You cannot see, smell, or taste PFAS in water, so certified laboratory testing is the only reliable way to know whether your water contains them. At-home mail-in kits use the same lab methods and work well as a first screening step, while instant dip strips cannot detect PFAS at all. If you are on a private well or live near a known contamination source, testing gives you a clear number to act on. This guide walks through why you might test, the difference between kit and lab options, the EPA methods labs actually use, approximate costs, how to collect a clean sample, and how to read your results against the EPA drinking-water limits.
Key takeaways
– PFAS are detected only by laboratory instruments (LC-MS/MS); no strip or color-change test can measure them.
– Certified labs use EPA Methods 537.1, 533, or 1633; mail-in home kits send your sample to these same labs.
– Compare your results against the EPA 2024 limits of 4.0 parts per trillion for PFOA and PFOS, then use a certified filter to reduce them.
Why you might test your water for PFAS
Most people never need to test, but a few situations make it worthwhile. The clearest case is a private well, because private wells are not covered by federal drinking-water rules and no utility is monitoring them for you. Another is living near a known or suspected source, such as a firefighting-training site, an airport, a landfill, or certain manufacturing plants, where PFAS have a documented history of reaching groundwater.
If you are on a public water system, your utility is required to begin monitoring for PFAS and report the results, so testing your own tap is usually unnecessary. You can often find recent data in your annual water-quality report first. To understand what these compounds are and why they matter, see our overview of what PFAS are and the specifics of PFAS in drinking water.
At-home kits versus certified lab testing
There are two honest paths, and one common trap. The trap is instant dip-strip or color-change tests marketed as PFAS detectors. PFAS are regulated at parts-per-trillion levels, which is far below what any strip can sense, so these products cannot give a meaningful reading. Skip them.
A mail-in home kit is the practical starting point for most households. You collect a sample in a supplied bottle and ship it to an accredited laboratory, which runs the same instrument-based analysis a professional lab would. A direct certified-lab test involves contacting an accredited environmental lab yourself, which can be useful when you need documentation for a property sale, a legal matter, or a specific regulatory panel. The table below compares the two.
| Factor | Mail-in home kit | Direct certified lab |
|---|---|---|
| Accuracy | High; analyzed by an accredited lab using EPA methods | High; same or broader EPA methods, more panel options |
| Approximate cost | Roughly $80 to $200 per sample | Roughly $300 to $600 per sample |
| Turnaround | About 5 to 14 business days after the lab receives it | Varies by lab; often 1 to 3 weeks |
| Best for | Homeowners screening their own tap or well | Documentation, custom panels, real-estate or legal needs |
Cost figures are approximate and depend on the panel size and lab. Both paths rely on the same underlying analysis, so a reputable mail-in kit is genuinely reliable, not a downgrade.
The EPA analytical methods labs use
Accredited labs measure PFAS using liquid chromatography with tandem mass spectrometry, written as LC-MS/MS. This equipment separates and identifies individual PFAS compounds at extremely low concentrations, which is why home strips are no substitute. Three EPA methods dominate drinking-water testing.
Method 537.1 is a solid-phase extraction method that covers 18 PFAS analytes and is one of the two methods approved for compliance monitoring under the federal drinking-water rule. Method 533 uses isotope dilution for extra quality control at parts-per-trillion levels and covers 25 analytes; together, 537.1 and 533 span 29 compounds in drinking water. Method 1633 is a broader multi-matrix method that covers 40 PFAS across water, soil, biosolids, and tissue, and is more common in environmental and wastewater work than routine home testing. When you buy a kit, check which method and how many compounds it reports.
How to collect a sample correctly
Sample handling matters because PFAS are so widespread that sloppy collection can contaminate the bottle. Follow the kit or lab instructions exactly, but the general rules are consistent. Do not use any water-resistant or stain-resistant gloves, and avoid handling the sample near food wrappers, cosmetics, or waterproof clothing, all of which can carry PFAS.
Use only the container the lab provides, since ordinary bottles and even some sample containers can add background contamination. Do not rinse the bottle, because many PFAS kits contain a preservative. Collect from the tap you actually drink from, let the water run as directed, fill to the marked line, seal, and ship promptly so the sample reaches the lab within its holding time. Label the sample and note the date. If anything is unclear, call the lab before you collect rather than risk a wasted sample.
How to interpret your results
Results come back in parts per trillion, written as ppt or the equivalent nanograms per liter (ng/L). In April 2024 the EPA finalized enforceable limits for six PFAS. PFOA and PFOS each have a maximum contaminant level of 4.0 ppt. PFHxS, PFNA, and HFPO-DA (known as GenX) each have a limit of 10 ppt. Mixtures of two or more of PFHxS, PFNA, HFPO-DA, and PFBS are governed by a Hazard Index of 1, an unitless value that accounts for combined exposure.
Read each reported compound against its limit. A single result at or above 4.0 ppt for PFOA or PFOS, or above the relevant limit for the others, is a signal to act. It is worth noting these federal limits apply to public water systems rather than private wells, but they remain the most useful health-based benchmark for interpreting any result. Reporting limits vary by lab, so a “non-detect” means below the lab’s detection threshold, not necessarily zero. If your numbers exceed the limits, the practical fix is filtration.
What to do if PFAS are present
If your test shows PFAS above the EPA limits, the reliable solution is a filter certified to reduce them. Look for systems certified to NSF/ANSI Standard 53 (for activated-carbon and anion-exchange filters) or NSF/ANSI Standard 58 (for reverse osmosis), which now carry PFAS-reduction claims. The older NSF protocol P473 has been retired and folded into these standards, so a current listing is what you want to see.
Match the certified reduction claim to the compounds and levels in your report, and confirm the certification covers PFOA and PFOS at minimum. Our guide to the best water filter for microplastics and PFAS walks through specific certified options, and our broader piece on how to avoid PFAS covers everyday exposure beyond drinking water. Testing tells you where you stand; a certified filter is how you lower the number.
FAQ
Can I detect PFAS with a home test strip?
No. PFAS occur at parts-per-trillion levels that no dip strip or color-change test can measure. Only laboratory LC-MS/MS analysis, whether through a mail-in kit or a direct lab, can reliably detect and quantify them.
How much does PFAS water testing cost?
Approximate costs range from about $80 to $200 for a mail-in home kit and roughly $300 to $600 for a direct certified-lab test. Prices vary with the panel size and the number of compounds analyzed, so check what each price includes.
Which EPA method should my test use?
For drinking water, Method 537.1 and Method 533 are the standard approved methods and together cover 29 compounds. Method 1633 covers more compounds across more sample types and is common in environmental testing. Any of these performed by an accredited lab is reliable.
What PFAS level is considered unsafe in drinking water?
Under the EPA’s 2024 rule, PFOA and PFOS each have a limit of 4.0 ppt, while PFHxS, PFNA, and GenX are each limited to 10 ppt. A Hazard Index of 1 governs certain mixtures. Results at or above these levels are a signal to act.
Do I need to test if I am on city water?
Usually not. Public water systems are required to monitor for PFAS and report results, so you can often check your utility’s water-quality report first. Testing your own tap makes the most sense for private wells or homes near a known contamination source.
