On April 10, 2024, the EPA finalized its first National Primary Drinking Water Regulation for PFAS. This rule set legally enforceable limits for six compounds in drinking water. NSF/ANSI/CAN 61 was updated the same year to match. In this guide, we cover what changed in the 2024 standard, how the new PFAS limits compare with the EPA’s, and where all of this fits alongside the lead-content requirements of NSF-372.
What Changed in the 2024 Standard
The 2024 edition of NSF 61 added an expanded PFAS test battery which covers seven compounds. These include the six regulated by the EPA plus one additional compound. The testing applies to a specific group of materials: PTFE, ETFE, PVDF, and fluoroelastomers. These are fluoropolymers, and they are commonly used in flanged assemblies as gasket materials, seal components, and linings on valves and fittings.
The pass or fail thresholds behind NSF-61’s PFAS testing come from the companion standard NSF/ANSI/CAN 600. This standard covers health-effects criteria for chemicals in drinking water. As part of the 2024 update, its Total Allowable Concentration limits were brought in line with the EPA’s drinking water standards for the six regulated PFAS compounds. Changes to NSF-61 are decided by the NSF Drinking Water System Components Joint Committee.
PFAS criteria for NSF 600-2024
| Compound | EPA Enforceable MCL | NSF 600-2024 Limit |
|---|---|---|
| Perfluorooctanoic acid (PFOA) | 4 ppt | 4 ppt |
| Perfluorooctane sulfonic acid (PFOS) | 4 ppt | 4 ppt |
| Perfluorohexane sulfonic acid (PFHxS) | 10 ppt | 10 ppt |
| Perfluorononanoic acid (PFNA) | 10 ppt | 10 ppt |
| HFPO-DA / GenX | 10 ppt | 10 ppt |
| Perfluorobutane sulfonic acid (PFBS) | Regulated in mixtures only | 2,000 ppt |
| Perfluorohexanoic acid (PFHxA) | Not individually regulated | 2,000 ppt |
| Mixtures of two or more of PFHxS, PFNA, GenX, and PFBS | 1.0 Hazard Index | 1.0 Hazard Index |
* That distinction matters for anyone specifying a full flanged connection. The metal body of a flange is not the material this update targets. The gaskets, seals, and any fluoropolymer-lined components in the assembly are.
The Compliance Deadline: January 1, 2028
The standard did not make the new PFAS testing requirement retroactive overnight. Manufacturers have until January 1, 2028 to bring PTFE, ETFE, PVDF, and fluoroelastomer components into compliance with the expanded test battery. This gives manufacturers time to requalify materials without removing currently certified products from the market.
The Optional "+PFAS" Tested Mark
Products that are tested and confirmed to meet the updated PFAS criteria ahead of the 2028 deadline can carry an optional “+PFAS” designation alongside the standard NSF mark. For buyers working on municipal or utility projects, PFAS has become an important point of specification level scrutiny. The designation helps identify components that have already met the newer requirements.
NSF 372 and PFAS Testing
NSF-61 and NSF-372 cover different chemical concerns. NSF-372 deals only with lead content. NSF-61 covers the broader range of contaminants a product can leach into drinking water, and PFAS testing falls under that broader scope. In practice the two go together, since a product certified to NSF-61 is also evaluated to NSF-372. What is new here is that the PFAS side of NSF-61 now targets fluoropolymer components like gaskets and seals, separately from the lead check that NSF-372 handles.
Conclusion
The 2024 PFAS update did not rewrite NSF 61. It extended a standard that has been adapting to new contaminant science since the 1980s. API International’s CleanLine is evaluated and certified to both NSF-61 and NSF-372 standards. See our official certification listing page for a list of our NSF-61-372 certified products. For a buyer specifying flanges for municipal water systems, treatment plants, or any potable or clean water application, that means the certification on the spec sheet reflects the full picture: health effects and lead content are both verified by an independent third party, not a manufacturer’s own claim.
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Frequently Asked Questions
What did the EPA's 2024 PFAS rule do?
On April 10, 2024, the EPA finalized its first national drinking water regulation for PFAS. It set legally enforceable limits for six compounds: PFOA, PFOS, PFHxS, PFNA, HFPO-DA (GenX), and PFBS as part of a mixture limit. NSF/ANSI/CAN 61 was updated the same year so its testing reflects those limits.
How does NSF-61 relate to the EPA's PFAS limits?
NSF-61 is the standard that drinking water components are certified to, and the EPA rule sets the underlying limits. The pass or fail thresholds come from the companion standard NSF/ANSI/CAN 600, whose limits were brought in line with the EPA's drinking water standards for the six regulated PFAS compounds.
Does PFAS testing apply to the metal flange body itself?
The metal body is not the target. The 2024 test battery applies to PTFE, ETFE, PVDF, and fluoroelastomer materials, which show up as gaskets and seals rather than in stainless steel or carbon steel flange bodies.
When do manufacturers have to comply, and what is the "+PFAS" mark?
The compliance deadline for the expanded PFAS test battery is January 1, 2028. Products tested and confirmed to meet the updated criteria ahead of that date can carry an optional "+PFAS" mark from NSF to show early compliance.
Is PFAS testing the same thing as NSF-372 lead-free certification?
They are two separate evaluations. NSF-372 covers lead content, while PFAS testing under the updated NSF-61 and NSF-600 standards covers a different set of contaminants. A product with both metal and fluoropolymer components usually needs both.