PFHxS in Tap Water
PFHxS is a shorter-chain PFAS "forever chemical" regulated under the EPA PFAS rule as part of a hazard index alongside other PFAS.
Also known as forever chemical
Firefighting foam and industrial sources; persistent and mobile in groundwater.
- 1Firefighting foam
- 2Industrial discharge
Most affected: Infants and pregnant people.
A result is read with its context
Reported here from EPA UCMR5 occurrence monitoring. A non-detect reflects the method reporting limit. PurityMap publishes this substance per water system on individual system and city-report pages, where the source dataset provides a value.
- Above reference
- Evidence exceeds a reference level.
- Detected
- This substance was found in the monitoring record. Being present is not the same as being above a reference level, and this signal does not say which.
- Not detected
- Somebody looked and the laboratory reported nothing above its reporting limit. This is a result, and it is not the same as nobody looking.
- Not monitored
- No sampling for this substance has been reported for this system. Nothing is known either way, and an empty row is not a clean one.
86 cities above the federal limit
15 other states on record have no city above the federal limit. Open any state to see its cities.
- AbileneTX→
- AnaheimCA→
- AnchorageAK→
- AnokaMN→
- AtwaterCA→
- AugustaGA→
- Big Bear CityCA→
- Big SpringTX→
- BoerneTX→
- Broken ArrowOK→
- Canyon LakeTX→
- CentervilleGA→
- ChicoCA→
- Citrus Utl/Charles A BlackFL→
- CollegeAK→
- CollinsvilleIL→
- Crest HillIL→
- Crestline Village CwdCA→
Showing 18 of 86. Open a state for its full list. A system-level result, not a measurement of any single home.
What can carry a PFHxS reduction claim
- Reverse osmosis
Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.
- Activated carbon (GAC)
Highly porous adsorption media targeting chlorine, disinfection byproducts, volatile organic compounds, and organic chemicals.
- Anion exchange
Synthetic polyvalent resin beads that exchange unwanted dissolved ionic contaminants for harmless benchmark ions.
Boiling does not remove a dissolved chemical compound and can concentrate it. Many pitcher and refrigerator filters carry no verified claim for a compound like this at all.
A finding establishes the need, the need names the capability, the capability requires a verified certification. No product appears before that sequence completes. Filter Finder →
Frequently asked
Answers cite the same records as the page. How PurityMap analyzes water data
PFHxS is a shorter-chain PFAS "forever chemical" regulated under the EPA PFAS rule as part of a hazard index alongside other PFAS.
The enforceable federal limit is 10 ng/L (MCL). EPA has proposed rescinding this limit; it applies until a final rule. The published health benchmark reads: 10 ng/L individual MCL (and a hazard-index limit combined with other PFAS). PurityMap reads every measurement against its stated benchmark and never sets its own.
Firefighting foam, Industrial discharge.
PFHxS is associated with thyroid and immune effects in studies. It is regulated both individually and as part of a combined PFAS hazard index.
Treatment technologies commonly certified to reduce PFHxS include Reverse osmosis, Activated carbon (GAC), Anion exchange. Match the exact certified claim to your water before buying. Holding a format is not the same as holding the claim.
In PurityMap's published record, PFHxS was detected in 569 cities (of 4,160 with a result) across 46 states, with 86 above the federal limit. This is the scope of our record, not a national prevalence estimate.