What Are PFAS "Forever Chemicals" and Are They in Your Tap Water?
In August 2025, researchers at UNSW Sydney made a finding that national media covered widely: they had detected 31 different PFAS chemicals in Sydney's tap water — including 21 types that had never before been recorded in Australian tap water, and one found in a drinking water supply anywhere in the world for the first time. The discovery did not indicate that Sydney's water was unsafe by Australian guidelines. What it indicated was that we have been looking at only a fraction of the PFAS picture — and that the full picture is significantly more complex than previously understood.
PFAS — per- and polyfluoroalkyl substances — are a family of over 12,000 synthetic chemicals used in manufacturing, firefighting, cookware, food packaging, textiles, and dozens of other applications since the 1940s. They are called "forever chemicals" for a specific reason: the carbon-fluorine bond that defines their structure is among the strongest in chemistry. PFAS do not break down meaningfully in soil, water, or the human body. They accumulate. And because they have been in widespread use for over 80 years, they are now effectively everywhere — including Australian tap water.
Yes — PFAS are present in Australian tap water, including in Sydney, Melbourne, and other major city supplies. The NHMRC updated its Australian Drinking Water Guidelines for PFAS in June 2025, setting new health-based limits for PFOS, PFOA, PFHxS, and PFBS — acknowledging potential carcinogenicity, bone marrow effects, and thyroid disruption as the critical health endpoints. Approximately 30 communities across Australia have recorded PFAS levels exceeding even the new 2025 guidelines, and roughly six million Australians — a quarter of the population — are exposed to PFAS in drinking water below but still at detectable guideline levels. Most major city supplies currently comply with Australian guidelines, but Australian limits remain up to 50 times less strict than the 2024 US EPA standards.
A NSW parliamentary inquiry in September 2025 found Sydney Water did not perform "an appropriate level of due diligence" before claiming in June 2024 that there were no known PFAS hotspots in its drinking water catchments — a claim made before any testing had been conducted in the Blue Mountains supply. The Blue Mountains Cascade Water Filtration Plant subsequently recorded PFOS at 16.4 ng/L — double the Australian guideline at the time.
📋 Table of Contents
- What are PFAS and why are they called "forever chemicals"
- Where PFAS in tap water come from
- The key PFAS types to know
- Australian guidelines — what the NHMRC says
- What PFAS do to the body — the health evidence
- The Australian PFAS story: 2024–2026 timeline
- What actually removes PFAS from drinking water
- Frequently Asked Questions
What Are PFAS and Why Are They Called "Forever Chemicals"
PFAS stands for per- and polyfluoroalkyl substances — a broad family of over 12,000 synthetic chemicals defined by their carbon-fluorine (C-F) bonds. The C-F bond is one of the strongest in all of organic chemistry: it resists heat, acid, oil, water, and biological degradation. This is exactly why manufacturers began using PFAS in the 1940s — for non-stick cookware, waterproof clothing, food packaging, fire-suppression foam, and dozens of industrial applications where chemical resistance was valuable.
The same chemical stability that makes PFAS industrially useful makes them environmentally permanent. They do not break down in the environment under normal conditions. They do not break down meaningfully in the human body. They accumulate in water, soil, sediment, and living tissue over time — building in concentration as they move through the food chain. "Forever chemicals" is not hyperbole; it is an accurate description of their environmental behaviour across any human-relevant timescale.
Where PFAS in Tap Water Come From
PFAS enter water supplies from multiple distinct contamination pathways — and in Australia, military and aviation sites have historically been the most significant point sources, due to the widespread use of Aqueous Film-Forming Foam (AFFF) in firefighting training exercises over decades.
Primary contamination pathways in Australian water supplies
- Aqueous Film-Forming Foam (AFFF) — legacy firefighting foam used extensively at military bases, airports, and training facilities; the primary source of PFAS in many regional Australian water supplies
- Industrial discharge — manufacturing facilities using PFAS in production processes discharge into waterways and groundwater
- Landfill leachate — PFAS from consumer products (non-stick cookware, waterproof textiles, packaging) leach from landfill sites into groundwater
- Agricultural runoff — PFAS-contaminated biosolids (sewage sludge applied as fertiliser) and irrigation water transfer PFAS into crops and waterways
- Atmospheric deposition — PFAS carried in rain and dust from industrial sites settle into catchment areas and surface water
- Product degradation — short-chain PFAS such as PFBA are increasingly detected as breakdown products of regulated long-chain PFAS compounds, and were the most abundant PFAS compound found in every Sydney tap water sample tested by UNSW in 2024
The Key PFAS Types to Know
Of the 12,000+ known PFAS compounds, a small number are most relevant to Australian drinking water — either because they are regulated under the NHMRC guidelines, have the most established health evidence, or are emerging as significant concerns from recent research.
PFOS — Perfluorooctane Sulfonate
PFOS is classified by the NHMRC as a potential carcinogen and is associated with bone marrow effects. The Australian guideline is 8 ng/L (set June 2025). It was the primary chemical in AFFF firefighting foam and is the main PFAS of concern at military base and airport contamination sites. The US EPA limit is 4 ng/L — half Australia's guideline. It was banned from production in Australia in July 2025.
PFOA — Perfluorooctanoic Acid
PFOA is classified as a potential carcinogen by the NHMRC. The Australian guideline is 200 ng/L — while the US EPA limit is just 4 ng/L (50 times stricter). PFOA was used in the production of Teflon and other non-stick coatings and has been phased out of Australian manufacturing, but persists in the environment from historical use. Detected at low levels in Sydney's treated water supply.
PFHxS — Perfluorohexane Sulfonate
PFHxS is associated with potential thyroid effects according to the NHMRC. The Australian guideline is 30 ng/L. It was detected alongside PFOS at the Blue Mountains Cascade Water Filtration Plant in June 2024 at levels that initially exceeded both Australian and international thresholds before a treatment upgrade was installed. Sydney Water now publishes regular monitoring results for PFHxS across all nine filtration plants.
PFBS — Perfluorobutane Sulfonate
PFBS is associated with potential thyroid effects. The Australian guideline is 900 ng/L. PFBS is a short-chain PFAS increasingly used as a "safer" replacement for PFOS in industrial applications — but it is still a persistent chemical and its health profile is less thoroughly studied than longer-chain compounds.
PFBA — Perfluorobutanoic Acid
PFBA was the most abundant PFAS compound found in every single Sydney tap water sample in the UNSW 2024 study. It is a short-chain PFAS and a common breakdown product of longer-chain PFAS compounds. It builds up in the body less than longer-chain variants, but is highly mobile in water and currently unregulated under Australian guidelines. Early studies suggest potential effects on liver, thyroid, and developmental health.
Australian Guidelines — What the NHMRC Says
The NHMRC conducted a comprehensive review of PFAS in drinking water between 2023 and 2025, publishing new health-based guideline values on 25 June 2025. The new guidelines substantially reduced the allowable concentrations for key PFAS compounds compared with the previous 2018 guidance — but critics note that they remain far less stringent than the 2024 US EPA standards.
| PFAS compound | Health endpoint (NHMRC) | Australia 2025 guideline | US EPA 2024 limit | How it compares |
|---|---|---|---|---|
| PFOS | Potential carcinogen; bone marrow effects | 8 ng/L | 4 ng/L | 2× stricter in US |
| PFOA | Potential carcinogen | 200 ng/L | 4 ng/L | 50× stricter in US |
| PFHxS | Potential thyroid effects | 30 ng/L | 10 ng/L | 3× stricter in US |
| PFBS | Potential thyroid effects | 900 ng/L | 2,000 ng/L | Australia stricter |
| PFBA | Liver, thyroid, developmental (early studies) | Not regulated | Not regulated | Most abundant in Sydney water — no limit set |
Experts responding to the June 2025 NHMRC guidelines noted that while the new values represent a significant improvement on the 2018 guidelines, they remain much higher than international standards in key areas — particularly for PFOA, where Australia allows 200 ng/L versus the US EPA's 4 ng/L. The NHMRC guidelines also cover only four PFAS compounds, while the UNSW study found 31 in Sydney's water alone. The remaining 27 — including PFBA, the most abundant compound found — have no regulatory limit in Australia.
What PFAS Do to the Body — The Health Evidence
The health evidence on PFAS has strengthened substantially in the past five years — moving from "potential concern" to recognised health endpoints in the NHMRC's own 2025 review. The effects are primarily associated with long-term, chronic low-level exposure rather than acute toxicity.
Health effects associated with PFAS exposure (NHMRC 2025 + peer-reviewed evidence)
- Potential carcinogenicity — PFOA and PFOS are classified by the NHMRC as potential carcinogens; PFOA is also classified Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC) as of 2023
- Thyroid disruption — PFHxS and PFBS are associated with potential thyroid effects; thyroid hormones regulate metabolism, energy, and development — disruption has broad downstream consequences including reproductive and developmental effects
- Immune system effects — PFAS have been shown to reduce vaccine antibody response in children; the WHO and IARC have noted immune system suppression as a significant concern at population level
- Liver effects — elevated liver enzymes and non-alcoholic fatty liver disease have been associated with higher PFAS blood levels in epidemiological studies
- Cholesterol elevation — among the most consistently observed effects; higher PFAS exposure is associated with elevated total and LDL cholesterol
- Reproductive and developmental effects — PFAS exposure during pregnancy is associated with reduced birth weight, preterm birth, and altered developmental markers in infants; PFBA specifically has been flagged for potential developmental effects in early studies
- Kidney and testicular cancer — the IARC's Group 1 PFOA classification is based substantially on epidemiological evidence linking PFOA exposure to kidney and testicular cancer in occupationally exposed populations
⚠️ Important framing: The health risks from PFAS in Australian tap water at current guideline-compliant levels are not well-quantified for the general population. Most exposure studies involve highly exposed occupational populations or communities near contamination sites — not the general public drinking guideline-compliant tap water. The concern is cumulative lifetime exposure across all pathways (drinking, food, consumer products) — not acute risk from a single glass. This does not mean the risk is negligible; it means the risk is chronic, long-term, and difficult to isolate from other PFAS sources.
The Australian PFAS Story: 2024–2026 Timeline
Australia's PFAS reckoning has accelerated significantly in the past two years — driven by parliamentary scrutiny, major water authority disclosures, and independent research that revealed the contamination picture was broader than official reporting had indicated.
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Jun 2024
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Jun 2024
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Aug 2025UNSW publishes study finding 31 PFAS types in Sydney tap water — including 21 not previously recorded in Australian tap water and one found in a drinking water supply globally for the first time. PFBA is identified as the most abundant compound, present in every sample.
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Jun 2025NHMRC releases updated PFAS drinking water guidelines — the first major revision since 2018. New health-based limits set for PFOS (8 ng/L), PFHxS (30 ng/L), PFOA (200 ng/L), and PFBS (900 ng/L). Independent experts note Australian limits remain significantly less stringent than US EPA standards for key compounds.
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Jul 2025The Federal Government bans the production and importation of certain PFAS substances, including some everyday consumer products. New PFAS ban covers long-chain legacy chemicals but does not extend to all short-chain PFAS replacement compounds.
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Sep 2025NSW parliamentary inquiry finds Sydney Water failed its "appropriate level of due diligence" with its June 2024 claim of no PFAS hotspots. John Dee from community group STOP PFAS says Sydney Water "falsely claimed there were no known PFAS hotspots" before any testing had been done in affected areas.
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Nov 2025
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Jan 2026
What Actually Removes PFAS from Drinking Water
Standard water treatment processes — including the coagulation, flocculation, sedimentation, filtration, and chlorination used at most Australian municipal plants — do not effectively remove PFAS. Removing PFAS requires specialised treatment at either the utility level or the household point of use.
Technologies that remove PFAS from drinking water
- Granular Activated Carbon (GAC) — the most widely used PFAS treatment at utility scale; adsorbs PFAS onto the carbon surface. Sydney Water installed GAC plus ion-exchange systems at the Cascade WFP in December 2024, with subsequent testing showing decreasing PFAS levels. At household scale, high-quality GAC filters remove a significant proportion of PFAS — effectiveness depends on contact time, carbon quality, and PFAS chain length
- Reverse Osmosis (RO) — the most effective household technology for PFAS removal. Reverse osmosis forces water through a semi-permeable membrane with pores small enough to exclude PFAS molecules — typically achieving 90–95%+ removal of regulated PFAS compounds. Point-of-use RO filters under the kitchen sink are the gold standard for household PFAS reduction
- Ion-Exchange Resin — highly effective for specific PFAS compounds, particularly short-chain variants that GAC captures less efficiently. Often combined with GAC in utility-scale treatment systems. Available in some advanced household filter cartridges
- Nanofiltration — membrane technology between ultrafiltration and reverse osmosis in terms of pore size; effective against many PFAS compounds but less effective than full RO for the complete range
⚠️ Important: Standard inline filters, basic carbon pitcher filters (including most jug filters), and shower filters are not designed or rated for PFAS removal. If PFAS removal is your primary goal, the relevant product is a reverse osmosis system or a certified PFAS-reduction filter tested to NSF/ANSI Standard 58 (RO systems) or NSF/ANSI Standard 53 (activated carbon, specific PFAS claims). Always check the certification and the specific compounds tested — not just general "contaminant reduction" claims.
Frequently Asked Questions
Is Australian tap water safe to drink given PFAS levels?
The NSW Government confirmed in 2025 that all NSW public drinking water supplies — metropolitan and regional — meet the updated Australian Drinking Water Guidelines for PFAS. Most major city supplies comply with current Australian guidelines. The relevant concern is twofold: Australia's guidelines remain much less stringent than US EPA standards for key compounds like PFOA; and guidelines cover only four PFAS while 31 have been detected in Sydney water alone. Compliance with guidelines does not mean zero risk — it means risk assessed as acceptable by current regulatory standards.
How do I know if my tap water has PFAS in it?
Every major Australian water authority now publishes PFAS monitoring results. Sydney Water publishes weekly PFAS testing data across all nine filtration plants on its website. Melbourne Water, Queensland Urban Utilities, and SA Water publish periodic monitoring reports. Friends of the Earth Australia has compiled Sydney Water's full PFAS detection history, which is a useful reference for Sydney residents. For independent household testing, PFAS water testing kits are available from certified laboratories.
Does boiling water remove PFAS?
No. Boiling water does not remove PFAS — in fact, boiling reduces water volume through evaporation, which concentrates any dissolved PFAS remaining in the water. PFAS are not volatile under normal cooking conditions. Only physical removal methods — reverse osmosis, granular activated carbon, ion exchange — are effective against PFAS. Boiling is not among them.
Does a shower filter remove PFAS?
Standard shower filters — including KDF and activated carbon models — are not rated or certified for PFAS removal. The contact time in a shower is too short, and shower filter media is not optimised for PFAS adsorption. If PFAS in shower water is a concern, a whole-house filtration system with certified PFAS reduction capability is the relevant product. For drinking water specifically, a point-of-use reverse osmosis system or NSF 53-certified activated carbon filter is the appropriate solution.
Which water filter removes PFAS in Australia?
The two most effective household options for PFAS removal are reverse osmosis (RO) systems — which achieve 90–95%+ removal of regulated PFAS — and high-quality granular activated carbon (GAC) filters certified to NSF/ANSI Standard 53 for PFAS reduction. Sydney Water itself uses GAC plus ion-exchange at its most PFAS-affected treatment plant. Look for filters that specifically list PFAS, PFOA, or PFOS in their certified contaminant reduction claims — not just general "chlorine removal."
🔑 Key takeaway: PFAS are present in Australian tap water at detectable levels across major city supplies — including 31 types in Sydney water. Current Australian guidelines are met by most urban supplies, but those guidelines remain far less stringent than US EPA standards, and cover only 4 of the 31+ PFAS types now being detected. The only effective household intervention is reverse osmosis or a certified PFAS-reduction activated carbon filter. The next article in this series covers the full state-by-state picture — which Australian cities and communities have the highest PFAS levels, and where the contamination is coming from. Read Part 2: PFAS in Sydney, Melbourne, and Brisbane — The State-by-State Data →
💧 PFAS Forever Chemicals Series
- Part 1 — What Are PFAS and Are They in Your Tap Water? (this article)
- Part 2 — PFAS in Sydney, Melbourne & Brisbane: The State-by-State Data
- Part 3 — PFAS Health Effects: What 85% of Australians Need to Know
- Part 4 — Can Water Filters Remove PFAS? What the Research Shows
- Part 5 — Best Water Filters for PFAS Removal in Australia (2026 Guide)
Already concerned about your shower water? Read our companion series: What's Actually in Your Shower Water — covering chlorine, chloramines, THMs, and what a shower filter can and cannot do.
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Disclaimer: This article is for general informational and educational purposes only. Water quality data is sourced from published government monitoring reports, peer-reviewed research, and parliamentary inquiries current as of April 2026. Always check your water authority's latest monitoring data for your specific supply zone.