings program and an associate professor at the Harvard T.H. Chan School of Public Health, coined the term in a 2018 Washington Post opinion piece. Allen used it to explain to a general audience why PFAS contamination was structurally different from conventional pollution - not just widespread, but chemically unable to degrade. The term spread rapidly because it accurately captures the defining property of the entire PFAS class: the carbon-fluorine bond that makes them useful is also the bond that makes them permanently persistent in the environment and the human body.

### Why don't forever chemicals break down?

The carbon-fluorine bond at the core of PFAS chemistry is the strongest single bond in organic chemistry, with a bond dissociation energy of approximately 485-544 kJ/mol. No enzyme in soil microbes, no UV light intensity at earth's surface, and no biological process in the human body operates with enough energy to break it under normal conditions. This is the same property that makes PFAS so commercially useful - they resist heat, water, oil, and chemical attack. The stability is structural, not incidental. PFAS don't fail to degrade because of some environmental deficiency - they are engineered, at the atomic level, to be permanent.

### Are all forever chemicals equally dangerous?

No - there is significant variation within the PFAS class. Long-chain PFAS like PFOA (8-carbon) and PFOS (8-carbon sulfonyl) have the most extensive health data and the most severe documented effects, including confirmed cancer links and immune suppression. Short-chain replacements (4-6 carbons) were developed specifically to be less bioaccumulative - they don't build up in blood as readily. But 'less bioaccumulative' is not the same as 'safe,' and shorter-chain PFAS are more water-soluble and travel farther in groundwater. PTFE, the nonstick polymer, is a high-molecular-weight polymer PFAS considered biologically inert when intact and cured - a different risk profile than PFOA or PFOS. The practical guidance is to avoid the entire class rather than trying to manage individual compound distinctions at the consumer level.

### How did the film Dark Waters change public awareness of forever chemicals?

Dark Waters (2019) dramatized attorney Rob Bilott's decades-long legal battle against DuPont over PFOA contamination in West Virginia. The film's November 2019 release coincided with an EWG analysis estimating PFAS in drinking water for an estimated 200 million Americans - and together, they represented the mainstream tipping point. Before Dark Waters, PFAS was primarily a concern tracked by environmental journalists and public health researchers. After it, 'forever chemicals' entered the general public vocabulary, consumer product scrutiny accelerated, and legislative pressure on state and federal agencies intensified. Several state PFAS product bans were introduced or accelerated in the 18 months following the film's release.

### How long do forever chemicals stay in the human body?

It depends on the specific compound. PFOA has a half-life of approximately 3.5 years in human blood - meaning 3.5 years after your last significant exposure, half of what you absorbed is still present. PFOS has a half-life of approximately 5 years. Some short-chain PFAS clear more quickly - on the order of months. But because exposure doesn't actually stop (ongoing low-level exposure from water, food, and household sources continuously tops up blood levels), body burdens don't naturally decline to zero. The 97% detection rate in American blood samples reflects continuous reexposure, not just historical accumulation.

### Is PFAS found in rainwater really above safe limits?

Yes - a 2022 study published in Environmental Science and Technology found PFAS in rainwater samples from remote locations including the Tibetan Plateau and Antarctic ice at concentrations exceeding EPA health advisory values. The researchers concluded the planetary boundary for PFAS - the safe operating limit for the Earth system - has already been exceeded. This doesn't mean drinking rainwater is acutely dangerous; EPA health advisories represent very conservative precautionary thresholds. But it confirms that there is no longer PFAS-free precipitation anywhere on Earth, and that atmospheric transport through the water cycle is distributing PFAS globally regardless of proximity to manufacturing sources.

### Can PFAS be destroyed or removed from the environment?

In concentrated waste streams, yes - emerging technologies including supercritical water oxidation, electrochemical oxidation with boron-doped diamond electrodes, and photocatalytic defluorination have demonstrated near-complete PFAS destruction in laboratory and pilot settings. A 2022 study in Science showed complete defluorination using UV light and bismuth-based photocatalysts at room temperature, which is considered a significant research breakthrough. But none of these technologies is yet deployable at the scale needed to address hundreds of Superfund sites and contamination affecting 176+ million Americans' drinking water. For dilute contamination in large water volumes, activated carbon and reverse osmosis filtration - which concentrates rather than destroys PFAS - remain the practical near-term tools.

### What is the difference between 'forever chemicals' and PFAS?

They refer to the same thing. 'Forever chemicals' is the plain-language consumer term; [PFAS](/learn/ingredients/pfas) (Per- and Polyfluoroalkyl Substances) is the scientific classification. PFAS is the broader term covering all 10,000+ compounds in the class - including PTFE, PFOA, PFOS, GenX, and thousands of others. 'Forever chemicals' is typically used when speaking to a general audience and emphasizes the defining property: these chemicals don't break down. Scientists, regulators, and researchers use PFAS. Journalists, advocates, and health communicators tend to use 'forever chemicals.' They describe the same chemical class.

## Sources

- [Joseph Allen Op-Ed: 'These Forever Chemicals Are in Your Popcorn Bag. They May Be in Your Blood' (originating the term)](https://www.washingtonpost.com/opinions/these-forever-chemicals-are-in-your-popcorn-bag-they-may-be-in-your-blood/2018/08/22/3e8f7258-a5de-11e8-97ce-cc9042272a8d_story.html) — *The Washington Post / Joseph Allen, Harvard T.H. Chan School of Public Health* (2018)
- [EPA PFAS Explained - Overview of Per- and Polyfluoroalkyl Substances](https://www.epa.gov/pfas/pfas-explained) — *U.S. Environmental Protection Agency* (2024)
- [PFAS National Primary Drinking Water Regulation - Final Rule](https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas) — *U.S. Environmental Protection Agency* (2024)
- [IARC Monographs Volume 135: PFOA Classified as Group 1 Carcinogen](https://www.iarc.who.int/news-events/iarc-classifies-perfluorooctanoic-acid-pfoa-as-carcinogenic-to-humans-group-1/) — *International Agency for Research on Cancer (WHO)* (2023)
- [Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS)](https://pubs.acs.org/doi/10.1021/acs.est.2c02765) — *Environmental Science and Technology - Cousins et al.* (2022)
- [Serum Vaccine Antibody Concentrations in Adolescents Exposed to Perfluorinated Compounds](https://jamanetwork.com/journals/jama/fullarticle/1217964) — *JAMA - Grandjean et al.* (2012)
- [Fifth Unregulated Contaminant Monitoring Rule (UCMR5) Data - PFAS in Public Water Systems](https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule) — *U.S. EPA Office of Water* (2023)
- [Photocatalytic Defluorination of PFAS Under Ambient Conditions](https://www.science.org/doi/10.1126/science.abm8868) — *Science - Zhang et al.* (2022)
- [PFAS and Your Health - ATSDR Toxicological Profile and Biomonitoring Data](https://www.atsdr.cdc.gov/pfas/index.html) — *Agency for Toxic Substances and Disease Registry (CDC)* (2024)
- [Scratched Non-Stick Cookware as a Source of PFAS Release](https://www.sciencedirect.com/science/article/pii/S0048969722061071) — *Science of the Total Environment - Nguyen et al.* (2022)
- [OECD Global Database on PFAS - Structural Definition and Compound Count](https://one.oecd.org/document/ENV/CBC/MONO(2021)25/En/pdf) — *OECD Environment Directorate* (2021)

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Source: https://www.r3recs.com/learn/concepts/forever-chemicals
Methodology: https://www.r3recs.com/methodology/how-we-score-products