A PFAS test can identify named compounds above the laboratory reporting limit in that sample.
Evidence snapshot
- NHMRC (2025): The Australian Drinking Water Guidelines are a risk-management framework, not a single national pass/fail law. They separate health-based, aesthetic and operational considerations.
- NSF (2026): NSF standard numbers are not quality rankings. NSF/ANSI 42 covers stated aesthetic claims, 53 health-effect claims, 44 softeners, 55 UV and 58 point-of-use RO; the exact certified claim still has to be checked.
- NHMRC (2025): NHMRC's 2025 values are 8 ng/L for PFOS, 200 ng/L for PFOA, 30 ng/L for PFHxS and 1,000 ng/L for PFBS. A result must be matched to the named compound and unit.
- US EPA (2025): For a household PFAS filter, the EPA recommends checking a specific certified reduction claim and replacing the filter as directed. Technology type alone is not proof of lifetime performance.
These figures and standards are reference points, not a diagnosis of one home. Local water data, premises plumbing, flow and maintenance determine how they apply.
A PFAS result is compound-specific and time-specific
Start with the property itself. Use a PFAS method suitable for the named compounds and keep the reporting limit and units visible. Nanograms per litre and micrograms per litre differ by a factor of 1,000. A non-detect only means the named compound was below that method's reporting limit in that sample. Any reduction claim should name the exact model, flow, tested capacity and replacement point.
The limit to keep visible
It cannot prove that every PFAS is absent, predict future levels or establish a filter's lifetime.
Official guidance describes population-level or supply-level risk; a component test describes stated test conditions; a household observation describes one property. None should silently stand in for another. Connect them only where the source, configuration and operating conditions genuinely match.
Keep the sample, unit and reporting limit together
Use an accredited method, check units and reporting limits, and compare the result with current Australian guidance.
Write the sample point, date, method, unit and laboratory reporting limit beside the result. A kitchen first-draw sample answers a different question from water collected after a two-minute flush. For a treatment check, use matched inlet and outlet samples and the same method. Do not use taste, colour or a TDS pen as a substitute for analysis of a named contaminant.
What to record before buying
If treatment is installed, verification should consider both inlet and treated water over time.
Follow the claim through four steps: target, mechanism, operating conditions and verification. A material test does not automatically prove the finished system; plumbing approval does not prove contaminant reduction; a micron number does not describe dissolved chemistry. The evidence should match the exact question the household is asking.
A practical household check
| Record | What to capture | Why it changes the decision |
|---|---|---|
| Claim | Write the exact target and unit | Prevents category errors |
| Conditions | Record flow, capacity and test basis | Tests relevance to the home |
| Verification | Choose a measure that matches the claim | Shows whether it worked |
Use the same notes when requesting more than one quote. Suppliers then have to answer the same water, flow and ownership brief rather than redefining the problem around their preferred product.
Where Water Analytics Australia fits
WAA's role is to turn the household brief into a proportionate design. That starts with source water, treatment goal, realistic peak flow, available pressure, installation access and the preferred service approach. Depending on the job, the answer may be whole-home staged treatment, point-of-use RO, the benchtop system or a combination. The written proposal should explain why each stage is present, the conditions behind each claim and what the customer will need to maintain.
Related WAA guides
- Lead in Drinking Water: Why the Problem Often Starts After the Meter
- Why WAA Adds Minerals Back After Reverse Osmosis
- WAA Full Home Water Refining Systems
Common questions
Does one specification prove the whole product claim?
No. A micron rating, material test, plumbing approval or TDS reading answers a limited question. Check the exact finished model, target, test method, flow and capacity.
What is the most useful measurement?
Use the measurement that matches the decision. Use a PFAS method suitable for the named compounds and keep the reporting limit and units visible. Nanograms per litre and micrograms per litre differ by a factor of 1,000. A non-detect only means the named compound was below that method's reporting limit in that sample. Any reduction claim should name the exact model, flow, tested capacity and replacement point.
What should WAA receive before recommending a system?
Provide the postcode, water source, household size, bathroom count, busiest-use pattern, observed issue, desired result and any laboratory report with its units and sample point.
Sources and further reading
- NHMRC: Australian Drinking Water Guidelines, version 4.0
- NSF: Standards for water treatment systems
- NHMRC: Updated Australian Drinking Water Guidelines: PFAS values
- US EPA: Identifying drinking water filters certified to reduce PFAS
The next useful step
Write down the source, the result you want, peak-use flow and the evidence already available. Then ask for a recommendation that gives every stage a defined job, states the operating assumptions and includes the service plan. That is enough detail to compare a WAA proposal with any alternative without relying on fear or brochure language.