Testing for PFAS depends on what you’re testing: your drinking water, your blood, or soil and products around your home. Each requires a different approach, and the details matter more than you might expect. Even the clothes you wear while collecting a water sample can skew the results if they’ve been treated with stain-resistant coatings.
Testing Your Drinking Water
Most people searching for PFAS testing want to know what’s in their tap water. You have two main options: request results from your water utility or send a sample to a certified lab yourself.
Public water systems serving more than 3,300 people are now required to monitor for PFAS under the EPA’s National Primary Drinking Water Regulation. Your utility may already have results available, and you can typically find them in your annual Consumer Confidence Report or by calling your provider directly. If your water comes from a private well, no one is testing it for you.
To test independently, you’ll need to send a sample to an accredited laboratory. The EPA has validated three methods for detecting PFAS in drinking water: Method 533, Method 537.1, and the older Method 537. Together, these methods can identify 29 different PFAS compounds. Methods 533 and 537.1 are the current standard, approved for regulatory monitoring through 2025 and beyond. Labs use a technique called liquid chromatography with tandem mass spectrometry, which essentially separates and identifies individual PFAS chemicals at extremely low concentrations, down to parts per trillion.
To find a qualified lab, the NELAC Institute maintains a searchable database called the Laboratory Accreditation Management System (LAMS). You can filter by your state, the type of sample (water), and the specific method or chemical you want tested. Many state environmental agencies also maintain their own lists of certified labs. Expect to pay roughly $200 to $400 for a comprehensive drinking water panel, though prices vary by lab and the number of compounds tested.
How to Collect a Water Sample Without Contaminating It
PFAS are so widespread in consumer products that collecting an uncontaminated water sample requires unusual precautions. The EPA’s sampling guidelines read almost like a dress code, because they essentially are one.
On the day you collect your sample, and ideally 24 hours before, avoid wearing or using:
- Cosmetics, moisturizers, sunscreen, or insect repellent (unless they’re 100% natural products)
- Waterproof or stain-resistant clothing, including Gore-Tex jackets and treated shoes
- New or unwashed clothing, or anything laundered with fabric softener or dryer sheets
- Hair products or fragrances of any kind
Use a ballpoint pen to label anything. Sharpies and other waterproof markers contain PFAS compounds. Don’t fill your gas tank before collecting the sample. Avoid sampling in the rain, but if you must, wear vinyl or PVC rain gear rather than anything waterproof-treated.
At the tap, remove any aerators, screens, washers, hoses, and water filters before collecting. Run the water for about five minutes first to flush out potential contamination from Teflon tape and valve components in the plumbing. Your lab will provide specific collection bottles, usually made of high-density polyethylene. Use only what they supply, and follow their instructions for filling, sealing, and shipping.
What the Numbers Mean for Drinking Water
The EPA finalized enforceable limits for six PFAS compounds in 2024. The two most commonly detected, PFOA and PFOS, each have a maximum contaminant level of 4.0 parts per trillion. That’s an extraordinarily small amount, equivalent to about four drops in an Olympic swimming pool. Three other compounds, PFHxS, PFNA, and GenX chemicals (HFPO-DA), have limits of 10 parts per trillion each.
If your results come back above these thresholds, a point-of-use water filter certified for PFAS removal (typically reverse osmosis or granular activated carbon systems) can significantly reduce levels. Whole-house systems are also available but cost considerably more. If you’re on a public system, your utility is now legally required to bring levels into compliance, though they have several years to do so.
Testing Your Blood for PFAS
Blood testing measures how much PFAS has accumulated in your body over time. Some PFAS compounds have half-lives of several years, meaning a single blood draw reflects both recent and past exposures. Your doctor can order this through any CLIA-certified commercial laboratory.
Most panels measure a core group of seven compounds: PFOS, PFOA, PFHxS, PFNA, PFDA, PFUnDA, and MeFOSAA. The National Academies of Sciences has recommended health screenings based on the combined total of these seven. National health surveys from 2017 to 2018 provide baseline comparison numbers for the general U.S. population:
- PFOS: average of 4.25 ng/mL, with 95% of people below 14.6 ng/mL
- PFOA: average of 1.42 ng/mL, with 95% of people below 3.77 ng/mL
- PFHxS: average of 1.08 ng/mL, with 95% of people below 3.70 ng/mL
- PFNA: average of 0.411 ng/mL, with 95% of people below 1.40 ng/mL
These figures come from the CDC’s National Health and Nutrition Examination Survey. If your results fall above the 95th percentile for any compound, it suggests your exposure has been higher than the vast majority of the population.
What Blood Results Can and Can’t Tell You
A PFAS blood test confirms exposure and gives you a number to compare against population averages. That’s genuinely useful. But it has real limits. The results won’t tell you where your exposure came from, whether your water, food packaging, workplace, or firefighting foam in your area. They won’t indicate whether any current health issue is caused by PFAS, and they can’t predict future health outcomes. Comparing results across different labs is also tricky because laboratories use different testing methods and measure slightly different sets of compounds. There’s currently no established guidance on how often to retest or how long a single result remains meaningful.
Testing Soil, Groundwater, and Products
Testing soil or consumer products for PFAS is more complex than testing drinking water, partly because concentrations tend to be much higher and the chemical mixtures more varied. Standard targeted analysis identifies specific known PFAS compounds, but thousands of PFAS exist, and targeted methods only catch the ones they’re designed to look for.
Broader screening methods try to capture the total PFAS load. These include total organic fluorine (TOF), extractable organic fluorine (EOF), and a technique called the total oxidizable precursor (TOP) assay, which converts PFAS precursors into measurable end products. The most widely used analytical technique for these broader measurements is combustion ion chromatography, used in over half of published studies. These methods are primarily available through specialized environmental and research laboratories rather than consumer testing services.
If you’re concerned about PFAS in soil around your property, particularly near military bases, airports, or industrial sites where firefighting foam was used, your state environmental agency is the best starting point. Many states have their own PFAS investigation programs and can direct you to appropriate testing resources or may already have data for your area.