What is Perfluorononanoic acid (PFNA)* and Why Does It Matter?

Perfluorononanoic acid, better known as PFNA, is one of the most persistent man-made chemicals found in American drinking water. It belongs to the PFAS family — a group of thousands of synthetic "forever chemicals" that don't break down naturally in the environment or in your body. PFNA enters water supplies through industrial discharge, the breakdown of older PFAS compounds, and runoff from sites where PFAS-containing products were manufactured or used. Common sources include fluoropolymer manufacturing plants, food packaging facilities, and locations where firefighting foam (AFFF) was historically used. Once PFNA reaches groundwater or surface water, it stays there — treatment plants that weren't designed to remove it simply pass it through to your tap.

The health concerns around PFNA are serious and well-documented. The EPA and independent researchers have linked PFNA exposure to kidney cancer, thyroid disease, immune system suppression, and developmental problems in infants and children. Even at very low levels — measured in parts per trillion (ppt) — PFNA can interfere with hormone function. The EWG (Environmental Working Group) has set a health guideline of just 0.2 ppt for PFNA, based on studies showing harm at extremely small doses. Children and pregnant women face the greatest risk, since PFNA crosses the placenta and has been associated with lower birth weight and disrupted fetal development.

The regulatory picture here is frustrating, and worth understanding clearly. The EPA's enforceable legal limit for PFNA is 10 ppt — but that number reflects what's technically feasible to measure and treat, not what's actually safe. The EWG's health guideline of 0.2 ppt is 50 times more protective than the EPA's limit. Of the 240 water systems in the U.S. that have detected PFNA, 239 of them — nearly every single one — exceed the EWG health guideline. The average detected level is 0.599 ppt, nearly 3 times above that guideline. The highest recorded level hit 32.3 ppt, which is more than 160 times what the EWG considers safe. In 2024, the EPA finalized new maximum contaminant levels for several PFAS compounds, which will require water utilities to take action — but full compliance won't happen overnight.

Geographically, PFNA contamination clusters in the Northeast and Mid-Atlantic, with North Carolina and New Jersey each reporting 39 affected water systems — the most of any state. Massachusetts follows with 32 systems, New York with 31, and California with 22. This pattern isn't random. New Jersey and North Carolina have long histories of fluorochemical manufacturing, including facilities tied to major chemical companies. Massachusetts and New York have dense populations, aging infrastructure, and proximity to industrial and military sites where PFAS use was widespread. California's affected systems are spread across regions with agricultural and industrial PFAS sources. If you live in any of these states, your water is worth testing — even if your utility reports compliance with current EPA limits.

The good news is that effective filtration options exist. Reverse osmosis (RO) filtration is the gold standard for PFNA removal, consistently eliminating 95% or more of PFNA and other PFAS compounds from drinking water. Activated carbon filters — especially those using granular activated carbon (GAC) — can also reduce PFNA levels significantly, though they're generally less effective than RO systems at very low concentrations. Standard pitcher filters and basic faucet attachments are not designed to handle PFNA and should not be relied on for protection. Echo Water's reverse osmosis systems are built specifically to address contaminants like PFNA, giving your family reliably clean water at the tap. If you're in a high-risk state like New Jersey, North Carolina, or Massachusetts, pairing an RO system with periodic water testing is the most practical way to stay ahead of this contamination. You don't have to wait for regulators to catch up — you can act now.

Regulatory Standards for Perfluorononanoic acid (PFNA)*

Cities With the Highest Perfluorononanoic acid (PFNA)* Levels

States Most Affected by Perfluorononanoic acid (PFNA)*

Frequently Asked Questions

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