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PFNA in drinking water

Also called Perfluorononanoic acid, Perfluorononanoic Acid (PFNA).

Legal limit
10 ppt
Health goal
10 ppt

Values in parts per trillion (ppt). Comes from the source.

Where the rules stand

Final MCL and health goal of 10 ppt, published April 26, 2024, with compliance due April 26, 2029. PFNA also counts toward the Hazard Index limit for PFAS mixtures. On May 20, 2026, EPA proposed rescinding the limits for PFHxS, PFNA and HFPO-DA and the Hazard Index. Comments closed July 20, 2026. As of Oct. 4, 2026, the Federal Register shows no final rule, so the 2024 limits still stand.

The scale every TapBuff report uses for this contaminant: the legal line at the middle, twice it at the right.

What EPA says about health

EPA based its 10 ppt health-based level on lower body weight gain and delayed development. When PFNA occurs with PFHxS, HFPO-DA or PFBS, EPA adds their effects together through the Hazard Index.

Where it comes from

PFAS have been used since the 1940s in products like nonstick cookware, food packaging, waterproof clothing, stain-resistant furniture and firefighting foam. They last a long time in the environment and can reach drinking water sources.

What EPA found nationally

Under UCMR 5, EPA tested 9,944 utilities for PFNA. It was found at 78 of them, which report serving 8.9 million people. The highest single sample was 99.8 ppt.

Highest single results for PFNA
UtilityHighest sampleFound in
Emmaus Borough Public WaterEmmaus, PA · serves 14,00099.8 ppt4 of 8
East Greenwich Twp Water DeptEast Greenwich Twp., NJ · serves 9,90073.3 ppt1 of 10
Capitol Water CorpBoise, ID · serves 9,00051 ppt4 of 8
Locust Valley WDOyster Bay (T), NY · serves 7,50029.6 ppt2 of 10
City of PflugervillePflugerville, TX · serves 63,46425.2 ppt4 of 8
Manville WSCCoupland, TX · serves 39,64824.3 ppt3 of 20
Quakertown BoroQuakertown, PA · serves 12,80024 ppt2 of 14
Palmerton Municipal AuthorityPalmerton, PA · serves 7,00021.1 ppt2 of 4
Georgetown Water DepartmentGeorgetown, DE · serves 7,25920 ppt3 of 4
Manhasset Lakeville WDNorth Hempstead (T), NY · serves 43,00019 ppt1 of 19
Highest single sample per utility, EPA UCMR 5 file of Aug. 27, 2026. One high sample is not a violation; compliance is judged on averages over time.

What handles it

  • NSF/ANSI 53

    Claim to look for: Total PFAS Reduction

    Also listed as: Perfluorononanoic Acid (PFNA)

    NSF listing footnotes include PFNA in Total PFAS. NSF says a PFAS claim means reducing PFAS below 20 ppt. EPA says current certifications do not yet show a filter reaches EPA's limits.

    WQA listing wording for a single-compound claim.

Filters with that claim on a certifier’s listing

  • PUR PLUS 11-Cup Pitcher (PPT111W)

    Pitcher

    • NSF listing: 42, 53, 401 · checked Oct. 4, 2026
    • WQA listing: 42, 53, 401 · checked Oct. 4, 2026
    • IAPMO listing: 42, 53, 401 · checked Oct. 4, 2026
    Maker’s page

  • PUR PLUS Faucet Filtration System, Horizontal (PFM400H)

    Faucet mount

    • NSF listing: 42, 53, 401 · checked Oct. 4, 2026
    • WQA listing: 42, 53, 401 · checked Oct. 4, 2026
    • IAPMO listing: 42, 53, 401 · checked Oct. 4, 2026
    Maker’s page

  • LARQ Under Sink Water Filter

    Under-sink carbon

    • NSF listing: 42, 53 · checked Oct. 4, 2026
    Maker’s page

  • Aquasana HealthShield (WH-HS)

    Whole house

    • WQA listing: 53, 401 · checked Oct. 4, 2026
    Maker’s page

Sources

  1. Per- and Polyfluoroalkyl Substances (PFAS): Final PFAS National Primary Drinking Water Regulation, U.S. EPA. Checked Oct. 4, 2026.
  2. PFAS National Primary Drinking Water Regulation (final rule, April 26, 2024), Federal Register. Checked Oct. 4, 2026.
  3. Rescission of Regulatory Determinations and Removal of Related Provisions for Four PFAS Substances (proposed rule, May 20, 2026), Federal Register. Checked Oct. 4, 2026.
  4. Proposed PFAS Rescission Rule, U.S. EPA. Checked Oct. 4, 2026.
  5. Federal Register: EPA documents mentioning PFAS, newest first (no final rule on either 2026 proposal), Federal Register. Checked Oct. 4, 2026.
  6. The Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) Data Summary: July 2026 (EPA 815-S-26-007), U.S. EPA. Checked Oct. 4, 2026.
  7. NSF listings for the NSF/ANSI 53 "Total PFAS Reduction" claim (footnotes define Total PFAS), NSF. Checked Oct. 4, 2026.
  8. PFAS in Drinking Water, NSF. Checked Oct. 4, 2026.
  9. Fact Sheet: Reducing PFAS in Your Drinking Water with a Home Filter (April 2024), U.S. EPA. Checked Oct. 4, 2026.
  10. Find WQA Certified Products (Gold Seal listings by standard and claim), Water Quality Association. Checked Oct. 4, 2026.
  11. SDWA Dataset Download Summary (codes from SDWA_REF_CODE_VALUES.csv, 2026 Q2 extract), U.S. EPA ECHO. Checked Oct. 4, 2026.